挤压道次对2024铝合金ECAP变形的影响

Effect of extrusion pass on ECAP deformation of 2024 aluminum alloy

以2024铝合金为研究对象,采用Deform-3D有限元软件对试件进行数值模拟和A路径8道次ECAP实验,研究在不同挤压道次下试件变形过程中金属流动性、挤压载荷和等效应变的变化情况.结果表明:试件的头部和尾部区域金属流动网格呈现弯曲变形,中部区域呈现纯剪切变形,且随道次的增加变形程度显著增强;挤压载荷随挤压道次的增加呈现先上升后下降的趋势,其变化受试件强度影响;试件等效应变值的大小与挤压道次成正比关系,且等效应变值从试件靠近内转角区域出现由大到小的层状分布,3道次后出现应变分布均匀性下降的趋势.

Taking 2024 aluminum alloy as the research object,Deform-3D finite element software was used to conduct numerical simulation of the specimen and 8-pass ECAP experiment of path A,and the changes of metal fluidity,extrusion load and equivalent strain in the deformation process of the specimen under different extrusion passes were studied.The results showed that the metal flow mesh in the head and tail region of the specimen presented bending deformation,while the central region presented pure shear deformation and the deformation degree increased significantly with the passes.The extrusion load increased first and then decreased with the increase of the extrusion pass,which was affected by the strength of the specimen.The size of the equivalent strain value of the specimen was proportional to the number of extrusion passes,and the equivalent strain value was distributed in layers from large to small from the area near the inner corner of the specimen,and the uniformity of strain distribution decreased after 3-pass.