镁稀土合金Mg-Gd-Y-Zr及Mg-Nd-Zn-Zr的强流脉冲电子束表面改性研究

发布时间：2018-07-06 18:24

本文选题：强流脉冲电子束 + 表面改性　；参考：《热加工工艺》2016年16期

【摘要】：采用强流脉冲电子束技术对Mg-Gd-Y-Zr和Mg-Nd-Zn-Zr两种镁稀土合金进行表面改性处理,并研究了处理后镁合金表层的相组成、形貌和性能变化。结果表明:Mg-Gd-Y-Zr合金经脉冲电子束处理后表层的Mg5Gd转变为Mg3Gd,而Mg-Nd-Zn-Zr合金表层的Mg12Nd相消失形成过饱和固溶体。两种稀土镁合金经脉冲电子束处理后均发生熔化和部分汽化,在快速凝固后表面形成波状形貌,且表面生成大量孪晶。脉冲电子束处理使得两种镁合金表面硬度显著提高。在模拟体液中的腐蚀测试结果显示,上述合金经强流脉冲电子束表面处理后自腐蚀电位均提高,但腐蚀电流密度有所增加。脉冲电子束处理后镁稀土合金表面组织成分均匀化、晶粒细化,稀土元素在镁中的固溶以及缺陷的生成导致表层硬度的提高和耐腐蚀性的改变。
[Abstract]:The surface modification of Mg-Gd-Y-Zr and Mg-Nd-Zn-Zr alloys was carried out by high current pulsed electron beam technique. The phase composition, morphology and properties of magnesium alloys were studied. The results show that the Mg5Gd in the surface layer of the Mg-Mg-Gd-Y-Zr alloy is transformed into Mg3Gd after pulsed electron beam treatment, while the Mg12Nd phase in the surface layer of the Mg-Nd-Zn-Zr alloy disappears to form a supersaturated solid solution. The two rare earth magnesium alloys were melted and partially vaporized after pulsed electron beam treatment. The surface of the two rare earth magnesium alloys formed wave-like morphology after rapid solidification and a large number of twins were formed on the surface. The surface hardness of the two kinds of magnesium alloys was significantly improved by pulsed electron beam treatment. The results of corrosion test in simulated body fluid show that the corrosion potential of the alloys treated by high current pulsed electron beam is increased, but the corrosion current density is increased. After pulsed electron beam treatment, the microstructure of magnesium rare earth alloy was homogenized, the grain size was refined, the solution of rare earth elements in magnesium and the formation of defects resulted in the increase of surface hardness and the change of corrosion resistance.
【作者单位】：上海工程技术大学材料工程学院;
【基金】：国家自然科学基金资助项目(51271121,51471109)
【分类号】：TG146.22;TG178

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