热障涂层对DD6 单晶燃气热腐蚀及力学性能的影响

DD6 single crystal high-temperature alloy material has a very broad application prospect in the field of multi type aviation engine manufacturing in China due to its excellent high-temperature service performance. With the continuous development of aviation engine technology in China, the service temperature of the combustion chamber turbine is constantly increasing. DD6 single crystal superalloy cannot fully meet the service environment of high temperature, high pressure, and high speed, and there is an urgent need to research DD6 single crystal surface thermal barrier coating technology. In view of this, this article uses multi arc ion plating technology to prepare NiCoCrAlY metal bonding layer on DD6 single crystal high-temperature alloy, and then uses electron beam physical vapor deposition technology to prepare Y2O3·ZrO2 ceramic surface layer, to study the effect of thermal barrier coating on the gas thermal corrosion resistance and mechanical properties of DD6 single crystal. The results indicate that, after 100 hours of gas hot corrosion performance testing at 900 ℃, a thickness of approximately 100 μm corrosion porosity, pores, and transverse cracks was formed on the surface of DD6. There were no corrosive elements such as Na, K, Ca, Cl, S present inside the BC coating or YSZ coating. A uniform and continuous Al2O3 layer was formed on the surface of the BC coating, and the Na2SO4 adhered to its surface did not undergo high-temperature decomposition. The corrosive medium did not corrode the BC coating. The YSZ coating columnar crystals have good strain tolerance. At high temperatures, the expansion of columnar crystals leads to a reduction in the gap between columnar crystals, and external corrosion media cannot effectively penetrate into the interior of YSZ coating, thus avoiding corrosion damage to the coating or substrate caused by corrosion media. Tensile strength of thermal barrier coating on DD6 single crystal alloy at 980 ℃, there is no adverse effects onσb, σ0.2, δ and ψ, and the fracture mode of the sample is basically consistent. High temperature endurance time and elongation of DD6 single crystal sample coated with thermal barrier coating at 980 ℃, 250 MPa, there is no significant difference, and the fracture has a typical dimple fracture morphology, with the fracture mechanism being a ductile fracture mechanism of plastic deformation and creep deformation. Based on the research results of this work, the technical support for the technical development and engineering application of DD6 single crystal super alloy TBCs is established.