Abstract
By using chemically nickel plated TiNx composite powders, we carried out an examination of sintering characteristics in order to improve the sintering effect, and also investigated some properties of sintered compacts showing maximum sintered density.
The results obtained were as follows:
(1) The shrinkage of Ni-plated TiNx powder compacts was remarkably promoted, whereas the Ni concentration and x in formula TiNx, showing the maximum density ratio and hardness of sintered compacts in the sintering condition at 1400°C for 3 hr., were approximately 23 wt%, x=0.75 and 18 wt%, x=0.75, respectively. Titanium nitride showed its maximum hardness near substoichiometric composition of TiN0.78.
(2) The Corrosion resistance in nitric acid at 25°C of TiN0.75-23.4 wt%Ni sintered alloy was comparable to that of stainless steel, Hastelloy, Inconel and cobalt-based cemented carbide, but in concentrated hydrochloric acid it was inferior to Hastelloy and Inconel.
(3) Oxidation resistance of TiN0.75-23.4 wt%Ni sintered alloy in air at 700-1000°C was superior to that of TiC-Ni alloy.
