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A new, potentially lower-cost approach for the production of advanced titanium and titanium-alloy materials has been demonstrated using cryogenic technology. The alloys produced have an ultra-fine grained structure, high-angle boundaries, and finely-dispersed particulates having near-nanometer-scale size. These features combine to impart excellent strength levels, good ductility, and excellent microstructural thermal stability. In addition, the powders are macroscopically in the micrometer range having pre-alloying capabilities. This feature allows for easy handling, cleaner surfaces, and no environmental dangers. This paper summarizes the preliminary results of the macrostructures, microstructures, chemistries, and mechanical properties achieved via the cryogenic processing.

Aluminum-lithium (Al-Li) alloys have been developed with reduced weight and increased durability characteristics. The application of these new alloys as primary aircraft structure has created the need for refinements in the mechanical joining and stress-coining processes currently employed throughout the aerospace industry. These processes deal specifically with fastener hole preparation, installation processes, and fatigue enhancement techniques associated with stress-coin cold-working methods for mechanical joints. This paper attempts to dispel the myths associated with such processing of 2090 Al-Li alloy sheet and extrusions. Presented are some lessons learned during assembly of the USAF's new C-17A STOL transport airlifter when utilizing Al-Li material.