银含量对多孔镁银合金组织和耐腐蚀性能的影响

摘要

The effect of Ag contents on microstructure, phase compositions and corrosion resistance for porous Mg-Ag alloys was studied. SEM images show that the compact degree of the material matrix of porous Mg-Ag alloys increases with Ag contents. XRD and EDS results show that porous Mg-3%Ag alloy is composed of α-Mg phase, and that the Mg-4%Ag alloys are composed of α-Mg and Mg4Ag phase which has cathodic strengthening merit and is reticulate in the grain boundary. The porous Mg-Ag alloys have better corrosion resistance than the pure porous Mg, while the porous Mg-3%Ag alloy is the best one. Its maximum self-corrosion potential is -1.4073 V, and its lowest passivation current density is 3.4169×10-4 A·cm-2. After immersed it in simulated body fluid for 48 h, the porous Mg-3%Ag alloys have the lowest corrosion rate and little corrosion products on its surface.%研究了银含量对粉末冶金技术制备的多孔镁银合金显微组织、物相组成和耐腐蚀性能的影响.SEM 分析表明在多孔镁基体中加入银元素后,多孔合金孔壁的晶粒细化,致密度增加.XRD和EDS分析表明多孔Mg-3%Ag合金由单相α-Mg固溶体组成,而Mg-4%Ag合金由α-Mg和Mg4Ag两相组成,具有阴极强化性质的 Mg4Ag 相呈网状分布在晶界上.耐腐蚀性测试表明,多孔镁银合金比纯多孔镁的耐腐蚀性好.多孔Mg-3%Ag合金具有最佳的耐腐蚀性能,其自腐蚀电位(-1.4073 V)最大、维钝电流密度(3.4169×10-4A·cm-2)最低,在人体模拟体液中浸泡48 h后腐蚀速率(0.162 mm/a)最低,腐蚀后其表面仅有少量的腐蚀产物.