Abstract
New sintering procedure of ODS-Ni powder which has very poor sinterability in an inert or a reductive atmosphere has been studied employing Ni-ZrO2 powder. It was found that sintering of Ni-ZrO2 powder was extremely accelerated by undergoing pre-sintering treatment in an atmosphere of air prior to ordinary sintering in a reductive atmosphere. In presintering process, caused by the mass-transfer of Ni to the surface of Nickel oxide layer from the matrix, NiO layer free from ZrO2 particles formed on the outside of the original matrix surface, and the presence of this NiO layer free from ZrO2 particles contributed to acceleration of sintering in subsequent ordinary sintering process. But if the pre-sintering temperature exceeded 1273K, the bending strength of the sintered body was lowered caused by coarsening and aggregating of ZrO2 particles.
