Differences and similarities between the induced residual stresses after ball end milling and orthogonal cutting of Ti-6Al-4V

Machining often defines the final residual stress state of a workpiece, which influences the fatigue properties and thus its functional performance. In literature, fundamental residual stress investigations are often limited to planing or orthogonal cutting and the findings are rarely transferred to complex machining processes used in industry. This paper compares the residual stress state after machining Ti-6AI-4V using the complex ball end milling process with the fundamental orthogonal cutting and orthogonal planing processes. Principal directions, depth profiles of residual stresses and influencing machining and tool parameters are discussed in terms of differences and transferability. It is shown that results can only be transferred if the deformation morphology of the subsurface is considered, which is defined by the tool kinematics and shape of the workpiece. (C) 2015 Elsevier B.V. All rights reserved.