In this study, composite samples were produced by adding WC particles in different proportions (2.5, 5, and 10%) by weight to the CuNiSi powder mixture by the powder metallurgy method. The prepared powders were mixed with a mechanical alloying device for 5 and 10 hours. After the mixing process, the powders were pressed with a cold press. In the cold pressing process, 600 MPa pressure was applied as pressing pressure. The sintering process of the pellets produced was carried out with an atmosphere-controlled heat treatment furnace. The sintering process was applied in an argon atmosphere at 900 °C for 1 hour. Scanning electron microscope (SEM-EDS) to determine the microstructure of the samples produced, X-Ray Diffraction method (XRD) analysis to determine the phases formed in the internal structures of the produced samples, and microhardness (HV0.05) to determine the effect of WC particles on hardness. From the microstructure results in the SEM pictures, it was determined that the WC particles were homogeneously distributed in the structure. It was determined that there was an increase in hardness measurement values due to the increasing amount of WC and mechanical alloying time in the produced samples. The highest hardness value of 198 HV0.05 was measured on a composite sample reinforced with 10% WC by weight and mechanically alloyed for 10 hours.