| 摘要 |
PURPOSE:To obtain the subject sintered compact possible to facilitate electrical discharge machining by reducing electric specific resistance, having high strength, by compounding Cr and Cr compd., one or more kinds among carbide, nitride and boride of group IVa, Va and VIa after the fifth period element in the periodic table, and Al2O3 powder in specified amts, respectively, with SiC powder and by sintering. CONSTITUTION:The subject sintered compact having <=10OMEGAcm electric specific resistance and >=400MPa bending strength is obtd. by compounding 5-25 pts. (hereinafter in weight) Cr and Cr compd. (e.g., Cr3C2, CrSi2) and 10-50 pts. one or more kinds among carbide, nitride and boride of group IVa, Va and VIa after the fifth period elements (e.g., TiC, ZrC, TiN, TiB2), on condition of 12-60 pts. the sum of the amt. of Cr and/or Cr compd. and one or more kinds of carbide, nitride and boride, and furthermore 5-25 pts. Al2O3 power or equiv. amt. of the precursor of Al2O3 powder (e.g., aluminum alkoxide) and, as occasion demands, <=10 pts. C, with 40-85 pts. SiC powder, and by sintering at 1700-2100 deg.C in an inert gas. |
