Executive Summary : | The principal aim of the project is to design a melt and gas nozzle combination for producing powders of high melting metals like steel with a narrow size distribution, based on the fluid dynamic analysis of the melt-gas interaction zone. The quest for making engineering and other components economically and with reduced production time has paved the way for the development of relatively new and rapidly evolving technologies. Powder metallurgy is one such manufacturing route where metal powders, which are mainly produced by the metal atomization process, are compacted followed by heat treatment to obtain near net shape structures. The metal atomization process is mainly classified on the basis of gas velocity, type of gas nozzle used and the mode of gas-metal interaction. Based on the position at which the gas and metal interact during atomization, it is classified as free-fall (FF), and close-coupled (CC) configurations. This project will involve using both experiments and simulations to arrive at a prototype close-coupled system to produce good quality powders, efficiently, from about 10 kg of metal in each run. The gas nozzle, and the melt delivery tube will be designed based on computational fluid-dynamics calculations and tested using non-intrusive experimental techniques. The atomization process will be visualized using an existing high-speed camera and light-emitting diode (LED) strobe arrangement, and the powder produced will be characterized using a particle analyzer. The effect of parameters that affect the efficiency of atomization, such as, the relative position of the MDT with respect to the gas nozzle, the gas flow rate, and the gas-to-metal ratio will be studied to arrive at an optimum configuration. The deliverables of the project include: a prototype system for producing powders of high melting metals by the gas-atomization process, and knowhow on the effect of various parameters on the size and yield of powders produced. |