University of California, Santa Barbara
Paul Gaurav Nalam
Faculty Sponsor's Department(s):
Fabrication and Characterization of High-Temperature Niobium Alloy Coatings
The alloys based on the combination of refractory metals with elements known for enhancing oxidation resistance, high-temperature strength, and thermal stability are desirable for high-temperature applications. Such alloys find widespread applications in many of the advanced aerospace and energy technologies. Niobium (Nb) is one of those refractory metals with a high potential to design and develop novel alloys for high-temperature applications. Therefore, in the present work, we performed a detailed study on the NbCrTaWV alloy coatings made by magnetron sputtering. The coatings were made under variable deposition temperature. Further characterization and analysis were made using X-ray Diffraction (XRD) and scanning electron microscopy (SEM). The results indicate the structure and morphology variation as a function of deposition temperature. We hypothesize that the composition and/or formation energy of each metal in the alloy would result in texturing and preferential orientations. To validate this hypothesis, combined used of XRD and crossectional SEM was performed. Finally, nanoindentation measurements were made to understand the mechanical properties of the Nb-based alloy coatings. The results will be presented and discussed to explain the structure-morphology- mechanical property correlation in Nb-based multicomponent alloy coatings.