激光重熔NiTi合金表面组织与腐蚀行为

Microstructure and corrosion behavior of laser surface re - melted NiTi alloy

采用2kWNd-YAG激光对生物医用NiTi形状记忆合金在空气、氩气和氮气环境中进行表面重熔处理以改善合金的表面性能。结果表明:在上述三种气氛中,通过激光重熔处理均可以明显提高NiTi合金表层的纯净度和致密度;改变合金的组成物和表面成分,使NiTi合金在模拟体液环境中具有更好的耐蚀性并降低合金Ni离子的溶出速度,进而提高合金的生物相容性。在相同激光处理参数条件下,氮气环境中重熔的NiTi合金表现出最低的Ni离子溶出速度。

A 2kW Nd - YAG laser was used to perform surface re - melting in air, argon and nitrogen environments on NiTi shape memory alloy for the purpose of improving the surface performance of the alloy. The results show that the purity and density of the re - melted layer are significantly increased, and the phase constituents and the surface composition of NiTi alloy are changed by the re - melting treatments in various atmospheres. The corrosion resistance of the laser re - melted NiTi alloy in various atmosphere environments is improved and the nickel ion release rate out of the alloy is decreased. A better biocompatibility can thus be expected. The NiTi alloy laser re - melted in nitrogen environment exhibited the lowest Ni ion release rate under the condition of the same laser parameters.