Thermal stability of a cathodic arc evaporated Cr0.74Ta0.26N coating

CrTaN coatings have recently received increasing industrial interest due to their combination of high hardness, promising fracture toughness and excellent oxidation resistance. However, up now no thorough investigation on the thermal stability this coating system is available. Thus, within work, evolution microstructure phase composition an arc evaporated were illuminated in inert atmosphere 1400°C. The crystallizes fcc-Cr0.74Ta0.26N solid solution with a preferred <311> orientation. Alternating Cr-enriched Ta-enriched layers are identified cross-section as-deposited coating, which arise from three-fold rotation during deposition. In-situ energy X-ray diffraction showed that powdered stable ∼1250°C, where fcc-CrxTa1-xN starts transform into t-Cr1.2Ta0.8N. Upon further temperature values exceeding 1300°C, h-Cr2N h-Ta5N4 start form. Vacuum annealing sapphire substrate at 1000°C results homogenization synthesis-related compositional fluctuations. While still maintaining solution, texture change <100> orientation observed after 1270°C. An treatment 1300°C formation t-Cr1.2Ta0.8N addition fcc-Cr1-xTaxN.