Hot deformation behavior of Cu-bearing antibacterial titanium alloy

We investigated the deformation behavior of a new biomedical Cu-bearing titanium alloy （Ti-645 （Ti-6.06AI-3.75V-4.85Cu, in wt%）） to optimize its microstructure control and the hot-working process. The results showed that true stress-true strain curve ofti-645 alloy was susceptible to both deformation tem-perature and strain rate. The microstructure of Ti-645 alloy was significantly changed from equiaxed grain to acicular one with the deformation temperature while a notable decrease in grain size was recorded as well. Dynamic recovery （DRV） and dynamic recrystallization （DRX） obviously existed during the thermal compression of Ti-645 alloy. The apparent activation energies in （α ＋ β） phase and β single phase regions were calculated to be 495.21 kJ mo1^-1 and 195.69 kJ mo1^-1, respectively. The processing map showed that the alloy had a large hot-working region whereas the optimum window occurred in the strain rate range of 0.001-0.1 s-1, and temperature range of 900-960℃ and 1000-1050℃. The obtained results could provide a technological basis for the design of hot working procedure of Ti-645 alloy to optimize the material design and widen the ootential application of Ti-645 alloy in clinic.

新型抗菌功能医用金属研究

不锈钢、钛及钛合金等医用金属材料已广泛应用于骨科、齿科及心血管介入等医疗领域,生物可降解镁合金是正在研究发展的新型医用金属材料,具有诱人的临床应用前景。面对目前临床上亟待解决的植入物引发的细菌感染问题,开展医用金属材料的抗菌功能研究意义重大,也是实现金属材料结构/功能一体化发展的新探索。简要介绍了作者近年来在不锈钢、钛合金、可降解镁基金属等医用金属材料的抗菌功能研究方面的主要进展,并展望了抗菌医用金属材料的临床应用前景。

Antibacterial Properties of Ti-6Al-4V-xCu Alloys

Surgical implant-associated bacterial infection is becoming a serious clinical problem. A series of copper-bearing titanium alloy, Ti-6Al-4V-xCu （x = 1, 3, 5 wt%）, were fabricated in the present study in order to reduce the hazard of the bacterial infection problem by means of the strong antibacterial ability of Cu element. The metallography, X-ray diffraction, antibacterial ability, corrosion resistance and cytotoxicity of Ti-6Al-4V-xCu alloys were preliminarily studied with comparison to the commercial medical Ti-6Al-4V alloy. The Ti-6Al- 4V-xCu alloys showed obvious antibacterial abilities with good corrosion resistance and cytocompatibility, and the antibacterial role was enhanced with increasing Cu content, which has significant potential for clinical applications as surgical implant materials.

In vitro insights into the role of copper ions released from selective laser melted CoCrW-xCu alloys in the potential attenuation of inflammation and osteoclastogenesis

In this study,the CoCrW-x Cu alloys(x=2,3 and 4 wt%)were fabricated using selective laser melting(abbreviated as Co-2 Cu,Co-3 Cu and Co-4Cu)with the purpose of reducing the inflammation responses and the activity of osteoclast.The metal ions releasing test showed that when the Cu content was less than 4 wt%,the releasing amount of Co and Cr ions was very small;however,when 4 wt%Cu was added in the CoCrW based alloy,the quantity of Co ions was significantly elevated with respect to the other groups due to the segregation of precipitates in the matrix;the Cu2+ion quantity of the Co-2Cu,Co-3Cu and Co-4Cu alloys were 0.05,0.09 and 0.27 g/(L cm2)after 7 d immersion,respectively;the RT-q PCR and ELISA data indicated that the expression levels of the pro-inflammatory cytokines(TNF-αand IL-6)were down-regulated in the Co-3Cu and Co-4Cu groups,whereas the expression level of the anti-inflammatory cytokine(IL-10)was up-regulated in all CoCrW-x Cu alloys;meanwhile,the Cu-containing CoCrW alloys significantly down-regulated the expression of the NF-B signal pathway in a Cu content-dependent manner,and the downstream transcription factors of NF-B signal pathway including NFATc1,TRAP and Cath-K were also down-regulated via potentially manipulating the NF-B signal pathway.After comprehensive consideration,it is considered that the Co-3Cu alloy is a potential material for self-alleviating inflammatory responses.