Enhanced Diamond Tools Made With CVD-coated TSP Diamonds Show Improved Thermal Stability And Performance

摘要

Diamonds are notoriously difficult to attach to a drilling or cutting tool body due to their poor wetting by molten metals. Above 400℃, in contact with catalysing metals (Fe, Ni, Co), diamonds lose their wear-resistance due to graphitisation; this further complicates tool production, adversely affects thermal stability and the performance of diamond tools. Innovative CVD (Chemical Vapour Deposition) Hardide™ coating can help overcome both these problems and facilitate the manufacture of diamond tools with enhanced performance. This tungsten/tungsten carbide composite coating completely covers polycrystalline TSP diamonds. The coating is strongly chemically bonded to diamond and has good wettability with brazing alloys, molten cobalt and other metals enabling stronger attachment of the coated diamonds to the tool’s surface. The pore-free coating provides an impermeable barrier against aggressive metal binders, protecting diamonds from graphitisation. Hardide-coated TSP diamonds are already used on the stabilisers of oil drilling tools; the coating improving the diamonds’ retention in extreme abrasive wear conditions.