Wear behaviour of hot rolled AZ31B magnesium alloy as candidate for biodegradable implant material
(1. Department of Manufacturing Engineering, Faculty of Technology, Gazi University, TR-06500 Ankara, Turkey;
2. Magnum Engineering Medical R&D Company, TR-06830 Ankara, Turkey)
Abstract: Surface integrity and tribological behaviour of implant materials have a critical impact on their performance in the body. To understand wear behaviour well, the present article focuses on the sliding wear behavior of hot rolled AZ31B magnesium alloy which is a good candidate for biodegradable implant material. Dry-sliding conditions which include pin-on disc method with heat-treated high-carbon steel disc as counterface were used. Wear rates at a fixed sliding distance of 5000 m were measured at sliding velocities of 0.25, 0.5, 1 and 2 m/s, and loads of 10, 20, 40 and 80 N. Microstructure of worn surfaces of pins was characterized using SEM/EDS. Wear mechanism maps of the investigated materials were composed to understand comprehensively. According to test results, abrasive wear occurred at load of 20 N and sliding speed of 0.25 m/s while melting wear was predominant at load of 80 N and sliding speed of 2 m/s. Results show that ultra-severe plastic deformation is the main wear mechanism at the highest applied load and sliding velocity speed for the investigated alloy. Consequently, hot rolled AZ31B magnesium alloy exhibited a good wear resistance due to fine microstructure and high hardness.
Key words: dry sliding wear; biomaterial; AZ31B magnesium alloy; wear mechanism; wear map