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对纯铝粉末烧结材料进行等通道转角挤压实验,结果表明:经一次挤压后主要变形区组织剪切变形特征明显,内部的孔隙基本闭合,组织明显细化;多道次挤压后,不同挤压路径得到材料组织形态及孔隙闭合效果不同。研究认为,单道次ECAE过程中的孔隙闭合效果取决于试样所处的应力状态,即剪应力和球应力张量的良好匹配是材料获得良好的致密效果的关键。多道次挤压由于变形量的累积和不同的剪切特征不断改变基体及孔隙的形状,使材料进一步致密。
The experimental results show that the primary shear deformation of the main deformation zone is obvious after the primary extrusion and the pores in the interior are basically closed and the microstructure is obviously refined. After multi-pass extrusion, Different extrusion path to obtain the material morphology and pore closure effect is different. The study shows that the pore closure effect of single-pass ECAE process depends on the stress state of the sample. That is to say, the good match between shear stress and ball stress tensor is the key to obtain a good compact effect of the material. Multi-pass extrusion due to the cumulative amount of deformation and shear characteristics of different continuous changes in the shape of the matrix and the pores, the material further densification.