Characterization and machining performance of laser-textured chevron shaped tools coated with AlTiN and AlCrN coatings

Owing to increased demands of more efficient cutting tools for machining difficult to cut materials and environment friendly cutting operations, laser textured tools have become necessary. The characterization and machining studies with such laser textured tools coated with hard ceramic coatings are the prime motivation for this present work. The main aspect of the study is to evaluate two different PVD coated (AlTiN and AlCrN) laser textured tools. In the first stage, laser textured tools were prepared with novel chevron shaped textures on tool rake face using nanosecond pulse laser. This stage is followed by PVD coatings of AlTiN and AlCrN coatings by cathodic arc evaporation (CAE) technique. Coating characterization studies were conducted considering coating morphology, surface roughness, coating elemental analysis and phase analysis of coated and coated textured tools. The performance of the different tools thus manufactured was evaluated by carrying out suitable turning experiments on cylindrical Ti6Al4V work material under dry cutting environment. Machining results were evaluated in terms of cutting force, flank wear progress, rake surface analysis, and chip underside study. Further, static diffusion couple test (SDCT) has been conducted to understand diffusion wear mechanism in plain and textured tools. A new concept of derivative cutting or interfacial multipoint micro-cutting (IMP-μC) on chip underside surface due to texture patterns and a reduction of derivative cutting due to coatings on the textured tools have been proposed.