变形时效对6061铝合金板材的组织和力学性能的影响

Influence of deformation aging on microstructure and mechanical properties of 6061 aluminum alloy plate

通过对6061铝合金轧制态板材变形时效工艺的研究,对比分析了其组织结构、硬度、抗拉强度和伸长率的变化规律。结果表明:时效前后,6061铝合金的组织均为纤维状,主要为Al基体相和Mg2Si强化相。随着时效温度升高,Mg2Si强化相在纤维状结构间逐渐析出和长大,在190℃/1 h时效工艺下,晶粒尺寸最大。时效前的6061铝合金存在加工硬化现象,其硬度、抗拉强度和伸长率分别为66. 8 HV、234 MPa和12%。变形时效使6061铝合金的塑性增大,合金的力学性能随时效温度升高而呈现先增大后降低的趋势,其在180℃时效1 h时达到峰值,硬度、抗拉强度和伸长率分别为66. 4 HV、279 MPa和16. 8%。

The microstructure,hardness,tensile strength and elongation of rolling plate for 6061 aluminum alloy were compared and analyzed by studying the deformation and aging process. The results indicate that before and after aging,the microstructure of 6061 aluminum alloy is fibrous mainly composed of Al matrix phase and Mg2Si strengthening phase. With the increasing of aging temperature,the Mg2Si strengthening phase gradually precipitates and grows up between the fibrous structures,while the grain size is the largest under 190 ℃/1 h aging process. Furthermore,there is work hardening in the 6061 aluminum alloy before aging,and the hardness,tensile strength and elongation of alloy are 66. 8 HV,234 MPa and 12%,respectively. The deformation aging increases the plasticity of alloy,and the mechanical properties of alloy increase first and then decrease with the increasing of aging temperature. Under 180 ℃/1 h aging process,the hardness,tensile strength and elongation of 6061 aluminum alloy reaches the peak values of 66. 4 HV,279 MPa and 16. 8%,respectively.