School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore.
The Manufacturing Technology Centre (MTC), Coventry, UK.
Proc Inst Mech Eng H. 2022 Aug;236(8):1169-1187. doi: 10.1177/09544119221105849. Epub 2022 Jun 23.
This paper focuses on the evaluation of mechanical and biological properties of laser shock peening (LSP) orthopaedic grade Ti-6Al-7Nb alloy. LSP surface treatment was conducted at laser energy of 3 to 7 J with overlaps of 33%-67%, and with a 3 mm laser spot size. Cell viability on laser shock peened surface was evaluated through in-vitro MTT assay, using osteoblast-like MG63 cells for the first-time. Residual stresses, microhardness, microstructure, sliding wear and wetting properties were investigated. Compressive residual stresses were found at various depths due to controlling the LSP parameters, compared to the as-received surface. The laser shock peened surfaces were hardened from 365HV to 405HV, while the as-received surface was 320HV. The average sub-grain size was refined from 14% to 36% after LSP. The wear resistance was also controllable by altering LSP parameters. The MTT results show that the cell viability on the laser shock peened surfaces was comparatively lower than that of the untreated surface after 24 h. However, after 72 h, the cell viability on modified surfaces were significantly improved. This work indicated that laser shock peened surfaces have a strong potential to decrease the pain from orthopaedic implant failures and promote the cytocompatibility between the bone and implant.
本文专注于评估激光冲击喷丸（LSP）骨科级 Ti-6Al-7Nb 合金的力学和生物学性能。LSP 表面处理的激光能量为 3 至 7 J，重叠率为 33%-67%，激光光斑尺寸为 3 毫米。首次使用成骨样 MG63 细胞通过体外 MTT 测定评估激光冲击喷丸表面的细胞活力。研究了残余应力、显微硬度、微观结构、滑动磨损和润湿性。通过控制 LSP 参数，在各种深度发现了压缩残余应力，与原始表面相比。激光冲击喷丸表面的硬度从 365HV 提高到 405HV，而原始表面为 320HV。亚晶粒尺寸平均从 14%细化到 36%。通过改变 LSP 参数还可以控制耐磨性。MTT 结果表明，激光冲击喷丸表面的细胞活力在 24 小时后明显低于未处理表面。然而，72 小时后，改性表面的细胞活力显著提高。这项工作表明，激光冲击喷丸表面具有降低骨科植入物失效引起的疼痛和促进骨与植入物之间细胞相容性的强大潜力。
