Tensile properties and thermal expansion behaviors of continuous molybdenum fiber reinforced aluminum matrix composites

The tensile properties and thermal expansion behaviors of continuous molybdenum fiber reinforced aluminum matrix composites (Mof/Al) have been studied. The Mof/Al composites containing different volume percents of Mo fibers were processed by diffusion bonding. The strengths of unidirectional Mof/Al composites were close to the rule-of-mixtures. The strengths of 0°/90° dual-directional composites increased with fiber content, while those of 45°/135° composites remained relatively low. The coefficients of thermal expansion (CTEs) of the composites decreased as the fiber content increased, close to the values of Mo fibers. With increasing temperature, the CTEs of unidirectional composites increased, while those of dual-directional composites decreased due to large accumulated thermal stresses. The CTEs of 45°/135° composites were lower than those of 0°/90° composites because of contraction effect. At temperatures above 250 °C, the CTEs of the dual-directional composites gradually increased due to matrix yielding and interfacial decohesion.