| 摘要 |
PURPOSE:To prevent peeling of a part containing high Si arranging an expendable pattern containing the specific Si at a part corresponding to at least near sliding face in a mold. CONSTITUTION:The Si powder 16 of 13-20wt.% having 30-100mum grain size is packed in claw part of a shift fork in cavity 12. After that, resin beads 18 of forming a polystyrene are packed into the remaining space in the cavity 16. Further, steam is supplied from a supplying hole 14 to foam the resin beads 18. The expendable pattern 20 of the foaming resin under compositing condition with Si powder 16 is formed at the part of the shift fork. Next, this expendable pattern 20 is put in a cavity 12a in the casting mold 22. Then, molten Al containing <=12wt.% Si is poured into the mold 22. The molten Al is brought into contact with the expandable pattern 20 in the cavity 12a and the foaming resin is expended by heat and also hyper-eutectic Si having 12-20wt.% is composited at the sliding part of the shift fork by putting together the Si powder contained in the pattern 20 and Si contained in the molten metal.
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