Microstructure, corrosion, and mechanical properties of compression-molded zinc-nanodiamond composites

Abstract

Zinc-nanodiamond (ND) composite is proposed as a novel biodegradable implant material due to its desirable corrosion, mechanical, and biocompatible properties. In this research, the microstructure, corrosion behavior, and mechanical properties of Zn-ND composites were investigated for the first time as a potential implant material in biomedical applications. Powder metallurgy manufacturing processes were used and different sintering conditions were studied. Grain size increased with increasing sintering temperature and longer sintering time. Corrosion resistance was improved 61.0, 65.9, and 70.7 % for 1, 2.5, and 5 % ND compared with pure Zn. Compression and hardness tests were performed to determine the mechanical properties. In the compression tests, Zn-1ND showed the highest Young’s modulus, with 10.95 and 27.32 % more than pure Zn and Zn-5ND. Pure Zn had the highest compressive strength, 11.8 and 29.5 % higher than Zn-1ND and Zn-2.5ND. Zn-1ND and Zn-2.5ND are 55.2 and 68.9 % lower in hardness compared with pure Zn (HV = 27). Compression-molded zinc with low concentrations of nanodiamond offers a promising combination of strength and low corrosion rate, and with strength approaching cortical bone and higher than most biological tissues.