(1. 山東建筑大學(xué) 材料科學(xué)與工程學(xué)院，濟(jì)南 250101；2. 山東省科技情報(bào)信息研究所，濟(jì)南 250100)
摘 要: 采用數(shù)值模擬和實(shí)驗(yàn)研究方法分析圓形純鋁擠壓件多道次等通道彎角擠壓工藝，發(fā)現(xiàn)單道次擠壓獲得的擠壓件的變形分布沿?cái)D壓件中心橫截面豎直方向變形分布不均勻。通過節(jié)點(diǎn)映射法實(shí)現(xiàn)各工藝路線的多道次擠壓，不同的工藝路線對應(yīng)的多道次擠壓變形分布具有明顯差異。多道次擠壓后晶粒得到顯著細(xì)化，變形后晶粒結(jié)構(gòu)較擠壓前的退火等軸晶粒大為不同，而且各工藝路線的晶界取向也各不相同，其中旋轉(zhuǎn)90˚擠壓能夠獲得大角度晶界分布的等軸晶粒試樣，實(shí)驗(yàn)結(jié)果與有限元分析結(jié)果十分吻合。
關(guān)鍵字: 等通道彎角擠壓；超細(xì)晶粒；有限元分析；等軸晶粒；工藝路線
（1. School of Materials Science and Engineering, Shandong Jianzhu University,Ji’nan 250101, China;2. Shandong Institute of Science and Technology Information,Ji’nan 250100, China）
Abstract: Multi-pass equal channel angular extrusion (ECAE) processes for round workpieces were investigated by using numerical simulations and experimental studies. The single-pass ECAE is a non-uniform shear deformation process in the cross-section of the workpiece. The different processing routes for equal round channel angular pressing process were conducted by using node mapping method in multi-pass pressing. The effective strain distributions of different processing routes are obviously different. The grains in the workpiece are refined obviously after multi-pass extrusion. The microstructures of the processed workpieces are different from the equiaxed grains of the annealing initial workpiece. And the microstructure evolution of the workpiece can be changed via different processing routes. The route with turning angle of 90˚ can get a distribution of high angle grain boundaries in the workpiece. In addition, the experimental results are in agreement with the finite element analysis results. The microstructure evolutions of grain refinement mechanisms for different multi-pass ECAE processing routes accord with the accumulated effective strain rules in the workpiece.
Key words: equal channel angular extrusion; ultra-fine grains; finite element analysis; equiaxed grains; processing route
