熱處理對Mg-8Gd-2.5Nd-0.5Zr合金組織和力學性能的影響熱處理對Mg-8Gd-2.5Nd-0.5Zr合金組織和力學性能的影響Effects of heat treatment on microstructure and mechanical properties of Mg-8Gd-2.5Nd-0.5Zr alloy 通過OM、XRD、TEM、SEM和電子拉力試驗機等，研究了固溶和時效處理對Mg-8Gd-2.5Nd-0.5Zr(質量分數，%)合金顯微組織和力學性能的影響。結果表明：合金鑄態組織由α-Mg 基體和含Mg5Gd相、Mg12Nd 相的粗大枝晶組成，經過熱處理后，合金中方塊狀顆粒相明顯增多，且分布在晶界處；固溶時效態合金析出的納米尺寸方塊相可有效強化合金。時效態合金中β′析出相形態類似多個紡錘形相連接而成，相互之間的夾角呈120°，且具有周期結構。鑄態、固溶態和時效態合金在不同狀態下的室溫拉伸強度分別為：189.3、 201.4和251.1MPa。 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.
|
