Dry Rotary Swaging - Tube Forming

Rotary swaging is an incremental cold forming process for tubes and rods. The established processes use lubricants based on mineral oil. The functions of the lubricant are the reduction of friction, wear and tool load, furthermore it cools the tools and flushes the working zone. But the use of lubricant increases the cost due to additional process steps and lubricant is diverted with the work piece during the process. Thus from economic and ecological points of view it is worthwhile to eliminate the use of lubricant. Therefore it is necessary to realize the functions of the lubricant in another way. For example by means of coating and micro-structuring of the tools the friction and wear can be influenced. In this study dry rotary swaging is tested with conventional tools and machine settings. The analysis of the recorded process parameters and the formed geometry of the workpiece reveal the potential of dry rotary swaging, but also the difficulties that arise. Dry rotary swaging needs a modification of the process and system parameters as well as an adjustment of the tools.