等径角挤扭工艺的研究

针对等径角挤压（ECAP）工艺和挤扭（TE）工艺中，材料变形不均匀，1道次变形获得的应变量不够大的缺点，将2种工艺有机结合，提出了等径角挤扭（ECAPT）工艺。利用UG和DEFORM-3D软件进行几何造型和有限元模拟，研究变形过程、应力应变分布和载荷变化，并用纯铝进行2道次ECAPT实验，测量试样显微组织和力学性能的变化。结果表明，ECAPT使组织产生更大的应变量，随着行程的增加，载荷增大，在TE通道平稳阶段达最大值，试样头部挤出TE通道后载荷降低；材料的宏观形貌同模拟结果一致，显微组织发生了明显细化，其中第1道次z面和第2道次y面细化效果明显；力学性能得以较大提高，屈服强度由43．31MPa提升至52．19MPa，抗拉强度由71．30MPa提升至130．38MPa。

Study of Equal Channel Angular Pressing and Twist

This paper introduces a new severe plastic deformation process named as ECAPT process which combines Equal Channel Angular Pressing with Twist Extrusion against the uneven deformation and small strain shaped by one pass of ECAP or TE. UG software was used for geometric modeling and DEFORM-3D software was used 5or finite element simulation, and then the deformation processing, distribution of stress and strain, and the change of load were researched. Two passes ECAPT experiment with pure Al was made, and the change of microstructure and mechanical properties of the sample was measured. The result shows that ECAPT process can make more strain and make the microstructure more uniform. It also shows that the load increase with the travel passing, and reach the maximum at the TE channel stable stage, then the load decrease when the head of sample out of the TE channel. According to the result, it can can be seen that the appearance of sample shaped by ECAPT is similar to the result of simulation, and the microstructure is obviously refined, especially in the face z of the first pass and face y of the second pass. And the mechanical properties are improved, the yield strength increases from 43.31 MPa to 52.19 MPa, and tensile strength increases from 71.30 MPa to 130.38 MPa.