Preliminary study of hap addition to Co-Cr-Mo alloy fabricated by powder metallurgy method

Abstract

This preliminary study of HAP addition in Co-Cr-Mo (F-75) was carried out by powder metallurgy method. The lab work comprises the mixing of Co-Cr-Mo with different HAP (hydroxyapatite) composition which varied from 0 wt. % to 25 wt. %. The premixed powders then have been milling for 20 minutes, cold compacted at 550 MPa, and sintered at 11000C in tube furnace for two hours. After sintering, sample A without HAP shows very good appearance condition. Starts from sample B (5 wt. % HAP) the small pores appear in the middle of the sample after sintering, sample C (10 wt. % HAP) shows cracks in the whole sample. Sintered sample with 15 wt. % HAP, (sample D) shows big crack in the upper part, while sample E (with 20wt% HAP) shows less cracks but the small cracks appear in the whole sample. The sample with higher amount of HAP, (25 wt% HAP, sample F), showed the worse cracks in the middle and upper part of the sample. It was found that the higher addition of HAP to F-75, the more tendencies for the composites to cracks. The optimum addition of HAP is below than 10% HAP.