Investigation of surface parameters using green coolant in drilling process

Abstract

Computer Numerical Control (CNC) is specialized and versatile form of soft Automation in which the functions and motions of a machine tool are controlled by means of a prepared program containing coded alphanumeric data. CNC can control the motions of the work-piece or tool, the input parameters such as feed, depth of cut, speed, and the functions such as turning spindle on/off, turning coolant on/off. CNC drilling machines are versatile and flexibly automatic drilling machines having box-column type rigid structure the work table movements and spindle are programmed and accomplished by CNC. Its programming and operation is simple and that is why it is increasingly popular. In addition, the CNC drilling machine can have built-in software that will calculate precise position of holes; these positions are important in making matrix, PCD patterns, line and skip drilling. This drilling machine can work at incredible speeds. Vortex tube is a non-conventional cooling device which will produce cold air and hot air from the source of compressed air without affecting the environment. When a high pressure compressed air is tangentially injected through the inlet nozzle. Swirl generators at the inlet plane create the vortex motion inside the tube. As the vortex moves along the tube, a temperature separation is formed. Hot air moves along the tube periphery, and cold air is in motion in the inner core. The hot air is then allowed to exit through the cone valve at the far end of the tube, while the cold air outlet is next to the inlet plane. This resulting radial temperature separation inside the vortex tube is also called the Ranque-Hilsch effect, named after its pioneers. 11 Department of Mechanical and Chemical Engineering, IUT. The author of this research endeavor, with the guidance of his supervisor and help from colleagues, has developed a unique mechanism to use vortex generated hot and cold air as coolant in drilling process instead of liquid coolant which is usually being used in daily work in drilling process. As coolant produced from vortex tube is totally environmentally friendly used in such a way that it doesn‟t disturb our environment and expresses less harm to human beings, animals and plants health. Holes of different diameters were drilled using green coolant instead of liquid coolant. Obtained results were then compared with the same process done with liquid coolant in terms of surface roughness, surface hardness.