Tribological behaviour of an electrochemical jet machinedtextured Al-Si automotive cylinder liner material

Walker, J.C.; Kamps, T.J.; Lam, J.W.; Mitchell-Smith, Jonathon; Clare, Adam T.

Abstract

This paper investigates the use of Electrochemical Jet Machining to surface texture a hyper-eutectic Al-Si cylinder liner material. Samples were lapped to a 6μm finish followed by immersion in 1mol NaOH to expose the primary silicon colonies above the aluminium surface. Texturing was carried out using a NC system comprising of a fine gauge nozzle (cathode) jetting a solution of 2.3 mol NaCl on the surface (anode) whilst applying a current density of 220A/cm2. An array of hemispherical dimples at 1.5mm spacing was created, with an average diameter of 420μm and depth of 40μm, corresponding to an ε ratio of 0.095. Lubricated reciprocating sliding was carried out at stroke length of 25mm in a bath of PAO (4cSt) against a 52100 cylinder of 6mm diameter and 16mm length.
Sliding frequencies were incremented at 1Hz intervals between 1-15Hz at 50N load increments from 50-200N. Stribeck curves indicated a reduction of the friction coefficient due to texturing of up to 0.05 in the mixed lubrication regime, representing a decrease of 38.5%. Optical profilometry and SEM indicated that abrasion and formation of a surface tribo-layer was mitigated in regions of the Al-Si surface where textured features were present parallel to the sliding direction.

Citation

Walker, J., Kamps, T., Lam, J., Mitchell-Smith, J., & Clare, A. T. (2017). Tribological behaviour of an electrochemical jet machinedtextured Al-Si automotive cylinder liner material. Wear, 376-377(B), 1611-1621. https://doi.org/10.1016/j.wear.2017.01.085

• Journal Article Type: Article
• Acceptance Date: Jan 23, 2017
• Online Publication Date: Jun 15, 2017
• Publication Date: Apr 15, 2017
• Deposit Date: Jan 27, 2017
• Publicly Available Date: Aug 9, 2018
• Journal: Wear
• Print ISSN: 0043-1648
• Electronic ISSN: 1873-2577
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 376-377
• Issue: B
• Pages: 1611-1621
• DOI: https://doi.org/10.1016/j.wear.2017.01.085
• Keywords: Surface Texturing; Automotive; Al-Si; Friction; Wear; Electrochemical Jet Machining
• Public URL: https://nottingham-repository.worktribe.com/output/839474
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0043164817302168
• Contract Date: Aug 9, 2018