Impact of process variables on surface roughness in negative incremental forming process

Abstract A pivotal development of the obsolescence of conventional methods of sheet forming has enhanced the need of augmenting an agile and novel method of fabricating the tailored components according to the requirements of customers and users. Moreover, businessmen are interested to promote their businesses by manufacturing the tailored and customized parts of intricated and complex geometries at a lower cost and with negligible waste. Single Point Incremental Forming (SPIF), also known as “negative incremental forming”, avoids the direct use of any kind of specific die-sets and produces the user-ready parts. The investigation of the surface quality of the formed specimen is important to study the suitability of this process for industrial applications. This paper explores the effects of the interactions of tool radius and forming angle on the surface roughness of parts formed by the SPIF process. A full factorial approach was taken into account as DOE. The average roughness was found to rise with the rise in forming an angle. On the other hand, the increase in tool diameter resulted in the decrease of Ra value of formed components because the increase in the tool diameter allows the decrease in the waviness on the surface of the specimen. It was observed that the Ra value of formed components was decreased by 83.87% when the experimental condition was changed from the combination of higher levels of wall angle (68°) and lower level of tool diameter (7.52 mm) to the combination of lower levels of wall angle (60°) and a higher level of tool diameter (19.50 mm).