Investigating the effects of B and Mo additions on the mechanical and physical properties of FeNiMnCrCoTi0,1 high entropy alloy

High entropy alloys (HEAs) are alloys with potential use in defense, aerospace, and space industries due to their properties such as high strength, hardness, wear resistance, corrosion resistance, and the ability to operate at high temperatures. Therefore, in this study, FeNiMnCrCoTi0,1BX (where x values in molar ratios are x = 0-1) and FeNiMnCrCoTi0,1MoX (where x values in molar ratios are x = 0-0,5) high entropy alloys were produced using the arc melting technique under a protective gas atmosphere with an inverted vacuum system. The changes in the microstructure due to the addition of B and Mo in this study were examined using a scanning electron microscope (SEM) and analyzed with energy dispersive X-ray spectroscopy (EDX) to evaluate semi-quantitative values and nominal values. It was observed that as the addition of B increased, the needle-like structures in the microstructure decreased, but their sizes grew. In the case of Mo addition, a dendritic structure was observed in the microstructure compared to B addition. The crystal structures of the produced HEAs were determined by X-ray diffraction (XRD) analysis. This analysis showed that a face-centered cubic (FCC) crystal structure was present in both the B-doped and Mo-doped studies. Microhardness and compression tests were conducted to determine the mechanical properties of the produced HEAs, which change with the addition of B and Mo. It was observed that the hardness of both the FeNiMnCrCoTi0,1BX high entropy alloys and the FeNiMnCrCoTi0,1MoX high entropy alloys increased as the amount of additive increased. The highest microhardness obtained was determined to be 593,8 HV in the FeNiMnCrCoTi0,1B alloy and 260,8 HV in the FeNiMnCrCoTi0,1Mo0,3 alloy. In the compression test, the yield strength increased as the amount of additive increased in both studies. The highest yield strength was determined to be 1329 MPa in the FeNiMnCrCoTi0,1B alloy and 467 MPa in the FeNiMnCrCoTi0,1Mo0,5 alloy. The changing magnetic properties of the produced HEAs with the addition of B and Mo were determined using a Vibrating Sample Magnetometer (VSM) device. Finally, to determine the electrical properties, the resistances of the alloys were measured using an LCR meter, and their specific resistance and conductivities were calculated.