MANUFACTURING METHOD OF IRON-BASED SINTERED ALLOY VALVE SEAT EXHIBITING WEAR RESISTANCE UNDER HIGH SURFACE PRESSURE APPLIED CONDITION

摘要

PPROBLEM TO BE SOLVED: To provide a method for manufacturing a valve seat having excellent wear resistance. PSOLUTION: The valve seat is manufactured by the following processes. (a) An Fe-based alloy powder of an average particle diameter of 20-50 m is used as a raw material powder for forming matrix, and a Co-based alloy powder of an average particle diameter of 20-50 m is used as a raw material powder for forming hard dispersed phase, (b) the Co alloy powder is blended and mixed with the Fe-based alloy powder so that it becomes 25-35 mass% of the amount of sum totals of the Fe alloy powder and the Co alloy powder, and the press-formed body of a mixed powder is subjected to solid phase sintering in a vacuum atmosphere, and the above-mentioned Co, Cr, and Si components in the Co base alloy powder are diffusion migrated in a matrix, and at the same time an Fe component in the Fe-based alloy powder is diffusion migrated in a hard dispersed phase, respectively, and as a result, adhesiveness of the hard dispersed phase to the matrix is remarkably improved. (c) The Fe-based sintered alloy product is infiltrated with molten copper or a copper alloy. PCOPYRIGHT: (C)2004,JPO