FRACTURE STRENGTH OF FREESTANDING CHEMICALLY VAPOR-DEPOSITED DIAMOND FILMS

The fracture strength of free-standing chemically vapor-deposited diamond films was assessed by four-point bending. A two-parameter Weibull analysis was performed on 130 μm thick films resulting in a Weibull modulus of 4.3 and a statistical scaling stress of 626 MPa. The residual stress in films was measured from the free-standing film curvature to be 384±10 MPa. The fracture surface chemistry was examined using scanning Auger spectroscopy. The fracture did not occur preferentially along grain boundaries.© 1995 American Institute of Physics.