J. Hebda, P. Finden, Wah Chang, Albany, OR; R. W. Davies, Pacific Northwest National Laboratory, Richland, WA

Summary:

The ATI-425 (Ti4Al-2.5V-1.5Fe-0.25O) alloy was developed for ballistic applications with the intent of providing a lower cost armor product. The advantage of this alloy is the ability to incorporate lower cost forms of recycle than are normally feasible for Ti-6Al-4V. While the vagaries of the titanium market saw the price of all available revert achieve record highs, Wah Chang discovered the ability of the ATI-425 alloy to be cold rolled. Moreover, the alloy exhibits room temperature mechanical properties in the lower Ti-6Al-4V ranges and cold rolls readily into sheet and coil forms. Cold rolling to final thickness permits a less costly product than the current hot, pack rolled process for Ti-6Al-4V which is labor intensive for building and removing the steel cans of the pack as well as grinding the individual sheets to remove oxide and alpha case. The alloy was first informally evaluated in SPF applications by Hi-Tech Welding of El Cajon, CA for a US Army trailer project. After the initial success of this trial, a detailed evaluation of the properties of the alloy under SPF conditions was conducted under laboratory conditions. This paper discusses the results of these laboratory tests, including a discussion of the flow stress, elongation, and strain rate sensitivity across a wide range of temperatures and strain rates. Furthermore, the work compares the properties of ATI-425 to Ti-6Al-4V and concludes that this new alloy exhibits properties that are suitable for commercial SPF applications.