DETERMINATION OF FRACTURE-TOUGHNESS FOR WHISKER-REINFORCED ALUMINUM-ALLOY MATRIX COMPOSITE USING CHEVRON-NOTCHED SPECIMEN

The objectives of this paper are to develop and standardize the plane-strain fracture toughness K(Ic) testing of whisker- and short-fiber-reinforced metal matrix composites. Fracture toughness tests using chevron-notched bend-type specimen were conducted on silicon carbide whisker-reinforced high-strength aluminium alloy matrix composite. Some problems in determining a valid K(Ic) were discussed on the basis of linear-elastic fracture mechanics and fractography. It is reconfirmed that the chevron-notched (CN) method is useful for whisker-reinforced aluminium alloy matrix composite to evaluate K(Ic) value. The effects of specimen orientation and loading type on K(Ic) were investigated, and a statistical analysis of the K(Ic) distribution was also performed.