| 摘要 |
PURPOSE:To improve durability and thermal conductivity, by a method wherein a seat part, engaging with the cylinder head of an annular valve seat, is made of a specific ingot metal, and a sintered alloy, forming a valve seat face part on the seat, is cemented in a diffusion manner with a seat metal. CONSTITUTION:A sintered alloy part 1 and a seat part 2 made of an ingot metal are cemented together to form a composite valve seat. In which case, the seat part 2, engaging with the cylinder head of an annular valve seat, may be made of an ingot metal, such as cast iron, or steel materials, having a liquid phase temperature which is within a sintering temperature range (1,150+ or -50 deg.C). The sintered alloy part 1 is placed on the seat part 2 so as to form a face part by means of iron series alloy powder, and in a sintering process, the sintered alloy part 1 and the seat part 2 are cemented together in a diffusion manner simultaneously with sintering of powder. This enables improvement of heat resistance, corrosion resistance, and erosion resistance of the valve seat face, and also improvement of thermal conductivity of the valve seat itself. |
