Processing, microstructure and tensile property of a tape-cast TiSiC fibre composite

Lightweight composites based on continuous SiC fibres and titanium matrices offer a very desirable combination of high-temperature strength, stiffness, and creep resistance, which are ideal for various components in the future generation of gas and steam turbine engines. However, potential applications of Ti/SiC fibre metal matrix composites have been largely hindered by high cost. This paper investigates the use of a low-cost tape casting technique for the manufacture of Ti based composites reinforced by SiC monofilaments, where microstructural control is essential at each stage of the process. The thickness uniformity and microstructure of the powder tape was first analysed. The resulting composites showed very uniform fibre distribution and no apparent signs of fibre damage. The corresponding tensile strength reached about 92% of the rule-of-mixtures value, which is comparable to those obtained using other manufacturing processes. Detailed microstructural analysis revealed that C-rich residuals existed in the composite if the organic binder was not completely removed. Further improvement of the properties is possible when the debinding condition is optimised.