Material Bonding For Lethal Air-to-Air Warheads

The objective of this Effort is the development of a Tantalum-Zirconium bonding technique suitable for air-to-air warheads and other munitions applications. Phase concentrates on proving the Metallurgical feasibility of joining, by HIP (hot isostatic pressing) diffusion bonding, 1.5mm zirconium sheet to 3mm tantalum plate in a sandwich configuration, and establishing the potential for this processing route to produce bonds of acceptable strength. These goals and objectives have already been substantially met: • A microcrack free HIP Ta-Zr HIP diffusion bond has been effected at about 735°C between 1.5mm Zr and 3.0mm Ta. • Chemical cleaning in HF containing acid solutions decreased microcracking. In Phase II Ta-Zr HIP diffusion bonding will be optimized and scaled-up using the Phase I successful experience. Larger assemblies will be HIP diffusion bonded and evaluated. Textron, a munitions DOD prime contractor, has agreed to provide services for explosive firing at their subscale warhead facility located in Wilmington Massachusetts. Textron will design and build test specific housings to capture and launch these Zr-Ta-Zr evaluation fragments. The Phase II effort will also incorporate conventional mechanical testing and microstructural evaluation of specimens and conditions prior to the explosive firing.