Wear Behavior and Mechanism of CoCrMo Alloy Fabricated by Powder Metallurgy Route

This research is devoted to study the wear behavior and mechanism of CoCrMo alloy due to the uitilization of the alloy in application mainly exposed to wear. Samples fabricated by powder metallurgy route compacted under (1000MPa) and sintered at (1200 degrees C) in the argon atmosphere. Wear test type pin-on-disc was performed under dry sliding condition over steel counterface disc. For the first group of wear tests four vertically loads (10,15,20 and 25) N were applied at fixed sliding speed (1.476) m.s(-1), time (15 min) and sliding distance (1329m). The second group of tests were conducted at fixed applied load (25) N for (60 min) interrupted to four equal intervals and at the same above sliding speed. The worn surface of the tested samples and formed wear debris particles were investigated and analyzed with aid of SEM and SEM-Mapping facilities. The results showed that the wear rate increased by increasing the applied load and a transition from mild wear to severe wear was occurred at (20 N) for fixed sliding time (15min). The maximum measured wear rate was (39.72x10(-7)) mm(3).mm(-1) at the highest applied load. While for the second group the wear rate was decreased when the sliding time exceeded 30 min. The main wear mechanism was adhesive type detected by material transfer, with lower abrasive type which is revealed from the existence of fine grooves. Oxidation and plastic deformation features are also observed.