Phase field simulation method for regulating and controlling microstructure of layered high-temperature alloy by temperature gradient

Abstract

The invention relates to a phase field simulation method for regulating and controlling the microstructure of a layered high-temperature alloy by temperature gradient. The method comprises the following steps: performing thermodynamic description on the alloy according to thermodynamic parameters of the alloy in combination with a sub-lattice model; according to the thermodynamic description of the alloy, solving the chemical potential and the net diffusion flux of the element; establishing a phase field evolution equation of the components and the sequence parameters under the temperature gradient by utilizing a phase field method; setting proper initial parameters, solving a component field and a sequence parameter field of the alloy, and drawing a visual image; analyzing an evolution diagram of the microstructure of the alloy along with time under the temperature gradient to obtain an influence rule of the temperature gradient on the morphology of the alloy structure; and analyzingthe microstructure diagram of the high-temperature alloy diffusion joint interface under the temperature gradient and the change of the volume fractions of precipitated phases on the two sides of thediffusion joint interface along with the time effect to obtain the influence of the temperature gradient on the high-temperature alloy structure evolution dynamics. The invention provides a phase field simulation method for regulating and controlling the microstructure of a layered high-temperature alloy through temperature gradient. Meanwhile, the method can also predict the structure evolution of a multi-element multi-layer alloy coating under the temperature gradient.

Description

technical field [0001] The invention relates to the technical field of microstructure control of metal materials, in particular to a phase field simulation method for controlling the microstructure of layered superalloys by temperature gradients. Background technique [0002] Due to its excellent oxidation resistance, thermal corrosion resistance, high strength and fatigue resistance above 600 °C, superalloys are widely used in aerospace, ground gas turbines, metallurgy and chemical industries. It is mainly It is used as the main material for high-temperature hot-end parts, but in high-temperature service, high-temperature diffusion has a very important impact on the microstructure of the material. For example, when nickel-based superalloys are used as coatings, they occur on superalloy substrates The interdiffusion behavior between the thermal barrier coating and the bonding layer will lead to the structural failure of the thermal barrier coating, which will cause the coati...

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Problems solved by technology

[0005]However, in the experimental research, the temperature gradient between multi-layer metals is difficult to control, and the experimental period is long and costly. Therefore, the use of phase field simulation It is very advantageous to study the influence of temperature gradient on the microstructure of multilayer superalloys by means of methods. At the same time, the existing simulation methods do not consider the influence of thermal migration. The phase field simulation method is very necessary

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