Huaiyin Institute of Technology
Mg-Zn-Ca合金因其较好的力学性能、良好的生物相容性和优异的可降解性，有望在人体骨组织植入材料得到推广应用，但由于镁合金耐生物腐蚀性能较差，限制了其临床的进一步应用。通过激光表面非晶化处理对共晶成分的Mg67Zn28Ca5合金进行了表面改性，研究了激光扫描速度对Mg67Zn28Ca5 合金表面非晶复合涂层的显微组织和相组成的影响；测试了合金表面改性前后在人工模拟体液中的生物腐蚀行为。研究结果表明，经激光表面非晶化处理后样品表面主要由大量的非晶和极少量的晶态物质组成。随着激光扫描速度的增大，合金表面形成的非晶相越多。晶相的形成主要是受到后续激光加工的热影响而产生热激活，部分非晶相发生了形核长大。与铸态镁合金相比，非晶复合涂层在人工模拟体液中的腐蚀电位正向偏移了0.16 V，腐蚀电流密度下降了约13倍。合金表面少量晶相的存在，使之成为表面腐蚀的活性通道，对合金表面的腐蚀性能产生轻微的影响。通过激光表面改性处理，可有效改善Mg67Zn28Ca5合金的耐生物腐蚀性能，在生物医用植入方面展现出良好的应用前景。
Mg-Zn-Ca alloys are expected to be widely used in human bone tissue implant materials due to its excellent mechanical properties, good biocompatibility and excellent degradability. However, the poor bio-corrosion resistance of magnesium alloys limits its further clinical application. The surface of Mg67Zn28Ca5 alloys with eutectic composition was modified by laser amorphization. The effect of laser scanning speed on the microstructure and phase composition of Mg67Zn28Ca5 alloys amorphous coating were studied. The bio-corrosion behavior of the alloy surface before and after laser amorphization in artificial body fluid was tested. The results show that a large amount of amorphous and a small amount of crystalline materials were formed on the surface of the specimens after laser amorphization. With the increase of laser scanning speed, more amorphous phases were formed on the alloy surface. The formation of crystal phase was mainly caused by thermal activation due to the thermal influence of subsequent laser processing, and some amorphous phases nucleated and grew up. Compared with the as-cast magnesium alloy, the corrosion potential of the amorphous layer in the artificial body fluid was positively shifted by 0.16 V, and the corrosion current density decreased about 13 times. The existence of a small amount of crystalline phase on the alloy surface became an active channel form surface corrosion, which had a slight impact on the corrosion performance of the alloy surface. The biological corrosion resistance of Mg67Zn28Ca5 alloy can be effectively improved by laser amorphization treatment, which shows a good application prospect in biomedical implants.
宋婕,丁浩,丁红燕,周广宏. Mg67Zn28Ca5合金激光表面非晶化处理及其生物腐蚀性能研究[J].稀有金属材料与工程,2023,52(10):3539~3546.[Song jie, DING Hao, DING Hong-yan, ZHOU Guang-hong `. Investigation on the laser amorphization of Mg67Zn28Ca5 alloy and its bio-corrosion[J]. Rare Metal Materials and Engineering,2023,52(10):3539~3546.]