摘要
采用高功率连续波固体Nd:YAG激光辐照,在置于N2反应室中的NiTi形状记忆合金表面制备激光气体氮化层。实验表明:选择适当的激光辐照工艺参数。可获得致密的TiN增强金属基复合材料(MMC)梯度涂层,改性层的表面被厚度为1μm-2μm的TiN陶瓷层封闭,涂层内部TiN增强相呈梯度分布。扫描电镜(SEM)及能谱(EDX)分析结果表明,MMC改性层与基体NiTi合金间存在良好的冶金结合,界面处成分均匀过渡,表面Ni含量极低。显微硬度测试及磨损试验结果表明,激光气体氮化显著提高了NiTi合金的表面硬度和耐磨性。说明激光表面改性有效地改善了NiTi形状记忆合金作为生物医学材料使用的表面成分和性能,并将有效地抑制有害元素Ni2+的释放。
After irradiated by a continuous wave of Nd-YAG laser in N-2 environment, a gradient TiN reinforced MMC coating can be obtained on the surface of NiTi shape memory alloy substrate. Experiments proved that the MMC coating reinforced with fine TiN and compact laser modified surface can be prepared by choosing optimum process parameters. There is a reinforced TiN ceramic layer of I gm similar to 2 mu m in thickness and a gradient distribution of reinforced TiN inside the coating. SEM and EDX results indicated that there was a good metallurgical bonding between the hard MMC modification layer and the NiTi alloy substrate. Microhardness and wear test results showed that the surface hardness and wear resistance were significantly enhanced. Therefore, the surface composition and performance of NiTi shape memory alloy can be effectively improved and the harmful Ni2+ ions to human body can be effectively restrained by using laser surface modification for biomedical materials.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2005年第6期986-989,共4页
Rare Metal Materials and Engineering
基金
国家高技术研究发展计划(863 计划)(2002AA305203)中国博士后基金(2002032170)辽宁省自然科学基金(20031024)中国科学院金属腐蚀与防护国家重点实验室基金资助项目。
