Effect of pulse current on the oxide layer during pulse current pressure sinteing of aluminum powder

The pulse current pressure sintering and hot press process were applied for sintering of aluminum powder produced by water and gas atomizing methods. The pulse current pressure sintering process could densify the water atomiz ed powder in a short time compared with the hot pressing because it could r emove the H-2 gas at lower temperature. The gas prevents sintering of alumi num powder. The tensile strength of the pulse current pressure sintered gas atomized powder which contains low H-2 was higher than that of hot pressed specimen. The electric resistivity of sintered specimens obtained by pulse current pressure sintering process was lower than that of hot pressed spec imen. The oxide layer destruction was confirmed by this measurement of elec tric resistivity. The oxide layers were supposed to be fractured by the hig h temperature zone which was attributed to joule heat by the contact resist ance.