Interfacial properties of SiC monofilament reinforced β′-SiAlON composites

Abstract

Interfacial mechanical properties of SiC monofilament-reinforced β′-SiAlON composites were characterized by a single fiber push-out technique. Interfacial parameters were studied as a function of embedded filament lengths, including comparisons of linear, nonlinear shear-lag, and progressive debonding analysis models. The interfacial debonding peak load ( P p) and maximum frictional sliding load ( P max) were both measured from the apparent load-displacement curves. Linear and shear-lag analyses were fitted to the data as a function of embedded filament lengths, respectively. In comparison, the progressive debonding analysis was conducted by fitting the effective load-displacement curves obtained by subtraction of machine compliance from the apparent load-displacement curves. The nonlinear shear-lag model gave better regression fits to the data than did the linear model, while the progressive debonding model provided much more interfacial information than did the shear-lag model. In addition to the coefficient of friction (μ) and radial residual stress ( σ N), axial residual load ( P r), critical load for interfacial crack initiation or propagation ( P d), interfacial fracture toughness ( G i), as well as the interfacial roughness amplitude ( A) and its contribution to the interfacial normal stress ( σ r) were extracted from the progressive debonding model, using a three-parameter, non-linear least squares fitting method on the effective load-displacement curves.