(1. 南昌航空大学 材料科学与工程学院，南昌 330063；2. 华中科技大学 材料科学与工程学院，武汉 430074)
摘 要: 对不同保压压力下真空差压铸造试样致密度进行分析，探讨真空差压铸造工艺的凝固补缩特性，建立凝固补缩过程的数学模型。结果表明：真空差压铸造工艺的凝固补缩速度和补缩能力主要取决于结晶凝固时保压压力的大小；对于晶间同一部位来说，保压压力越大，补缩速度和补缩能力越强，组织越致密；对于晶间不同部位来说，致密度成V形变化趋势，且随着保压压力的逐渐增大，致密度越来越均匀。
关键字: 真空差压铸造；凝固补缩；数学模型；保压压力；致密度
（1. School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063, China;2. School of Materials Science and Engineering, Huazhong University of Science and Technology,Wuhan 430074, China）
Abstract:Through analyzing the density of vacuum counter-pressure casting samples under different keeping pressures, their solidification feeding behavior and mathematical model were discussed. The results indicate that both the solidification feeding velocity and ability of vacuum counter-pressure casting technology depend on magnitude of keeping pressure mainly. As for the same location among dendrite, the higher the keeping pressure is, the stronger the feeding velocity and ability are, the denser the microstructure is. Meanwhile, as for the different location among dendrite, changing trend of the density become V shape, moreover, the density is much more even with the increase of keeping pressure.
Key words: vacuum counter-pressure casting; solidification feeding; mathematical model; keeping pressure; density
