Additive manufacturing of Ti-6Al-4V alloy components for spacecraft applications

In the last two decades, there have been significant advancements in the field of additive manufacturing of Ti-6Al-4V alloy and other metallic components for aerospace applications. Generally, metallic brackets used in spacecraft applications are machined from the bulk-rolled or extruded products of the specific alloy. Using Arcam´s electron beam melting-based (EBM) additive manufacturing process, several Ti-6Al-4V alloy brackets were produced, finish machined, and tested to determine their mechanical properties compared to the bulk alloy. This paper describes the use of several EBM-processed Ti-6Al-4V brackets on the Juno spacecraft. Initially, the three-dimensional (3-D) CAD model of each of the bracket drawings was developed to include slightly excess surface layers for machining to a smooth surface finish. Multiple parts were built simultaneously in the available chamber size. Preliminary cost and benefit analysis was also performed to assess the merit of using additive manufacturing for future spacecraft components. Under the same EBM processing conditions, multiple Ti-6Al-4V rod specimens were built to prepare the subscale test specimens for mechanical property measurements. Results of these tests indicated that the average material properties were quite comparable to the wrought alloy. Each of the manufactured parts was inspected using a nondestructive test method to ensure the quality of the finished product. A few component-level destructive tests validated that the component had adequate margin of safety to survive operational load conditions. Based on these results, several Ti-6Al-4V brackets were used on the Juno spacecraft which was launched in August 2011. Successful insertion of EBM-processed parts should pave the way for the use of Additive manufacturing in future spacecraft components.