Characterization of wear and friction between tool steel and aluminum alloys in sheet forming at room temperature Show others and affiliations
2021 (English) In: Journal of Manufacturing Processes, ISSN 1526-6125, Vol. 64, p. 774-784Article in journal (Refereed) Published
Abstract [en]
This work investigates the coefficient of friction (COF) at room temperature between tool steel 1.2343 and aluminum alloys EN AW-5182, EN AW-6016 as-delivered (T4) and EN AW-6016 naturally aged (T4*) using a strip drawing tribometer. In order to simulate the contact conditions of industrial sheet metal forming processes, the surfaces of the steel pins and of the aluminum strips were maintained as-delivered, i.e., the pins were wire-cut from a hardened and ground plate and the strips were cut from electrical discharge textured (EDT) and dry-lubricated sheets. Two sliding velocities, 50 mm/s and 250 mm/s, and two nominal contact pressures, 10 N/mm2 and 20 N/mm2 , were considered. The sliding distance on each strip was 0.5 m. Each pair of pins was utilized for testing 10 or 20 strips to study the influence of increasing the sliding distance on the COF. Before and after the tribological experiments, surface topographies of selected pins and strips were analyzed using 3D optical surface profilometry, optical microscopy and scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDS). Strain hardening due to plastic surface deformation of the strips was investigated using an automated hardness tester. In general, an increasing trend of the COF was observed with increasing sliding distance. The mean COF obtained for each of the tests was in the range of 0.09−0.17; however, it was considerably higher if aluminum was transferred from the strip to the pins. Moreover, moist pin surfaces were identified to increase the COF, as the originally dry lubricant became pasty and sticky which promoted entrapment of abraded aluminum particles. Slightly higher strain hardening of alloy EN AW-5182 compared to alloy EN AW-6016 caused less flattening of the strip asperities and more severe wear of the pin surface.
Place, publisher, year, edition, pages Elsevier, 2021. Vol. 64, p. 774-784
Keywords [en]
Coefficient of friction, COF, Sheet metal forming, Aluminum alloy, Tool steel, Galling, Contact pressure, Sliding velocity, Strip drawing tribometer
National Category
Other Mechanical Engineering
Research subject Machine Elements
Identifiers URN: urn:nbn:se:ltu:diva-83081 DOI: 10.1016/j.jmapro.2021.02.007 ISI: 000642073600002 Scopus ID: 2-s2.0-85101105716 OAI: oai:DiVA.org:ltu-83081 DiVA, id: diva2:1531603
Note Validerad;2021;Nivå 2;2021-02-26 (alebob);
Finansiär: Erasmus+ Programme of the European Union
2021-02-262021-02-262025-02-14 Bibliographically approved