On the Molten State Processing of Refractory Complex Concentrated Alloys

The field has witnessed significant growth in the experimental exploration and understanding of RCCAs. Molten state processing of RCCAs through vacuum arc melting has been the main processing path to produce components. However, there are still challenges in controlling impurity elements in RCCAs. Moreover, the behavior of the impurity elements in the RCCAs is not well understood. In this work, the chemistry of the chamber environment during arc melting was studied using a mass spectrometer. Process methodologies were studied to control impurity gas elements such as oxygen and nitrogen in arc melted RCCAs. Furthermore, by arc melting NbMoTaW and TiNbZr RCCAs in various environments, relationships between RCCA constituents and impurity element absorption were explored. Through mechanical testing, X-Ray diffraction, and electron microscopy, the behavior of impurity elements in various RCCA compositions will be reviewed and discussed.