Abstract
Reasonably inexpensive sources for SiC whiskers and/or particulates have spurred the development of SiC-reinforced AI-base alloys. The published information on the metallurgical science of AI-SiC composites is reviewed. It is found that the elastic stiffening benefits of the SiC whiskers are understood in terms of continuum mechanics models. The strengthening effects of SiC, including the influence of such microstructural details as whisker quality, aspect ratio, and loading fraction, are not as well as understood. The properties of the matrix itself appear to be very important. Analysis of strengthening in terms of continuum mechanics models indicates that strengthening can be a combination of whisker pull-out and matrix properties, There does not seem to be a conceptual framework for fracture properties within which the limited data on the fracture behaviour of AI-SiC composities can be understood. An analytical framework for the fracture toughness of AI-SiC composites that can form a basis for future work and for evaluation of fracture data in these composites is given. Another conclusion is that intrinsic (SiC whisker dependent) and extrinsic (processing and cleanliness dependent) factors require experimental and analytical separation.
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