Evaluation of adhesion of diamond coating by thermal quench method

Adhesion of a diamond coating on metal was quantitatively evaluated by a thermal quench method combined with micro-Raman spectroscopy. It was found that the diamond Raman peak located at wave numbers higher than 1332 cm(-1) before the thermal quench, due to the presence of a compressive stress in the diamond film. After a quench from 413 to 273 K (ice water), the Raman peak shifted to similar to 1332 cm(-1), implying that the diamond film detached from the substrate and became free from biaxial stresses. The coating adhesion is considered to be comparable to the thermal stress induced by the quench. According to a mismatch of the thermal expansion between the film and the substrate, the thermal stress was calculated and the adhesion of a diamond film coated on copper with a titanium interlayer was estimated, being about 2.54 GPa. (C) 1998 American Institute of Physics.