Abstract
High pressure sintered bodies of polycrystalline diamond or carbide ceramics are rendered more resistant to cracking by establishing dispersed, localized "stress centers" of submicron size particles of lonsdaleite, diamond, or other form of metastable, high density carbon which has the capability of transforming crystallographically to graphite in situ in the body. When an incipient crack in the body approaches entrapped metastable particles along its path, the crack promotes or permits transformation of the metastable particles to graphite particles, with concomitant increase in their size, thereby resisting further propagation of the crack.
Recommended Citation
P. D. Ownby, "Fracture Toughening of High Pressure Sintered Diamond and Carbide Ceramics," U.S. Patents, Nov 1990.
Department(s)
Materials Science and Engineering
Patent Application Number
US07/383,590
Patent Number
US4968647A
Document Type
Patent
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 1990 The Curators of the University of Missouri, All rights reserved.
Publication Date
01 Nov 1990
