Effect of whisker breakage on the forgeability and the tensile properties of the forged 2024Al/Al₁₈B₄O₃₃w composite

The effect of the whisker breakage on the forgeability of 2024Al/Al₁₈B₄O₃₃w composite is investigated. The 2024Al/Al₁₈B₄O₃₃w composite is forged according to the forgeability at the different temperatures. The tensile properties of the as-cast and forged composites are also studied. The results shows that the rotation and breakage of the whiskers and the microcracks contribute to the strain softening during compression. The whiskers with the orientation angle of about 45° to the applied axial stress are serious broken resulting in the lower average aspect ratio of the whiskers. Due to the lower flow ability of the matrix at the lower temperature than 400 °C, the microcracks between the broken whiskers connecting with others result in the major surface crack oriented to approximately 45° with respect to the compression direction. The composite forged at the temperature of 450 °C and at the strain rate of 0.1 s^{− 1} shows the no major surface cracks and the increase in the elongation, yield strength and tensile strength.