论文部分内容阅读
利用数值模拟和实验研究方法分析圆形纯铜挤压件多道次等通道转角挤压(ECAP)工艺,发现多道次挤压获得的挤压件形变充分,形变分布较为均匀。通过分析挤压件截面的等效应变值与分布,发现模具的内角对挤压后材料等效应变值的影响较大,当内角为90°时,材料单次挤压的等效应变值达1.40,是内角为135°时的2.3倍,但材料的均匀性相对较差;挤压路径和通道形状对挤压后材料的形变均匀性至关重要,Bc路径和圆形通道效果最佳,不易形成应力集中等现象;挤压次数增加,材料的累积应变值和均匀性显著提高。实验中,挤压后棒材的横截面与表面的显微硬度值分别由原始的99HV上升至145HV和148HV,变化趋势与有限元模拟结果吻合。
The numerical simulation and experimental research methods were used to analyze the multi-pass channel angle extrusion (ECAP) process of round pure copper extrusion. It was found that the extrusion obtained by multi-pass extrusion had sufficient deformation and uniform deformation distribution. By analyzing the equivalent strain distribution and distribution of the cross section of the extruded part, it is found that the internal angle of the die has a great influence on the equivalent strain value of the extruded material. When the internal angle is 90 °, the equivalent strain value of single extrusion 1.40, which is 2.3 times when the internal angle is 135 °, but the material uniformity is relatively poor. The extrusion path and the shape of the channel are crucial to the uniformity of the deformation of the extruded material. The Bc path and the circular channel have the best effect, Not easy to form the phenomenon of stress concentration; extrusion times increase, the cumulative strain value and uniformity of materials increased significantly. In the experiment, the micro-hardness of the cross-section and the surface of the extruded rod increased from original 99HV to 145HV and 148HV, respectively. The changing trend coincided with the result of finite element simulation.