Production and characterization of WC reinforced CuNiSi composites by powder metallurgy method

Among the methods applied recently, CuNiSi alloys produced by powder metallurgy (PM) have been found to be notable. Chemical composition control of the alloy can be achieved with the PM method. It has been developed as an alternative to production methods such as powder metallurgy, casting, machining, hot and cold pressing. By obtaining composites with powder metallurgy method, properties such as abrasion resistance, corrosion resistance, surface friction and increasing surface tensions can be given to materials. Composite materials have an indispensable place among the material groups used in engineering applications. As a result of the development of thinner and lighter composites with the increase in strength / weight ratio, the unit cost of production and operating costs is reduced. Composite materials with very good mechanical properties are produced with CuNiSi alloys, which are successful in terms of lightness and strength. Within the scope of this thesis, the changes in microstructure and mechanical properties of CuNiSi alloy pressed at constant pressing pressure and sintered at constant temperature were compared. 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 powder metallurgy method. The prepared powders were mixed with the mechanical alloying device for 5 and 10 hours. After the mixing process, the powders were pressed with a 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 argon atmosphere at 900 ℃ for 1 hour. Scanning electron microscopy (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, it was determined that the WC particles were homogeneously distributed in the structure. There was an increase in hardness values due to the increasing WC amount and mechanical alloying time in the samples produced. Besides, as a result of the experiments, 198 HV0,05 was measured as in the sample, where 10% WC was added to the highest hardness value and mechanically alloyed for 10 hours.