Synthesis, thermo-mechanical and tribological properties of advanced multicomponent materials of high entropy

Abstract

The increasing demand for advanced materials combining unique and unusual properties has encouraged the study of new high entropy compounds, such as high entropy alloys (HEA) and ceramics (HEC). The synthesis of these materials was stimulated by the advent of recent computational modeling techniques that consider entropy during material design, which is a fundamental key to explain the stabilization of complex, multicomponent compounds of technological importance. Therefore, the challenge of this proposal focuses on designing and synthetizing high entropy alloys (HEA) at small scales, i.e., as thin and ultrathin films, as well as advancing the fundamental physical knowledge on this new type of materials (scientific goal) and also evaluating the thermo-mechanical and tribological behaviors (technological goal). We expect to achieve these goals by using computational modeling and thermodynamic analysis, followed by the materials synthesis and characterization, understanding of the physical fundaments leading to the desired final properties and the measurement of friction coefficients of tribological systems. The use of plasma spectroscopy in real time during the synthesis of the HEA samples will allow us to control the precursors of the films looking for gaining understanding on the physical fundaments involved in the film growth. In addition to the tribological properties, studies of thermo-mechanical properties will be carried out. We will investigate the mechanical stress as a function of temperature, coefficient of thermal expansion, Young's modulus and Poisson's ratio using methodology developed in our laboratories. These properties are important for applications in device manufacturing. (AU)