Investıgation of the mMicrostructure and mechanical characteristics of TiC/WC reinforced AlCuNiFeCr high entropy alloys produced by hot pressing method

In this study, TiC (titanium carbide) and WC (tungsten carbide) reinforced AlCuNiFeCr high entropy alloys (HEA) were produced using the hot pressing technique. The AlCuNiFeCr powder mixture, TiC and WC were added at 5%, 10% and 15% respectively. Sintering processes were carried out in a protective argon atmosphere to prevent the samples from oxidizing. High entropy alloys were produced at 900 ℃ sintering temperature and 35 MPa pressure for 4 minutes. SEM and EDS analyzes, XRD analysis, fractured surface SEM images, SEM mapping of elemental distribution and EDX spectra, hardness, three-point bending test and corrosion tests were applied to determine the microstructure and mechanical properties of the produced samples. In the SEM images taken from the produced samples, it is seen that the TiC and WC particles are generally homogeneously distributed. In addition, EDS analysis results support the samples produced. When SEM mapping was examined, it was clearly seen that reinforcement particles were distributed homogeneously. It was determined that solid solutions with YMK and HMK lattice structures were formed in XRD graphs. It was determined that the unreinforced high entropy alloy had higher cross fracture strength than the reinforced samples. As a result of the three-point bending test, it has been determined that the increase in percentage (%) of TiC and WC particles creates a notch effect in the samples and has lower strength values. Cracks and pores in the samples were detected in the fracture surface SEM images taken after the three point bending test. The hardness of high entropy alloys increased due to the addition of reinforcing particles (TiC and WC). In tafel curves, it was determined that the increase in TiC and WC did not increase the corrosion performance of the produced samples. As a result, AlCuNiFeCr with optimum properties was determined as the best example of -15% WC.