The Method of Dosed Directional Solidification (DDS) for Casting Turbine Blades

摘要

In this paper it is study a problem of multigrid schemes in two space dimensions and differential operator formula of Laplace and Lagrang for numerical tests, including a composition parameters of microstructures obtained by the DDS method. This technological possibilities of directed crystallization are broad and make it possible to manufacture castings from high- temperature alloys with various sets of properties. The present work is devoted to the possibilities of intensifying directed crystallization of the Ni_3Al intermetallic compound by improving of feeding the growth casting, which makes it possible to control the process of structure formation and thus change the properties of material. Directed crystallization of the intermetallic compound is a very complex and unsteady process. This seems to be connected not only with that aluminum segregates in the mother solution that feeds the growing casting but also with the scale factor, i. e., the height of the column of the mother melt and its mold. We can infer from these data that the crystallization conditions in fabricating castings by the developed method are in better equilibrium. These conditions are provided by the dosed feeding of the liquid metal into the casting zone. The alloy obtained by the suggested method has higher mechanical characteristics for temperature ranging from room temperature to 1200 than metal melted with the use of directed crystallization by the conventional method (CDS).