Investigation on Tribological Behaviour of Aluminosilicate Reinforced AA7075 Composites for Aviation Application

Abstract

In this study, AA 7075 and its composites were developed using ex situ (stir casting) process for varying compositions 1–3 in weight fraction (wt%) of aluminosilicate (nanoclay) at an interval of 1 wt%. The developed alloy and its composites have undergone T6 heat treatment condition. As per the ASTM standard G99-95, tribological study of the developed alloy and its composites were performed using pin-on-disc equipment under ambient temperature. The composites with 1 and 2 wt% of nanoclay showed increase in wear resistance compared to matrix material with mild wear. Coefficient of friction (CoF) value increased by addition of nanoclay compared to matrix material, due to applied load and sliding speed. To understand the wear mechanism, worn specimen’s surface morphology were examined using field emission-scanning electron microscope (FE-SEM). Further addition of nanoclay above 2 wt% showed some severe wear, cluster formation and poor bonding of nanoclay into the matrix material. Hardness value increased at 1 and 2 wt% of nanoclay and decreased at 3 wt% due to the improper bonding with matrix material. Reinforcement of nanoclay particles with 1 and 2 wt% reduced the wear rate and improved the durability of the matrix material. AA7075 (T6) material showed that it has suffered from abrasive wear mechanism. Also, nanocomposites showed the oxidation and adhesive as a dominant wear mechanism.