喷射沉积颗粒梯度增强铝合金活塞的锻压工艺

提出了采用喷射沉积高硅铝合金碳化硅梯度增强复合材料，进行墩挤锻压制备汽车发动机活塞的方法，设计了该方法所用的活塞锻压模具，并研究了变形速率、始锻温度、坯料保温时间等工艺参数对梯度增强高硅铝合金活塞锻件组织及力学性能的影响.结果表明：所提出的方法可以制备出碳化硅梯度分布的铝合金活塞，活塞壁部外表面沿裙部末端至环槽区碳化硅分布为3.7%～13.6%；且最佳的锻压工艺参数为：变形速率为0.05 s-1，始锻温度为465 ℃，坯料保温时间为2 h.活塞取样并经固溶+时效热处理后，其性能指标为抗拉强度达382 MPa，延伸率为6.0%.
The method to use high Si composition SiC particle reinforced Al Si alloy to make automotive engine piston by upsetting extrusion was proposed.The forging process mold of piston was designed.The influence on microstructure and mechanical properties of composition Particle Reinforced Al Si alloy by the technological parameters including forging speed，initial forging temperature，holding time of the billet on formability was studied．The results show that gradient distributed SiC particle reinforced Al Si alloy can be made by this method.The SiC particle distributing inside from piston skirt to ring groove zone was 3.7% to 13.6%.The formability of the Al 20%Si/SiCp alloy by spray forming was better with the initial forging temperature at 465 ℃，the forging rate was 0.05 s-1，and the holding time of the billet was 2 h.After solution and aging heat treatment on the piston，the tensile strength is reaching 382 MPa and the elongation of 6.0%.