Abstract
The sintering process of Co and diamond mixed powder compact in normal sintering and hot pressing was investigated by dilatometric and microscopic examinations. The density, hardness of sintered compacts and the weight loss of diamond when heated at different temperatures were measured. The results were summarized as follows:
(1) In the case of normal sintering, the shrinkage of Co (1.4μm) powder compact started at 500°C and finished at about 1200°C. On the other hand, Co (3.4μm) powder compact was not completely densified, even under the sintering condition of 1200°C×1hr.
(2) The shrinkage behavior of Co and diamond mixed powder compact was similar to that of Co powder compact. However, a remarkable diffusion layer could not be observed near the interface between Co and diamond, and diamond changed from transparent to black body at 700°C.
(3) In the case of hot pressing, the shrinkage of Co (1.4μm) powder compact started at about 200°C and finished at 900°C, and Co and diamond mixed powder compact was denser than normally sintered compacts.
