Fretting fatigue tests on 6201-T81 aluminum alloy conductor wires at room temperature and 75 °C

Abstract

The aim of this work was to conduct a test campaign to investigate the effect of temperature on the fretting fatigue life of aluminum alloy 6201-T81 wires taken from All Aluminum Alloy Conductors (AAAC) 900 MCM. To this end, fretting fatigue tests were conducted at room temperature (25 °C) and 75 °C. A three actuators fretting fatigue rig was upgraded with a heating system to allow the tests at elevated temperatures with an accuracy of ±2 °C. A methodology to ease the control of the temperature within the contact region was proposed and the details of the wire-against-wire fretting fatigue test were described. Two S–N curves were then obtained under the same load conditions, but each one at a different temperature. The results showed that at higher temperature the fretted wires could face up to 72 % reduction in fatigue life. Failure analysis of the fracture surfaces proved that the fatigue phenomenon in both conditions, i.e., at 25 °C and 75 °C, were very similar even though fatigue lives are quite different.