Effect of the interfacial reaction layer thickness on the thermal residual stresses in SiCf/Ti–6Al–4V composites

A three-dimensional finite element model was developed to study the effects of the interfacial reaction layer thickness on the distribution of the thermal residual stresses near the interfacial reaction layer in continuous SiC fiber reinforced Ti–6Al–4V composite. The interfacial reaction layer thicknesses in real composites were adopted in the present analysis. The hoop, radial and axial stresses at the fiber and interfacial reaction layer (f/i interface), middle of the interfacial reaction layer and interfacial reaction layer and matrix (i/m interface) were studied for each thickness. The results show the interfacial reaction layer thickness has a significant influence on the distribution of the thermal residual stresses near the interfacial reaction layer. X-ray stress measurements indicate that the prediction data have a good agreement with the experimental results. The interfacial radial cracks appear not only in the as-processed sample but also in the heat-treated samples. Experimental observations suggest that the f/i interfacial debonding is not significant during the transverse tensile loading.