International Journal of Current Engineering and Technology E-ISSN 2277 – 4106, P-ISSN 2347 – 5161 ©2016 INPRESSCO ® , All Rights Reserved Available at http://inpressco.com/category/ijcet Research Article 46| International Journal of Current Engineering and Technology, Vol.6, No.1 (Feb 2016) Investigation on formability of Aluminium 6061 alloy Sheet under various forming conditions through Erichsen Cupping Test machine Bhav Gautam †* , Vaibhav Chandra † , Praveen Kumar † , Narayan Agrawal † and Sunny Kumar † † Department of Tool Engineering, Delhi Institute of Tool Engineering, Okhla, New Delhi, India Accepted 30 Dec 2015, Available online 02 Jan 2016, Vol.6, No.1 (Feb 2016) Abstract In forming aluminium 6061alloy sheet, heat generated, due to friction between die and sheet, is greatly reduced by the application of lubricants. In this study, a comparison has been done between lubricant coated and uncoated (unlubricated) aluminium AA6061-T6 alloy sheet using Erichsen Cupping Test. For uncoated sheets, test was done under dry and heated conditions whereas for lubricant coated sheets, effectiveness of three lubricants (boric acid, graphite and Teflon or PTFE) was examined. The performance of lubricants was based on two parameters i.e.Draw Force and Draw Depth. The results of lubricant coated and uncoated AA606-T6 sheets were compared to determine the optimum performance of lubricants used. It was found that sheet under uncoated heated condition required minimum draw force whereas maximum was found in uncoated dry condition. The draw force for lubricant coated sheets was between dry uncoated and heated conditions. Also, the application of lubricants showed more draw depth when compared with uncoated conditions. This study concluded that the application of boric acid as lubricant onAA6061-T6 alloy sheets had optimum performance when compared with other lubricants. Keywords: Erichsen Cupping Test, Solid lubricants, Draw force, Draw depth, formability,AA6061-T6 alloy sheet. 1. Introduction 1 A wide range of consumer and industrial products, such as metal desks, appliances, beverage cans, car bodies, and kitchen utensils, are now being produced using sheet metal forming operations. Sheet metal forming, also called as press working, press forming or stamping, is amongst the most ancient and important metalworking process. Sheet metal parts offer the advantages of light weight and shape versatility, over those made by casting or forging. Unlike bulk deformation processes, sheet forming, involves work pieces with a high ratio of surface area to thickness. A sheet thicker than 6 mm is generally called plate. Formability is defined as the ability of the material (metals) to be deformed into desired shape, on applying mechanical force on it. Generally, forming of sheets metals is carried out by tensile force in the plane of the sheet, or else the application of external compressive force could lead to buckling, folding or wrinkling of the sheet. The success or failure of the formed sheet metal components depends on the material flow properties, ductility, die geometry, die materials, lubrication conditions and press speed. 1.1 Need for formability Tests The major reason for formability of sheet metals has been of great and continued interests is due to its *Corresponding author: Bhav Gautam technological as well as economic significance. Sheet metal formability is generally defined as the ability of a sheet to undergo the desired shape change without any failure such as necking, tearing, or splitting. In recent times, a lot of importance is given to the kind of lubricants used worldwide, in order to check the various health and environmental hazards caused by certain toxic lubricants. Moreover, lubricants are often flammable and thus possess great risk. It is also found that some very common lubricants contain active elements such as chlorine, sulphur, and phosphorous, which are potentially hazardous. 1.2 Factors influencing the formability Three factors have a major influence on formability: a) Properties of sheet metal, like yield point elongation, anisotropy, grain size, residual stresses, springback, wrinkling, coated sheet. b) Friction and lubrication at various interfaces in the operation c) Characteristics of the equipment, tools, and dies used 1.3 Various cupping tests used in sheet metal industries The following are the cupping tests used for measuring the formability of sheet metals: