Elastic-Plastic Characterisation of Aluminium Bearing Alloys

Abstract

A method is proposed to determine the elasto-plastic properties of a thin aluminium alloy lining of a bearing system from micro-indentation tests. This indentation process was modelled using an axi-symmetric FE model which was validated against experimental force-indentation curves from materials with known elasto-plastic properties. A fuller database of force-indentation curves has been generated by running the FE model with a range of elasto-plastic properties. This larger database has been used in adaptive numerical modelling to derive a generic model for the indent size as a function of load, elastic limit, yield strength and strain hardening coefficient and exponent in aluminium alloys. The adaptive numerical model was subsequently used to interpolate between the time-intensive FE results. Based on iterations of the most appropriate adaptive model, the elastic limit, yield strength and strain hardening exponent of a bearing alloy have been determined from the experimental micro hardness force-indentation depth curves for the same material.