Effect of Al Content on Microstructure and Properties of AlxMoNbTiV RCCA's Alloys

The objective of this study is the evaluation of high entropy alloys for aeroengines applications up to 1000 degrees C. AlxNbMoTiV alloys with 10 and 20 at.% Al have been produced by arc melting. As-cast microstructure and phase transformations during heat treatments have been investigated through SEM, DRX and TEM, revealing the possibility of homogenization at 1400 degrees C and the stability of the BCC structure at 1000 degrees C and 800 degrees C for both alloys. Mechanical properties have been evaluated through micro-hardness and compression tests up to 800 degrees C. It appears that, although both alloys show a similar microstructure and hardness evolution with heat treatment, the Alloy containing 10 at.% of Al show a higher yield strength at room temperature and 800 degrees C, related to the brittle character of the alloy containing 20 at.% of Al.