Gas/solid interactions in the evolution of graded microstructures in hardmetals

摘要

Turning now to functionally graded hardmetals, we come to the latest chapter in life: fruitful collaboration between sponsor Kennametal Widia and TU Vienna. Interested readers will find it rewarding to read the data-rich original paper. Gas/solid interactions are in no sense a side issue in the formation of graded microstructures. They are the modus operandi of the process, generally involving highly complex hardmetal alloys. Those examined in this investigation-simplified in Table 3-were of the general type WC + (Ti,W)(C,N) + Co, with the addition of some TaC, NbC and carbon black. The object of adding carbon was to maintain near-stoichiometry whilst outgassing the adsorbed or combined oxygen as CO. The ultimate object of the research was to produce high-grade performance-enhancing coatings during a modified sintering schedule, eliminating the costly separate coating operation of conventional manufacture.