Drilling performance of Al-Ni eutectic alloy with scandium addition

Abstract

Al-Ni eutectic alloys are an alternative alloy for high-temperature applications because of their excellent thermal stability of the Al3Ni eutectic fibers. Since the matrix of eutectic Al-Ni is weak, adding Sc to the alloy (Al-6Ni-0.4Sc) is able to increase its strength and hardness. This study is to investigate the machinability of Al-6Ni-0.4Sc alloy compared to Al-6Ni alloy through a drilling process. The results revealed that the Al-6Ni-0.4Sc alloy required less power, torque, and thrust force in the drilling process than Al-6Ni, despite having higher strength and hardness. The average specific energy for the drilling of Al-6Ni-0.4Sc alloy was 1.011 W s/mm3. This was 12.77% less than the value for Al-6Ni alloy. The chip velocity in the drilling of the alloy with Sc addition was twice that of the alloy without Sc, implying low heat accumulation in the cutting tool, less tendency for built-up edge formation, and a low wear rate on the drill’s rake face when drilling Al-6Ni-0.4Sc alloy.