(1. 东北大学 材料与冶金学院, 沈阳 110004;
2. 大连交通大学 材料科学与工程学院, 大连 116028)
摘 要: 介绍一种制备超细晶材料的新技术——连续等径角挤压, 它将连续挤压技术应用于制备超细晶材料的等径角挤压工艺, 解决了传统等径角挤压不能制备大尺寸超细晶材料的问题, 该技术对超细晶材料的推广应用具有重要意义。 通过DEFORM3D对铜的连续等径角挤压过程的数值模拟, 得到变形过程中金属的流动、 应变场和温度场情况, 并对不同变形速度和摩擦条件下的变形过程进行比较, 得到优化的工艺参数, 并以此参数进行实验。 实验结果表明, 连续等径角挤压后铜的硬度明显上升, 连续等径角挤压3道次后, 硬度趋于饱和; 连续等径角挤压12道次后, 铜的平均晶粒尺寸为400 nm。
关键字: 铜; 连续等径角挤压; 超细晶; 有限元模拟
(1. School of Materials and Metallurgy, Northeastern University,
Shenyang 110004, China;
2. School of Materials Science and Engineering, Dalian Jiaotong University,
Dalian 116028, China)
Abstract: The continuous equal channel angular pressing introduced is a new method to produce ultra-fine grain(UFG) materials, which applies continuous extrusion technology in ECAP technology to manufacture UFG materials and solves the problem that can't manufacture large bulk UFG materials by traditional ECAP. Through simulating continuous ECAP process of copper by DEFORM-3D, the metal flow, strain field and temperature field are obtained. The deformation processes are compared under the conditions of various speeds and different friction factors, the optimum process parameters are obtained. The experiments are performed by optimum process parameters, the results indicate that the hardness increases clearly during the first 2 passes of continuous ECAP, and the hardness is saturated after 2 passes, the grain size of about 400 nm is achieved after 12 passes.
Key words: copper; continuous equal channel angular press; ultra-fine grain; finite element simulation