摘要
通过激光熔凝处理对共晶成分的Mg_(67)Zn_(2)8Ca_(5)合金进行了表面改性,研究了Mg_(67)Zn_(2)8Ca_(5)合金激光熔凝处理前后的显微组织、相结构和元素分布以及在人工模拟体液中的耐生物腐蚀性能。研究结果表明,Mg_(67)Zn_(2)8Ca_(5)合金经激光熔凝处理后,在合金的表层形成了平均厚度约508μm的熔凝层,熔凝层晶粒平均尺寸约10μm。与铸态和固溶态的合金相比,熔凝层在人工模拟体液中的腐蚀电位分别正移了76和60 mV;熔凝层的腐蚀速率分别降低了82%和78%。经激光熔凝处理后,合金表面的氧化膜也更为致密,提高了合金初期的耐腐蚀性能;MgZn_(2)相含量减少和第二相尺寸的减小,降低了电偶腐蚀,减缓了α-Mg基体相的腐蚀。
The microstructure,phase structure and element distribution of the Mg_(67)Zn_(2)8Ca_(5)alloy modified by laser melting treatment were studied.The bio-corrosion performance of that in simulated body fluid was also investigated.The results show that a melted layer with an average thickness of about 508μm forms on the surface of the Mg_(67)Zn_(2)8Ca_(5)alloy after laser surface melting treatment;the average grain size of the melted layer is about 10μm.Compared with the as-cast and solid-solution treated alloys,the corrosion potential of the melted layer in the simulated body fluid positively shifts 76 and 60 mV,respectively;the corrosion rate of the melted layer reduces by 82%and 78%,respectively.The oxide film on the surface of the alloy is denser,which improves the corrosion resistance of magnesium alloy at the early stage.With the decrease of MgZn_(2)content and the size of the second phase,the degree of galvanic corrosion reduce s and the corrosion ofα-Mg matrix phase is inhibited.
作者
丁浩
王国庆
仇安
宋婕
厉虹
丁红燕
周广宏
Ding Hao;Wang Guoqing;Qiu An;Song Jie;Li Hong;Ding Hongyan;Zhou Guanghong(Huaiyin Institute of Technology,Huaian 223003,China;Suqian University,Suqian 223800,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2021年第7期2486-2494,共9页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51775221,51875231)。
