Compressive behavior of Csf/AZ91D composites by liquid–solid extrusion directly following vacuum infiltration technique

10 vol. % short carbon fiber reinforced AZ91D composites (Csf/AZ91D) were fabricated by liquid–solid extrusion directly following vacuum infiltration (LSEVI) technique. Liquid–solid extrusion of the composite induced reasonably uniform distribution and oriented arrangement of the carbon fibers. Compressive behaviors of the composites were investigated in the temperature range from room temperature to 300 °C. The shapes of the compressive stress–strain curves at temperatures below and above 200 °C are very different, which can be attributed to the combined influence of matrix work hardening and strain softening induced by the rotation of the fibers. The ultimate compressive strength (UCS) and compressive yield strength (CYS) of the composites are enhanced by 86.5% and 123% than those of matrix alloy at room temperature, respectively. The composites are thermal stable up to 200 °C, where the CYS is approximately 2.8 times as high as that of the AZ91D matrix. However, both the UCS and CYS of the composites are slightly less than those of monolithic AZ91D at 300 °C. The plastic deformation of the Csf/AZ91D composites mainly localizes in a shear band along the diagonal axis, 45° to the loading axis at the center of samples. The main failure mechanism of the composite samples is shear fracture or plasticity instability induced by shear deformation, and the failure strain increases with the increasing test temperature.

► Csf/AZ91D composites were produced by infiltration/extrusion integrated technique. ► Compressive behaviors of the obtained composites were studied at RT-300 °C. ► A large strength improvement was evident for the composites at RT-200 °C. ► The main compressive failure mode was shear fracture or plasticity instability.