| Al-(20,30wt%)Si-(3,5,8wt%)Fe alloy powders were consolidated by hot extrusion and the change powder microstructure during extrusion was investigated. The effects of Fe addition to Al-Si alloy on the mechanical properties, wear and heat resistance of extruded bars were examined, too. During extrusion of Al-Si-Fe alloy powders, primary Si is broken into fragments from 10∼20 ㎛ size to size less than 10 ㎛ and intermetallic compound from 20∼50 ㎛ size to size less than 5 ㎛. The intermetallic compound in matrix is broken finely, too. Additionally, during extrusion metastable δ phase(Al₄FeSi₂) intermetallic compound disappears and the equilibrium β phase(Al_5FeSi) is formed. Al-Si-Fe alloys showed better mechanical properties, wear and heat resistance than Al-Si binary alloys, resulting from the composite like hardening and matrix hardening by finely distributed primary and eutectic intermetallic compound. Especially, Al-20Si-8Fe alloy showed best physical properties in this work |
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