DENSE SINTERING OF LONG ROD AND SHOULDER COMPONENT THROUGH TRAVELING ZONE HEATING METHOD

摘要

A traveling zone heating technique was examined with the aim of creating a long dense rod or a shoulder component through the pressurized pulse discharge sintering. Based on a local heating method enabled by electric power supplied perpendicular to the loading axis through the electrode attached on a mold, a one-direction continuous sintering process was successfully achieved, in which the electrode was able to slide along the side wall of the cylindrical mold in the direction of the loading axis while remaining in continuous contact with it. The heating zone was limited to within the range corresponding to the thickness of the electrode. Four successive local heatings over a range 30 mm wide while moving the heating zone distances of 20 mm led to the production of a 55 mm long aluminum rod with a relative density of 99.7%. Much longer rods can be sintered well by expanding the moving range of the heating zone. The concept of multi-way loading system was also proposed. This loading system is able to control the pressure in a powder compact body constant even if it has irregular sectional profile. Based on this idea, the conventional sintering procedure with a perforated spacer was practiced to produce a shoulder component through the PDS process. This spacer decided the loading stroke in the thin side. This sintering concluded that an aluminum shoulder component of the diameters in 15 mm as the thin side and 25 mm as the thick side was successfully produced. The relative density of the sample was beyond 99%, which guaranteed the sintered body was well densified. The versatility of the PDS process can be much expanded assisted by these new techniques.