Zn对Mg-Si合金组织与生物腐蚀行为的影响

Effects of Zn on Microstructure and Bio-corrosion of Biodegradable Mg-Si Alloy

研究了Zn对Mg-1.38Si合金凝固组织和生物腐蚀行为的影响。结果表明,Zn对合金中的MgSi相具有较好的变质作用。添加Zn后,多边形状的初生MgSi相转变为尺寸更为细小的颗粒状,同时,共晶MgSi相也得到细化。随着Zn含量增加,合金中MgSi相的数量逐渐降低,试样在SBF溶液中的腐蚀速率和自腐蚀电流密度均逐渐降低,自腐蚀电位也逐渐向正向移动,表明合金的耐腐蚀性能逐渐提高。Zn添加量为1.5%时,合金的耐腐蚀性能最佳。

The effects of Zn on microstructure and bio-corrosion of biodegradable Mg-1.38 Si alloy were investigated. The results show that Zn has preferable modification effect on MgSi phase in as-cast Mg-1.38 Si alloy. The morphology of primary MgSi phase is converted from polyhedral to finely particle-like and the eutectic MgSi phase is refined after Zn addition. With the increase of Zn contents, the amount of MgSi phase is further decreased, and the corrosion rate and corrosion current density of the alloy are gradually decreased, while the corrosion potential of the alloy is gradually moved towards positive direction, indicating the enhancement of corrosion resistance. When the Zn content is 1.5%, the corrosion resistance of the alloy presents desirable.