Mo powder compacts are generally sintered at high temperature by direct sintering method. Recently instead of this method, the activated sinterings are studied, in order to promote the densification of No powder compacts.
We investigated the behavior of No powder compacts which are activated by the addition of B₄C powder. The results of this experiment are as follows:
1)Sintered No powder compacts are slightly activated by the addition of B₄C powder.
2)With an increase in sintering temperature, compounds of Mo-B boride and Mo-C carbide are pro-duced in the sintered No powder compacts.
At next time, we added Ni and B₄C powders to Mo powder compacts and sintered. Following results were obtained:
3)The liquid phase is produced at sintering. This liquid phase is brought by the eutectic reaction of Ni-B boride which is combined Ni powder with B element of B₄C powder.
4)The hardness of the sintered No powder compacts with addition of Ni powder gets Hv2300.