Microstructure and Properties of the Co2NiWV0.5Mo1.5, Co2NiWV0.5Mo2, and Co2NiWV1.0Mo2 Multi-Principal Elements Alloys

The Co2NiWV0.5Mo1.5, Co2NiWV0.5Mo2 and Co2NiWV1.0Mo2 multi-principal elements alloys were prepared by vacuum arc melting. The microstructure, compressive property and corrosion resistance of the alloys were investigated by means of X-ray diffraction, scanning electron microscope with energy dispersive spectroscopy, electrochemical workstation and material testing machine. Results indicated that all of these alloys were composed of primary dendrite with BCC structure. Inter-dendrite regions were filled with irregular and lamellar eutectics with a mixture of FCC solid solution and Co7Mo6-type μ phase. Compression tests indicated that fracture strength of Co2NiMo2V1.0W, Co2NiMo2V0.5W and Co2NiMo1.5V0.5W alloys was 2308MPa, 1983MPa and 1861MPa, respectively. The solid-solution strengthening of BCC matrix and μ phase were the two main factors to strengthen the alloys. Alloys corrosion resistance showed the alloy with higher Mo or lower V content has better corrosion resistance.