【摘要】 为分析稀土元素Ce对镁的组织和性能的影响,在纯镁中分别加入1%~4%的Ce制备了Mg-(1-4)Ce系列合金.采用金相显微镜、扫描电子显微镜、X射线衍射仪和电子万能试验机对铸态合金的显微组织、相组成、拉伸性能和抗蠕变性能进行了研究.实验结果表明:Mg-(1-4)Ce合金的铸态组织由α-Mg基体和沿晶界分布的共晶(α-Mg+Mg12Ce)组成,随着Ce含量的增加,晶界处的共晶组织数量逐渐增加,分布也由离散点状转变为网状;随Ce含量的增加,铸态Mg-(1-4)Ce合金的抗拉强度和屈服强度都逐渐增大,而塑性逐渐降低;合金的强度随温度的增加而下降,但下降的幅度不大,表现出较好的高温稳定性,而延伸率则随温度增加明显上升;铸态Mg-(1-4)Ce合金表现出良好的抗蠕变性能,Mg-4Ce铸态合金的稳态蠕变速率为1.55×10-9s-1.更多还原

【Abstract】 In order to analyze the effect of rare earth Ce on the microstructure and properties of magnesium,Mg-(1-4) Ce alloys with 1% to 4% Ce addition were prepared.The microstructure,phase composition,tensile properties and creep resistance of the as-cast alloys were studied by metallographic microscope,scanning electron microscope,X-ray diffractometer and electronic universal testing machine.The results indicate that the as-cast microstructure of the Mg-(1-4) Ce alloys consists of the dendritic α-Mg and eutectic(α-Mg + Mg12Ce) distributing along the grain boundaries.The eutectic amount increases with the increase of Ce addition and its morphology changes from discrete to netlike.Both tensile strength and yield strength increase with the increase of Ce addition but the elongation decreases.With the increase of the temperature,the tensile strength and yield strength of the Mg-(1-4) Ce alloys decrease slightly,indicating a good thermal resistance,but the ductility increase obviously.The as-cast Mg-(1-4) Ce alloys exhibit good creep resistance.The steady state creep rate of the as-cast Mg-4Ce alloy is 1.55 × 10- 9s-1.更多还原