Microstructure And Antibacterial Property Of CoCrMoCu Alloy

In present paper, four different CoCrMoCu alloys were prepared with Cu content of 0 wt.%, 1 wt.%, 2 wt.% and 4 wt.%, respectively. Microstructure of the as-cast alloys and the alloys heat treated at 1060 and 1250 and annealed at 650 was investigated ℃ ℃ ℃by optical microscope and scanning electron microscope. The effects of the Cu content and the heat treatment on the corrosion property, tensile property and wear property were measured on the electrochemical work station and tested on universal testing machine and pin-on-disk friction wear tester. Antibacterial properties of the alloys were assessed by a plate-count method.The microstructure observation showed that the as-cast alloy mainly consisted of a dendritic matrix with carbide dispersion at grain boundaries and fine Cu-rich phase in the matrix and at the carbide/matrix interface. When the alloys were solution treated at 1060℃, the quantity of secondary carbides increased as time extension and the Cu-rich phase was completely dissolved in matrix after 24 hours treatment. When the alloy was solution treated at 1250℃, the quantity and the size of primary and secondary carbide both decreased as time extension and only little primary carbide existed in the matrix after 4 hours treatment. After aging heated at 650℃, the particular particle transformed into acicular carbide as time extension.The corrosion and wear results showed that the alloys treated at 1250 C for 4h had the highest corrosion resistance and the highest wear resistance while the as-cast alloys had the lowest corrosion resistance and wear resistance. The alloys aged at 650 ℃had better corrosion resistance and wear resistance than the alloy treated at 1060℃. The tensile mechanical property result showed that the alloy treated at 1250 and the alloy ℃aged at had the better mechanical properties than other alloys. The antibacterial test results showed that CoCrMo has no antibacterial property while the three CoCrMoCu alloys showed good antibacterial property under all conditions. The interaction between Cu2+ and bacteria was considered as the antibacterial mechanism.