Friction-Spinning - Influence of Tool and Machine Parameters on the Surface Texture

Abstract

The incremental forming process of “friction-spinning” is suited to the manufacture of functionally graded workpieces made from tubes and sheets with the defined adjustment of material properties. The innovative feature of this new process is the use of process elements from both metal spinning and friction welding. As the workpieces are being processed, friction sub-processes are employed to achieve self-induced heat generation. Compared with conventional spinning processes, this in-process heat treatment permits the extension of existing forming limits and allows more complex geometries to be achieved, together with defined, favorable part properties. These properties, like strength, grain size or surface conditions, can be influenced by the set of specific temperature profiles that prevail during the manufacturing process in combination with the degree of deformation. The temperature profiles can be adjusted by selecting appropriate process and tool parameters in a defined manner. This paper presents the influence of the aforementioned parameters on the surface texture. The results presented start with the analysis of the surface texture development. Following this, the effects of the significant process parameters and tool geometries that give rise to the typical structure and hardness are explained.