大规格Cu-15Ni-8Sn合金棒材热挤压数值模拟及工艺参数优化

Numerical Simulation and Process Parameter Optimization of Hot Extrusion of Large Cu-15Ni-8Sn Alloy Bars

以热压缩实验数据为基础,构建了直径100 mm的Cu-15Ni-8Sn合金棒材热挤压有限元模型。使用MSC. Marc软件进行热挤压过程数值模拟,分析温度、应变率、应力以及晶粒尺寸的分布规律,优化热挤压工艺参数。结果表明:在热挤压过程中,应力、应变速率、温度以及再结晶晶粒分布不均匀。由于热传导作用,坯料与模具接触部位温度最低,同时由于摩擦生热以及变形生热作用,模具出口处温度高于模具入口处温度;应力和应变速率的分布规律一致,最大值出现在模具入口处及出口处;在坯料与模具锥角接触区域的晶粒最细小;最佳热挤压参数为:挤压温度900℃和挤压速度4 mm/s。

The thermal extrusion finite element model of Cu-15Ni-8Sn alloy bar with diameter of 100 mm was constructed based on the experimental data of thermal compression. MSC.Marc software was used to simulate the thermal extrusion process, the distribution of temperature, strain rate, stress and grain size were analyzed, and the parameters of hot extrusion process were optimized. The results show that the distribution of stress, strain rate, temperature and recrystallization grain is not uniform during hot extrusion. The temperature of the contact part between the sample and die is the lowest due to the heat conduction. At the same time, the temperature at the die outlet is higher than that at the die inlet due to the heat generation by friction and deformation;the distribution law of stress and strain rate is the same, and the maximum value appears at the entrance and exit of die;the grain size at the contact area between the sample and die cone angle is the smallest. The optimized hot extrusion process parameters are the extrusion temperature of 900℃ and extrusion speed of 4 mm/s.