Session: 18-02: Additive Manufacturing II

Paper Number: 152506

Micro-Mixing Injector Manufacturing in Refractory Metal Using Laser Powder Bed Fusion Process 

The decarbonization and reduction of pollutant emissions are at the center of the research done in the field of gas turbine combustion. One of the hot topics is the integration of hydrogen, which comes with design challenges and combustor operability limits due to its higher flame temperatures and its propensity to attached flame combustion regime. These characteristics lead to higher operating temperature requirements for hydrogen fuel injectors. Therefore, there is a need for the manufacturing of injectors with material suited for higher temperatures. While CMCs and their manufacturing processes are well adapted for liners, the geometry complexity of injectors prevents the use of CMCs. Refractory metals are interesting because their melting temperatures are significantly higher than combustor flame temperatures, granting new design possibilities. However, multiple challenges arise with refractory metals, such as oxidation and manufacturing issues. Laser powder bed fusion (LPBF) process is rising in the manufacturing of injectors, especially micro-mixing injectors, because of its geometrical flexibility. This additive manufacturing process can be applied to refractory metals, easing their manufacturing. In this paper, a micro-mixing injector in molybdenum was manufactured with the LPBF process to demonstrate the possibility to manufacture micro-mixing injector in refractory metals. The geometric precision achieved was acceptable for micro-mixing combustion requirements. Injection holes with a nominal diameter of 300µm were successfully printed as well as small inner channels. Environmental barrier coating (EBC) was developed in parallel and applied to the molybdenum micro-mixing injector to address the critical oxidation issues.

Presenting Author: Xavier Bellavance Université de Sherbrooke

Presenting Author Biography: Xavier Bellavance is a PhD student in the Createk Design Lab of the University of Sherbrooke, working on micro-mixing combustion. He is also working on the integration of refractory metals in the design of micro-mixing injector in the Shape Memory Alloys and Intelligent Systems Laboratory (LAMSI) of the École de Technologie Supérieure (ÉTS).

Authors:

Xavier Bellavance Université de Sherbrooke
Aurore Leclercq École de Technologie Supérieure
Thibault Mouret École de Technologie Supérieure
Alexandre Landry-Blais Université de Sherbrooke
Mathieu Picard Université de Sherbrooke
Vladimir Brailovski École de Technologie Supérieure