Particle motion behavior during gasiication of foam carrier in lost foam-squeeze casting of 20%TiC/ZG270-500 composites  

作　　者：Bin Shibo Xing Shuming Guo Lijun Bao Peiwei 

机构地区：[1]School of Mechanical, Electronic,Control Engineering, Beijing Jiaotong University

出　　处：《China Foundry》2013年第6期367-373,共7页中国铸造（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Grant No.51275031)

摘　　要：The particle motion behavior affects the distribution of particles in the metal matrix and finally determines the mechanical properties of the particle reinforced metal-matrix composites. To obtain a uniform distribution of TiC particles and excellent strengthening effect in 20%TiC/ZG270-500 composites fabricated by lost foam-squeeze casting （LFSC）, the particle motion behavior in the gas gap and the conditions of the particles getting into the molten steel were investigated. The results show that the airflow velocity （vl） and TiC particle motion velocity （up） change little with the pouring temperature （Tp）, increase with an increase in metal filling velocity （Vp）, ratios of cross sections of in-gate/orifice （AAAo） and orifice/mould cavity （AolAI）, but the increase trend of up is more intense. The airflow pressure （P1） changes little with Tp and Ao/A1, but increases with the increasing of vp and AJAo. Besides, there is a critical velocity （v ＋｜3YLG cosθ/ppdp｜1/2）for the particles getting into the molten steel. The higher the particle motion velocity, the easier the particles get into the molten steel and the more uniform the distribution of the particles in the steel matrix. When Tp = 1,873 K, vp = 30 mm.s-1, AJAo =10 and Ao/AI = 0.02 in this study, the biggest TiC particle motion velocity （20.59 m.s-~） can be gained, and the steel matrix with the most uniformly distributed TiC particles and fine grains are obtained.The particle motion behavior affects the distribution of particles in the metal matrix and finally determines the mechanical properties of the particle reinforced metal-matrix composites. To obtain a uniform distribution of TiC particles and excellent strengthening effect in 20%TiC/ZG270-500 composites fabricated by lost foam-squeeze casting(LFSC), the particle motion behavior in the gas gap and the conditions of the particles getting into the molten steel were investigated. The results show that the airflow velocity(v1) and TiC particle motion velocity(uP) change little with the pouring temperature(TP), increase with an increase in metal filling velocity(vP), ratios of cross sections of in-gate/orifice(AP/A0) and orifice/mould cavity(A0/A1), but the increase trend of u P is more intense. The airflow pressure(P1) changes little with TP and A0/A1, but increases with the increasing of vP and AP/A0. Besides, there is a critical velocity(+|3yLGcosθ/ρpdp|1/2) for the particles getting into the molten steel. The higher the particle motion velocity, the easier the particles get into the molten steel and the more uniform the distribution of the particles in the steel matrix. When TP = 1,873 K, vP = 30 mm·s-1, AP/A0 =10 and A0/A1 = 0.02 in this study, the biggest TiC particle motion velocity(20.59 m·s-1) can be gained, and the steel matrix with the most uniformly distributed TiC particles and fine grains are obtained.

关 键 词：lost foam-squeeze casting （LFSC） particle motion velocity critical velocity particle distribution 

分 类 号：TG249.6[金属学及工艺—铸造] TG142[一般工业技术—材料科学与工程]