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对粉末冶金铍铝合金进行了-100~500℃的拉伸性能测试,分析了其力学性能随温度变化的规律,并采用扫描电镜获取不同温度下的断口形貌。结果表明,铍铝合金的抗拉强度和屈服强度均随温度升高而降低,延伸率随温度升高先上升再下降。随温度升高铍铝合金的断裂机制发生转变:低温时表现为由Be相的解理断裂及Al相的韧性断裂构成的混合型断裂,随温度升高转变为铍铝两相界面的开裂和Al相的韧性断裂。采用ABAQUS有限元软件模拟铍铝合金在高低温拉伸过程中的内部应力场分布,揭示了铍铝合金高温拉伸断裂模式发生转变的力学机制。
Tensile properties of powder metallurgy beryllium aluminum alloy were tested at -100 ~ 500 ℃. The mechanical properties of the beryllium aluminum alloy were analyzed with temperature. The morphology of the fracture at different temperatures was obtained by scanning electron microscope. The results show that the tensile strength and yield strength of beryllium-aluminum alloy decrease with increasing temperature, and the elongation increases first and then decreases with the increase of temperature. The fracture mechanism of beryllium-aluminum alloy changes with increasing temperature: at low temperature, it appears as a mixed fracture composed of the cleavage fracture of Be phase and the ductile fracture of Al phase, and it changes to the cracking and Al-phase ductile fracture. ABAQUS finite element software was used to simulate the distribution of internal stress field during beryllium-aluminum alloy drawing at high temperature and low temperature, revealing the mechanical mechanism of high temperature tensile fracture mode of beryllium-aluminum alloy.