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The mechanism of incremental sheet metal forming is based on plastic and localized deformation of sheet metal. The sheet metal is formed using a hemispherical-head tool in accordance with the path programmed into the computer numerical control milling machine controller. Experimental and numerical analyses have been performed previously on the application of ultrasonic vibration to various metal forming processes. However, thus far, the effects of ultrasonic vibration on incremental sheet metal forming have not been investigated. This article presents the process of design, analysis, manufacture and testing of a vibrating forming tool for the development of ultrasonic vibration–assisted incremental sheet metal forming. The results obtained from modal analysis and natural frequency measurement of the vibrating tool confirmed the emergence of a longitudinal vibration mode and resonance phenomenon in the forming tool. Then, the effect of ultrasonic vibration on incremental sheet metal forming was studied. The obtained experimental results from the straight groove test on Al 1050-O sheet metals showed that ultrasonic vibration led to decrease in the following parameters as compared with conventional incremental sheet metal forming: applied force on forming tool axis, spring-back and surface roughness of formed sample.

Austenitic stainless steels are hard materials to machine, due to their high strength, high ductility and low thermal conductivity. The last characteristic results in heat concentration at the tool cutting edge. This paper aims to optimize turning parameters of AISI 304 stainless steel. Turning tests have been performed in three different feed rates (0.2, 0.3, 0.4 mm/rev) at the cutting speeds of 100, 125, 150, 175 and 200 m/min with and without cutting fluid. A design of experiments (DOE) and an analysis of variance (ANOVA) have been made to determine the effects of each parameter on the tool wear and the surface roughness. It is being inferred that cutting speed has the main influence on the flank wear and as it increases to 175 m/min, the flank wear decreases. The feed rate has the most important influence on the surface roughness and as it decreases, the surface roughness also decreases. Also, the application of cutting fluid results in longer tool life and better surface finish.