Micro-hardness and wear behavior of AA2014/Al2O3 surface composite produced by friction stir processing

The present study aimed to improve the micro-hardness and wear properties of AA2014 aluminum alloy. Surface composite of AA2014 was produced using Al2O3 as reinforcement by friction stir processing (FSP) technique. FSP was performed by using a constant traverse speed of 40 mm/min and two rotating speeds of 1000 and 1400 rpm. After FSP, the average grain size of AA2014 was reduced from 21.9 µm in base material to 9.2 µm in FSP with a rotating speed of 1000 rpm and 3.8 µm in FSP with rotating speed of 1400 rpm. Optical microscopy showed that the Al2O3 reinforcement particles were distributed homogeneously in AA2014 after FSP. The micro-hardness test showed that the hardness property in AA2014/Al2O3 surface composite was improved after FSP and was increased with an increase in rotating speed. The micro-hardness was improved by 30% after FSP. The wear test revealed that both the wear performance and coefficient of friction (COF) were improved after FSP. The COF was improved from 0.27461 in base material to 0.22570 in FSPed samples. Surface roughness test showed that the sample with more micro-hardness showed better surface roughness as compared to the other samples.