Friction stir back extrusion (FSBE) has been identified as a manufacturing method for producing tubing with both stronger and more ductile tubing for applications such as hydroforming, biomedical, energy, and MEMS. Additionally, FSBE has been identified as a technology that can be potentially down scaled. However, the process is still not fully understood because of the multitude of process parameters such as geometry, work piece material, friction and heat transfer, and other parameters that go into producing tubes.
The goal of this project was to design and test instrumented tooling for FSBE that were capable of producing a wide variety of tubing diameters, measure temperature and force in real-time both, and save process data for further analysis.
The current status of this project is that the die has been fully instrumented and tested for measuring temperature, a design for the tool holder and probe capable of measuring plunge force for a CNC mill has been completed, and sample tests measuring temperature have been performed. In addition, a simple steady state heat transfer analysis has shown that the work pieces were approximately 29 degrees hotter than the temperature at the thermal couple. Those temperatures are above the recrystallization temperature of 150°C.
Tooling geometry, and a comparison of test results are presented and the future uses for this tooling are discussed.