摘要
对等通道转角挤压技术的基本原理和近年来的最新研究进展进行综述.对挤压过程中晶粒细化机理和变形机理、影响挤压效果的因素分析认为,降低挤压温度、增加背压、减小入口摩擦并适当加大出口摩擦可以有效增加材料组织的均匀性.认为ECAP加工后材料内部大角度晶界数的增加导致变形机制的改变,晶界滑移导致晶粒转动趋势的增加,这2方面的原因是产生超塑性的主要原因.提出从单晶材料的织构层面揭示材料的微观组织演变及定量计算多晶体的宏观性质是今后的研究方向.
The principle of equal-channel angular pressing （ECAP）, and its recent research progressing were summarized. It was recognized from the analysis of refinement mechanism of grain size, the deformation mechanism of materials, and the influencing factors on pressing effect that the structural uniformity of materials could effectively be improved by means of decreasing the pressing temperature, increasing the back pressure, decreasing the inlet friction, and increasing appropriately the outlet friction. It was also recognized that, after the processing with ECAP, the increase of the numbers of large-angle grain boundary would result in the change of deformation mechanism and the slip of grain boundary would cause the increase of the trend to grain rotation. The main origin of all of these was the generation of super plasticity in the material. It was proposed that revealing the microstructural evolution of the structure of monocrystalline materials and evaluating quantitatively the macroscopic property of polycrystals should be the topics of future investigation.
出处
《兰州理工大学学报》
CAS
北大核心
2008年第6期19-24,共6页
Journal of Lanzhou University of Technology
关键词
等通道转角挤压
超细晶
塑性变形
equal-channel angular pressing
ultra-fine grain
plastic deformation
