한국주조공학회

Mechanical and thermal properties o f spray-cast hypereutectic Al-20wt.%Si-xwt.%Fe alloys (x=0, 1,3，5) were investigated. After the spray-casting, hot extrusion was performed at 400°C. Intermetallic compound ((3-Al5FeSi) and primary Si are observed in the spray-cast aluminum alloys. The size o f primary Si and intermetallic compound o f the spray-aluminum alloys became finer and more uniformly distributed than that o f the permanent mold cast ones. Ultimate tensile strength o f the spray-cast aluminum alloys increased by increasing Fe contents, but that o f the permanent mold cast aluminum alloys decreased by increasing Fe contents possibly due to increased amount o f coarse intermatallic compound. The coefficient o f thermal expansion (CTEs) o f the aluminum alloys became lower with finer primary Si and intermetallic compound, and this is attributed to the increased amount o f interfacial area between the aluminum matrix and the phases o f finer Si and intermetallic compound.

Spray-cast, Hypereutectic Aluminum alloys, Primary Si, p-Al5FeSi, CTEs.