PURPOSE: To prevent the outflow of a liq. phase from a sintering powder and to impart sufficiently high density to a sintered body by covering the sintering powder with another powder which is not sintered at the sintering temp.
CONSTITUTION: An alumina powder 9, etc., other than a sintering powder are placed in a recess 8 formed by the tip surface of a lower punch 6 and the hole 5 of a die 4 to form an alumina powder layer 9. The lower punch 6 is lowered to form a recess 10, and a sintering metallic powder 11 is put in the recess to form a metallic powder 11 layer. The lower punch 6 is further lowered to form a recess 12 on the upper surface of the metallic powder 11 layer, and the alumina powder is placed in the recess. An upper punch 17 is lowered to cover the metallic powder 11 layer with the alumina powder 9 layers from above and below, and the metallic powder 11 layer is set in a space 13. The metallic powder 11 layer is then compressed, energized and sintered. Although a part of the metallic powder 11 layer is liquefied, the flow of the liq. phase is blocked by the alumina 9 layer which is not sintered at this sintering temp., and the outflow of the liq. phase to each clearance from the metallic powder 11 layer is obviated.
SASAKI NAOKI
MAZDA MOTOR