热处理对A356/6082复合板界面组织及力学性能的影响

采用液-固轧制复合技术制备A356/6082复合板,研究热处理温度对A356/6082复合板界面组织及力学性能的影响。结果表明,随着热处理温度的升高,A356铝合金一侧共晶Si组织发生颈缩、溶断、球化,并且球化现象首先在界面处发生,界面区剪切强度逐渐增大。当热处理温度为550℃时,复合界面处组织分布均匀,Si颗粒细小圆整,界面区元素得到充分扩散,元素扩散宽度约为136μm,复合板剪切强度最大值约为145MPa,复合界面在受到均匀塑性变形时,其剪切断裂方式为脆性断裂。

Effects of Heat Treatment Temperature on Interfacial Microstructure and Mechanical Properties of A356/6082 Clad Sheet

A356/6082 clad sheets were fabricated by liquid-solid rolling composite process.Effects of heat treatment temperature on interfacial microstructure and mechanical properties of A356/6082 clad sheet were investigated.The results reveal that the necking,melting and spheroidization of eutectic silicon on the side of A356 aluminum alloy occur with the increase of heat treatment temperature.Moreover,spheroidization first occurs at the interface of clad sheet,so the shearing strength of the interfacial zone is increased gradually.When the heat treatment temperature is 550℃,the composite interface presents uniform microstructure and the silicon particles are fine with round shape.In addition,elements in the interfacial region are fully diffused and the diffusion width is about 136μm.Interfacial shearing strength measured by push-out test is about 145 MPa.When the composite interface is subjected to uniform plastic deformation,the fracture form of the clad sheet is characterized by brittle fracture.