Studying the Machining Performance of DSS Steel Using Single and Multilayered TiAlSiN Coated Tools Deposited by HiPIMS

The naval industry and oil and gas exploration are areas of great demand for the use of materials, since some applications require high resistance to corrosion, with duplex stainless steel being the most used (DSS). However, DSS is known to be difficult to machine when compared to other materials. Thus, it becomes necessary to make coatings, on DSS tools, to overcome this difficulty, taking advantage of its properties. In the present work, two TiAlSiN coatings obtained with two different structures, single-layer, and multilayer, were studied. These coatings were obtained by high power impulse magnetron sputtering (HiPIMS). In the deposition process, targets with different atomic contents of titanium (Ti), aluminum (Al), silicon (Si), and nitrogen (N) were used. In the first coating process, four TiAlSi targets (38/57/5 at.%) were used, and in the second, two TiAl targets (30/70 at.%) plus two TiSi targets (90/10 at.%). The coatings were characterized, and differences in morphology and mechanical properties of coated tools were validated. Machining tests were carried out with constant values for axial and radial depth of cut and cutting speed for different length and feed. After the tests, it was verified that the tools coated with multilayer TiAlSiN exhibited better performance in machined surface quality, sustained flank wear, and general sustained wear. Also, the multilayer structure promotes greater hardness and adhesive strength, thus improving the wear resistance of the coating. The wear mechanisms were more intense in single-layer coated tools, namely, abrasive wear and material adhesion.