Cubic Boron Nitride/diamond Composite Structures for Tooling Applications

This proposal aims at the development of advanced coatings for tooling applications, based on materials with extreme properties, namely diamond and cubic boron nitride (cBN), which is the second hardest and second most thermally conductive material next to diamond. Using a new technique developed recently by the investigators, cBN/diamond (cBND) composite films will be synthesized on cutting inserts for extreme applications involving tooling for very hard materials including ferrous metals and alloys. Several approaches will be used to improve the stability and adhesion of cBND films to the cutting inserts. The effects of substrate pretreatment and deposition parameters of the deposited films will be investigated. The results will be correlated to the films properties, especially the mechanical properties, and the performance of the composite films in the tooling applications will be evaluated. The output data will finally be fed back to optimize the parameters for the deposition of adherent cBND films.