| 摘要 |
PROBLEM TO BE SOLVED: To provide a valve guide enhanced in heat resistance, wear resistance, seizing resistance, scuffing resistance and thermal emission by subjecting the atomized powder of an alloy composed of specified weight ratios of Si, Fe, Cu, Mg and one or more kinds among Zr, Ni, Mn and Zn, and the balance Al to extrusion molding. SOLUTION: The atomized powder of an alloy composed of, by weight, 15 to 40% Si, 1.0 to 10.0% Fe, 0.5 to 5% Cu, 0.1 to 3.0% Mg, one or more kinds of Zr, Ni, Mn and Zn by <3%, and the balance Al is used. Preferably, either or both of hard particles of SiC and Al2O3 having <=5μm average particle size and a solid lubricant of graphite, sulfide and fluoride are added to this powder by 1 to 10 weight% of the whole weight. As for the high silicon aluminum alloy, by atomizing molten metal by gas atomizing, rapid solidification of >=103K/sec can be executed, and fine powder of precipitates including primary crystal Si is obtd.
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