Investigation of Surface Roughness in Incremental Sheet Forming of AA 2014-T6 using Taguchi's Method

Abstract

Aluminium alloy "AA 2014-T6" has widespread applications in aerospace industry and also used for making military weapons. This paper proposes incremental sheet forming as newer and cost effective approach over the conventional die forming for making AA 2014-T6 components in lesser time. The quantitative effects of three levels of seven input parameters namely-type of tool path (profile and spiral), sheet thickness (1.2 mm, 2 mm and 2.3 mm), spindle speed (0 rpm, 100 rpm and 200 rpm), tool diameter (16 mm, 18 mm and 20 mm), step size (0.3 mm, 0.5 mm and 0.7 mm), feed rate (1500 mm/min, 2000 mm/min and 3000 mm/min) and type of lubrication (coolant, oil and grease) are analysed over the "surface roughness". Further, Taguchi technique has been utilized for designing the experimentation, mathematical analysis and finding the trends of variation in output response with change in individual factor. Sheet thickness and spindle speed emerged as the most influencing parameters in determining the final quality of fabricated parts. Zero spindle speed (free tool rotation) turned out most critical because at this level wear particles are stuck between sheet and tool, which degraded the surface due to unwanted abrasion.