Title: Local fatigue and wear behaviours of 7075 aluminium alloy induced by rotational fretting wear

Authors: Ming-Xue Shen; Zhen-Bing Cai; Ji-Liang Mo; Xu-Dong Peng; Min-Hao Zhu

Addresses: Engineering Research Center of Process Equipment and Its Remanufacture, Ministry of Education, Zhejiang University of Technology, Hangzhou 310032, China ' Tribology Research Institute, Key laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China ' Key Laboratory of Advanced Technologies of Materials, Tribology Research Institute, Ministry of Education, Southwest Jiao Tong University, Chengdu 610031, China ' Engineering Research Center of Process Equipment and Its Remanufacture, Ministry of Education, Zhejiang University of Technology, Hangzhou 310032, China ' Key Laboratory of Advanced Technologies of Materials, Tribology Research Institute, Ministry of Education, Southwest Jiao Tong University, Chengdu 610031, China

Abstract: Rotational fretting (RF) wear tests of 7075 aluminium alloy were conducted and the local fatigue and wear behaviours were analysed. Results showed that the cracks initiated at the contact edge and propagated along a sharp angle (∼15° to 30° with respect to the base alloy) in the mixed fretting regime (MFR). However, only some delamination induced by the parallel cracks can be observed in the partial slip regime (PSR) and the slip regime (SR). In MFR, the rate of crack propagation was higher than that of wear, and thus the local fatigue dominated the competition between fretting-induced wear (FIW) and fretting-induced fatigue (FIF). For RF, it was a unique phenomenon that protrusion was generated at the contact centre due to the plastic-flow accumulation of materials, which also indicated that the initiation of fatigue crack may be closely related to the central protrusion, and the protrusion played an important role in controlling the local fatigue behaviour. In addition, the friction-dissipated energy method can be used to characterise the running behaviours of RF.

Keywords: fretting wear; rotational fretting; fatigue cracks; fretting induced wear; fretting induced fatigue; aluminium alloys; delamination; crack propagation; protrusion.

DOI: 10.1504/IJSURFSE.2015.072833

International Journal of Surface Science and Engineering, 2015 Vol.9 No.6, pp.520 - 537

Received: 17 Jun 2014
Accepted: 02 Nov 2014

Published online: 04 Nov 2015 *

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