Change search
Link to record
Permanent link

Direct link
BETA
Publications (10 of 107) Show all publications
Jain, A., Somberg, J. & Emami, N. (2019). Development and Characterisation of Multi-Scale Carbon Reinforced PPS Composites for Tribological Applications. Lubricants, 7(4), Article ID 34.
Open this publication in new window or tab >>Development and Characterisation of Multi-Scale Carbon Reinforced PPS Composites for Tribological Applications
2019 (English)In: Lubricants, E-ISSN 2075-4442, Vol. 7, no 4, article id 34Article in journal (Refereed) Published
Abstract [en]

 Polymer-based materials show to be of increasing interest in replacing metal based

materials in tribological applications due to their low weight, cost and easy manufacturability.

To further reduce the environmental impact of these bearing materials recyclability is becoming

more crucial, stimulating the need for high performing thermoplastic materials. In this study,

polyphenylene sulfide (PPS) composites were prepared in an effort to enhance the polymers’

tribological properties. Short carbon fibres (SCFs), graphene oxide (GO) and nano diamonds (NDs)

as well as polytetrafluoroethylene (PTFE) were used as micro and nano reinforcements. The addition

of SCFs especially decreased the linear coefficient of thermal expansions while enhancing the

micro hardness and wettability of the polymer. Under water lubricated conditions, a decrease

in friction up to 56% and a reduction of wear rate in the order of 103  was observed by the addition

of SCF. The reduction in friction and wear was further enhanced by the addition of NDs, providing

a synergistic effect of the reinforcements in micro and nano scale. By testing the individual

reinforcements under dry conditions, PTFE and SCFs were especially effective in reducing friction

while the release and consequent abrasion of NDs and SCFs increased the wear under a higher

contact pressure.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
PPS, short carbon fiber, nanocomposites, PTFE, wear, friction
National Category
Composite Science and Engineering Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-73529 (URN)10.3390/lubricants7040034 (DOI)000467292800006 ()2-s2.0-85066439713 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-17 (johcin)

Available from: 2019-04-09 Created: 2019-04-09 Last updated: 2019-06-17Bibliographically approved
Palmeira Belotti, L., Vadivel, H. S. & Emami, N. (2019). Tribological performance of hygrothermally aged UHMWPE hybrid composites. Tribology International, 138, 150-156
Open this publication in new window or tab >>Tribological performance of hygrothermally aged UHMWPE hybrid composites
2019 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 138, p. 150-156Article in journal (Refereed) Published
Abstract [en]

In this work, the effect of hygrothermal aging on friction and wear of water lubricated, Ultra High Molecular Weight Polyethylene (UHMWPE) hybrid composites were evaluated. Graphene Oxide (GO), Nano Diamonds (ND) and Short Carbon Fibers (SCF) were used as reinforcements as they previously exhibited promising improvements in the tribological behavior of UHMWPE in water-lubricated sliding contacts. Hygrothermal aging and pin-on-disc tribological experiments were performed to evaluate the response of the UHMWPE composites. It was observed that the friction and wear of the composites were not significantly affected by the aging conditions, which was attributed to the structural integrity of the newly developed UHMWPE based hybrid composites.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
UHMWPE, Thermoplastics, Hybrid composites, Hygrothermal aging, Friction, Wear
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-75038 (URN)10.1016/j.triboint.2019.05.034 (DOI)2-s2.0-85066240520 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-26 (johcin)

Available from: 2019-06-26 Created: 2019-06-26 Last updated: 2019-07-08Bibliographically approved
Emami, N. (2018). Biocompatibility, Mechanical and Tribological properties of GO reinforced thermoplastic polymer”. Flow Process Composite Materials Conference. In: : . Paper presented at 14th-Flow Process Composite Materials Conference.
Open this publication in new window or tab >>Biocompatibility, Mechanical and Tribological properties of GO reinforced thermoplastic polymer”. Flow Process Composite Materials Conference
2018 (English)Conference paper, Oral presentation only (Refereed)
National Category
Materials Engineering Composite Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-71922 (URN)
Conference
14th-Flow Process Composite Materials Conference
Available from: 2018-12-06 Created: 2018-12-06 Last updated: 2018-12-06
Emami, N. (2018). Design and manufacturing of Graphene Oxide reinforced high performing thermoplastics hybrid composites for Tribological applications. In: : . Paper presented at SIO-grafen National expert meeting-graphene as polymer composite reinforcement.
Open this publication in new window or tab >>Design and manufacturing of Graphene Oxide reinforced high performing thermoplastics hybrid composites for Tribological applications
2018 (English)Conference paper, Oral presentation only (Other academic)
National Category
Composite Science and Engineering
Research subject
Polymeric Composite Materials
Identifiers
urn:nbn:se:ltu:diva-71911 (URN)
Conference
SIO-grafen National expert meeting-graphene as polymer composite reinforcement
Funder
VINNOVA
Available from: 2018-12-06 Created: 2018-12-06 Last updated: 2018-12-06
Homayoun, M.-R., Golchin, A. & Emami, N. (2018). Effect of Hygrothermal Ageing on Tribological Behaviour of PTFE-Based Composites. Lubricants, 6(4), Article ID 103.
Open this publication in new window or tab >>Effect of Hygrothermal Ageing on Tribological Behaviour of PTFE-Based Composites
2018 (English)In: Lubricants, E-ISSN 2075-4442, Vol. 6, no 4, article id 103Article in journal (Refereed) Published
Abstract [en]

The present study investigates the influence of hygrothermal ageing on the tribological behaviour of polytetrafluoroethylene (PTFE) polymer composites. Three PTFE composites along with unfilled PTFE were tested in sliding contact against Inconel 625 (a Ni-based alloy) plates in both dry and water-lubricated conditions, utilising a unidirectional pin-on-disc tribometer. The tribo-tests were performed at a constant sliding speed of 0.13 m/s with a normal load of 84N providing an apparent contact pressure of 5 MPa. Hygrothermal conditioning was carried out at two different temperatures, and the water absorption evolution and kinetic parameters were estimated. Various characterisation methods were used to identify the wear mechanisms and influence of hygrothermal ageing on the degradation of the filler/matrix. The different tribological behaviour for different PTFE composites was observed within the ageing timeframe. The wear resistance of the fibre-filled samples was reduced compared to the non-aged ones over the ageing timeframe. However, the friction and wear resistance of the bronze-filled PTFE were enhanced by hygrothermal ageing.

Place, publisher, year, edition, pages
MDPI, 2018
Keywords
hygrothermal ageing, PTFE, friction, wear
National Category
Mechanical Engineering Materials Engineering Composite Science and Engineering Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-71930 (URN)10.3390/lubricants6040103 (DOI)000455618500019 ()2-s2.0-85059383793 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-02-01 (inah)

Available from: 2018-12-06 Created: 2018-12-06 Last updated: 2019-02-01Bibliographically approved
Emami, N. & Belotti, L. (2018). Effect of surface roughness and hygrothermal aging of multiscale carbon reinforced UHMWPE composites. In: : . Paper presented at 14th-Flow Process Composite Materials Conference.
Open this publication in new window or tab >>Effect of surface roughness and hygrothermal aging of multiscale carbon reinforced UHMWPE composites
2018 (English)Conference paper, Oral presentation only (Refereed)
National Category
Materials Engineering Composite Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-71923 (URN)
Conference
14th-Flow Process Composite Materials Conference
Available from: 2018-12-06 Created: 2018-12-06 Last updated: 2018-12-06
Emami, N. & Melk, L. (2018). Fracture toughness and thermal characterisation of GO based UHMWPE composites. In: : . Paper presented at 14th-Flow Process Composite Materials Conference.
Open this publication in new window or tab >>Fracture toughness and thermal characterisation of GO based UHMWPE composites
2018 (English)Conference paper, Oral presentation only (Refereed)
National Category
Materials Engineering Manufacturing, Surface and Joining Technology Composite Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-71925 (URN)
Conference
14th-Flow Process Composite Materials Conference
Available from: 2018-12-06 Created: 2018-12-06 Last updated: 2018-12-06
Belotti, L., Vadivel, H. & Emami, N. (2018). Influence of counter surface topography on the tribological behavior  of  hybrid UHMWPE composites. In: : . Paper presented at Nordtrib-2018.
Open this publication in new window or tab >>Influence of counter surface topography on the tribological behavior  of  hybrid UHMWPE composites
2018 (English)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Composite Science and Engineering Mechanical Engineering
Identifiers
urn:nbn:se:ltu:diva-71927 (URN)
Conference
Nordtrib-2018
Available from: 2018-12-06 Created: 2018-12-06 Last updated: 2018-12-06
Melk, L. & Emami, N. (2018). Mechanical and thermal performances of UHMWPE blended vitamin E reinforced carbon nanoparticle composites. Composites Part B: Engineering, 146, 20-27
Open this publication in new window or tab >>Mechanical and thermal performances of UHMWPE blended vitamin E reinforced carbon nanoparticle composites
2018 (English)In: Composites Part B: Engineering, ISSN 1359-8368, E-ISSN 1879-1069, Vol. 146, p. 20-27Article in journal (Refereed) Published
Abstract [en]

Ultrahigh molecular weight polyethylene (UHMWPE) is a known to be the material of choice for bearing components in joint arthroplasty. However, oxidation wear of UHMWPE components is considered to be a major drawback limiting the lifespan of implants. Vitamin E was considered as a promising antioxidant to prevent long-term oxidation and reduce the wear degradation of UHMWPE material. Nevertheless, there are limited results on the improvements of vitamin E on the mechanical and thermal properties of UHMWPE. In this study, we investigated the incorporation of 0.5–3 wt.% carbon nanoparticles: Multiwalled Carbon Nanotubes (MWCNTs), Graphene (GO) and Nanodiamonds (ND) on the mechanical and thermal properties of UHMWPE blended vitamin E (UHMWPE-E). Surface analysis of the composite powders showed well-dispersed carbon nanoparticles within the UHMWPE-E matrix. Thermogravimetric (TGA) and Differential Scanning Calorimetry (DSC) were used to study the thermal behavior of the nanocomposites. It was found that the addition of GO, MWCNTs and ND improved the thermal stability of the nanocomposites compared to neat UHMWPE-E. However, the addition of carbon nanoparticles had no significant effect on the crystallization parameters of the composites. In addition, the incorporation of MWCNT and ND improved significantly the fracture toughness of the composites. The addition of 0.7 wt.% ND and 1 wt.% MWCNT increased the fracture toughness from 5.93 MPa m1/2 for neat UHMWPE-E to 7.38 and 9.19 MPa m1/2 respectively. The enhanced fracture toughness and thermal stability of the nanocomposites could be due to the successful powder processing technique where an optimized mixing and ball milling parameters were used.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Other Mechanical Engineering Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Other Materials Engineering
Research subject
Machine Elements; Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-68088 (URN)10.1016/j.compositesb.2018.03.034 (DOI)000436224500003 ()2-s2.0-85044546322 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-04-03 (rokbeg)

Available from: 2018-03-27 Created: 2018-03-27 Last updated: 2019-01-18Bibliographically approved
Emami, N. (2018). Processing of high performance thermoplastic multiscale composites for tribological applications. In: 45th Leeds-Lyon Symposium on Tribology: . Paper presented at 45th Leeds-Lyon Symposium on Tribology, September. 4th-7th.
Open this publication in new window or tab >>Processing of high performance thermoplastic multiscale composites for tribological applications
2018 (English)In: 45th Leeds-Lyon Symposium on Tribology, 2018Conference paper, Oral presentation with published abstract (Refereed)
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:ltu:diva-71912 (URN)
Conference
45th Leeds-Lyon Symposium on Tribology, September. 4th-7th
Available from: 2018-12-06 Created: 2018-12-06 Last updated: 2018-12-06
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-8676-8819

Search in DiVA

Show all publications