Friction-Spinning-An Innovative Incremental Forming Process for the Manufacture of Functional Graded Parts

摘要

Friction spinning is an innovative incremental forming process for the manufacture of tailor-made components with defined functionally graded properties. The process is characterized by the use of friction sub-processes for self-induced heat generation that can be employed for the defined thermo-mechanical treatment. Due to this in-process heat treatment, it is possible to extend the forming limits and achieve more complex geometries as well as favorable part properties. One very interesting application for friction spinning is the sealing of tube ends. There are a lot of conceivable application fields, including the substitution of soldering or welding operations in chemical engineering. Another interesting field is the use of this incremental forming process for industrial or automotive applications such as the manufacture of very slim cylindrical cups. An advantage of this method is the feasibility of defined control of the thickness distribution in the bottom and side wall area. This is supported by a new tool system with a pivoting forming tool. The pivot movement is controlled by a process control system. This system makes it possible to achieve different contact conditions between the tool and the workpiece during the process so as to attain a defined influence on the material flow and hence to enhance the attainable bottom wall thickness compared with previous fixed-angle tools. This tool concept thus offers an opportunity to improve the properties of the components as well as to manufacture new and complex geometries, such as hollow, fully closed roll type parts.