SOME INVESTIGATIONS ON ABRASIVE JET MACHINING

Abstract

Over the years, much has transpired in the design, engineering, manufacturing and applications of products to serve the needs of industry. With newer materials evolving, the primary challenge is the accelerated pace of matching advanced materials to precision industrial application technologies. The demand for components of complex shapes made of expensive, microtolerenced, super alloy and. advanced composite piece parts calls for critical, uniform quality repetitive precision material removal and finishing methods, along with closely controlled manufacturing techniques using NC, CNC and robotic devices in, eliminating or minimizing the burr formation. Thus, to the more than a century old traditional material removal concept involving plastic deformation and formation of chips, addition of the nontraditional machining concept has taken place. In this nontraditional field, abrasives have found a significant role, apart from the existing role in operations like grinding, honing, lapping, superfinishing etc. the manufactures have found abrasives to be effectives in low material removal operations, especially in deburring. In the nontraditional techniques, one method, which is highly flexible, cheap and found useful on ductile, hard and brittle materials alike is 'Abrasive Jet Machining. Converging to this technique, in this reped analysis of the abrasive et for this process is done. Due to the large number of parameters involved, difficulties in listing these variables and the interdisciplinary nature of the problem-requiring the knowledge of fluid mechanics, solid mechanics, material science and Stochastic Theories — a 111 complete analysis of the abrasive 'et machinin process is an extremely complex task. So, by considering this as a two phase flow problem, as gas and abrasives in the form of a homogeneous mixture pass through a nozzle and enter the free jet region before impacting and incorporating the stochastic theories in material removal, which is by the erosive action The major problem in abrasive jet machining is low material removal rate. The present work is associated with the application of Simulated Annealing Algorithm in order to maximize the material removal rate. For maximizing material removal rate two models given by Pandey and Sarkar[13] and Murty, Roy and Mishra [6] have been modified for calculation of parameters involved in the problem.lhe parameters or the material removal rate are velocity of abrasives, density of abrasives and stress induced on the work surface. The number of sequences to be perturbed in order to get the optimum results is approx 150x25x151, which equals to 266250. The search for each sequences leads to very-very large computational times. Hence for -this problem heuristic is required. With the help of Simulated Annealing Algorithm and computer programme for this Algorithm the maximurr material removal rate has been achieved. The purpose of this work is to explore the number of sequence pertaining tc these variables, in order to get optimal results.