(太原理工大學(xué) 機(jī)械工程學(xué)院，太原 030024)
摘 要: 通過OM、XRD、TEM、SEM和電子拉力試驗(yàn)機(jī)等，研究了固溶和時(shí)效處理對Mg-8Gd-2.5Nd-0.5Zr(質(zhì)量分?jǐn)?shù)，%)合金顯微組織和力學(xué)性能的影響。結(jié)果表明：合金鑄態(tài)組織由α-Mg 基體和含Mg5Gd相、Mg12Nd 相的粗大枝晶組成，經(jīng)過熱處理后，合金中方塊狀顆粒相明顯增多，且分布在晶界處；固溶時(shí)效態(tài)合金析出的納米尺寸方塊相可有效強(qiáng)化合金。時(shí)效態(tài)合金中β′析出相形態(tài)類似多個(gè)紡錘形相連接而成，相互之間的夾角呈120°，且具有周期結(jié)構(gòu)。鑄態(tài)、固溶態(tài)和時(shí)效態(tài)合金在不同狀態(tài)下的室溫拉伸強(qiáng)度分別為：189.3、 201.4和251.1MPa。
關(guān)鍵字: Mg-8Gd-2.5Nd-0.5Zr合金；熱處理；顯微組織；力學(xué)性能
（College of Mechanical Engineering, Taiyuan University of Technology, Taiyuan 030024, China）
Abstract:Microstructure and mechanical properties of Mg-8Gd-2.5Nd-0.5Zr (mass fraction, %) alloy after solid solution and aging treatment were studied by OM, XRD, TEM, SEM and tensile experiment. The results show that the microstructure of as-cast alloy is composed of α-Mg matrix and crystal containing Mg5Gd and Mg12Nd phases. After heat treatment, more cuboid-shaped particles are founded. The nanoscale stripe phase is precipitated out, and the alloy is strengthened effectively. The β'''' phase of aged alloy is multiple spindle with periodic structure, and the mutual angle is 120°. The tensile strength of the alloy are 189.3MPa (as-cast), 201.4 MPa (solid solution state) and 251.1 MPa (aging state), respectively.
Key words: Mg-8Gd-2.5Nd-0.5Zr alloy; heat treatment; microstructure; mechanical property
