726|Int. J. of Multidisciplinary and Current research, Vol.3 (July/Aug 2015) International Journal of Multidisciplinary and Current Research Research Article ISSN: 2321-3124 Available at: http://ijmcr.com Effect of Process Variables in improvement of Surface Roughness during Finishing of Al-6061 Alloy using Abrasive Flow Machining Mejar Singh † and Sushil Mittal ‡ † Research Scholar, ‡ Assistant Prof, Department of Mechanical Engineering, HCTM Kaithal, Haryana, India Accepted 15 July 2015, Available online 20 July 2015, Vol.3 (July/Aug 2015 issue) Abstract Abrasive flow machining is unconventional machining process which is used to remove material and improve surface roughness. Abrasive flow machining (AFM) is very efficient and suitable for finishing of complex inner surface and difficult to reach surface. In the present study the effect of different input parameters in improving surface roughness has been investigated by using Taguchi method. An experimental study was carried out on Aluminium-6061 work piece. The abrasive size, properties of carrier, no of cycles and abrasive concentration are important parameters that affect the performance of AFM. The objective is to study the effect of process variables in improving surface roughness. Keywords: Abrasives, Machining, Finishing, Surface roughness, Taguchi method 1. Introduction Abrasive flow machining is unconventional machining process. In this process machining of work piece is done by passing pressurized abrasive with carrier to the surface for attaining good surface finish. Basically there are three types of AFM processes. One way, Two ways and Orbital AFM. In Two ways AFM process there are two cylinder stocks, one from the lower cylinder pumping an abrasive laden medium throughout and one from the upper cylinder makes up one process [1]. For the finishing of the components which have complex unsymmetrical shape/profile, holes and undercut, a need is being felt to expand finishing operations which can produce parts with superior quality performance and higher productivity. The abrasive with carrier flows under pressure inside the work piece. The properties of carrier in AFM are very important. They should be viscoelastic and non-sticky in nature. The polymer abrasive medium which is used in this process possesses easy flow ability, better self- deformability and fine abrading capability. Generally carrier belongs to silicon polymer. This is very viscous fluid in any blind recess [2]. Commonly used abrasive grains are silicon carbide, aluminium oxide, boron carbide and diamond. Fixture design is important feature that affects the output responses. The type of abrasion and place where to abrade depends upon type of machine and fixture. 2. Literature Survey M. Ravi Sankar et al. [1] Abrasive Flow Machining was developed in 1960s as a method to deburr, polish, and radius difficult to reach surfaces like intricate geometries and edges by flowing an abrasive laden viscoelastic polymer over them. It uses two vertically opposed hydraulic cylinders, which extrude medium back and forth through passage formed by the work piece and tooling. Abrasion occurs wherever the medium passes through the highly restrictive passage. The key components of AFM process are the machine, tooling and abrasive medium. Process input parameters such as extrusion pressure, number of cycles, grit composition and type, tooling and fixture designs have impact on AFM output responses (such as surface finish and material removal). AFM is capable to produce surface finish (Ra) as good as 0.05 μm, deburr holes as small as 0.2 mm and radius edges from 0.025 mm to 1.5mm. AFM has wide range of applications in industries such as aerospace, medical, electronics, automotive, precision dies and moulds as a part of their manufacturing activities. For better surface integrity, texture and its performance, continuous developments are taking place for modifying the existing AFM process technology and AFM machine configuration. To overcome some of the draw backs such as low finishing rate and inability to correct the form geometry, researchers have proposed various versions of AFM machines abbreviated as M-AFM, DBGAFF, CFAAFM, spiral polishing and R-AFF. T.R. Loveless et al. [3] presented the results of an investigation of the effects of AFM on surfaces produced by turning, milling, grinding, and wire electrical-discharge machining. The machining characteristics studied included material removal and surface finish