Investigation of tribological performance of ZK60 material alloyed with rare earth elements (Nd, La) in body fluid environment

Abstract Biomaterials are materials used particularly in implant manufacturing and are becoming increasingly important in the healthcare sector. The production of alternative biomaterials and the study of their wear behaviour are also significant. Therefore, the rare earth elements Neodymium (Nd) and Lanthanum (La) were added to the biodegradable ZK60 magnesium alloy at 0.5% and the alloy was produced by casting. AZ31 was also commercially available. Microstructure images, hardness measurements, and XRD graphs were obtained for material characterisation. Wear tests of the samples were conducted in a simulated body fluid (SBF) environment and at body temperature under three different loads (10N, 20N, 30N), a speed of 17 mm s −1 , and a sliding distance of 200 m. Post-wear surfaces were examined in detail using SEM and EDX. The highest average hardness was 73.05 HV in the ZK60+La sample, and the lowest was 50.36 HV in the AZ31 sample. The formation of secondary main phases (MgO, MgZn, La 2 O 3 and Nd 3 Zn 11 ) with the addition of Nd and La was detected by XRD. It was observed that the highest average volume loss occurred in the ZK60+Nd (3.287 mm 3 ) sample, while the lowest average volume loss occurred in the AZ31 (1.648 mm 3 ) sample. The obtained data were statistically analysed using ANOVA. According to the ANOVA results, the material factor had a 56.85% and 87.1% effect on the friction coefficient and volume loss, respectively. The load factor was found to affect volume loss by 9.26% and the friction coefficient by 33.16%. As a result, the ZK60+La alloy exhibited higher hardness and wear resistance than the ZK60+Nd alloy.