Title: Effect of Fiber Coating on Mechanical Properties of Nicalon Fibers and Nicalon-Fiber/SiC Matrix Composites
Abstract:The effect of fiber-coating thickness on retained in-situ fiber strength and the resulting mechanical properties of composites was investigated. Flexure tests in a four-point-bend mode were used to ev...The effect of fiber-coating thickness on retained in-situ fiber strength and the resulting mechanical properties of composites was investigated. Flexure tests in a four-point-bend mode were used to evaluate ultimate strength and work-of-fracture of the composites with various fiber-coating thicknesses. Retained in-situ fiber strength in the fractured composites was evaluated by fractographic techniques. Retained in-situ fiber strength, ultimate strength, and work-of-fracture of the composites increased with increasing fiber-coating thickness, reaching a peak value at a coating thickness of {approximately}0.3{mu}m. Further increases in coating thickness did not improve the mechanical properties of either the fibers or the composites. A direct correlation between retained in-situ fiber strength and mechanical properties of the composites suggests that retained in-situ fiber strength has a significant influence on the mechanical properties of composites.Read More