60201 - Design, Development and Validation of Additively Manufactured 1st Stage Turbine Vane for F Class Industrial Gas Turbine 

Emerging additive manufacturing technology offers many opportunities for improved cooling design in gas turbine components by enabling design of cooling passages and shapes that are not manufacturable with conventional methods.  Many of combustion components have already taken advantage of these design opportunities however adaptation of this technology in turbine components has been slower due to challenges with demanding turbine environment and restriction on material properties obtained from additive manufacturing.  This paper represents application of additive manufacturing technology in an F class industrial gas turbine including design, development and validation steps of a 1^st stage turbine vane.  Systematic design approach was undertaken to examine all aspects of operation and cooling of the component and down-select appropriate design, material and processing.  Detail characterization of multiple relevant material properties such as LCF, fracture toughness and creep was conducted to obtain material data suitable for component design.  Cooling design studies and coupon specimen testing were conducted to determine heat transfer and flow characteristics of micro channels used in the airfoil design.  Detailed conjugate heat transfer analyses were used to iterate and optimize the cooling design. Once final design requirements were achieved, a number of prototype engine components were manufactured and tested in continuous engine operation for a duration of more than 6 months.  These prototype components were removed from the engine after successful operation for product validation purposes.  Uniform crystal temperature sensors (UCTS) were used to validate the new cooling design.  Destructive microstructural evaluations were performed to determine the impact of in-service operation on additive manufactured material.  Subsequent microstructural analyses of creep specimen were conducted to validate part life predictions.  Detail of the design and development steps as well as the results of prototype tests and microstructural evaluations are presented and discussed in this paper.  It is shown that with proper considerations of the resulting material properties, adaptation of additive manufacturing technology in turbine components is feasible with a comprehensive development process.