Friction stir processing of Al0.3CoCrFeNi high entropy alloy

Abstract

The alloying principle has been developed to obtain the desired properties of materials, which typically involves adding secondary or foreign elements of minor quantities to a primary component. Thus alloys are named after the major component of the alloy, for example, Fe-base, Al base, and Ni-base alloys. However, in the past two decades, a new alloying strategy that consists of the combination of multiple primary elements in large concentrations led to the development of a new class of metallic materials called High Entropy Alloys (HEAs). Due to this distinct alloying concept, HEAs often exhibit unusual properties compared to conventional alloys. Very few investigations were carried out on multi-dimensional alloys and are primarily focused on experimental analysis. The literature shows that a few high-entropy alloys possess exceptional properties exceeding those of conventional alloys. But enhancing its material properties for engineering applications is a challenge. One of the primary and effective methods to enhance the material properties of high entropy alloys is through surface modification. The Friction stir process (FSP) is one of the effective processes for improving material properties by microstructural modification. The mechanical and microstructural properties are controlled by processing parameters like rotational and translational speeds. In the present study, FSP is carried out on Al0.3CoCrFeNi High entropy alloy, using two different tool geometries (i.e., cylindrical and square-shaped) by varying the process parameters, mainly tool rotational speed and traverse speed. A numerical study was performed using ABAQUS CAE finite element software to understand the complex thermo-mechanical process involved with friction stir processing. The simulation primarily aims to study the effect of process parameters and tool geometry on the HEA workpiece.