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pISSN : 1598-706X / eISSN : 2288-8381


(논문)연구논문

한국주조공학회지 (10권4호 316-323)

A Study on the Gravity Segregation in Monotectic Al Alloys.(I);The Effect of Melting Treatment on the Distribution of Pb, Bi Particles.

Al계 편정합금의 중력 편석에 관한 연구 (I);Pb, Bi 입자의 분산에 미치는 용탕처리의 영향

Ho-Eul Hwang*, Jai-Ha Lee**, Sung-ln Jung***, Jeong-Cheol Choe****, Eui-Park Yoon***

*Samson Industrial Co., **Jeonbuk Univ., ***Hanyang Univ., ****Ajou Univ.

Abstract

To improve free-cutting property, fine Pb, Bi particles is necessary to be distributed evenly in Al-Cu alloy. The control of added element size and distribution are very difficult because of the insolubility and gravity segregation of Pb, Bi in the matrix. Therefore, in this study, mechanical stirring of the melt, inert gasbubbling, the addition of degasser are used for the fine distribution of Pb, Bi particles. The best distribution are obtained by stirring with 500 rpm for 10min., Ar gas bubbling with 600cc/min for 5min. and degassing with 0.8wt% degasser. As increasing cooling rate, fine grain size and finely dispersed particles were observed. The optimum pouring temperature was 650℃.

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