INDENTATION RESPONSE OF MOLYBDENUM DISILICIDE

The influence of microstructure on the indentation cracking behavior o f molybdenum disilicide (MoSi2) has been examined. The indentation res ponse of samples produced by various methods has been measured to exam ine the elastic/plastic nature, hardness, and fracture toughness. Frac ture toughness comparisons were made by measuring indentation crack le ngths, observing the elastic/plastic indentation response, and quantif ying the differences in the indentation cracking behavior. Further inf ormation was gained by monitoring the acoustic activity during indenta tion for selected specimens. It has been observed that the fine grain size and the dispersion of the silica phase promote microcracking and crack deflection.