Defects analysis of (AlBO)_w/Al composites

Aluminum borate whisker reinforced aluminum matrix composites ((AlBO)_w/Al) were fabricated by liquid infiltration extruding technique. Optical microscope (OM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS), scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to observe the fractograph and microstructure of the composites. The results indicated that the main defects of the composite are not the products of the interface reaction of the reinforcement and matrix, but rather the segregation and remelting of the aluminum borate whisker, the micropores in the composites and the compound (Al₂Cu) of copper and aluminum separating out from matrix alloys in the process. The Al₂Cu and micropores are the microcrack origins of main defects, lowering the mechanical properties of the composites.