Preparation and Mechanical Properties of Whisker Reinforced Aluminum Composites

Abstract

The present paper deals with the preparation mechanical properties of three kinds of whisker reinforced aluminum matrix composites (Si₃N₄/Al, SiC/Al and K₂O·6TiO₂/Al). The squeeze casting method was employed for the preparation, and the bending and tensile strengths, the elastic modulus and the identation hardness of the composites were investigated. The results obtained are summarized as follows:
(1) The composites were producible within the range of 10 to 45% volume fraction of whisker.
(2) The bending and tensile strengths of the composites increased with an increase in the volume fraction of whisker, and the maximum bending strength was 860MPa at the volume fraction of 45% SiC whisker and the maximum tensile strength was 435MPa at the volume fraction of 43% SiC whisker.
(3) The elastic modulus of the composites increased with an increase in the volume fraction of whisker, and agreed appoximately with the prediction based on the rule of mixture.
(4) The indentation hardness of the composites increased with an increase in the volume fraction of whisker.
(5) The Si₃N₄ and SiC whisker reinforced aluminum matrix composites fractured, accompanying the failure of whisker. On the other hand, the K₂O·6TiO₂ whisker reinforced aluminum matrix composites fractured by separating at the whisker-matrix interface.