Development and Material Characterization of an Additively Manufactured Nickel Alloy for Turbine Applications

The introduction of laser powder bed fusion, and other additive manufacturing processes, represents a disruptive force in the gas turbine industry. While LPBF provides opportunities to create geometries that were impossible with other techniques, a high potential exists to create designs which are also outside the experience of designers and analysts. Some of the most interesting opportunities for an LPBF application are components that would normally be investment cast superalloys. These materials present significant challenges due to their susceptibility to strain age cracking and the importance of creep capability in the final design. In order to minimize the risk of encountering unexpected failures during fabrication or operation, a systematic approach to material development and characterization was needed. This paper will discuss the development of a nickel-based LPBF process, from the selection of powder composition and material processing to optimization the material for its intended application. The formulation of material tests during and after material development will be discussed. Data from the material testing was used first to select required heat-treatments and then to create preliminary material models for use in the design and analysis of turbine hardware. The systematic development of a nickel LPBF manufacturing and material characterization presented in this paper facilitates the design innovative turbine hardware.