Stress analysis of the multi-layer stagger-split die for synthesizing gem quality large single crystal diamond

To obtain large sample volume and prolong service life, a novel high pressure die for synthesizing diamond was investigated using the finite element method. This device was the multi-layer stagger-split type die with prism type cavity which the cylinder and two layers supporting rings were divided into several parts. In this paper, we studied the stress features of this type pressure die, at the same time the results were compared with those of traditional belt type die. Numerical simulation results showed that the stress and stress distribution of the multilayer stagger-split type die were reasonable and the materials were utilized effectively. Experiment results indicated that the multi-layer stagger-split type die with prism type cavity was able to bear the greatest pressure, furthermore the split type die has strong pressure bearing capacity and replaceable performance.