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7259 |
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Thursday, May 05, 2022, Hall G2 4:40 PM High Entropy Alloys I |
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Influence of microstructure on hardness and electric resistivity of flame sprayed high entropy alloy coatings |
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Sanhita Pal* / University of Alberta, Canada Andre McDonald / University of Alberta, Canada Rakesh Bhaskaran Nair/ University of Alberta, Canada |
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Influence of microstructure on hardness and electric resistivity of flame sprayed high entropy alloy coatings High entropy alloys (HEAs) are classified as a new class of advanced metallic materials that have received significant attention in recent years due to their stable microstructures and promising properties. In this study, three mechanically-alloyed equiatomic AlCoCrFeMo, AlCoCrFeMoW, and AlCoCrFeMoV HEA coatings were fabricated on stainless steel substrates using flame spray manufacturing technique. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Vicker’s microhardness were utilized to characterize the fabricated HEA coatings. Furthermore, Joule Heating experiments using a modified version of the two-probe test has been used for measuring the electrical resistivity of the HEA coatings. To prevent short-circuiting of the metallic coatings, a thin layer of alumina was deposited as insulating materials prior to the deposition of HEA coatings. The microstructure of the HEA coatings showed the presence of multiple oxide regions along with solid-solution phases. The porosity levels were approximately 2 to 3% for all the HEA coatings. The HEA coatings exhibited a coating thickness of approximately 130 to 140 µm, whereas the alumina layer showed around 120 to 160 µm. The electrical resistivity values were higher for all the HEA coatings, which may be attributed to the characteristics of HEAs, such as severe lattice distortion and solute segregations. The combined interaction of high hardness and better electrical resistivity suggests the flame-sprayed HEA coatings can be served as multi-functional wear-resistant materials for sustainable industrial features. Keywords: Electrical Resistivity, Flame spray, High Entropy Alloys (HEAs), Manufacturing, Wear Resistant Coatings. |