Wear response of laser remelted and aluminized CoFeNiCr0.5Mo0.1 medium entropy alloy

Abstract

In this study, mechanically alloyed and sintered CoFeNiCr0.5Mo0.1 alloys under pressure were also subjected to a laser melting process in order to improve their surface properties. In addition, these samples were thermochemically coated with a pack aluminizing process to provide hardness and wear resistance on the surface. While the produced alloys were predominantly composed of FCC phases, aluminide phases were formed on the surface after the aluminizing process. While approximately 10 % hardness increase was achieved with laser remelting, an increase of approximately 2 times was observed in the average hardness change after the aluminizing process. As a result of the aluminizing process, fracture toughness decreased and values were found as 2.78 and 4.49 MPa. m1/2 for aluminized Aluminized MEA and Aluminized MEA + Laser. In order to examine the wear loss and friction coefficient, the samples were subjected to dry sliding wear tests and examined comparatively. It was observed that laser remelting improved wear resistance while aluminizing had a negative effect. When averaged for all loads, the wear coefficients were determined as 0.05 for MEA + Laser, 0.1 for MEA, 0.21 for Aluminized MEA + Laser and 0.26 10-3 x mm3/N.m for Aluminized MEA. Although the aluminizing process increased the surface hardness, it decreased the fracture toughness and increased the volume losses and friction coefficient.