具有柱状晶组织的镁合金高温力学性能及断裂机制
发布时间：2019-05-06 06:38
【摘要】：利用定向凝固技术制备具有(11 2 0)á0001?择优取向的柱状晶Mg-6.52Zn-0.67Y合金。对定向凝固Mg-6.52Zn-0.67Y合金进行室温及高温拉伸实验,并利用SEM、XRD和EBSD等分析方法研究合金的拉伸断口、形变过程中组织演变及断裂机制。结果表明:定向凝固Mg-6.52Zn-0.67Y合金的室温σ_(0.2)和σ_b分别为124和196MPa,δ为13%,表明定向凝固合金室温下具有一定的均匀塑性变形能力;随着拉伸温度的升高,合金的强度降低,塑性升高,150℃拉伸时其σ_b为146 Ma,δ升至27%;300℃拉伸时其σ_b降至73 MPa,δ高达35%。150℃和200℃拉伸时其主要形变机制为锥面、棱柱面滑移及{10 1 2}孪生和{10 1 1}孪生等共同作用,合金的断裂机制为韧性断裂和准解理的复合断裂;300℃拉伸时,主要形变机制则为锥面滑移和动态再结晶,合金的断裂机制为韧性断裂。
[Abstract]:Preparation of (11.20) 谩 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，
本文编号：2469959
[Abstract]:Preparation of (11.20) 谩 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，
本文编号：2469959
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