DEVELOPMENT AND VALIDATION UNDER ENGINE OPERATION ENVIRONMENT OF ADDTIVELY MANUFACTURED HOT TURBINE PARTS

Paper in proceeding, 2023

Additive Manufacturing (AM) has emerged as an innovative manufacturing method in comparison to traditionally subtractive method. Its unparalleled design freedom opened up the applications in gas turbine business where the efficiency improvement is consistently needed. While the AM application in combustion section has gained a lot of experience, the AM application in turbine hot gas path is still limited, e.g., most of the applications like vane 1 and vane 2 are limited to the gas turbines with relatively low operation temperatures. This paper presents the project where vane 1, heat shield 1 (HS1) and vane 2 in SGT-800 were redesigned with only AM enabled in-wall cooling schemes and these parts were tested and validated under the real engine operation environment. Through Design for Additive Manufacturing (DfAM), these parts were redesigned with lower cooling air consumption, reduced average metal temperature and more even temperature distribution. After that, these parts were additively manufactured in EOS M400-4 and post print quality checks were conducted to ensure the part quality. The quality check includes cut-up metallurgical investigation, hot air thermography test and water test, etc. All three AM parts were instrumented with thermo-couples and thermo-crystals, and tested under the full load engine operation condition. The crystal measurement results confirmed the reliability of the design tool as well as the design targets. For AM vane 1, a cooling air saving of more than 20% was achieved and the average metal temperature was reduced by 56 °C from the baseline of the cast vane 1. For AM HS1 and AM vane 2, the cooling air saving is not significant, but the average temperature was reduced by approximately 80 °C. This will result in significant increase in part life time, either to increase the part service interval or use it as basis for cooling air saving. With this validation under the engine environment, the implementation of these three AM parts is planned in the customer engines.