Micromechanical Modelling of SCS-6 Fibre Reinforced Ti-6A1-4V under Transverse Tension—Effect of Fibre Coating

Abstract

Finite element micromechanical modelling of SCS-6 SiC fibre reinforced Ti-6A1-4V has been performed. The fibres have a relatively thick coating consisting of pyrolytic carbon and SiC. The mechanical and thermal properties are estimated by considering both components, among which the properties of pyrolytic carbon are highly anisotropic. The effects of the low stiffness and highly anisotropic coating have been ignored in most other studies on the same material. However, it is shown that the coating has a significant effect on the composite thermal residual stresses, elastic transverse tensile properties and interface debonding. Methods of estimating the interface tensile strength are proposed. The transverse loading-unloading-reloading behaviour of this material is modelled and compared with experimental results. Possible ways of improving the transverse properties of SCS-6/Ti-6-4 unidirectional composite are suggested.