Fracture of synthetic diamond
- Crystallume, 3506 Bassett Street, Santa Clara, California 95054 (United States)
- Center for Advanced Materials, Materials Sciences Division, Lawrence Berkeley Laboratory and Department of Materials Science and Mineral Engineering, University of California, Berkeley, California 94720 (United States)
The fracture behavior of synthetic diamond has been investigated using indentation methods and by the tensile testing of pre-notched fracture-mechanics type samples. Specifically, the fracture toughness of free-standing diamond plates, grown by chemically-vapor deposited (CVD) methods, was measured using Vickers indentations and by the use of disk-shaped compact-tension specimens; the latter method provides an evaluation of the through-thickness fracture properties, whereas the indentation method was performed on the nucleation surface of the sample. Measured fracture toughness ({ital K}{sub c}) values were found to be approximately 5--6 MPa{radical}m by both methods, indicating that the fracture resistance of CVD diamond does not vary appreciably with grain size (within the certainty of the testing procedures). Complications, however, arose with the fracture-mechanics testing regarding crack initiation from a relatively blunt notch; further work is needed to develop pre-cracking methods to permit more reliable fracture toughness testing of diamond. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
- Research Organization:
- Lawrence Berkeley National Laboratory
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 90471
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 5 Vol. 78; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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