【摘要】：利用定向凝固技術制備具有(11 2 0)á0001?擇優(yōu)取向的柱狀晶Mg-6.52Zn-0.67Y合金。對定向凝固Mg-6.52Zn-0.67Y合金進行室溫及高溫拉伸實驗,并利用SEM、XRD和EBSD等分析方法研究合金的拉伸斷口、形變過程中組織演變及斷裂機制。結果表明:定向凝固Mg-6.52Zn-0.67Y合金的室溫σ_(0.2)和σ_b分別為124和196MPa,δ為13%,表明定向凝固合金室溫下具有一定的均勻塑性變形能力;隨著拉伸溫度的升高,合金的強度降低,塑性升高,150℃拉伸時其σ_b為146 Ma,δ升至27%;300℃拉伸時其σ_b降至73 MPa,δ高達35%。150℃和200℃拉伸時其主要形變機制為錐面、棱柱面滑移及{10 1 2}孿生和{10 1 1}孿生等共同作用,合金的斷裂機制為韌性斷裂和準解理的復合斷裂;300℃拉伸時,主要形變機制則為錐面滑移和動態(tài)再結晶,合金的斷裂機制為韌性斷裂。
[Abstract]:Preparation of (11.20) 謾 0001? Columnar Mg-6.52Zn-0.67Y alloy with preferred orientation. The tensile test of directionally solidified Mg-6.52Zn-0.67Y alloy was carried out at room and high temperature. The tensile fracture, microstructure evolution and fracture mechanism of the alloy during deformation were studied by SEM,XRD and EBSD. The results show that the room temperature 蟽 _ (0.2) and 蟽 _ b of unidirectionally solidified Mg-6.52Zn-0.67Y alloy are 124,196MPa and 13%, respectively, indicating that the directionally solidified alloy has a certain uniform plastic deformation capacity at room temperature. With the increase of the tensile temperature, the strength of the alloy decreases and the plasticity increases, and the 蟽 _ b of the alloy increases to 27% at the tensile temperature of 146 Ma, 未. When tensile at 300 鈩，

本文編號：2469959