Session: 03-13-01: Testing and Characterization
Paper Number: 151658
151658 - Simulating Elastic Wave Propagation in RR1000 Alloy: Impact of Grain Size and Texture
RR1000, a nickel-based superalloy, is largely used in aero-engine turbine discs due to its excellent high-temperature performance. The microstructure of these discs varies radially, with finer grains near the bore and coarser grains towards the rim. This gradient in grain size is vitally important for optimizing the disc’s resistance to fatigue at the bore and creep at the rim. The thermomechanical environment within aeroengines affects the crystallographic orientations of the grains. It causes the formation of twin boundaries (high-angle grain boundaries, with grains aligned along <111> direction) and crystallographic texture development. In order to simulate the ultrasonic characterization of turbine discs, elastic wave propagation simulations were performed through a synthetic microstructure with grain size varying from fine to coarse. Three microstructures with a mean grain diameter of 70 μm, 90 μm and 125 μm were generated using DREAM.3D software and stitched together to create a representative volume element (RVE) of 1050 x 100 x 100 μm^3, mimicking the microstructural grain size gradient of a turbine disc. Group wave velocities (Vg) are measured by propagating a plane longitudinal wave from one end to the other end of the RVE. The Vg obtained from this RVE fell between the velocities calculated for the individual RVE of the same dimensions generated for the three grain size distributions individually. Introducing crystallographic texture to the preceding microstructure confirms that the texture effect is more sensitive to the Vg than the grain size variation alone. Furthermore, the Vg standard deviation was found to be reduced to almost half when we see the impact of just the grain size variation vs the combined influence of grain size and crystallographic texture.
Presenting Author: Anay Mohan Shembekar Indian Institute of Science
Presenting Author Biography: Anay Mohan Shembekar is a Prime Minister’s Research Fellow pursuing his Ph.D in the Department of Aerospace Engineering at the Indian Institute of Science (IISc), Bengaluru. He holds a B.Tech in Mechanical Engineering and an M.Tech in Robotics from Indian Institute of Technology (IIT) Madras. His research centres on multiscale modelling, computational wave mechanics, and blending physics-based with data-driven approaches.
Simulating Elastic Wave Propagation in RR1000 Alloy: Impact of Grain Size and Texture
Paper Type
Technical Paper Publication