| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a sintered compact with excellent wear resistance obtained by the discharge plasma sintering method, a tapered nozzle with an excellent wear resistance obtained by the same method, and its manufacturing method. <P>SOLUTION: The nozzle is sintered by the discharge plasma sintering method and contains carbon of 0.05-2.0 wt.%. It comprises a sintered compact having a black or gray color inside and is tapered down toward its spout. The manufacturing apparatus of the nozzle is equipped with a molding die 34 having a through hole where a material to be sintered is charged, a pair of cylindrical punches 36, 37 facing each other between which the charged material is present, and a core placed along the axis of the through hole. The through hole has a small-diameter cylindrical hollow part 56 at one side, a tapered hollow part 54 tapered down toward the small-diameter hollow part and formed at the middle part, and a large-diameter cylindrical hollow part 53 at the other side. A powder to be sintered is charged into the tapered hollow part and pressed; then the material-facing surface and the surface of the powder are separated to form a space in the cylindrical hollow part with the small diameter; and an additional powder to be sintered is charged into the space, pressed to be integrated, and sintered by passing a pulse electric current through the pressed powder. <P>COPYRIGHT: (C)2004,JPO |
