Abstract
A pulsed current sintering is a new sintering process that powder in the conductive mold is heated by applying current under a pressure. This new sintering process is able to apply high-speed heating and densification at lower sintering temperature. Therefore, this process is effective for consolidation of nanocrystalline materials.
In this study, we focus attention on the pressure during the pulsed current sintering of varied functional materials. In the ordinary pulsed current sintering process, the powder in the graphite die was consolidated under a pressure of about 30 MPa. The mechanically alloyed Fe-48at%Cr powder was consolidated in this process without brittle phase. In addition, the Fe-48at%Cr compact with a complex shape was able to be formed.
The pulsed current sintering under a pressure of less than 10 MPa was effective to prepare the homogeneous porous materials. The porous material prepared by this process from copper fiber can be applied to heat sink for cooling CPU. The pulsed current sintering with a pressure of more than 500 MPa was effective to consolidate amorphous powder and to obtain a bulk nanocrystalline compact at s sintering temperature more than crystallized temperature of the amorphous powder. The nanocrystalline Ti-2at%Fe-10at%Si compact had high strength and was applied to the mold for consolidation of NaCl powder.
