University of Pittsburgh researchers have developed and built a hybrid advanced manufacturing system integrating wire-based Directed Energy Deposition (DED) technology, Friction Stir Welding (FSW), and milling. The development of a standalone system combining these three technologies can lead to enhanced mechanical properties and a more streamlined, efficient production process.
Description
DED and FSW are both advanced manufacturing processes. In this novel system, they are integrated with a milling tool in a single machine to allow for simultaneous or sequential performance of DED and FSW followed by milling, to modify a microstructure, increase mechanical properties and improve dimensional accuracy of DED produced material. This novel system could allow industries to harness the productivity of DED with the strength of FSW and the precision of milling, potentially manufacturing multi-material components with strong material interfaces and high dimensional accuracy.
Applications
1. Fabrication of multi-materials components 2. Increasing welding temperatures 3. High precision fabrication
Advantages
DED is a commonly used method in manufacturing due to its high productivity and large part fabrication capability. This method of metal additive manufacturing deposits metal in layers but can lead to the formation of columnar grain structures along the build direction, impacting on the strength and creating structural anomalies in the final product, along with relatively low geometric accuracy. To overcome these problems FSW is used to enhance the microstructure and mechanical properties of the printed DED product. Milling is then used to ensure dimensional accuracy. This approach combines all three methods in a single integrated device. Integrating an FSW machine into a wire-arc DED system allows for FSW to occur immediately after printing. Heat generated from DED processing can immediately be used to facilitate FSW, potentially allowing FSW to process high-temperature materials more easily. The feature is unique to this novel approach and is not found in other hybrid advanced manufacturing systems.
Invention Readiness
A prototype device has been built containing a welding torch, friction stir tool, and milling tool in close proximity. Testing on an aluminum alloy found material processed using this system demonstrated refined grain size from 78 ﾵm to 1.8 ﾵm, increased microhardness, and enhanced mechanical properties compared with current available methods.
IP Status
Patent Pending
