| 摘要 |
PROBLEM TO BE SOLVED: To determine optimum alumina ceramics texture for obtaining favorable surface roughness and to establish manufacturing technique for embodying the texture in an alumina ceramics product for a sliding part. SOLUTION: The alumina ceramics product for the sliding part is characterized by that the product has >=99.9% purity, relative density of >=99%, maximum of maximum circumscribed circle diameter of alumina particles is <=5 μm and an average grain size thereof is <=1.4 μm in an observation visual field 20 of 20 μm×15 μm of a sintered compact when observed by using a scanning type electron microscope of 5,000 magnifications. The alumina ceramics product is manufactured by using alumina particles of single crystal as a raw material, adding MgO by <1000 ppm (0 ppm is not included) as a sintering assistant and sintering at 1250 to 1590 deg.C otherwise by using alumina particles of single crystal or polycrystal as the raw material, sintering at 1250 to 1590 deg.C and then subjecting to hot hydrostatic pressing sintering at 1200 to 1550 deg.C. |
