Ceramic and metal additive manufacturing of monolithic rotors aerodynamic performance study for small scale turbomachines

The gas turbine industry is constantly working to improve the performance and durability of components that are exposed to extreme conditions by experimenting with new materials and manufacturing techniques. Materials like SiAlON and Inconel 718 are particularly wellsuited for use in turbomachinery because of their high strength and ability to withstand high temperatures. To determine whether additive manufacturing can be used to produce small-scale turbomachinery for microturbines with a capacity of 300W, researchers developed a monolithic rotor that operates at a speed of 450,000 RPM and contains both a radial turbine and a compressor. The rotor's geometry was created using lithographic ceramic manufacturing for the SiAlON parts and selective laser melting for the Inconel 718 parts, and the manufacturing and thermal process parameters were carefully controlled. The rotors were then examined using surface scans and computerized tomography. The ceramic rotor was found to have a high level of precision and surface quality, while the metallic rotor had a large number of defects and printing artifacts. An aerodynamic test facility was also built to measure the performance of the rotors at engine-like speeds, and the ceramic rotor was found to be more efficient and have a higher pressure ratio than the Inconel rotor. This is likely due to the ceramic rotor's more accurate physical representation of the model geometry and better surface finish.