جستجوی مقالات مرتبط با کلیدواژه « wc-10co-4cr coating » در نشریات گروه « مواد و متالورژی »

Application of WC-10Co-4Cr coating deposited by High Velocity Oxygen Fuel (HVOF) has been significantly developed in key parts of various industries, nowadays. These coatings are ground to achieve the desired surface roughness. In this study, the residual stress of as-sprayed and ground coating was determined by the X-ray diffraction (XRD) technique using sin2 method and finite element method(FEM). In the experimental evaluation, the chemical layer removal process was used to measure the through thickness residual stress. In the finite element analysis of the grinding process, the temperature distribution of workpiece is initially obtained by applying the thermal flux from the grinding process. Then the workpiece cools until it reaches the ambient temperature. The temperature history of thermal analysis is applied to the stress analysis and the final distribution of residual stress is determined by applying grinding forces and residual stress caused by the HVOF process. The results showed that there was a good agreement between the experimental and simulation results and after the grinding process, the value of compressive residual stress of coating surface increases was increased. Also, in the experimental and simulation investigation, the increase in compressive residual stress compared with the pre-grinding was up to 100 μm and 120 μm, respectively. There is no increase in compressive residual stress in the higher depth of coating and also in the interface of the coating and substrate.

Application of WC-10Co-4Cr coating deposited by High Velocity Oxygen Fuel (HVOF) has been widely developed for its high wear and corrosion resistance. The residual stresses created during the coating deposition process greatly effects the wear resistance and the adherence of coating to the substrate. In this study, the residual stress of coating was determined by the X-ray diffraction (XRD) technique using sin2 method and finite element method(FEM). In the experimental evaluation, the chemical layer removal process was used to measure the through thickness residual stress. In the finite element method, the impingement of the WC-10Co-4Cr particle on substrate was studied. Afterwards, the results from the impingement analysis are subsequently utilized as an input data in thermomechanical model to develop the residual stress of as-sprayed coating. The results showed that there was a good agreement between the experimental and simulation results. Final surface residual stress of WC-10Co-4Cr coating was compressive. The value of residual stress was increased with the greater thickness of coating. These compressive stresses reached to maximum compressive stress at the coating-substrate interface. Simulation results showed that the distribution of stress in the coating, except for the edges of the sample, was uniform. Residual stress on the edge of the sample had a tensile stress concentration in the interface of the coating and substrate which was prone to cracks, separations and defects of coating.

Application of cermet coating deposited by High-Velocity Oxygen Fuel (HVOF) has received considerable attention in a variety of industries, nowadays. Since the surface roughness of carbide coatings is higher than the permissible limits under specific conditions, finishing the coated surface by grinding is essential in order to achieve the desired roughness. The present study investigates the effect of simultaneous changes in the grinding parameters including depth of cut, feedrate and cutting speed on the adhesion and cohesion strength of WC-10Co-4Cr coating by HVOF. A full factorial design of experiment was selected for experimental planning and the analysis of variance was employed to find the significant grinding parameters, for the first time. The adhesive and cohesive properties were measured using fracture toughness with Vickers’ Indentation Test. The results showed that adhesion and cohesion strength of WC-10Co-4Cr coating increased after grinding process, and they increased with the increase of the depth of cut and feedrate and the decrease of the cutting speed. The most influencing parameters were the depth of cut, feedrate and cutting speed respectively. At the end of the current study, the relation between the grinding parameters and adhesive and cohesive propertieshas been modeled using regression analysis.