(1. 南昌航空大學(xué) 材料科學(xué)與工程學(xué)院，南昌 330063；2. 華中科技大學(xué) 材料科學(xué)與工程學(xué)院，武漢 430074)
摘 要: 對不同保壓壓力下真空差壓鑄造試樣致密度進(jìn)行分析，探討真空差壓鑄造工藝的凝固補(bǔ)縮特性，建立凝固補(bǔ)縮過程的數(shù)學(xué)模型。結(jié)果表明：真空差壓鑄造工藝的凝固補(bǔ)縮速度和補(bǔ)縮能力主要取決于結(jié)晶凝固時(shí)保壓壓力的大小；對于晶間同一部位來說，保壓壓力越大，補(bǔ)縮速度和補(bǔ)縮能力越強(qiáng)，組織越致密；對于晶間不同部位來說，致密度成V形變化趨勢，且隨著保壓壓力的逐漸增大，致密度越來越均勻。
關(guān)鍵字: 真空差壓鑄造；凝固補(bǔ)縮；數(shù)學(xué)模型；保壓壓力；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
