Optimization of mechanical properties, biocorrosion properties and antibacterial properties of wrought Ti-3Cu alloy by heat treatment

Abstract

Previous study has shown that Ti-3Cu alloy shows good antibacterial properties (>90% antibacterial rate), but the mechanical properties still need to be improved. In this paper, a series of heat-treatment processes were selected to adjust the microstructure in order to optimize the properties of Ti-3Cu alloy. Microstructure, mechanical properties, biocorrosion properties and antibacterial properties of wrought Ti-3Cu alloy at different conditions was systematically investigated by X-ray diffraction, optical microscope, scanning electron microscope, transmission electron microscopy, electrochemical measurements, tensile test, fatigue test and antibacterial test. Heat treatment could significantly improve the mechanical properties, corrosion resistance and antibacterial rate due to the redistribution of copper elements and precipitation of Ti2Cu phase. Solid solution treatment increased the yield strength from 400 to 740 MPa and improved the antibacterial rate from 33% to 65.2% while aging treatment enhanced the yield strength to 800–850 MPa and antibacterial rate (>91.32%). It was demonstrated that homogeneous distribution and fine Ti2Cu phase plays a very important role in mechanical properties, corrosion resistance and antibacterial properties.

Biological applications of copper-containing materials

“…Combined with the above conditions, Nisshin Steel (Tokyo, Japan) first developed antibacterial Cu-containing SS in the 1990s 102 . Related research demonstrated that the strong and broad-spectrum antibacterial ability of Cu-containing SS is mainly due to the Cu ions released from the steel's surface, which damage bacterial cell walls and cell membranes, adsorb electrons from bacteria, and generate reactive oxygen species (ROS), resulting in severe damage to and death of bacteria and fungi [ 24 , 110 , 111 ], such as Staphylococcus haemolyticus [ 112 , 113 ], Escherichia coli [ 114 ], and Candida albicans [ 111 , 115 ]. Subsequently, Yang et al from the Institute of Metal Research, Chinese Academy of Sciences (Shenyang, China), proposed a new concept of a bio-functional design for metallic biomaterials, focusing on the development of new metallic biomaterials with the combination of excellent mechanical properties, corrosion resistance, and antibacterial ability [ 21 ].…”

The effect of different surface topographies of titanium implants on bacterial biofilm: a systematic review

“…Conversely, element alloying by adding copper (Cu) in titanium to develop Ti-Cu alloys, presented a very stable and strong anti-bacterial ability to obstruct biofilm attachment efficiently by damaging bacterial cell walls, better wear resistance, higher mechanical properties and better anti-corrosion resistance than commercially pure titanium [33]. The anti-bacterial rate was found to be greater than 90% when the Cu content in Ti-Cu alloy was at least 3 percent by weight (wt%) [3]. This finding is similar to another included study in this systematic review which confirmed the strong antibacterial property of Ti-3Cu alloy [56].…”

Tuning osteoporotic macrophage responses to favour regeneration by Cu-bearing titanium alloy inPorphyromonas gingivalislipopolysaccharide-induced microenvironments

“…Cu has been shown to be a multi-functional agent that not only increases angiogenesis and osteogenesis, but also inhibits osteoclastogenesis and displays broad-spectrum antibacterial properties [ 9 , 11 ]. Numerous researches have demonstrated that Cu incorporated into a variety of biomaterials would promote their bioactivities [ 8–10 ]. Cu ions released from Cu-containing materials are involved in regulating the cellular activities and inhibiting growth of bacteria.…”

“…Cu deficiency has been proven to be a potential pathogenic factor of osteoporosis, and Cu supplementation is recommended [ 6 , 7 ]. In addition, the use of Cu in regenerative medicine has been proposed due to its broad-spectrum antibacterial activities and its stimulating effects on a variety of cellular activities [ 8–11 ]. Our previous studies have shown that Cu-bearing Ti6Al4V alloys can be used to fabricate patient–individual mesh to fit alveolar bone defects by the use of selective laser melting (SLM) technology.…”