Enhancement in mechanical properties, antimicrobial properties and osseointegration ability of porous TC4-5Cu alloys prepared via additive manufacturing

The aim of this study was to address insufficient load-bearing capacity, and lack of antibacterial properties of porous Ti6Al4V (TC4) alloy, porous TC4-5Cu alloy with designed honeycomb structure were prepared by additive manufacturing technology. The effects of wall thickness (100-300 mu m) on the microstructure, mechanical properties, antimicrobial properties and osseointegration ability of porous TC4-5Cu alloys were systematically investigated. Results indicated that the porous TC4-5Cu alloy was composed of alpha'/alpha, beta and Ti2Cu phases. With the increase of wall thickness, the elastic modulus, yield strength, and Vickers hardness of the porous alloys increased. The yield strength increased slightly especially for the wall thicknesses of over 200 mu m. Compared with the other porous TC4 alloy with various structures, the porous TC4-5Cu alloy with the wall thicknesses of 200-300 mu m exhibited high yield strength (702.0-711.1 MPa), considerable elastic modulus (23.6-25.4 GPa) and high Vickers hardness (415.4-421.2 HV). Porous TC4-5Cu alloy revealed excellent antimicrobial rate 100% against both S. aureus and E. coli. Moreover, the porous TC4-5Cu alloy with the wall thickness of 200 mu m displayed osseointegration ability and lower concentration of TNF-alpha during in vivo test. Therefore, the designed porous TC4-5Cu alloy exhibited immense potential of clinical application.