Fracture-mechanical simulation is constructed based on the information of the crack propagation mechanisms through discontinuously-reinforced MMCs that have been clarified by the in-situ fracture toughness tests. Shielding and anti-shielding effects caused by both microcracks and reinforcements, effect of crack deflection, and growing crack singularity are evaluated to calculate local crack-tip driving forces using adequate microcrack initiation criteria and mixed-mode crack propagation criterion. Consequently actual crack growth mechanisms are well simulated by the computation. Parametric studies are carried out to calculate effects of microstructures on crack initiation and growth characteristics in the SiC whisker-reinforced 6061 Al alloy composites. Based on the results of the simulation, the MMC with improved microstructures has been proposed. It has been actually fabricated by high pressure infiltration casting, and it is confirmed that the crack growth resistance of the MMC is significantly improved by controlling the microstructures without spoiling the other mechanical properties.
|ジャーナル||Materials Science Forum|
|出版ステータス||出版済み - 12 1 1997|
All Science Journal Classification (ASJC) codes