Effect of Porosity on the Wear Performance of Ti-18Nb-9Cu Alloy

This study examined the influence of porosity on the mechanical behavior and wear performance of Ti-18Nb-9Cu alloys (wt%) fabricated via powder metallurgy using ammonium bicarbonate as a space holder at varying volume fractions (30%, 40%, 50%, and 60%). Compression tests showed that increasing porosity led to significant mechanical degradation: the elastic modulus decreased by approximately 80%, and the ultimate compressive strength dropped by 74% as porosity increased from 29.7% (30 vol% space holder) to 48.1% (60 vol% space holder). Tribological evaluations under dry sliding conditions revealed that the specific wear-rate increased nearly eightfold. Surface roughness (Ra) values rose from 0.969 µm to 1.982 µm, indicating increased topographical irregularity. These results underscore the critical influence of controlled porosity on the mechanical integrity and wear resistance of Ti-18Nb-9Cu alloys, highlighting their potential for load-bearing biomedical implant applications.