粉末粒度对热等静压法制备2A12铝合金组织与性能的影响

发布时间：2018-07-20 19:02

【摘要】：分别用3种不同粒度的氮气雾化2A12铝合金粉末为原料,采用热等静压法制备2A12铝合金,研究粉末粒度对合金组织与力学性能的影响。结果表明:热等静压可实现2A12铝合金粉末的近全致密化,粉末粒径越小,粒径分布范围越广,则致密化程度越高,同时几何尺寸收缩较大,压坯的相对密度最高达到97.6%;粒度较大的粉末经过热等静压后,颗粒边界趋于平直,边界与边界的夹角趋于均匀的120°,而粒度较小的粉末原始边界严重变形,部分小颗粒甚至融合在一起;随粉末粒度减小及粒径分布范围增大,Al和Cu等合金元素的析出相由点状连续分布变为集中分布在粉末颗粒的三向交叉处,微观组织更致密均匀,颗粒边界细小,颗粒之间的扩散连接加强。粒度最小的2A12铝合金粉末经热等静压后,析出的合金元素第二相对合金有强化作用,抗拉强度和伸长率都提高,分别达到306 MPa和10.5%。
[Abstract]:The results show that the 2A12 aluminum alloy powder can be nearly densified by hot isostatic pressing. The smaller the particle size, the wider the particle size distribution, the higher the densification degree and the larger the shrinkage of geometric dimension. The relative density of compaction billet is up to 97.60.After hot isostatic pressing, the grain boundary of the larger powder tends to be straight, the angle between the boundary and the boundary tends to be 120 掳, and the original boundary of the powder with smaller particle size is seriously deformed. With the decrease of particle size and the increase of particle size distribution, the precipitation phase of alloy elements such as Al and Cu changed from point-like continuous distribution to concentrated distribution at the three-way intersection of powder particles, and the microstructure was more compact and uniform. After hot isostatic pressing of the 2A12 aluminum alloy powder with the smallest particle size, the second relative alloy element precipitated can strengthen the alloy, and the tensile strength and elongation increase to 306 MPA and 10.5 MPA, respectively.
【作者单位】：北京航空航天大学机械工程及自动化学院;
【分类号】：TF125.22

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