On Potential Turbine Coating Materials Cr0.19Ni0.06Al0.75

Undergraduate #80
Discipline: Physics
Subcategory: Materials Science

Jose Nicasio - Farmingdale State College
Co-Author(s): Dr. Jack Simonson - Farmingdale State College Gareth Schaefer - Farmingdale State College Huma Ilyas - Farmingdale State College Dr. Christine Horvat - University of New Haven Jen Misuraca - JEOL USA Inc. Ryan Duke - Farmingdale State College

Over the past decades, the effects of anthropogenic climate change have been increasing, motivating the search for high-efficiency energy solutions. The efficiency of turbine-based power plants is dependent on steam temperature, which is limited by such factors as thermal deformation of turbine materials, as well as their vulnerability to oxidation and creep due to mechanical stress. For the purpose of protecting the steel in these generators under such extreme conditions, we have synthesized the τ1 phase of Cr-Ni-Al as a potential coating material. We grew single crystals of this compound from an Al-rich solution. We found the composition to be 75% Al, 19% Cr, and 6% Ni using EDX and XRD measurements, with lattice parameters confirming the τ1 phase. Vickers micro-hardness measurements determined the hardness to be comparable to that of extra-high-hardness military armor plating. This high hardness is ideal for providing impact resistance from the particulate contaminants that are often present in steam-based power generation. Fracture toughness measurements are underway using the B3B test, with the cracking load force already found. By measuring the Poisson’s ratio using resonant ultrasound spectroscopy we calculate the fracture toughness with a polynomial equation. Low temperature electrical resistance measurements confirm τ1 is a thermally-insulating metal. In light of these results, we discuss the viability of this compound for high temperature coating applications.

Funder Acknowledgement(s): Farmingdale State College ; Petroleum Research Fund of the American Chemical Society ; CSTEP ; LSAMP

Faculty Advisor: Dr. Jack Simonson, Simonsjw@farmingdale.edu

Role: Measured the samples . Sealed the samples . Synthesized the crystals. Tested fracture toughness. Assisted in plotting crystal structure. Calculated electrical component of thermal conductivity. Currently measuring oxidation resistance. Currently measuring Poisson's ratio.