ABRASION RESISTANT Al-Si ALLOY SUPERIOR IN MACHINABILITY, AND CASTING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide an Al-Si alloy containing Si in an amount near to a eutectic composition in which adequate abrasion resistance is obtained, and having the machinability improved, and to provide a casting method therefor.;SOLUTION: The Al-Si alloy includes, by weight ratio, 9.5-14.5% Si, 40-400 ppm Sr and 90 ppm or less P, and satisfies the relation of Sr ≥40+P×4 (ppm). The Al-Si alloy can further include 0.45-3.0% Cu, 0.15-1.0% Mg, and 0.8% or less Fe. The Al-Si alloy includes Si particles containing Si having a maximum circle-equivalent particle size of preferably 30 μm or less, when the cross section of the alloy in an as cast state is observed. The method for casting the Al-Si alloy is to control the time between the beginning and the end of solidification for the molten metal of the Al-Si alloy to 300 seconds or shorter.;COPYRIGHT: (C)2004,JPO&NCIPI