MODELLING AND PARAMETRIC ANALYSIS IN PRODUCTION OF NANOSTRUCTURE STAINLESS STEEL POWDER USING MODIFIED TAGUCHI TECHNIQUE

In the world of materials science and technology, scientists pay close attention to Nano crystalline materials. Scientists have been drawn by the improved mechanical properties such as high strength and hardness of these materials. But the expensive equipment used in it and the low output makes the cost of nano crystal materials high. Attempts are being done to produce nano crystal materials through oblique machining and ball milling route. Oblique machining is done by the huge strain plastic deformation imposed by cutting tool. For this purpose, a stainless steel 318 L (SS) bar of 50 mm dia. and length 300 mm are taken. Machining parameters such as feed, depth of cut, speed, and rake angle vary with various cutting conditions. Modified Taguchi L-16 orthogonal array optimizes the machining parameters. The cutting tool used here is coated Tungsten carbide. Using an ultrasonic machine for microstructure analysis, machined chips were collected and cleaned. In addition, scanning electron microscope (SEM) and X-ray diffraction (XRD) are used to characterize the chips. The chips obtained by the optimised machining conditions are processed further with high energy ball mill and hence nano crystal powders are obtained. Here modified Taguchi method is used to optimize the ball mill parameters like milling speed, milling time and ball mill to Nano powder ratio. Thus obtained nano powder is then characterised by using transmission electron microscope, scanning electron microscope, and X-ray diffraction. The milled powders in the range of 15-60 nm will be obvious from the tests.