Elastic Properties of Advanced Superhard Thin Films by Surface Brillouin Scattering: Effects of Structure and P-T Environments

摘要

Recent theoretical predictions of the new superhard materials and production of the new superhard films such as cubic boron nitride (cBN), carbon nitride Beta-C3N4, B4C and chemical vapor deposited (CVD) diamond films have surged considerable interest in mechanical properties of thin hard and superhard films. Their hardness and abrasive qualities, highly valued in applied technology and defense industry, are controlled by their large elastic moduli. Elastic properties of the superhard films need to be determined experimentally because they strongly depend on the synthesis conditions, and they cannot be derived from theoretical considerations and modeling alone. The goals of this project were to determine the elastic properties and microstructure of the new superhard thin (30-500 nm) coatings, such as those based on the B-C-N triangle, by surface Brillouin spectroscopy (SBS), in conjunction with atomic force microscopy, as a function of composition, structure and P-T environments. We focused our research work on thin films that had best mechanical properties. Results of the research conducted have so far resulted in 17 publications.