Abstract
Structure changes of TiC-10vol%Mo2C-10vol%Ni and TiC-20vol%TiN-10vol%Mo2C-10vol%Ni cermets occurring during short-time bending creep tests were mainly studied to elucidate the reason why the creep strength of nitrogen(N) contained cermets was superior to that of the other. It was found that micro-cracks formed in both cermets In the early stage of creep tests and the number of cracks increased with increasing creep strain or testing time, showing that creep curves obtained were by no means steady-state ones, and the creep strength of those cermets could not be now discussed from the viewpoint of steady-state creep. It was suggested that the superior creep strength of N contained cermets was caused by the fact that the uniform plastic flow during the tests was highly suppressed owing to the increased carbonitride/carbonitride interfaces, and moreover micro-cracks formation needed for Increasing creep strain was much more difficult comparing with N free cermets.
