Abstract
Using the specially designed impact testing machine, the fracture characteristics of carbide material P 20 and its deterioration process by impact repetition are examined quantitatively under various temperature less than 800°C and under various impact duration. The main results obtained are as follows: (1) The fracture stress decreases with temperature increase, however the features of fracture are seen as a brittle one even at 800°C. (2) Both temperature and heating duration have no effect on the deterioration process by impact. The rate of deterioration depends on the impact stress and the number of impact but on the temperature. (3) Many small cracks or voids with random size and directions around WC particles in a sintered carbide are generated by both the cyclic uniaxial compressive and tensile impact, thus the isotropical deterioration may be expected in a carbide material. (4) The hypothesis for evaluation of the deterioration process by multiaxial stressing at any temperature less than 800°C is proposed.
