Impact Welding and Phase Change Enabled Sealing for High-Temperature Metal-Composite Interfaces

To be Funded by: National Center for Defense Manufacturing & Machining; Faculty: Stebner & Thadhani

This project will involve a three university collaborative effort aimed at alloy development and processing to technology transition planning. Fundamentally, a new Nb-Ru high temperature shape memory alloy (HTSMA) will be developed, processed, characterized, and deployed into a one-dimensional prototype that demonstrates phase-changed enabled sealing and joining using HTSMAs. The phase-change physics, training of the HTSMA, and performance of the prototype will be simulated using physical models and design tools that will be validated using the test data from the one-dimensional prototype. The simulation of the phase change and of prototypes will be versatile enough to simulate future HTSMA candidates and proposed seal geometries as the technology evolves. These simulation tools combined with expertise of an industry partner will be used to design and simulate the performance of one or more 3-D concepts.

The Georgia Tech group will focus its effort on the development, processing, and characterization of Nb-Ru high temperature shape memory alloys. These will be processed under a range of compositions using in-house capabilities. The alloys will then be characterized in terms of structure, crystallography of the transformation, the critical stress and temperature conditions for the phase transformation, and the transformation strain that can be accommodated. The data generated will be used by the physical models and design tools. Samples will then be prepared for joining and prototype development. Although Nb-Ru alloys are relatively expensive, the project will also demonstrate how alloys can be recycled during and after the investigation through re-alloying and processing.