Evaluation of tribological properties of AlMg4.5Mn0.7 in massive microforming using the barrel compression test

Tribology is one of the major issues in forming processes. It is influenced by many factors such as workpiece and tool material, lubrication, process parameters, geometric scale etc. Especially in microforming processes, friction plays an important role due to an increased surface to volume ratio and the domination of open over closed lubricant pockets [1-3]. A simple and sensitive method to quantify the friction factor under realistic conditions of massive forming is the barrel compression test [4]. The friction factor is calculated out of the friction-dependent barreling of cylinder samples while being compressed between two parallel tool surfaces. In these investigations, the barrel compression test was applied to determine the friction factor between cylindrically shaped samples made of the aluminium alloy AlMg4.5Mn0.7 (EN AW 5083) and polished surfaces made of the tool steel 1.3343. The specimen diameter was varied between 0,5 mm and 10 mm. The focus of investigations was the size-dependence of the friction factor under the variation of the parameters such as forming degree, lubrication conditions, and die velocity. In addition to the calculation of the friction factor, surfaces were evaluated by microscopy and roughness measurements.