1978 Volume 25 Issue 6 Pages 193-197
Values of electric resistance and power input as a function of sintering time were calculated by using wave shapes of current and voltage measured during resistance sintering of titanium powder, and the resistance sintering process was analyzed. The results are as follows.
(1) Contribution of Joul's heat generated from two main sources in the resistance sintering (i.e., the one heat source is the titanium particle itself, and another is the contact areas between the particles) has been quantitatively explained.
(2) In the earlier stage of resistance sintering, the compact is chiefly heated by an electric current passing through the contact areas between the particles. In the intermediate stage, the heat is generated both within the particle itself and at the contact areas between the particles. In the later stage, the specimen is heated only by a current passing through the particle itself whose resistance can be estimated from the bulk resistivity of titanium at elevated temperatures. (3) Owing to positive temperature coefficient of resistance, an increase in resistivity of metal with in-creasing temperature gives rise to homogenize and to stabilize the process of resistance sintering.