Sintering Mechanisms of Mechanically Alloyed 2Nb/Al Powder by Puls Current Pressure Sintering

The mechanically alloyed powder of 2Nb/Al composition was sintered in the temperature ranges from 973K to 1173K using either the pulse current pressure sintering (PCPS) apparatus or a conventional electric furnace. X-ray diffraction patterns for the compacts sintered by PCPS showed the weak Al peaks in halo, although the diffraction patterns for the compacts sintered by conventional electric heating did not show the Al peaks. A sets of 2Nb/Al powder cmpact and balls of SUS304 stainless steel were sintered at 973K by PCPS in order to make clear the reason why the Al peaks were detected. Using EDX, Nb were not, but Al were detected in the circumference are in contact with 2Nb/Al compact on the surface of SUS ball. This fact indicates that evaporation and deposition of Al occured during PCPS. It can be estimated that the contact area in the earlier stages of PCPS was heated up to the order of 2000 to 4000K.