Method for preparing nano-carbides to enhance matrix stability based on eb-pvd

Abstract

The invention discloses a method for preparing nano-carbides to enhance the stability of a substrate based on EB‑PVD. EB‑PVD equipment is used to deposit a layer of dense carbon film, combined with diffusion treatment, so that carbon elements and single crystal superalloy substrates in the near surface area Combining refractory elements in situ to generate dispersed nano-carbides, fix the refractory elements in the matrix in the form of carbides, so as to inhibit the loss rate of refractory elements in the matrix during the service process, and enhance the high-temperature structure stability of the matrix To prevent the formation of secondary reaction zone (SRZ) during service. The present invention adopts EB‑PVD equipment to deposit a carbon film on a single crystal substrate, uses pure carbon as a carbon source, overcomes the difference in carbon activity during diffusion, maintains the consistency of carbon activity, and avoids other carburizing processes, such as During the process of chemical vapor carburizing, gas composition fluctuations or carbon activity are not easy to control, which improves the controllability of carbide quantity, morphology, distribution and depth.

Description

technical field [0001] The present invention relates to protective coating systems for blades in service at high temperatures. More specifically, the present invention relates to a method for preparing nano-carbides to enhance matrix stability based on EB-PVD. Background technique [0002] In a gas turbine engine, air is sucked into the engine, compressed by the compressor, mixed with fuel, and sent to the combustor for combustion. The gas flows through the turbine to drive the turbine to rotate to generate thrust. According to the service environment of turbine blades, it can be known that turbine blades will withstand complex loads such as high temperature, thermal cycle, thermal shock, oxidation, corrosion, and fatigue during service. In order to increase the thrust-to-weight ratio of an aero-engine, the most effective way at present is to increase the temperature of the combustion chamber of the aero-engine. Therefore, with the increasing requirements for the thrust-to...

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Problems solved by technology

[0011] The above three U.S. patents all use the chemical vapor phase carburizing method, which has some problems: the fluctuation of the carburizing gas composition makes it difficult to control the consistency of carbon activity, resulting in unstable carburizing results; there are many variables that need to be controlled, Increased variability of carburizing results; carrier gas for vapor-phase carburizing is toxic and explosive

The patent uses C 10 h 8 or C 14 h 14 There are certain problems as a target material: the target material needs to go through the process of chemical decomposition and deposition during deposition, and the chemical decomposition process is difficult to achieve precise control, resulting in fluctuations in the composition of the carbon source, and because the boiling point of this target material is very low , when the electron beam scans to the target, rapid gasification or even splashing will occur, and the process stability is poor

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