Crystallisation characteristics of primary silicon particles in cast hypereutectic Al–Si alloy. (April 2013)

• Record Type: Journal Article
• Authors: Okayasu, M; Takeuchi, S; Shiraishi, T
• Is Part Of: International journal of cast metals research. Volume 26:Number 2(2013)
• Page Start: 105
• Page End: 113
• Publication Date: 2013-04
• Subjects: Aluminium alloy -- Silicon -- Crystallisation -- Microstructure -- Wear; Metal castings -- Periodicals; Founding -- Periodicals; Foundry research -- Periodicals; Foundry chemistry -- Periodicals; 671.2
• DOI: 10.1179/1743133612Y.0000000040
• Languages: English
• ISSNs: 1364-0461

Abstract

Abstract : The crystallisation characteristics of primary silicon particles in a cast hypereutectic Al–Si alloy were examined using various casting processes. The size of the primary silicon particles depends on the cooling rate. However, the primary silicon particles cannot be crystallised completely when the cooling rate is >20 K s −1, since uncrystallised Si atoms migrate to the regions at low cooling rates, producing large primary Si particles. Moreover, turbulent metal flow under conditions of high cooling rate leads to the macrosegregation of the primary Si particles, resulting in poor mechanical properties. From the crystallisation characteristics obtained, a suitable solidification criterion can be proposed.