Microstructure and thermal properties of copper matrix composites reinforced with titanium‐coated graphite fibers

Abstract

Abstract Milled form of mesophase pitch‐based graphite fibers were coated with a titanium layer using chemical vapor deposition technique and Ti‐coated graphite fiber/Cu composites were fabricated by hot‐pressing sintering. The composites were characterized with X‐ray diffraction, scanning/transmission electron microscopies, and by measuring thermal properties, including thermal conductivity and coefficient of thermal expansion (CTE). The results show that the milled fibers are preferentially oriented in a plane perpendicular to the pressing direction, leading to anisotropic thermal properties of the composites. The Ti coating reacted with graphite fiber and formed a continuous and uniform TiC layer. This carbide layer establishes a good metallurgical interfacial bonding in the composites, which can improve the thermal properties effectively. When the fiber content ranges from 35 vol% to 50 vol%, the in‐plane thermal conductivities of the composites increase from 383 to 407 W·(m·K) −1 , and the in‐plane CTEs decrease from 9.5 × 10 −6 to 6.3 × 10 −6 K −1 .