Low-Cost Titanium Propellant Tankage

Aerospace rocket propellant tankage has been made of machined Ti-6Al-4V titanium alloy forgings for many years. These tanks have been substantially lighter than if made of other materials and have provided reliable performance. However, the tanks are very costly in connection with excessive machining labor and the loss of large quantities of titanium as chips. In connection with a need for still larger tankage for space application, investigations were conducted with the objective to develop an approach for the manufacture of titanium tanks at a lower cost. It was found that the Air Force developed Ti-15V-3Cr-3Al-3Sn alloy is an excellent candidate for low-cost propellant tankage, through the use of draw forming to fabricate tank segments. Drawn hemispheres may be finished to tank hemispheres by chem-milling, or a combination of conventional machining and chem-milling, at a relatively low cost.