TiB2/7050颗粒增强铝基复合材料热变形行为与热压工艺优化

分析TiB₂/7050颗粒增强铝基复合材料的热变形行为及工艺参数的影响规律，对其热变形后的组织设计和获得理想性能参数至关重要。基于此，针对TiB₂/7050颗粒增强铝基复合材料开展了相关研究。用Gleeble-3500热模拟机进行热压缩试验，研究了TiB₂/7050颗粒增强铝基复合材料在变形温度300~450 ℃、应变速率0.001~1 s-1时的热变形行为，建立了材料的双曲正弦本构方程；根据动态材料模型计算得出热加工图，优选了材料的热加工工艺窗口；对原始挤压成型坯料和优化工艺的热压成型坯料进行了力学性能测试和微观组织形貌分析。结果表明:两种成型工艺相比，热压件强度指标略有提高，但塑性大幅提高，其长横向断后延伸率提高400%；热压工艺件晶粒更加细小、且无明显择优取向；拉伸断裂机制均为准解理断裂，热压件断口韧窝更深、撕裂棱更粗大，表明塑性撕裂持续时间更长。 

Hot deformation behavior and hot pressing process optimization of TiB2/7050 particle reinforced aluminum matrix composites

Analysis on the hot deformation behavior of TiB₂/7050 particle-reinforced aluminum-matrix composite and the influence of process parameters is significant for microstructure design and obtaining ideal performance after hot deformation.Based on this，related research on TiB₂/7050 particle-reinforced aluminum-matrix composites was carried out.Hot compression experiments were carried out on Gleeble-3500 thermal simulator to study the hot deformation behavior of TiB₂/7050 particle-reinforced aluminum-matrix composites at deformation temperature of 300-450 ℃ and strain rate of 0.001-1 s-1，and the hyperbolic sine constitutive equation of the material was established.According to the dynamic material model，the processing map was calculated，and the processing window of the material was optimized.The mechanical properties and microstructure of the original extruded billet and the optimized hot pressed billet were analyzed.Results showed that，comparing these two processes，the strength index of hot pressed parts was slightly improved，but the plasticity was greatly improved，and the elongation after long transverse fracture was increased by 400%；the grain size of hot pressed parts was smaller and there was no obvious preferred orientation；the mechanism of tensile fracture was quasi cleavage fracture.The dimples of fracture surface of the hot pressed parts were deeper and the tearing edges were larger，indicating the longer duration of plastic tearing.