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

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 carbi de whiskers. Experiments showed that the rising R-curve behavior is strongl y 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 el ucidate the effects on the R-curve of the composite. The validity of the si mulation was confirmed by good agreement between the experimental and the c alculated R-curves. In addition to the R-curve, the distribution of crack c losure stresses as well as crack tip opening displacements was also calcula ted, which directly reflects crack face whisker bridging processes in the c omposite. Then the dependence of whisker content and dimensions on the R-cu rve was analytically discussed taking the bridging processes into account.