Development of novel CoCu 0.5 FeNiVTi x ( x  = 0,0.5,1,1.5,2) high-entropy alloys

Abstract

CoCu_0.5FeNiVTi _x (x = 0, 0.5, 1, 1.5, 2) high-entropy alloys (HEAs) were prepared using vacuum arc melting. The microstructures, crystal structures, hardness, compressive properties and wear resistances of the alloys were studied. The alloys always contained face-centred cubic (FCC) and body-centred cubic (BCC) solid solution regardless of the increase in Ti content. The microstructure of alloys exhibited typical dendritic characteristics, which were more and more unapparent with the increase in the Ti content. The alloys with a high content of Ti had a high compressive strength and low ductility. Owing to the formation of nano-precipitates and BCC as the major phase, the CoCu_0.5FeNiVTi₁ alloy exhibited the highest compressive strength of 2747 MPa and a plastic strain limit of 7.4%. As the content of Ti was increased, the wear resistance of CoCu_0.5FeNiVTi _x alloys displayed a rapid increase and reached the highest value when x = 1, and finally decreased. Because of the large volume fraction of BCC, the CoCu_0.5FeNiVTi₁ alloy exhibited high hardness so exhibiting the best wear resistance. Adhesive wear and abrasive wear dominated the wear behaviour of CoCu_0.5FeNiVTi _x alloys during sliding against SUJ2 steel.