ON THE MECHANICAL BEHAVIOURS OF SiC WHISKER REINFORCED Al COMPOSITES BY POWDER METALLURGICAL PROCESS

Studies were undertaken to evaluate the tensile behaviour of SiC-reinforced Al composite made by powder metallurgical process, where Al 2124 and X7091 were used as matrix alloys. Although the measured tensile strength did not reach to the predicted value, it was higher than that of the wrought Al alloys and increased with increasing volumic fraction of SiC whisker. By modifying Fukuda's probabilistic theory of short fiber composite strength, it turned out that the composite strength is dependent mainly upon critical zone width, maximum whisker alignment angle and critical fiber length. Composite failure was attributed to matrix fracture with fine dimples and patially whisker pull-out due to whisker/matrix debonding