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  • 1.
    Ahmadzadeh, Farzaneh
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Strömberg, Thomas
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Multivariate process parameter change identification by neural network2013Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 69, nr 9-12, s. 2261-2268Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Whenever there is an out-of-control signal in process parameter control charts, maintenance engineers try to diagnose the cause near the time of the signal which is not always lead to prompt identification of the source(s) of the out-of-control condition and this in some cases yields to extremely high monetary loses for manufacture owner. This paper applies multivariate exponentially weighted moving average (MEWMA) control charts and neural networks to make the signal identification more effective. The simulation of this procedure shows that this new control chart can be very effective in detecting the actual change point for all process dimension and all shift magnitudes considered. This methodology can be used in manufacturing and process industries to predict change points and expedite the search for failure causing parameters, resulting in improved quality at reduced overall cost. This research shows development of MEWMA by usage of neural network for identifying the step change point and the variable responsible for the change in the process mean vector.

  • 2.
    Ahmer, Muhammad
    et al.
    Manufacturing and Process Development, AB SKF, Gothenburg, Sweden.
    Sandin, Fredrik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Marklund, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Gustafsson, Martin
    Manufacturing and Process Development, AB SKF, Gothenburg, Sweden.
    Berglund, Kim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Failure mode classification for condition-based maintenance in a bearing ring grinding machine2022Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 122, s. 1479-1495Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Technical failures in machines are major sources of unplanned downtime in any production and result in reduced efficiency and system reliability. Despite the well-established potential of Machine Learning techniques in condition-based maintenance (CBM), the lack of access to failure data in production machines has limited the development of a holistic approach to address machine-level CBM. This paper presents a practical approach for failure mode prediction using multiple sensors installed in a bearing ring grinder for process control as well as condition monitoring. Bearing rings are produced in a set of 7 experimental runs, including 5 frequently occurring production failures in the critical subsystems. An advanced data acquisition setup, implemented for CBM in the grinder, is used to capture information about each individual grinding cycle. The dataset is pre-processed and segmented into grinding cycle stages before time and frequency domain feature extraction. A sensor ranking algorithm is proposed to optimize feature selection for failure classification and the installation cost. Random forest models, benchmarked as best performing classifiers, are trained in a two-step classification framework. The presence of failure mode is predicted in the first step and the failure mode type is identified in the second step using the same feature set. Defining the feature set in the failure detection step improves the predictor generalization with the classifiers’ performance accuracy of 99%99% on the test dataset. The presented approach demonstrates an efficient failure mode classification by selecting crucial sensors resulting in a cost-effective CBM implementation in a bearing ring grinder.

  • 3.
    Bektas, Oguz
    et al.
    Warwick Manufacturing Group, University of Warwick, Coventry, UK.
    Jones, Jeffrey A.
    Warwick Manufacturing Group, University of Warwick, Coventry, UK.
    Sankararaman, Shankar
    Data Science and Analytics Manager,Pricewaterhouse Cooper, San Jose, USA.
    Roychoudhury, Indranil
    Stinger Ghaffarian Technologies, Inc.NASA Ames Research Center, Moffett Field, USA.
    Goebel, Kai
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik. NASA Ames Research Center, Moffett Field, USA.
    A neural network filtering approach for similarity-based remaining useful life estimation2019Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 101, nr 1-4, s. 87-103Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The role of prognostics and health management is ever more prevalent with advanced techniques of estimation methods. However, data processing and remaining useful life prediction algorithms are often very different. Some difficulties in accurate prediction can be tackled by redefining raw data parameters into more meaningful and comprehensive health level indicators that will then provide performance information. Proper data processing has a significant importance on remaining useful life predictions, for example, to deal with data limitations or/and multi-regime operating conditions. The framework proposed in this paper considers a similarity-based prognostic algorithm that is fed by the use of data normalisation and filtering methods for operational trajectories of complex systems. This is combined with a data-driven prognostic technique based on feed-forward neural networks with multi-regime normalisation. In particular, the paper takes a close look at how pre-processing methods affect algorithm performance. The work presented herein shows a conceptual prognostic framework that overcomes challenges presented by short-term test datasets and that increases the prediction performance with regards to prognostic metrics.

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  • 4.
    Bergström, Per
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Edlund, Ove
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Söderkvist, Inge
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Repeated surface registration for on-line use2011Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 54, nr 5-8, s. 677-689Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We consider the problem of matching sets of 3D points from a measured surface to the surface of a corresponding computer-aided design (CAD) object. The problem arises in the production line where the shape of the produced items is to be compared on-line with its pre-described shape. The involved registration problem is solved using the iterative closest point (ICP) method. In order to make it suitable for on-line use, i.e., make it fast, we pre-process the surface representation of the CAD object. A data structure for this purpose is proposed and named Distance Varying Grid tree. It is based on a regular grid that encloses points sampled from the CAD surfaces. Additional finer grids are added to the vertices in the grid that are close to the sampled points. The structure is efficient since it utilizes that the sampled points are distributed on surfaces, and it provides fast identification of the sampled point that is closest to a measured point. A local linear approximation of the surface is used for improving the accuracy. Experiments are done on items produced for the body of a car. The experiments show that it is possible to reach good accuracy in the registration and decreasing the computational time by a factor 700 compared with using the common kd-tree structure.

  • 5.
    Breese, Philipp Peter
    et al.
    Technische Universität Berlin, Coating Technology, Straße des 17. Juni 135, 10623, Berlin, Germany; Siemens AG, Otto-Hahn-Ring 6, 81739, Munich, Germany.
    Hauser, Tobias
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling. Siemens AG, Otto-Hahn-Ring 6, 81739, Munich, Germany.
    Regulin, Daniel
    Siemens AG, Otto-Hahn-Ring 6, 81739, Munich, Germany.
    Seebauer, Stefan
    Siemens AG, Otto-Hahn-Ring 6, 81739, Munich, Germany; Institute of Solid State Physics, TU Vienna, Wiedner Hauptstr. 8-10, 1040, Vienna, Austria.
    Rupprecht, Christian
    Technische Universität Berlin, Coating Technology, Straße des 17. Juni 135, 10623, Berlin, Germany.
    In situ measurement and closed-loop control for powder supply processes: Retrofittable solution in the context of laser metal deposition2021Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 116, nr 3-4, s. 889-903Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The powder mass flow rate is one of the main parameters regarding the geometrical precision of built components in the additive manufacturing process of laser metal deposition. However, its accuracy, constancy, and repeatability over the course of the running process is not given. Reasons among others are the performance of the powder conveyors, the complex nature of the powder behavior, and the resulting issues with existing closed-loop control approaches. Additionally, a direct in situ measurement of the powder mass flow rate is only possible with intrusive methods. This publication introduces a novel approach to measure the current powder mass flow rate at a frequency of 125 Hz. The volumetric powder flow evaluation given by a simple optical sensor concept was transferred to a mass flow rate through mathematical dependencies. They were found experimentally for a nickel-based powder (Inconel 625) and are valid for a wide range of mass flow rates. With this, the dynamic behavior of a vibration powder feeder was investigated and a memory effect dependent on previous powder feeder speeds was discovered. Next, a closed-loop control with the received sensor signal was implemented. The concept as a whole gives a repeatable and accurate powder mass flow rate while being universally retrofittable and applicable. In a final step, the improved dynamic and steady performance of the powder mass flow rate with closed-loop control was validated. It showed a reduction of mean relative errors for step responses of up to 81% compared to the uncontrolled cases.

  • 6.
    Bunaziv, I.
    et al.
    Norwegian University of Science and Technology, Trondheim, Norway.
    Akselsen, O.M.
    Norwegian University of Science and Technology, Trondheim, Norway; SINTEF Industry, Trondheim, Norway.
    Frostevarg, Jan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Kaplan, Alexander
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Application of laser-arc hybrid welding of steel for low-temperature service2019Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 102, nr 5-8, s. 2601-2613Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Laser-arc hybrid welding (LAHW) is more often used in shipbuilding and oil and gas industries in recent years. Its popularity arises due to many advantages compared to conventional arc welding processes. The laser beam source is used to achieve much higher penetration depths. By adding filler wire to the process area, by means of an arc source, the mechanical properties can be improved, e.g. higher toughness at low temperatures. Therefore, LAHW is a perspective process for low-temperature service. Applicability of LAHW is under concern due to process stability and mechanical properties related to heterogeneous filler wire distribution through the whole weld metal in deep and narrow joints. This can cause reduced mechanical properties in the weld root as well as problems with solidification cracking. The fast cooling rate in the root provides hard and brittle microconstituents lowering toughness at low temperatures. Numerical simulations and experimental observations showed that an increase in heat input from the laser beam is an effective way to reduce the cooling rate, which is also possible by applying preheating.

  • 7.
    Bunaziv, Ivan
    et al.
    Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, Trondheim.
    Frostevarg, Jan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Akselsen, Odd M.
    Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, Trondheim.
    Kaplan, Alexander
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    The penetration efficiency of thick plate laser-arc hybrid welding2018Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 97, nr 5-8, s. 2907-2919Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Double-sided fiber laser-arc hybrid welding was used to join 45 mm thick high strength steel over a wide range of parameters in order to investigate the efficiency of the process. Air gap size, I- and Y-groove type preparation, pulsed and cold metal transfer pulsed arc modes, arc-laser setup, and travel speeds were compared, and in all cases, sufficient filler material was provided to fully fill the gap. The welds were investigated using high speed imaging and cross-sectional analysis to identify penetration depths, morphology, and imperfections. Larger joint air gaps were found to contribute most to weld penetration depth. Surprisingly, increased line energy decreased penetration efficiency in most cases. The laser-arc interdistance was also investigated, revealing an arc size and melt flow dependency for achieving higher penetration depth for a leading arc. It was found that, although penetration can be optimized, solidification cracking can be a limiting factor in the application of deep penetration hybrid welding for thick steel section joining.

  • 8.
    Guo, Xiaolei
    et al.
    College of Materials Science and Engineering, Nanjing Forestry University, No. 159 Longpan Road, Nanjing, Jiangsu, China.
    Wang, Jinxin
    College of Materials Science and Engineering, Nanjing Forestry University, No. 159 Longpan Road, Nanjing, Jiangsu, China.
    Buck, Dietrich
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Träteknik.
    Zhu, Zhaolong
    College of Furnishings and Industrial Design, Nanjing Forestry University, Nanjing, Jiangsu, China.
    Ekevad, Mats
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Träteknik.
    Cutting forces and cutting quality in the up-milling of solid wood using ceramic cutting tools2021Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 114, nr 5-6, s. 1575-1584Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although many studies have focused on the cutting performance of ceramic blades in processing different materials, few have reported on their application in wood processing. Thus, it is necessary to explore the cutting performance of ceramic tools in solid wood machining. The aims of this paper were to evaluate the cutting performance of Al2O3 and Si3N4 ceramic tools in the process of machining Manchurian ash (Fraxinus mandshurica Rupr.) and Chinese fir (Cunninghamia lanceolata) by means of analysing cutting force and surface roughness and to provide guidelines for factories for applying ceramic tools in the manufacture of solid wood furniture. Up-milling tests were conducted for each combination of cutting speed, tool material, and workpiece material, and each combination was replicated five times. Results showed that (1) cutting force and surface roughness decreased with increase of cutting speed and (2) cutting force and surface roughness resulting from using Al2O3 ceramic cutting tools were larger than those of Si3N4 ceramic cutting tools, especially when cutting Manchurian ash with its extractives. Overall, ceramic tools can be used in high-speed cutting of solid wood. Compared with Al2O3 ceramic cutting tools, Si3N4 ceramic cutting tools are more suitable for cutting solid wood, especially those with extractives. Si3N4 ceramic tools provided not only chemical stability, but improved final product quality.

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  • 9.
    Hauser, Tobias
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling. Technology Department, Siemens AG, 81739 Munich, Germany.
    Reisch, Raven T.
    Chair of Robotics, Artificial Intelligence and Real-Time Systems, Technical University of Munich, 80333, Munich, Germany; Technology Department, Siemens AG, 81739, Munich, Germany.
    Kamps, Tobias
    Technology department, Siemens AG, D-81739 Munich, Germany.
    Kaplan, Alexander F.H.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Volpp, Joerg
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Acoustic emissions in directed energy deposition processes2022Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 119, nr 5-6, s. 3517-3532Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Acoustic emissions in directed energy deposition processes such as wire arc additive manufacturing and directed energy deposition with laser beam/metal are investigated within this work, as many insights about the process can be gained from this. In both processes, experienced operators can hear whether a process is running stable or not. Therefore, different experiments for stable and unstable processes with common process anomalies were carried out, and the acoustic emissions as well as process camera images were captured. Thereby, it was found that stable processes show a consistent mean intensity in the acoustic emissions for both processes. For wire arc additive manufacturing, it was found that by the Mel spectrum, a specific spectrum adapted to human hearing, the occurrence of different process anomalies can be detected. The main acoustic source in wire arc additive manufacturing is the plasma expansion of the arc. The acoustic emissions and the occurring process anomalies are mainly correlating with the size of the arc because that is essentially the ionized volume leading to the air pressure which causes the acoustic emissions. For directed energy deposition with laser beam/metal, it was found that by the Mel spectrum, the occurrence of an unstable process can also be detected. The main acoustic emissions are created by the interaction between the powder and the laser beam because the powder particles create an air pressure through the expansion of the particles from the solid state to the liquid state when these particles are melted. These findings can be used to achieve an in situ quality assurance by an in-process analysis of the acoustic emissions.

  • 10.
    Holmberg, Jonas
    et al.
    Department of Manufacturing Processes, RISE Research Institutes of Sweden AB, Argongatan 30, Mölndal, Sweden.
    Berglund, Johan
    Department of Manufacturing Processes, RISE Research Institutes of Sweden AB, Argongatan 30, Mölndal, Sweden.
    Brohede, Ulrika
    Department of Production Technology, Swerim AB, Isafjordsgatan 28A, Kista, Sweden.
    Åkerfeldt, Pia
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Sandell, Viktor
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Rashid, Amir
    Department of Production Engineering, KTH Royal Institute of Technology, Brinellvägen 68, Stockholm, Sweden.
    Zhao, Xiaoyu
    Department of Production Engineering, KTH Royal Institute of Technology, Brinellvägen 68, Stockholm, Sweden.
    Dadbakhsh, Sasan
    Department of Production Engineering, KTH Royal Institute of Technology, Brinellvägen 68, Stockholm, Sweden.
    Fischer, Marie
    Department of Industrial and Materials Science, Chalmers University of Technology, Hörsalsvägen 7B, Göteborg, Sweden.
    Hryha, Eduard
    Department of Industrial and Materials Science, Chalmers University of Technology, Hörsalsvägen 7B, Göteborg, Sweden.
    Wiklund, Urban
    Department of Material Science, Ångströmlaboratoriet, Uppsala University, Lägerhyddsvägen 1, Uppsala, Sweden.
    Hassila, Carl Johan Karlsson
    Department of Material Science, Ångströmlaboratoriet, Uppsala University, Lägerhyddsvägen 1, Uppsala, Sweden.
    Hosseini, Seyed
    Department of Manufacturing Processes, RISE Research Institutes of Sweden AB, Argongatan 30, Mölndal, Sweden.
    Machining of additively manufactured alloy 718 in as-built and heat-treated condition: surface integrity and cutting tool wear2024Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 130, nr 3-4, s. 1823-1842Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Additive manufacturing (AM) using powder bed fusion is becoming a mature technology that offers great possibilities and design freedom for manufacturing of near net shape components. However, for many gas turbine and aerospace applications, machining is still required, which motivates further research on the machinability and work piece integrity of additive-manufactured superalloys. In this work, turning tests have been performed on components made with both Powder Bed Fusion for Laser Beam (PBF-LB) and Electron Beam (PBF-EB) in as-built and heat-treated conditions. The two AM processes and the respective heat-treatments have generated different microstructural features that have a great impact on both the tool wear and the work piece surface integrity. The results show that the PBF-EB components have relatively lower geometrical accuracy, a rough surface topography, a coarse microstructure with hard precipitates and low residual stresses after printing. Turning of the PBF-EB material results in high cutting tool wear, which induces moderate tensile surface stresses that are balanced by deep compressive stresses and a superficial deformed surface that is greater for the heat-treated material. In comparison, the PBF-LB components have a higher geometrical accuracy, a relatively smooth topography and a fine microstructure, but with high tensile stresses after printing. Machining of PBF-LB material resulted in higher tool wear for the heat-treated material, increase of 49%, and significantly higher tensile surface stresses followed by shallower compressive stresses below the surface compared to the PBF-EB materials, but with no superficially deformed surface. It is further observed an 87% higher tool wear for PBF-EB in as-built condition and 43% in the heat-treated condition compared to the PBF-LB material. These results show that the selection of cutting tools and cutting settings are critical, which requires the development of suitable machining parameters that are designed for the microstructure of the material.

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  • 11.
    Moritz, Juliane
    et al.
    Fraunhofer Institute for Material and Beam Technology, Winterbergstraße 28, Dresden, Germany.
    Seidel, André
    Fraunhofer Institute for Material and Beam Technology, Winterbergstraße 28, Dresden, Germany.
    Kopper, Michael
    Westsächsische Hochschule Zwickau, Dr.-Friedrichs-Ring 2A, 08056, Zwickau, Germany.
    Bretschneider, Jörg
    Fraunhofer Institute for Material and Beam Technology, Winterbergstraße 28, Dresden, Germany.
    Gumpinger, Johannes
    ESA/ESTEC, European Space Research and Technology Center, 2201, Noordwijk, AZ, Netherlands.
    Finaske, Thomas
    Fraunhofer Institute for Material and Beam Technology, Winterbergstraße 28, Dresden, Germany.
    Riede, Mirko
    Fraunhofer Institute for Material and Beam Technology, Winterbergstraße 28, Dresden, Germany.
    Schneeweiß, Michael
    Westsächsische Hochschule Zwickau, Dr.-Friedrichs-Ring 2A, 08056, Zwickau, Germany.
    López, Elena
    Fraunhofer Institute for Material and Beam Technology, Winterbergstraße 28, Dresden, Germany.
    Brückner, Frank
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling. Fraunhofer Institute for Material and Beam Technology, Winterbergstraße 28, Dresden, Germany.
    Leyens, Christoph
    Fraunhofer Institute for Material and Beam Technology, Winterbergstraße 28, Dresden, Germany. Technische Universität Dresden, Helmholtzstr. 7, 01069, Dresden, Germany.
    Rohr, Thomas
    ESA/ESTEC, European Space Research and Technology Center, 2201, Noordwijk, AZ, Netherlands.
    Ghidini, Tommaso
    ESA/ESTEC, European Space Research and Technology Center, 2201, Noordwijk, AZ, Netherlands.
    Hybrid manufacturing of titanium Ti-6Al-4V combining laser metal deposition and cryogenic milling2020Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 107, nr 7-8, s. 2995-3009Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hybrid manufacturing, which, e.g., combines additive manufacturing with conventional machining processes, can be a way of overcoming limitations currently encountered in additive manufacturing. Cryogenic milling might be a viable option for hard-to-cut materials, as it leaves a contamination-free surface and can increase surface quality and tool life compared to conventional cooling concepts. In this study, the influence of cryogenic milling with carbon dioxide on titanium Ti-6Al-4V specimens manufactured with laser metal deposition (LMD) was investigated regarding tool wear and surface integrity in comparison to dry machining and machining with cooling lubricants. Moreover, additional layers of material were deposited on top of conventionally and cryogenically machined surfaces by means of LMD. The interface zone was then examined for defects. The milling process was closely monitored by means of thermal and high-speed imaging. Optical and tactile surface analysis provided evidence that lower roughness values and improved surface qualities could be obtained with cryogenic machining in comparison to dry machining. Moreover, significantly less tool wear was observed when a cryogenic cooling medium was applied. Although the utilization of conventional cooling lubricants resulted in satisfying surface qualities, substantial residual contamination on the milled surface was detected by means of fluorescence analysis. These contaminants are suspected to cause defects when the next layer of material is deposited. This is supported by the fact that pores were found in the weld bead applied on top of the milled specimens by means of LMD. Conversely, cryogenic machining resulted in very clean surfaces due to the residue-free evaporation of the coolant. Hence, a good metallurgical bonding between the weld bead and the milled substrate could be achieved. The results indicate the great potential of cryogenic milling in hybrid manufacturing, especially in terms of intermediate machining, as it provides residue-free surfaces for subsequent material deposition without an additional cleaning step and can significantly prolongate tool life.

  • 12.
    Najeh, Taoufik
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Degradation state prediction of rolling bearings using ARX-Laguerre model and genetic algorithms2021Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 112, nr 3-4, s. 1077-1088Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study is motivated by the need for a new advanced vibration-based bearing monitoring approach. The ARX-Laguerre model (autoregressive with exogenous) and genetic algorithms (GAs) use collected vibration data to estimate a bearing’s remaining useful life (RUL). The concept is based on the actual running conditions of the bearing combined with a new linear ARX-Laguerre representation. The proposed model exploits the vibration and force measurements to reconstruct the Laguerre filter outputs; the dimensionality reduction of the model is subject to an optimal choice of Laguerre poles which is performed using GAs. The paper explains the test rig, data collection, approach, and results. So far and compared to classic methods, the proposed model is effective in tracking the evolution of the bearing’s health state and accurately estimates the bearing’s RUL. As long as the collected data are relevant to the real health state of the bearing, it is possible to estimate the bearing’s lifetime under different operating conditions.

  • 13.
    Neikter, Magnus
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Huang, A.
    Monash Centre for Additive Manufacturing, Monash University, Melbourne, Australia. School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China.
    Wu, X.
    Monash Centre for Additive Manufacturing, Monash University, Melbourne, Australia.
    Microstructural characterization of binary microstructure pattern in selective laser-melted Ti-6Al-4V2019Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 104, nr 1-4, s. 1381-1391Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Selective laser melting (SLM) is an additive manufacturing process that offers efficient manufacturing of complex parts with good mechanical properties. For SLM, process parameters and post-processing are of importance as they affect the microstructure and consequently the mechanical properties. A feature in the microstructure, which is formed in SLM due to the fast cooling rate, is a binary microstructure pattern (BMP). The BMP is found in the horizontal plane and is formed with various laser scan angles between adjacent layers. The easiest distinguishable strategy is 90°, which renders a shape similar to a chessboard. In this work, the BMP phenomenon was investigated in detail and a microstructural characterization was performed on the fine microstructure zone (FMZ) that separates the coarse microstructure zones (CMZ), by using light optical and scanning electron microscopes (SEM) that were equipped with electron backscattered (EBSD) and energy dispersive x-ray spectroscopy (EDS) detectors. Moreover, the effect of the process parameter hatch distance on the BMP was investigated and the overlapping between neighboring scan tracks in SLM was found to influence the size of the BMP, while the thickness of the FMZ remained constant. Different post-SLM heat treatments were performed and it was shown that the BMP retained unless the heat treatment temperature reached above the β transus temperature. EBSD and β grain reconstruction were performed as well to reveal the columnar β grain orientations. The result showed that each CMZ and FMZ originates from a respective parent β grains.

  • 14.
    Odenberger, Eva-Lis
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik. Division Materials and Production, RISE IVF ABRISE Research Institutes of Sweden, Olofström.
    Pederson, Robert
    Division of Subtractive and Additive Manufacturing, University West, Trollhättan.
    Oldenburg, Mats
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Finite element modeling and validation of springback and stress relaxation in the thermo-mechanical forming of thin Ti-6Al-4V sheets2019Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 104, nr 9-12, s. 3439-3455Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, a hot forming procedure is developed using computer-aided engineering (CAE) to produce thin Ti-6Al-4V sheet components in an effective way. Traditional forming methods involve time- and cost-consuming furnace heating and subsequent hot sizing steps. A material model for finite element (FE) analyses of sheet metal forming and springback at elevated temperatures in Ti-6Al-4V is calibrated and evaluated. The anisotropic yield criterion proposed by Barlat et al. 2003 is applied, and the time- and temperature-dependent stress relaxation behavior for elastic and inelastic straining are modeled using a Zener–Wert–Avrami formulation. Thermo-mechanical uniaxial tensile tests, a biaxial test, and uniaxial stress relaxation tests are performed and used as experimental reference to identify material model parameters at temperatures up to 700 °C. The hot forming tool setup is manufactured and used to produce double-curved aero engine components at 700 °C with different cycle times for validation purposes. Correlations between the predicted and measured responses such as springback and shape deviation show promising agreement, also when the forming and subsequent holding time was as low as 150 s. The short cycle time resulted in elimination of a detectable alpha case layer. Also, the tool surface coating extends the tool life in combination with a suitable lubricant. 

  • 15.
    Olaogun, O
    et al.
    Department of Mechanical Engineering Science University of Johannesburg, Johannesburg, South Africa;Department of Mechanical Engineering, Kwara State University, Malete, Nigeria.
    Edberg, Jonas
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Lindgren, Lars-Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Oluwole, O. O.
    Department of Mechanical Engineering, University of Ibadan, Ibadan, Nigeria.
    Akinlabi, E.T
    Department of Mechanical Engineering Science, University of Johannesburg, Johannesburg, South Africa.
    Heat transfer in cold rolling process of AA8015 alloy: a case study of 2-D FE simulation of coupled thermo-mechanical modeling2019Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 100, nr 9-12, s. 2617-2627Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The finite element method (FEM) is one of the most applicable mathematical analytic methods of rolling processes and is also an efficient method for analyzing coupled heat transfer. Thermal analysis of cold rolling process is not frequently used due to the widespread assumption of insignificant impact during rolling process. This research focuses on the development of coupled thermo-mechanical 2-D FE model analysis approach to study the thermal influence and varying coefficient of friction during the industrial cold rolling process of AA8015 aluminum alloy. Both deformable-rigid and deformable-deformable rigid contact algorithms were examined in the 2-D FE model. Findings revealed that temperature distribution in the roll bite rises steadily in a stepwise manner. The deformable-deformable contact algorithm is the best investigations of thermal behavior of the rolled metal and work rolls necessary for typical application in work roll design. The predicted roll separating force is validated with industrial measurements.

  • 16.
    Prasad, Himani Siva
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Brueckner, Frank
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling. Fraunhofer IWS, Winterbergstrasse 28, 01277, Dresden, Germany.
    Volpp, Joerg
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Kaplan, Alexander F. H.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Laser metal deposition of copper on diverse metals using green laser sources2020Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 107, nr 3-4, s. 1559-1568Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Green laser sources are advantageous in the processing of copper due to the increase of absorptivity compared with more commonly available infrared lasers. Laser metal deposition of copper with a green laser onto various substrate metals namely copper, aluminium, steel and titanium alloy was carried out and observed through high-speed imaging. The effects of process parameters such as laser power, cladding speed and powder feed rate, and material attributes such as absorptivity, surface conditions and thermal conductivity are tied together to explain the size and geometry of the melt pool as well as the fraction of the power used for melting material. The copper substrate has the smallest melt pool with a high angle, followed by aluminium, steel and titanium alloy. The incorporation times for powder grains in the melt pools vary based on the substrate materials. Its dependency on material properties, including surface tension forces, melting temperatures and material density, is discussed. Oxide skins present on melt pools can affect powder incorporation, most significantly on the aluminium substrate. The lower limits of the fraction of power irradiated on the surface used purely for melting were calculated to be 0.73%, 2.94%, 5.95% and 9.78% for the copper, aluminium, steel and titanium alloy substrates, respectively, showing a strong dependence on thermal conductivity of the substrate material. For a copper wall built, the fraction was 2.66%, much higher than a single clad on a copper substrate, due to reduced workpiece heating. The results of this paper can be transferred to other metals with low absorptivity such as gold.

  • 17.
    Pérez Caro, Lluís
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik. Division of Materials and Production, RISE IVF AB, Vällaregatan 30, SE-293 38, Olofström, Sweden.
    Odenberger, Eva-Lis
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik. Division of Materials and Production, RISE IVF AB, Vällaregatan 30, SE-293 38, Olofström, Sweden.
    Schill, Mikael
    DYNAmore Nordic AB, Brigadgatan 5, SE-587 58, Linköping, Sweden.
    Steffenburg-Nordenström, Joachim
    GKN Aerospace Engine Systems Sweden, SE-461 38, Trollhättan, Sweden.
    Niklasson, Fredrik
    GKN Aerospace Engine Systems Sweden, SE-461 38, Trollhättan, Sweden.
    Oldenburg, Mats
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Prediction of shape distortions during forming and welding of a double-curved strip geometry in alloy 7182020Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 107, nr 7-8, s. 2967-2981Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The finite-element method (FEM) has considerably contributed to the development of more advanced manufacturing methods for metal structures. The prediction of the final shape of a component is of great interest to the manufacturing industry. In addition to its inherent difficulties, the presence of various types of processes in the manufacturing chain may dramatically increase the level of demand. Therefore, including all steps of the manufacturing process in the simulations is key to being successful. This has been done for a long time in the stamping industry, which involves sequences of forming, trimming, and springback. However, more complex manufacturing procedures, that include assembling of formed parts with forgings and castings via welding, have been modeled with simplifications, resulting in a reduced prediction accuracy. This hinders the compensation of accumulated shape distortions based on the simulation results. One such example is the fabrication of aero-engine structures, in which the history from the forming procedure has not been considered in subsequent welding and heat treatment analyses. In the present study, a double-shaped part manufactured from alloy 718 is formed at 20 °C and laser-welded using the bead-on-plate procedure. The coupling of different manufacturing analyses, including cold forming, trimming, result mapping, welding, cooling, and springback, is achieved using LS-DYNA. Additionally, the effect of adding the GISSMO damage model in the forming simulation is studied. The results of the forming analysis are used as inputs for the material model *MAT_CWM in the welding simulation. The anisotropic thermomechanical properties of alloy 718 are determined at temperatures up to 1000 °C. Encouraging agreement is found between the model predictions and the results of forming and welding tests. The findings underscore the importance of including the material history and accurate process conditions along the manufacturing chain to both the prediction accuracy of shape distortions, and to the potential of the industry.

  • 18.
    Reisch, Raven T.
    et al.
    Technology Department, Siemens AG, 81739, Munich, Germany; Chair of Robotics, Artificial Intelligence and Real-Time Systems, Technical University of Munich, 80333, Munich, Germany.
    Hauser, Tobias
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling. Technology Department, Siemens AG, 81739, Munich, Germany.
    Lutz, Benjamin
    Technology Department, Siemens AG, 81739, Munich, Germany.
    Tsakpinis, Alexandros
    Chair of Robotics, Artificial Intelligence and Real-Time Systems, Technical University of Munich, 80333, Munich, Germany.
    Winter, Dominik
    Technology Department, Siemens AG, 81739, Munich, Germany; Chair of Robotics, Artificial Intelligence and Real-Time Systems, Technical University of Munich, 80333, Munich, Germany.
    Kamps, Tobias
    Technology Department, Siemens AG, 81739, Munich, Germany.
    Knoll, Alois
    Chair of Robotics, Artificial Intelligence and Real-Time Systems, Technical University of Munich, 80333, Munich, Germany.
    Context awareness in process monitoring of additive manufacturing using a digital twin2022Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 119, nr 5-6, s. 3483-3500Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Wire Arc Additive Manufacturing allows the cost-effective manufacturing of customized, large-scale metal parts. As the post-process quality assurance of large parts is costly and time-consuming, process monitoring is inevitable. In the present study, a context-aware monitoring solution was investigated by integrating machine, temporal, and spatial context in the data analysis. By analyzing the voltage patterns of each cycle in the oscillating cold metal transfer process with a deep neural network, temporal context was included. Spatial context awareness was enabled by building a digital twin of the manufactured part using an Octree as spatial indexing data structure. By means of the spatial context awareness, two quality metrics—the defect expansion and the local anomaly density—were introduced. The defect expansion was tracked in-process by assigning detected defects to the same defect cluster in case of spatial correlation. The local anomaly density was derived by defining a spherical region of interest which enabled the detection of aggregations of anomalies. By means of the context aware monitoring system, defects were detected in-process with a higher sensitivity as common defect detectors for welding applications, showing less false-positives and false-negatives. A quantitative evaluation of defect expansion and densities of various defect types such as pore nests was enabled.

  • 19.
    Robertson, Stephanie
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Frostevarg, Jan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Ramasamy, Anandkumar
    Lincoln Electric Europe, Nijmegen, Netherlands.
    Kalfsbeek, Bert
    Lincoln Electric Europe, Nijmegen, Netherlands.
    Volpp, Jörg
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Kaplan, Alexander F.H
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Microstructures of high strength steel welding consumables from directed thermal cycles by shaped laser pulses2020Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 109, nr 9-12, s. 2653-2662Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Filler wire metallurgy was modified through temporally shaped laser pulses, controlling cooling cycles in a recently developed method. Trends were identified through efficient mapping while maintaining representative thermal cycles of welding processes. A primary pulse melted preplaced filler wires while a secondary, linearly ramped-down pulse elevated the nugget to re-austenization temperatures. Ramped-down pulses resulted in linear cooling rates comparable with and exceeding furnace-based methods, between 50 and 300∘C/s. The linear decay of laser output power guided the temperature through a regime to obtain desired microstructures. For three very high-strength steel filler wire chemistries, quenching resulted in smaller plates with cross-hatched microstructures, accompanied by grain boundary ferrite. Finer bainite microstructures started forming for fast linear temperature decay, about 250∘C/s. Slower decay or a weaker third cycle formed coarser microstructures with coalescent sheaves and less cross-hatching.

  • 20.
    Volpp, Joerg
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Behavior of powder particles on melt pool surfaces2019Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 102, nr 5-8, s. 2201-2210Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Additive Manufacturing is in progress to change the production and manufacturing environments and possibilities; however, thecomplex processes taking place are not completely understood yet. A better understanding of the incorporation mechanism of theparticles into the melt pool during blown powder processes could lead to methods to increase the powder and energy efficiency.Therefore, the incorporation mechanism was investigated in experiments and simulation. High-speed images made it possible toobserve the behavior of single particles on the melt pool. A model based on the temperature-dependent surface tension/energydifference between the particle and the melt pool calculated the time until particle incorporation. It was shown that the surfacetension characteristics during particle heating can even lift the particle from the melt pool. The calculated wetting behavior incombination with high kinetic energies should lead to an immediate immersion of the particle into the melt pool. Since observationsdo not show this behavior, it is concluded that the surface tension plays a role in the incorporation mechanism, but othereffects like the occurrence of oxide layers or additional particle heating by the laser beam seem to lead to different mechanismsand heat conductions to support an earlier incorporation.

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  • 21.
    Volpp, Joerg
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Dewi, Handika Sandra
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Fischer, Andreas
    Institute of Materials Engineering, Metallic Materials, University of Kassel, 34125, Kassel, Germany.
    Niendorf, Thomas
    Institute of Materials Engineering, Metallic Materials, University of Kassel, 34125, Kassel, Germany.
    Influence of complex geometries on the properties of laser-hardened surfaces2020Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 107, nr 9-10, s. 4255-4260Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Laser surface hardening provides for many advantages in terms of flexible production due to very localized and controlled energy input into the material. Laser processing offers the possibility to treat surfaces in order to locally strengthen the areas that are prone to fatigue cracking. It is well known that laser energy absorption depends on many parameters, e.g., the surface structure and the surface orientation. The incident angle of the laser beam plays a key role in this regard. When complex geometries like crankshaft fillets are treated, the surface cannot be considered a series of flat surfaces. Obviously, this leads to locally varying degrees of energy absorption. In the present work, curved surface structures were chosen in order to analyze the impact of the geometrical characteristics on surface and subsurface material properties after laser treatment. Microstructure evolution generally was found to be similar for flat and curved geometries. However, even if higher absorption in the groove due to the illumination at larger incident angles was expected, the outer parts of the curved geometry were not fully hardened. Thus, the increased effective length of the complex geometry-treated and the larger heat-affected volume are expected to have a more dominant influence on the final appearance of the subsurface microstructure. Eventually, for austenitization of the complete illuminated surface volume, the energy density needs to be increased.

  • 22.
    Wu, Zhanwen
    et al.
    Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, China; College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China.
    Buck, Dietrich
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Träteknik.
    Zhang, Feng
    College of Mechanical Engineering, Wanjiang University of Technology, Maanshan, 243000, China.
    Yu, Yingyue
    College of Furnishings and Industrial Design, Nanjing Forestry University, Nanjing, 210037, China.
    Guo, Xiaolei
    Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, China; College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China.
    Cao, Pingxiang
    Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, China; College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China.
    Zhu, Zhaolong
    Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, China; College of Furnishings and Industrial Design, Nanjing Forestry University, Nanjing, 210037, China.
    Finite element method and its application to cutting processes of stone–plastic composite2023Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 129, s. 4491-4508Artikel i tidskrift (Refereegranskat)
  • 23.
    Xi, Yinhu
    et al.
    Theory of Lubrication and Bearing Institute, Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System, Xi’an Jiaotong University, Xi’an, .
    Zhao, Yang
    Theory of Lubrication and Bearing Institute, Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System, Xi’an Jiaotong University, Xi’an, .
    Larsson, Roland
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Mao, Junhong
    Theory of Lubrication and Bearing Institute, Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System, Xi'an Jiaotong University.
    Time-dependent hysteresis friction behaviors of linear rolling bearings2018Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 94, nr 9-12, s. 3109-3116Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hysteresis friction behaviors of linear rolling bearings (LRBs) are important for precision positioning applications, which are related to the displacement and the traversed trajectory history within pre-rolling friction region. Although these behaviors have been pointed out in literature, the time dependence of transient hysteresis friction behaviors has not been reported before. In this work, the effects of initial conditions induced by the applied forces prior to commencement of the hysteresis motion are considered, which are denoted by the differences between the magnitudes of positive endpoints and the magnitudes of negative endpoints of virgin curves for the obtained asymmetrical hysteresis loops. The evolution of the time dependence is denoted by the decaying of the differences with the increasing dwell time. The effects of the damping and the junction growth during the dwell time are used to explain the time-dependent hysteresis friction behaviors of the LRB. The experiments of higher preload and lubrication-free conditions have been implemented as well, and the results indicate that the conditions are positive to diminish the time-dependent hysteresis friction behaviors.

  • 24.
    Zhu, Zhaolong
    et al.
    Nanjing Forestry University.
    Guo, Xiaolei
    Nanjing Forestry University.
    Ekevad, Mats
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Träteknik.
    Cao, Pingxiang
    Nanjing Forestry University.
    Na, Bin
    Nanjing Forestry University.
    Zhu, Nanfeng
    Nanjing Forestry University.
    The Effects of Cutting Parameters and Tool Geometry on Cutting Forces and Tool Wear in Milling High-density Fiberboard with Ceramic Tools2017Ingår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 91, nr 9-12, s. 4033-4041Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, the effects of cutting parametersand tool geometry on cutting forces and tool wear whenup-milling high-density fiberboard with alumina ceramiccutting tools were investigated. Under the condition ofthe same feed per tooth, average chip thickness, andclearance angle, the results shown are as follows: first,the tangential forces Ft and normal forces Fr at lowspeedcutting were higher than those at high-speed cutting,but increased slowly with the increase of cuttinglength and rake angle decrease. Second, increased cuttingspeed and decreased rake angle had a great effecton rake face wear. Third, the wear patterns of tool wearwere rake wear and flank wear, which included pull-outof grain, flaking, and chipping. The wear mechanismswere adhesive wear and abrasive wear. Finally, at lowspeedcutting, the cutting tools with bigger rake anglecan be selected to reduce the energy consumption ofmachine tools. The tools with smaller rake angle canbe used for high-speed cutting to improve tool lifeand productivity of processing.

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