METHOD FOR MANUFACTURING PISTON FOR INTERNAL COMBUSTION ENGINE, AND PISTON FOR INTERNAL COMBUSTION ENGINE

摘要

A concave part (5) is formed in a crest surface of a peak part of a piston (1) made of an aluminum alloy. This concave part (5) is filled with a mixed powder (P) consisting essentially of zirconia power as a filler member and pure aluminum powder as a bonding member. A solid cylindrical rotary implement (10) is brought in contact with the concave part (5) filled with the mixed powder (P), and a load is applied while the implement is rotated to press the implement into the piston (1). The mixed powder (P) is softened by frictional heat with the rotary implement (10), whereby the mixed powder (P) is bound in a solid phase to the concave part (5) and a low-thermal-conductive part (4) is formed. The bonding strength of the low-thermal-conductive part (4) in the crest surface of the peak part of the piston is thereby improved.