Properties of SiC-fibre reinforced titanium alloys processed by fibre coating and hot isostatic pressing

The properties of SiC-fibre reinforced Ti-6Al-4V and Ti-IMI834 alloys processed by fibre coating with matrix and hot isostatic pressing are discussed. A variable fibre volume fraction between 0.2 and 0.6 is obtained with nearly ideal fibre distribution and a matrix with a small grain size. Three methods for matrix deposition were tested: electron beam physical vapour deposition, magnetron sputtering and random arc deposition. The strength and matrix ductility of the composites are influenced by the amount of oxygen incorporated into the matrix during matrix deposition on the fibre. For composites with a low oxygen content in the matrix the tensile strength and Young's modulus measured in the fibre direction are in agreement with the rule of mixtures. For composites with a high oxygen level in the matrix tensile strength is reduced by 20%. The high temperature tensile strength was measured for composites with the Ti-IMI834 alloy as matrix up to temperatures of 970 °C and values of 1800 MPa at 600 °C and 1500 MPa at 800 °C were obtained for a fibre volume fraction of 0.40.