The Elevated Temperature Response of Silicon Carbide and Boron Reinforced Aluminum and Titanium Metal Matrix Composites

Abstract

The elevated temperature modulus and strength of aluminum, titanium, and hybrid aluminum/titanium metal matrix composites were investigated. Aluminum (6061-F) and titanium (Ti-6AI-4V) metal matrix composites reinforced with AVCO silicon carbide or boron fibers were vacuum hot pressed and their tensile properties evaluated to temperatures in excess of 300°C. Microstructure, fracture modes and mechanical properties were characterized to assess the effect of fibers and matrix on composite strength and modulus as a function of temperature. Finally, a comparison of specific strength and modulus is provided as a function of temperature. In general, the metal matrix composites exhibited low density (<2.8 g/cm3), high modulus (200 GPa), and strengths equivalent to 1250 MPa at 250–300°C. The effect of fiber orientation on axial stiffness was investigated using boron fiber reinforced aluminum (6061-F).