Modeling of the build up process for production of Ni-Al based high temperature wear resistant coatings

A mathematical model of liquid metal and slag phases interaction in technological process of arc welding and building up was developed. The model is based on thermodynamic and kinetic analyses of high temperature chemical reactions on phase boundaries. The model takes into consideration the initial compositions of welding materials, technological parameters (current, voltage, welding speed), temperature, hydrodynamic conditions and so on. The model application makes it possible to optimize the technological process and to develop compositions of new welding materials to yield necessary composition and properties of weld or coating. The model has been used to develop the build up stick electrodes composition for Ni-Al coating creation. In the basis of research on the effect of Cr, Al, Mo and Fe on resistance of cavitation erosion, the scale of composition of Ni3Al based alloys were determined. With the model, different build up electrodes were fabricated and welds free of hot crack which has been a big problem for Ni3Al electrode were obtained.