Investigation of the properties of WC layer grown on the nodular graphite cast iron by thermoreactive diffusion technique

In this thesis study, the WC coating ability of the surface of the new generation GGG70 spherical graphite cast iron, which is preferred due to its high silicon content and properties, was examined using the thermo-reactive diffusion method. A mixture of 45% Al2O3 + 45% FeW and 10% NH4Cl was used as coating powder, and the surface of GGG70 spherical graphite cast iron, which was the substrate material, was coated by the thermo-reactive diffusion method. The coating morphologies, thicknesses and microhardness were examined by taking sections from the samples that were successfully coated at 1000 °C for 4 hours and at 1100 °C for 1 hour, 2 hours, 3 hours, 4 hours and 6 hours. When the coating surfaces of the materials are examined by optical microscope, scanning electron Microscope (SEM), energy distribution X-ray spectrometry (EDX) and X-Ray diffraction (XRD) methods. It was observed that a coating layer with a morphology rich in Fe, W and C was formed on the substrate surface. The lowest coating thickness was observed on the sample coated at 1000 °C for 4 hours. Although the highest coating thickness was observed in the sample coated at 1100 °C for 6 hours, peeling began to occur in the coatings. As a result of the microhardness analysis, it was seen that the hardness of the coating layer increased approximately 8 times (2400 HV) compared to the hardness of the substrate material.