Study of matrix microstructure of SiC_f/Ti–43Al–9V composites

Abstract

Four different microstructures of the Ti–43Al–9V alloy were obtained through heat treatment or thermal deformation process. Alloys with different microstructures were cut and ground into thin foils. The foils would be used to fabricate the SiC fibre reinforced composites via foil–fibre–foil method. Then, the matrix microstructures of composites were investigated by means of optical microscopy, scanning electron microscopy and microarea X-ray diffraction. The results show that near lamellae and massive gamma microstructure transform into duplex during the consolidation process, but the transformation mechanism of the two microstructure is different. Fully lamellae microstructure remains in the matrix, while B2 phase precipitates in the matrix. Duplex microstructure does not change during the consolidation process. No matter what kind of microstructure the foils have, there is only gamma phase formed close to the fibres in the matrix of composites.

Keywords:

• Titanium matrix composites
• γ-TiAl
• SiC fibre
• Microstructure
• Vacuum hot pressing

Thanks are given to the financial supports of the Natural Science Foundation of China (grant no. 51071122), the Aviation Science Foundation of China (grant no. 2009ZF53062), the NPU Foundation for Fundamental Research (grant nos. NPU-FFR- JC2010021 and JC2011100) and the State Key Laboratory of Solidification Processing in NWPU (grant no. SKLSP201107).