Effects of whisker content and dimensions on the R-curve behavior of an alumina matrix composite reinforced with silicon carbide whiskers

Abstract

A study was made of the effects of whisker content and dimensions on the R-curve behavior of an alumina matrix composite reinforced with silicon carbide whiskers. Experiments showed that the rising R-curve behavior is strongly enhanced by the increase in the volume fraction and the size of whiskers. Simulation based on a model of crack face whisker bridgings was made to elucidate the effects on the R-curve of the composite. The validity of the simulation was confirmed by good agreement between the experimental and the calculated R-curves. In addition to the R-curve, the distribution of crack closure stresses as well as crack tip opening displacements was also calculated, which directly reflects crack face whisker bridging processes in the composite. Then the dependence of whisker content and dimensions on the R-curve was analytically discussed taking the bridging processes into account.