Pulsed current sintering (PCS) is a process to sinter powders by applying directly a pulsed current to. The process prepares densely a sintered body at a low temperature by heating with pressing in a vacuum. In particular, this is effective to sinter metal powders with a surface oxide film, which makes those difficult to do.
To produce amorphous sintered bodies from amorphous powders requires sintering the powders at a temperature lower than the crystallization temperature of those. It is difficult that sintering of amorphous powders synthesized by mechanically alloying (MA), because the glass transformation temperature of the amorphous powder is not observed usually. By pulsed-current-sintering under a coaxial pressure more than 400 MPa, an amorphous magnesium bulk was produced from amorphous powder prepared by MA. The amorphous magnesium alloy had a high compressive strength and a high corrosion resistance. This process is applicable to an amorphous titanium powder prepared by MA.
A ferritic stainless steel consisting of iron and chromium has generally σ phase, which is hard and brittle, and it is difficult to produce a high chromium alloy. A formed body with no σ phase can be produced by pulsed-current-sintering Fe-48at%Cr mechanically alloyed powder. The sintered body showed higher than 1GPa of tensile strength and 10% of elongation. Then to use an assembling carbon die set can form a complicated near-net-shape.
A dense cermet with a fine TiC particle is hard to be made on account of the bad wettability of melted Ni to the TiC particle. To heat at a high rate by pulsed-current-sintering Ti-C-Ni mechanically alloyed powder synthesizes TiC particle in-situ while heating and produces a dense cermet. The cermet had a complicated material with fine TiC particle smaller than 1μm.
The PCS makes possible producing alloys that are hard to sinter by combining with mechanical alloying, which is a method of synthesizing powders.