Preparation of high fracture performance SiCp-6061Al/6061Al composite

To overcome the disadvantages of low toughness and low fracture energy of conventional particle reinforced metal matrix composites, a SiCp-6061Al/6061Al composite which has an architecture similar to concrete was designed and successfully fabricated by vacuum pressure infiltration method followed by hot extrusion at a ratio of 60:1. Compared with a conventional SiCp/6061Al in the case of same particle size and volume fraction the designed composite has a much higher fracture toughness and its strengthening effect is kept. It is remarkable that the fracture toughness of the designed composite is close to the level of an unreinforced 6000 series aluminum alloy. In addition, the designed composite has a very large fracture energy and its fracture process occurs in distinct stages. This can protect the designed composite from catastrophic failure on the maximum load. The fracture procedure and toughening mechanisms of the designed composite are discussed in detail. (C) 2000 Elsevier Science S.A. All rights reserved.