ISSN: 2319-8753 International Journal of Innovative Research in Science, Engineering and Technology (An ISO 3297: 2007 Certified Organization) Vol. 2, Issue 12, December 2013 Copyright to IJIRSET www.ijirset.com 7675 Control and measurement of abrasive flow rate in an Abrasive Waterjet Machine S. R. Patel 1 , Dr. A. A. Shaikh 2 Associate Professor, Mechanical Engineering Department, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, India 1 Associate Professor, Mechanical Engineering Department, Sardar Vallabhbhai National Institute of Technology, Surat, Gujarat, India 2 Abstract: A state of the art in unconventional machining is the use of high pressure waterjet as cutting tool. Abrasive is mixed to such high pressure pure waterjet to attain abrasive waterjet to increase its cutting capability many times and can almost any material. Abrasive waterjet machining is a versatile process and widely being used for cutting profiles from various materials. The abrasive in the water jet would provide numerous cutting edges to increase its cutting potential many folds. Evidently the increased cutting capability would depend upon the amount and type of abrasive blended in to the abrasive waterjet. Therefore, the flow rate of the abrasive becomes very important machine parameter that could be adjusted to control the machining performance of the abrasive waterjet. To study the influence of the abrasive flow rate on machining performance experimentally, accurate control and measurement is called for. This paper presents an attempt for the calibration of abrasive flow control system mounted on an Abrasive Waterjet Machine intended to perform research oriented experiments. Keywords: Waterjet, Abrasive, Abrasive Waterjet, Abrasive flow rate (AFR), Calibration I. INTRODUCTION Abrasive waterjet machining is an unconventional machining process that uses erosive effect of high velocity water jet mixed with abrasive for profile cutting and being used successfully for milling & carving 3D contours as well. Other than cutting, pure waterjet and abrasive waterjet have been employed for paint removal, cleaning, surgery, peening, and numerous different applications. This is a versatile machining technology and the advantages over most other machining processes performing same operation are; (i) it can cut intricate profiles out of any material; from thin foils up to thick slabs with the accuracy and precision of the CNC positioning system, (ii) it leaves small kerf width, nearly equals jet diameter makes it possible to use tight nesting for optimal material usage, (iii) it does not require additional/special tooling, so saves on tool changing time and inventory, (iv) it can ensues almost burr free cutting and with appropriate setting of parameters, gives good surface finish that might not require secondary operation, (v) it has very low cutting forces in jet direction and lesser in other directions requires minimum clamping, (vi) inherently cool cutting, hence no heat affected zone (HAZ), very important for heat sensitive material, (vii) it tend to be ‘Environment friendly’ since water carry away the debris (and fumes in case of plastics) of cutting, (viii) it is superior process in terms of productivity due to faster rate of cutting minimal change over time etc. [1-11] The idea of machining with waterjet (WJ) is adopted from nature that has been showing phenomena of erosion of hardest of the rock by a stream of water. The rate of erosion is observed to be faster when the water stream is mixed with sand particles and that has lead to the development of abrasive waterjet (AWJ) technology. High velocity waterjet is created by passing high pressure water through a very small orifice while the abrasive is added to it in a so called mixing chamber to generate Abrasive Waterjet. These added cutting edges provided by abrasive particles increase the cutting capability of abrasive waterjet many times more than pure waterjet. This enhancement can be related to the abrasive flow rate along with abrasive types in terms of shape, size and hardness. Once the abrasive type is selected, the flow rate of the abrasive would become an important parameter that affects the machining performance in terms of cutting speed as well as kerf quality. Therefore to perform experimental work to study the relationship between abrasive flow rate and cutting performance as single factor or in combination with other affecting machine parameters, accurate measurement and control of abrasive flow would be very important. Hence it would require calibration of the abrasive supplying system in terms of control adjustment vs. abrasive mass flow rate. Since the machine being