多孔Cu-Ni-Al合金的高温压缩变形行为及本构关系  

High Temperature Deformation Behaviors and Constructive Relation of the Porous Cu-Ni-Al Sintered Alloys

作　　者：李微[1] 梁慧[1] 陈荐[1] 杨嘉伟[1] 李贤泽 

机构地区：[1]长沙理工大学能源与动力工程学院,长沙410076

出　　处：《机械工程学报》2015年第2期58-64,共7页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51075044;51205030;51471036);能源高效清洁利用湖南省高校重点实验室开放基金(2011NGQ006;12K079)资助项目

摘　　要：采用雾化法制备Cu-Ni-Al粉末,对其进行真空热压烧结制取多孔Cu-Ni-Al合金,研究该材料的微观组织、高温压缩变形行为及其影响因素,分析压缩变形机理。结果表明,多孔Cu合金的抗压强度、弹性模量以及屈服强度随着变形温度的增加、应变速率的减小而减小;多孔Cu合金的压缩变形过程分为初始的线性弹性变形、孔壁的塑性变形、弯曲或断裂的屈服平台区以及孔洞密实化后的塑性变形三个阶段;在高温压缩变形过程中,多孔Cu合金容易在孔洞比较集中,孔壁较薄的地带出现应力集中,发生变形。采用回归分析方法建立多孔Cu合金的高温压缩变形本构方程,得出的计算曲线与试验曲线在压缩变形的第一、二阶段非常吻合,在第三阶段,计算曲线稍微高于试验曲线,分析原因认为可能是多孔Cu合金中的孔隙分布不均有关。The Cu-Ni-Al powders are prepared by atomization method, are hot pressing sintered in the vacuum furnace to prepare the porous Cu-Ni-Al alloy. The microstructure, high-temperature compressive deformation behavior and its effect factors are investigated, respectively. The deformation mechanism of the porous Cu alloy is also analyzed and discussed. The results show that the compression strength, elastic modulus and yield strength decrease with increasing temperature and decreasing strain rate. The compression deformation process is classified in terms of three stages of linear elastic deformation, yield platform area with pore wall buckling, collapse, and plastic deformation with pore densification. In the high temperature compression deformation process, stress concentration and deformation are preferred to occur at the areas with pore concentration and thinner pore walls. The compressive mechanical model of the porous Cu alloy is established using the method of linear regression. It is obvious that the calculation curves is in accordance with the experimental curves in the first and second stages of the deformation process, however, at the third stage, the former is above the experimental curves, which is possibly attributed to the inhomogeneous pore distribution of the porous Cu alloy.

关 键 词：多孔Cu-Ni-Al合金 高温压缩变形 变形行为 本构关系 

分 类 号：TG115[金属学及工艺—物理冶金]