Strength of Diamond

Science  21 Oct 1994:
Vol. 266, Issue 5184, pp. 419-422
DOI: 10.1126/science.266.5184.419


The yield strength of diamond is measured under a pressure of 10 gigapascals at temperatures up to 1550°C by the analysis of x-ray peak shapes on diamond diffraction lines in a powdered sample as a function of pressure and temperature. At room temperature, the diamond crystals exhibit elastic behavior with increasing pressure. Significant ductile deformation is observed only at temperatures above 1000°C at this pressure. The differential yield strength of diamond decreases with temperature from 16 gigapascals at 1100°C to 4 gigapascals at 1550°C. Transmission electron microscopy observations on the recovered sample indicate that the dominant deformation mechanism under high pressure and temperature is crystal plasticity.