Machining parameter optimization for production of nanocrystalline materials

Nanocrystalline materials are a new class of materials draws the attention of researchers in the field of materials science engineering because of enhanced mechanical properties such as high strength and high hardness. Several processes are available for the production of nanocrystalline materials. However, most of them are expensive and so the cost of production is high. This research focuses on the large strain plastic deformation imposed by the cutting tool during machining is utilized to produce nanocrystalline materials with low cost. High carbon steel was chosen for the production of nanocrystalline structure. Machining parameters such as Rake Angle, Depth of Cut, Feed, Heat Treatment Conditions and Cutting Velocity were considered for optimization. Coated tungsten carbide cutting tool was used for the study. Machined chips were collected and cleaned ultrasonically. These chips were then mounted, polished and etched for microstructure evaluation. Scanning electron microscope (SEM), X-ray Diffraction (XRD) and Vicker hardness tester were used for characterization of the machined chips. Taguchi L16 orthogonal array was adopted for optimizing the machining parameters so as to obtain minimum crystalline size and maximum micro hardness. Confirmation test were also conducted. Identified the optimum cutting conditions which yield the nanocrystalline structure using Taguchi method.