A Comprehensive Study of Al0.6Ti0.4N Coatings Deposited by Cathodic Arc and HiPIMS PVD Methods in Relation to Their Cutting Performance during the Machining of an Inconel 718 Alloy

Abstract

The structural, physical–chemical, and micromechanical characteristics of Al0.6Ti0.4N coatings deposited by different physical vapor deposition (PVD) methods, such as cathodic arc deposition (CAD), as well as advanced HiPIMS techniques were investigated in terms of their cutting performance during the machining of an Inconel 718 alloy. XRD studies had revealed that the HiPIMS coating featured lower residual stresses and more fine-grained structure. Electrochemical characterization with the potentiostat-impendence method shows that the HiPIMS coating has a significantly lower porosity than CAD. SEM and AFM studies of the surface morphology demonstrate that the HiPIMS coating has a smoother surface and an absence of droplet phases, in contrast with CAD. XRD, combined with FIB/TEM studies, shows a difference in the crystal structure of both coatings. The micromechanical characteristics of each coating, such as hardness, elastic modulus, fracture toughness, and adhesion to the substrate, were evaluated. The HiPIMS coating was found to possess a more beneficial combination of micromechanical properties compared to CAD. The beneficial characteristics of the HiPIMS coating alleviated the damage of the coated layer under operation. Combined with grain size refinement, this results in the improved adaptive performance of the HiPIMS coating through the formation of a greater amount of thermal barrier sapphire tribo-films on the friction surface. All of these characteristics contribute to the reduction of flank and crater wear intensity, as well as notching, leading to an improvement of the HiPIMS coating’s tool life.

Enhancement of Multi-Scale Self-Organization Processes during Inconel DA 718 Machining through the Optimization of TiAlCrSiN/TiAlCrN Bi-Nano-Multilayer Coating Characteristics

“…In contrast to the other coatings tested, the new nano-multilayer (C) coating is capable of generating beneficial tribo-films multiple times throughout the entire cutting process. This can be attributed to the enhanced adaptive response [45] of the coating C layer to the buildup edge formation during the machining of Inconel DA 718 [46]. Improved adaptability at elevated temperatures is a typical feature of high-entropy coatings [47].…”

Microstructure and Antimicrobial Properties of Zr-Cu-Ti Thin-Film Metallic Glass Deposited Using High-Power Impulse Magnetron Sputtering

“…High-power impulse magnetron sputtering (HiPIMS) is widely used to produce hard coatings, due to the fact that the ionization rate is equivalent to that of a cathodic arc [ 18 , 19 ]. This approach has proven highly effective in producing coatings with a smooth surface [ 20 , 21 ] with a density higher than that of DC magnetron sputtering (DCMS) [ 22 ].…”