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


(논문)연구논문

한국주조공학회지 (14권3호 258-266)

Microstructure of Squeeze Cast AC4A Al/Al_2O_3+SiC_p Hybrid Metal Matrix Composite

용탕단조한 AC4A Al/Al_2O_3+SiC_p 하이브리드 금속복합재료의 미세조직과 기계적 성질

Min-Soo Kim*, Kyung-Mox Cho*, lk-Min Park**

*Pusan National University, **Pusan National University

Abstract

AC4A Al/Al_2O_3+SiC_p hybrid composites were fabricated by the squeeze infiltration technique. Effect of applied pressure, volume fraction of reinforcement$Al_2O_3 and SiC particle siz(4.5μм, 6.5μм and 9,3μм) on the solidification microstructure of the hybrid composites were examined. Mechanical properties were estimated preliminarly by fractographic observation, hardness measurement and wear test. Results show that the microstructure of the hybrid composites were quite satisfactory, namely revealing relatively uniform distribution of reinforcements and refined matrix. Some aggregation of SiC particle caused by particle pushing was observed especially in the hybrid composites containg in fine particle(4.5μм). Refined matrix was attributed to applied pressure and increased nucleation sites with addition of reinforcements. Fractured facet also revealed finer for the hybrid composites possibly due to refined matrix. Hardness and wear resistance increased with volume fraction of reinforcements. For hybrid composites with 9.3μм SiC, hardness was somewhat lower and wear resistance higher than other composites.

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