等通道转角挤压制备超细晶材料的研究与发展

等通道转角挤压(Equal channel angular pressing,ECAP)是大塑性变形制备超细晶材料的方法之一,具有大晶粒尺寸的材料可以在室温下挤压达到超细晶尺度。从ECAP模具参数、工艺条件影响因素、模具及制备方法改进、细化机理、制备的超细晶材料组织稳定性及性能方面进行总结,并结合部分研究结果可知,ECAP模具正在不断被优化和改进,复合挤压技术不断出现,目前已实现超细晶材料的连续ECAP挤压制备技术。等通道转角挤压的晶粒细化主要是由于剪切力的作用和第二相粒子的作用,ECAP晶粒细化机理及组合工艺的研究是目前研究的热点。超细晶材料在不同领域的应用对其性能提出的更高要求,对其大塑性变形制备技术本身也是挑战。

Producing Ultrafine-grained Materials by Equal Channel Angular Pressing:A Review

Equal channel angular pressing is one of the methods to prepare ultrafine grained materials by sever plastic deformation. The materials with large grain size can be extruded at room temperature. This thesis summarized the mold parameters of ECAP, influence factors of process conditions, the improvement of mold and preparation method, refinement mechanism, microstructure stability and properties of manufacturing ultrafine grained materials. Combined with the part of the research results, it shows that the ECAP mold is constantly being improved and optimized and composite extrusion technologies has appeared. Nowadays, it makes continuous ultrafine grained ECAP technology come true. Grain refinement of ECAP is mainly due to shear stress and the effect of the second phase particles. ECAP grain refinement mechanism and combined technology have become a hot research to-pic. Higher application requirements of ultrafine grained materials are raised in different areas. It is also a challenge severe plastic deformation manufacture technology itself.