Jaikishan Sambharia, Dr. Harlal S. Mali, Jasa Ram Rheological Investigation and Comparative Study on Synthesized Low Cost Consumables for Abrasive Flow Finishing Processes Jaikishan Sambharia, Dr. Harlal S. Mali, Jasa Ram Figure 1. Effect of Abrasive concentration on viscosity of media. Advance manufacturing and Mechatronics, Mechanical Engineering Department Malaviya National institute of Technology, Jaipur ABSTRACT RESULTS/DISCUSSIONS ANY OTHER RELEVANT DETAILS Though presently Abrasive Flow Finishing (AFF) process is mainly used in high end industries e.g. aerospace, automobile, tool & die and prosthetic etc. due to the high cost of the process but if alternative consumables are developed the process has the potential to bring revolution to finishing industry and in turn improving the efficiency of many fuel guzzling / power consuming systems. In this paper, different approaches have been attempted to synthesize an alternative to commercially available media. To ensure the desired properties i.e. visco-elasticity, non-adhesiveness, porosity, permeability, self-lubrication and higher heat transfer coefficient of the synthesized media; different alternative base and plasticizer are used during the synthesization process. Rheological investigation are carried out to observe the effects of media variables on these properties. Putty+ Gel +Abrasive Comparative study of alternative media base and additives Table 1.shows the results and comparison of each alternative media in terms of their desired properties in which higher the numeric value (value from 1-6) represents higher that property in synthesized alternative media. Property/Composition Visco elastic Non-Adhesiveness Porosity Self- lubrication Ability to remain fluid Percentage of Abrasive holding capacity Putty + Gel +Abrasive 3 4 Putty + Grease + Gel + Abrasive Natural Polymer + Grease + Gel + Clay + Abrasive 2 Putty + Clay + Gel +Abrasive 1 Putty + Clay + Grease + Gel + Abrasive Putty + Lube Oil + Abrasive Putty + Lube Oil+ Clay + Abrasive Putty + Lube Oil + Clay + Gel + Abrasive Effect of Abrasive concentration on viscosity of media. Effect of gel concentration on viscosity of media INTRODUCTION/MOTIVATION Current manufacturing industries, especially, in aviation, automobiles, tools, die and medical implant industries are facing challenges from these advanced emerging materials viz. ceramics, super alloys, composites and nanomaterials that are hard and difficult to finish, demanding high surface quality and accuracy. Low surface quality, finishing of complex and intricate shape workpieces, micro, nano level finish with tight tolerances are the major challenges that leads to development of advance finishing process called Abrasive Flow Finishing (AFF). AFF process was first patented by the Extrude Hone Corporation in 1970 in which two opposed cylinders extrude a semisolid abrasive media back and forth through passages formed by the workpiece and the tooling. An AFF system consists of three basic elements, that is, machine, tooling, and medium. The machine consists of a hydraulic system and media cylinder that are arranged on a supporting structure. The machine controls the amount of abrasion in the finishing section. Tooling is one of the key components of the AFF system. The main functions of tooling are to direct the flow of the AFF media and specifically control the region of abrasion. Abrasive media is most important element of the process, which is considered a proprietary item of machine manufacturers. Abrasive media is comprised of a base carrier (viscoelastic polymer), rheological additives and abrasive particles. The base carrier is a high-molecular-weight material, with dominant elastic properties and poor viscous properties. In this paper, on the bases of literature review possible contents of media were identified to synthesize an alternative to commercially available media. Based on comparison of properties of different additives and base, some alternatives media are synthesized. Rheological investigation are carried out for the alternative consumables which are superior in properties to observe the effects of media variables on these properties. CONCLUSIONS Effect of shear rate on viscosity Putty + Grease + Gel +Abrasive Based on rheological investigation of different alternative consumables following important conclusions have been withdrawn: 1. Based on literature review some AFM media ingredients were identified which have properties like viscoelastic, non-adhesive, good porosity, permeability, self-lubrication property while flowing in complex cavities and higher heat transfer coefficient. 2. After comparison with the properties achieved the best alternative AFM media identified were Putty + gel + abrasive, Putty + grease + gel + abrasive and Natural polymer + grease + gel + bentonite clay + abrasive. 3. Rheological study shows the effect of media variables (abrasive concentration, gel percentage and grease percentage) on viscosity of media by varying temperature and shear rate. 4. When grease is mixed before gel than the synthesized media shows higher viscosity, stiffness and elasticity. When gel is mixed in natural polymer base and abrasives before grease, it become softer and lesser viscous and elastic as compared to media synthesized earlier. 5. Results shows that viscosity increases with increased in abrasive concentration in media when gel concentration (20%) is kept constant. Also viscosity decreases with increased in percentage of gel in media when abrasive concentration (35%) is kept constant. 6. Rheological studies shows decrease in viscosity of media with increased in shear rate. This shows the shear thinning behavior of non-Newtonian types of fluid. 7. From rheological study, results shows that media viscosity decreases with decrease in concentration of Grease (Gr) and increase concentration of gel (G). Effect of Abrasive concentration on viscosity of media at 10, 15% Gel concentration Effect of abrasive concentration on viscosity of media at 5, 10% Grease concentration. MATERIALS/METHODOLOGY Based on literature review some AFM media ingredients were identified which have properties like viscoelastic, non-adhesive, good porosity, permeability, self-lubrication property while flowing in complex cavities and higher heat transfer coefficient. Based on literature some media base are silicon rubber (a-silicon, p-silicon), ester based polymer, commercial putty (silly putty); abrasives (Silicon carbide, aluminum oxide, cubic boron nitrides abrasives, diamond) and additives i.e. clay (bentonite, salacious earth powder), silicon oil, lube oil, crude oil, varnish oil. Different samples were synthesized by mixing variants of base and additives to get alternative AFM media which have greater permeability to absorb more quantity of abrasive and capability to hold the abrasives with higher bonding strength. During synthesization of alternative AFM media, abrasive mesh size of 320 is used and for gel preparation 2% by weight powder is used to make solution of gel. The rheological experiment were conducted on atmospheric condition (at 25 °C). The rheological experiment were carried out on Anton Paar make Rotational Rheometer with temperature range (-20 °C to 180 °C) and shear rate range (0.01 to 4000 sec.-1). During rheological experiment, shear rate was in range of 1-100 sec-1. After synthesization, rheological study were carried out to study the effect of media variables (abrasive concentration, gel percentage and grease percentage) on viscosity of media by varying temperature and shear rate. REFERENCES Effect of shear rate on viscosity of media. Effect of temperature (25-95°C) on viscosity for two alternative media (putty + gel and putty + grease + gel). M. R. William, "Method of honing by extruding". USA Patent 3521412, 21 08 1970 L.J.Rhoades, "Abrasive flow machining : A case study," J. of Mat. Processing Tech., 1991 vol. 28, pp. 107-116. L.J.Rhoades, " Abrasive flow machining," Manuf. Engg.,1988; pp. 75-78. V.K.Jain, “Micromanufacturing Processes”, USA : Taylor and Francis Group T.R.Loveless et al., "A study of the effects of abrasive flow finishing on various machined surfaces," J.Mat. Processing Tech, 1994; vol. 47, pp. 133-151. J. Sambharia et al., "Characterization and Performance Evaluation of Developed Alternative Polymer Abrasive Gels for Abrasive Flow Finishing Process," Int. J. of Precision Tech., 2015. ; no. In Press. H.S.Mali et al., " Current status and application of abrasive flow finishing processes: a review," Proc. of the Inst. of Mech. Engg., Part B: J/ of Engg. Manuf., 2009; vol. 223, pp. 809-820. H. S. Mali et al., "DEVELOPING ALTERNATIVE POLYMER ABRASIVE GELS FOR ABRASIVE FLOW FINISHING PROCESS," in AIMTDR2014, IIT Guwahati, 2014. I. Inasaki et al., Abrasive machining in future," Annals of the CIRP, 1993; vol. 42, no. 2, pp. 723-732. L. J. Rhoades, "Method of finishing machining the surface of irregularly shaped fluid passages". 1990; Patent 4,936,057. L. J. Rhoades, "Process and apparatus of abrading by extrusion"., 1990; USA Patent 4,996,796. Natural polymer + Grease+ Gel + Clay + Abrasive Effect of gel and grease concentration on viscosity for different abrasive concentration alternative media Effect of gel and grease concentration on viscosity of alternative media. ACKNOWLEDGEMENT We acknowledge Department of Science and Technology (DST), New Delhi, India, for their financial support for project no.SR/FTP/ETA-0078/2011 Dated 17/09/2012. Effect of shear rate (1-100 sec-1) on viscosity of alternative media.