Hot Forging to Produce Pore Free Near Net Shape Ceramic Composites

摘要

Researchers have demonstrated that it is possible to hot forge ceramic composites without damaging the whisker reinforcement and to reduce flaw size and population. Hot forging was investigated for the systems A1203, A1203/ZrO2, mullite, AlN, and SiC with reinforcements of SiCw and TiB2. The system Al203/SiCw was demonstrated to be forgeable at 1400 C which is 500 C lower than hot pressing temperatures. At high strain rates of greater than 0.1/sec, the density achieved was 99.7 percent with strength values comparable to hot pressing. The hot forging of ceramic-whisker composites offers the opportunity to produce low cost components and, because the process reduces the size and population of flaws, it can result in better mechanical properties with greater reliability.