生物医用钛及其合金是外科植入首选的替代材料，激光表面改性是改善钛合金表面磨损和腐蚀性能的有效方法。采用高功率连续波Nd:YAG激光在Ti6Al4V合金表面进行激光气体氮化改性，获得了均匀致密、无孔洞裂纹等缺陷的氮化物改性层，合金表面对人体有害元素Al、V含量明显降低。利用扫描电子显微镜(SEM)、显微硬度计、振动摩擦磨损实验机及恒电位仪对Ti6Al4V合金气体氮化改性层的组织、磨损及在模拟人体体液中的电化学腐蚀性能进行研究。实验结果表明，激光气体氮化改善了Ti6Al4V合金作为生物医学材料使用的表面性能，其抗磨损及腐蚀性能显著提高。

Pure titanium and titanium alloys are the optimum replacement materials for the surgical implants. Laser surface modification is an attractive method to enhance the surface hardness and wear and corrosion resistance of titanium alloys. In the present study, the investigation into laser gas nitriding processing of the Ti6Al4V alloy can be used 2 kW continuous wave Nd:YAG laser under an N2 environment. With optimum process parameters, a compact laser modified coating was achieved, free of crack and porosity. The percentage composition of pernicious elements Al and V in the nitriding coating surface is very low. Morphology and composition and the frictional wear and electrochemical corrosion activities in Hank’s simulated body fluid at 37 ℃ were individually investigated by using SEM, EDX, ball-on-disc tribometer and anodic polarization measurements. The results indicated that the wear resistance and electrochemical corrosion behavior are improved significantly by laser gas nitriding without changing the property of the Ti6Al4V substrate used as biomaterial.