Experimental Study And Design Analysis Visualization For Ceramic/Metal Gradient Wear-Resistant Coatings

Slurry pumps are widely used for mining. Suffering from running liquid, their covering plates, volutes and vanes are easily corroded and worn, and the mechanical efficiency decreases to failure in a short time. Now users and manufactures are paying great attention to improving the pumps' wear-resistance ability and expending their work life. The conventional method is to apply hard-alloy to wearing parts, but hard-alloy processes difficultly and costs highly, so inconvenient for maintenance and replacement, needless to say that the effects of wear and corrosion resistance is not satisfied. In this thesis, ceramic/metal gradient wear-resistance coatings are sprayed on slurry-suffering surfaces of the pumps, and the wear-resistance ability is obviously improved and work life greatly enlarged.According to the work conditions of the pumps, optimal design of the wear-resistance material is carried out with the help of reference documents in this thesis, which is based on formal experiments. Specimens are designed according to GB standard. Wear-resistance coatings are prepared by plasma spray method. The substrate of the specimens is HT200, with NiCrAl as its combining layer. Transition layer, WC & NiCrAl or NiCrBSi are applied; and work layer is WC correspondingly, with a thickness of 0.4mm, 0.7mm and 1.0mm for each kind of specimen. The thermal stress during spraying is simulated and analyzed by element birth and death method with ANSYS software.Assessing the properties of wear-resistance coatings is also emphasized in this thesis, which directly reflects the qualities of the coatings. Combination between coatings and substrate, micro structures and hardness of the coatings are examined, and wearing test under simulative work conditions are carried out. The results confirm the advantage of the coatings prepared here, and provide a good foundation for further experiment under work condition.Visualization technology of CMWRCDS (Ceramic/Metal Gradient Wear-Resistant Coating Design System) is also studied in this thesis. C++ Builder, Fortran and OpenGL programming languages are integrated; that is,C++ Builder 5 as interface, Fortran for calculation with the parameters derived form C++Builder' s Visualization Component Library (VCL), and OpenGL for the generation of equivalence lines, contours and cubic curves with the data derived from data files or data-base produced by Fortran and C++ Builder. This method enhances the ability of CMWRCDS' post process, fully brings into play the merits of each language, and makes system development quicker and more efficient. The technology and methods referred here are common in use, and worthy for the development of other similar systems.