(1. 华中科技大学 材料科学与工程学院 材料成形与模具技术国家重点实验室，武汉 430074；
2. 深圳市万泽中南研究院有限公司，深圳 518000；
3. 中南大学 粉末冶金国家重点实验室，长沙 410083；
4. 深圳市万泽航空科技有限责任公司，深圳 518000)
摘 要: 采用有限元模拟和实验验证的方法研究一种新型镍基粉末高温合金包覆挤压过程中工艺参数的影响规律，并对工艺窗口进行优化。结果表明，挤压速度和坯料初始温度对应变的影响不显著，挤压比与挤压变形程度呈线性相关，挤压比的增加和模角的减小可以提高挤压棒材沿径向应变分布的均匀性。挤压速度和坯料初始温度的增加、挤压比和模角的减小可以提高挤压棒材温度分布的均匀性。基于组织控制准则，对工艺窗口进行优化并进行工艺实验。挤压后的高温合金无宏观开裂，析出相均匀分布，晶粒尺寸细小，验证了工艺优化的可行性。
关键字: 镍基粉末高温合金；包覆挤压；数值模拟；晶粒尺寸；工艺窗口优化
（1. State Key Laboratory of Materials Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China;
2. Shenzhen Wedge Central South Research Institute Co., Ltd., Shenzhen 518000, China;
3. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
4. Shenzhen Wedge Aviation Technology Co., Ltd., Shenzhen 518000, China）
Abstract:The influence of processing parameters on the extrusion process of hot isostatic pressed nickel-based powder superalloy was studied by means of finite element simulation and experimental verification. The process window was optimized. The results show that the effect of extrusion speed and initial temperature on strain is not significant, the extrusion ratio is linearly correlated with the degree of extrusion deformation. The increase of extrusion ratio and the decrease of die angle can improve the uniformity of the radial distribution of the extruded bar. The uniformity of temperature distribution can be improved with the increase of extrusion velocity and initial temperature of billet and the decrease of extrusion ratio and die angle. Based on the microstructure control criterion, the process window was optimized. Then, the extruded bar with uniform fine grain and without defects is obtained by experiment. This study verifies the feasibility of the optimum design of parameters in the engineering practice of nickel-base powder superalloy cladding extrusion.
Key words: nickel-based powder superalloy; cladding extrusion; numerical simulation; grain size; process window optimization
