Mechanical, corrosion, and wear properties of biomedical Ti-Zr-Nb-Ta-Mo high entropy alloys

The microstructures, mechanical, corrosion, and wear behaviors of the TixZrNbTaMo (x = 0.5,1,1.5, and 2, molar ratio) high entropy alloys (HEAs) were studied. It was found that the Ti-Zr-Nb-Ta-Mo HEAs showed a dendrite structure with two body-centered-cubic (BCC) solid solution phases. The Ti0.5ZrNb-TaMo HEA exhibited a high hardness of about 500 HV, high compressive strength approaching 2,600 MPa, and large plastic strain of over 30%. Furthermore, the highly-protective oxide films formed on the surface of Ti-Zr-Nb-Ta-Mo HEAs in the phosphate buffer saline (PBS) solution, which resulted in the high corrosion resistance of the HEAs. The Ti-Zr-Nb-Ta-Mo HEAs exhibited the greater dry- and wet-wear resistance than that of the traditional biomedical Ti6Al4V alloy. The results also indicated that with the decrease in the Ti content, the wear resistance of the Ti-Zr-Nb-Ta-Mo HEAs in the PBS solution improved. Finally, the Ti0.5ZrNbTaMo alloy presented the highest corrosive wear resistance among the four HEAs owing to its combination of good mechanical properties and high chemical stability. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The study on TixZrNbTaMo high entropy alloys revealed excellent properties in hardness, corrosion resistance, and wear resistance, with improvement in wear resistance in phosphate buffer saline solution as the titanium content decreases. The Ti0.5ZrNbTaMo alloy showed the highest corrosive wear resistance among the four HEAs due to its superior mechanical properties and chemical stability.