中文摘要：

综述了金属结构材料和功能材料基体相晶体结构、层错能、Hollomon参数lnZ对等通道转角挤压ECAP变形组织演变规律影响的研究进展,试样基体相的晶体结构对变形组织的演变起重要的影响作用。随着应变量的增大,密排六方结构金属先形成形变孪晶、再启动优先存在的但被阻塞的滑移系统;面心立方结构金属的位错滑移主导着组织演变与晶粒细化过程,先形成亚晶界,再增大组织取向差,最终形成大角度晶界。在高层错能材料中,随着Hollomon参数lnZ增大,位错运动受到抑制,驱使变形机制从位错滑移逐渐转变成形变孪晶;当Z参数减小时,在ECAP高层错能材料中会形成微尺度的剪切带。在低层错能材料中形成丰富的孪晶,极低层错能的材料形成宏观剪切带。而中等层错能材料的变形机制则取决于Z值的高低。分析了ECAP过程动态再结晶的影响因素,认为γm·ln^2Z〉30不宜作为ECAP过程是否发生动态再结晶的判据,ECAP过程动态再结晶的影响因素还有待进一步研究,如弄清ECAP过程温升规律、分析淬火保存ECAP变形组织将有助于研究ECAP动态再结晶。

英文摘要：

The research progress in the influences of crystal structures of matrix phases,stacking fault energy,and Hollomon parameter lnZ on the microstructural evolutions of equal-channel-angular-pressing（ ECAP） structural and functional materials was reviewed.The matrix phases played important roles in the evolutions. As the strains increased,the deformation twins firstly appeared in the materials with close packed hexagonal crystal structure,and then the blocked slipping systems were triggered. And in the materials with the face cubic crystal structure,the evolutions and grain refinements were dominated by the dislocation slipping,firstly sub-grain-boundaries formed,then the orientation difference enlarged,and finally large angle grain-boundaries appeared. Among materials with the higher stacking fault energy,if the Hollomon parameter lnZ increased,the dislocation motion was restricted,the deformation mechanism was then changed from the dislocation slipping to the deformation twinning. But if the Hollomon parameter decreased,the microscale shear bands appeared in the materials during the ECAP process. In the materials with the low stacking fault energy,there existed abundant twins,but macroscopic shear ones appeared in the materials with the lower stacking fault energy. And in the materials with themedium stacking fault energy,the mechanism depended on the Hollomon parameter. The effects of the dynamic crystallization during ECAP were also discussed. γm·ln^2Z〉 30 could not be its criterion. Its mechanism during ECAP would be studied in the future. It would be helpful to uncover the law of temperature increasing during ECAP and the evolution of microstructures quenched instantly after ECAP to be firstly understood.