Si、Ca对Mg-2Mn变形镁合金组织和性能的影响

Influence of Si?Ca on Microstructure and Properties of Mg-2Mn Alloy

利用OM、XRD、硬度和抗拉强度测定、腐蚀电位测量等手段,研究了添加微量元素Si、Ca对Mg-2Mn变形镁合金组织和性能的影响。结果表明:Mg-2Mn-0.8Si-0.3Ca合金(简称低Si合金)和Mg-2Mn-1.5Si-0.3Ca合金(简称高Si合金)的铸态组织均由α-Mg固溶体和Mg2Si以及β-Mn组成。低Si合金中的Mg2Si呈较小的颗粒状。高Si合金的晶粒较低Si合金细小,其Mg2Si数量多,呈现相对较大的块状。两者均未出现有害的粗大汉字状Mg2Si。两种合金都只含α镁、Mg2Si相和Mn相,未出现MnSi相。高Si合金的硬度和抗拉强度均略高于低Si合金,耐蚀性也优于低Si合金。

By using OM and XRD analysis, hardness, strength and corrosion potential measurement, the influence of Si, Ca on the microstructure and properties of Mg-2Mn alloy was studied, The results show that the microstructure of Mg-2Mn-0. 8Si-0.3Ca and Mg-2Mn-1.5Si-0.3Ca alloy both includs α-Mg,β-Mn and Mg2Si particles. Mg2Si appears as tinny particles in lower Si alloy. The grains of the higher Si alloy are smaller than that of the lower Si alloy. The quantity of the Mg2Si is more and appear as blocks in the higher Si alloy. The Mg2Si does not appear as Chinese character in both alloys. Those alloys are both comprised of α -Mg, Mg2Si and Mn phase,MnSi phase does not appear. The hardness, strength and corrosion resistance of the higher Si alloy is better than that of the lower Si alloy.