Microstructure and tribological behavior of Ti-Si eutectic alloys with Al addition

The effect of Al element alloying on the microstructure and tribological behavior of Ti-Si eutectic alloys has been studied. The experimental results show that Al element changes the microstructure from large eutectic cells that consist of layered tablet phases Ti5Si3 and alpha-Ti (for the Al-free alloy) to near-equiaxed or rod-like Ti5Si3 particle reinforced continuous alpha-Ti (Al, Si) solid solutions. This microstructural change greatly improves the ductility and reduces brittle fracture of massive superficial materials during wear process. Microplough and local delamination are the main wear mechanisms of Al-added Ti-Si alloys. Therefore, the wear resistance and friction stability are simultaneously improved.