AlCrO Diffusion Barrier On The High Temperature Protection Performance Of NiCrAlYsi Coating

With the development of gas turbine and aviation technology,the working temperature of the turbine blade has also increased while obtaining higher working efficiency.As the key part of the engine,the MCrAlYSi high temperature protective coating is used to meet the working needs of the blade.Widely used in aero-engine blades.However,with the increasing temperature of the aero-engine,it is found that there is a serious interdiffusion of elements between the MCrAlYSi coating and the superalloy matrix,which seriously affects the performance of the coating and the blade,but a diffusion barrier is added between the coating and the matrix.Layers can effectively solve the element diffusion problem.A series of AlCrO diffusion barriers and MCrAlYSi/AlCrO systems were deposited using arc ion plating techniques.The phase,morphology and composition of the diffusion barrier layer and the coating system before and after oxidation were tested and investigated by XRD,SEM,EDS and other methods.judge.Using AlCr alloy targets with different target ratios,AlCrO diffusion barrier layers with different composition ratios were deposited at different deposition temperatures.The phase in the AlCrO layer is mainly?-(Al,Cr)₂O₃ or Cr₂O₃.When the deposition temperature is constant,the Cr content in the alloy target increases,and the metastable alumina in the coating will gradually convert to?-Al₂O₃ and then to?-Al₂O₃ or Cr₂O₃ deviates,when Al₄₀Cr₆₀ is selected,the deposition temperature increases,and the metastable alumina in the coating will be converted into?-Al₂O₃;the deposition temperature is constant,as the Cr content in the AlCr alloy target ratio increases,the deposition rate increases.will be higher and higher,and the bonding strength of the coating will gradually increase;using the Al₄₀Cr₆₀ alloy target,the deposition process at the deposition temperature of480°C,the working pressure increases,and the coating deposition rate increases first and then decreases.When the oxygen ratio is increased,the main phase in the coating is converted from?-Al₂O₃ to?-(Al,Cr)₂O₃ solid solution.When the oxygen flow rate continues to increase,various impurity phases will appear in the diffraction peaks and are not The crystal content is high.The coating system with or without diffusion barrier was simultaneously oxidized at 1000°C for300 h at high temperature,and the oxidation weight gain curve showed that the weight gain of the coating with AlCrO diffusion barrier was significantly smaller than that of the system without diffusion barrier;no diffusion The Ni Cr Al YSi coating system of the barrier layer has a certain high temperature protection effect on the superalloy substrate,but the coating will degrade rapidly due to the high temperature promoting the interdiffusion of elements;after adding the AlCrO diffusion barrier layer,the oxidation resistance of the coating is improved.The reason is that the AlCrO diffusion barrier layer can effectively inhibit the mutual diffusion between the substrate and the superalloy,and effectively improve the oxidation resistance of the coating system.After constant temperature oxidation,the diffusion barrier layer remains continuous and combines well with the coating and the substrate.Good element diffusion barrier ability.