| 摘要 |
PROBLEM TO BE SOLVED: To provide a sintered compact capable of meeting the recent demand for a product requiring airtightness. SOLUTION: In the airtight sintered compact 1 prepared by compacting and sintering a raw-material powder composed mainly of metal, the sintered compact contains 0.006 to 0.1 mass% carbon and 0.2 to 1.5 mass% phosphorus and also the sintered compact has≤12% open porosity and≤40μm average grain size and contains nitrogen, and further, a surface treatment layer 3 having airtightness is provided. Since, the percentage of the oxidation of phosphorus at sintering is decreased by a reducing effect by carbon, phosphorus lowers the melting point of the raw-material powder and promotes the formation of liquid-phase components and also the diffusion of iron and phosphorus is smoothly performed and phosphorus combines with iron and is allowed to enter into solid solution, by which the sintered compact minimal in pores and excellent in airtightness can be obtained. Further, the surface treatment layer 3 can be provided without performing sealing treatment. Owing to this surface treatment layer 3, airtightness can be secured. COPYRIGHT: (C)2005,JPO&NCIPI
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