2529 Processing of Boron fiber Reinforced Ti-15V-3Cr-3Al-3Sn Alloy Matrix Composites by Pulsed Current Hot Pressing(PCHP)

Abstract

Boron fiber reinforced Ti matrix composites were fabricated by pulsed current hot pressing (PCHP) process at various processing conditions at a pressure of 32MPa in vacuum of 2Pa. Good bonding between the fiber and matrix was obtained by PCHP at 1123K for less than 450s. When fabricated at the holding temperature higher than 1173K, TiB_2 layer was formed along the interface between the fiber and matrix, and the crystallization of boron in the vicinity of tungsten core in the fiber occurred. The thickness of TiB2 layer formed and the crystallized boron increased with increasing the holding temperature. Tensile tests were carried out at room temperature for the composites fabricated by PCHP at 1073K. Tensile strength of the composites containing 17.2vol.% boron fiber attained at 706MPa. This value was about 80% of the tensile strength calculated by the force equilibrium equation of a composite along with the fiber axis direction.