BASIC RESEARCH IN NONOXIDE CERAMICS.
MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF METALLURGY AND MATERIALS SCIENCE
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Work on non-oxide ceramics was begun to develop basic understanding of the properties of this class of materials. Preprints and reprints of published work which was supported by this contract are appended. As written, they generally do not reflect the overall intent of the program. The yield stresses and hardness values for ZnTe, HgTe, and CdTe single crystals were correlated with total bond energy and the percent ionic bonding. The high temperature creep behavior of polycrystalline SiC was found to be governed by diffusion at grain boundaries and was attributed to control by diffusion of carbon. Dislocation dynamics were studied in CaF2 as a typical ionic compound but with a different structure fluorite than those which have been commonly studied rock salt. As a related part of the program, the diffusion coefficients for carbon in SiC was determined as a function of temperature in both p-type and n-type materials. In the course of attempting to prepare TiC and subsequently TiN for electrical property measurements, it was learned that chemical vapor deposition of TiN was similar in behavior to metals as well as oxide ceramics. Thus, there is no distinction noted for the non-ionic character of bonding for this process.
- Ceramics, Refractories and Glass
- Solid State Physics