Coating fracture toughness

Measurement of coating fracture toughness and interfacial adhesion strength... 

Fig. 7,2. Fracture toughness, R, of Kevlar 49-epoxy matrix composites (a) under varying strain rates in three-point bending and (b) at different temperatures under impact loading (O) uncoated fibers (0)41%, (Q) 63% and ( ) 100% Estapol coated fibers (A) silicone vacuum fluid (SVF) coated fibers. After Mai...

Fig. 7.4. Fracture toughness (O) and flexural strength ( ) of silicone rubber coated carbon fiber-epoxy matrix composites as a function of coating thickness. After Hancox and Wells (1977).

Fig. 7.5. (a) Transverse impact fracture toughness and (b) fiber pull-out length versus testing temperature for carbon fiber-epoxy matrix composites with and without PVAL coatings on fibers. After Kim and... 

It is shown in Section 7.2 that the PVAL coating applied onto Kevlar and carbon fibers is potentially beneficial for improving the transverse fracture toughness of the composites made therefrom. Encouraged by this promising result, further studies were conducted on the effects of the compliant interlayer on the stress distributions. 

Table 10.4 Comparison of Vickers hardness and fracture toughness for cemented carbide sintered with and without SiC-coated diamond particles...

Dense composites of cemented carbide containing SiC-coated diamond particles can be fabricated without conversion of diamond to graphite. The fracture toughness of the composite is double that of cemented carbide due to the deflection and blocking effects against crack propagation by the dispersed diamond particles. 

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