주조용 B390 알루미늄합금의 조직과 기계적 성질에 대한 각종 주조법의 영향

Effect of Casting Processes on the Microstructures and Mechanical Properties of B390 Aluminium Alloy

The effects of casting processes-direct and indirect squeeze casting, permanent mold casting and die casting on the microstructure and mechanical properties were studied for the hypereutectic B390 aluminium alloy. The effects of T5 and T6 heat treatment were also examined. The direct and indirect squeeze casting showed no casting defects such as porosity and shrinkage were observed in permanent mold castings and die castings. The primary silicon phase was refined and homogeneously distributed in the order of indirect squeeze casting, diecasting, direct squeeze casting and permanent mold casting. Depletion of primary silicon phase in die casting surface was disappeared in indirect squeeze casting. Tensile strength of cast and heat treated specimens were increased in the order of direct squeeze casting, permanent mold casting, indirect squeeze casting and die casting. Hardness of indirect squeeze castings was larger than that of other castings. As indirect squeeze casting of B390 aluminium alloy, the time of T6 heat treatment to achieve high strength can be reduced.