Abstract
The effect of grain growth of hot-pressed SiCs on the hardness of its grain size was investigated. Two hot-pressed SiCs were heat treated in argon at 2250 °C, 2500 °C, and greater than 2550 °C. Massive grain growth and an equiaxed-to-acicular grain structure change resulted in both SiCs at all three temperatures. It was found that the minor amount of oxygen in both silicon carbides was gone after 2250 °C and 2500 °C exposures and a silicide having iron or aluminum or both remained. The coarse-grained SiC lost little density to 2500 °C, whereas porosity started to form in the fine-grained SiC at 2250 °C. It was also found that Knoop hardness decreased by 25 and 15% in the fine- and coarse-grained SiC, respectively, after they had been subjected to 2250 °C or 2500 °C exposure, while it decreased by 50% and 40%, after they had been subjected to a temperature in excess of 2250 °C.
Original language | English |
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Pages (from-to) | 4996-5000 |
Number of pages | 5 |
Journal | Journal of Materials Science |
Volume | 41 |
Issue number | 15 |
DOIs | |
State | Published - Aug 2006 |
Funding
Research sponsored by WFO sponsor US Army Tank-Automotive Research, Development and Engineering Center under contract DE-AC05-00OR22725 with UT-Battelle, LLC.