THERMAL-EXPANSION ANISOTROPY IN HOT-PRESSED SIC-WHISKER-REINFORCED ALUMINA COMPOSITES

The measured linear thermal expansion coefficients alpha of hot-presse d SiC-whisker-reinforced aluminas decrease as the SiC whisker content is increased from 1 to 60 vol.%. However, owing to the preferred orien tation of the whiskers, the alpha value for each SiC whisker content i s greater in the direction parallel compared with the direction perpen dicular, to the hot-pressing axis. The observed behavior is generally consistent with that predicted by a model based on the effects of inte rnal thermal mechanical mismatch strains in composites with oriented r einforcements.