As a structural material widely used in the hot end parts of modern industrial fields such as weapons and equipment, aviation and aerospace, niobium alloy has a high temperature.
Serious ablative phenomenon occurs under the scour of oxygen-rich combustion flow, which affects its performance in ultra-high temperature environment. The study found that using table.
Surface coating technology can effectively improve the high temperature ablative resistance of niobium alloy. Therefore, combined with the hot end parts of the oxygen-rich, ultra-high temperature actual service environment, Firstly, the research status of anti-oxidation ablative coatings on niobium alloy at home and abroad was introduced. Advantages and disadvantages of free oxidation and ablation resistance; Then, the research progress of thermal barrier coatings at home and abroad in recent years was reviewed, and ZrO2 base was summarized. The characteristics of ceramic coating, rare earth zirconate ceramic coating and perovskite structure ceramic coating; Finally, the niobium alloy surface heat. The structure design and future research direction of protective coating are prospected.
Niobium metal has the characteristics of high melting point (2467 ℃), low density (8.57g /cm3) and excellent machining performance. It is found that niobium and niobium alloys can be used at higher temperatures and maintain higher strength at 1400 ℃ compared with traditional nickel-based superalloys. Based on the above characteristics, niobium alloy is considered as an alternative to nickel-based superalloys. And has been widely used in liquid and solid rocket engine nozzle. However, similar to W, Mo and other refractory metals, niobium has a high affinity with oxygen and a large oxygen solubility. Oxygen will appear when exposed to the atmosphere at 600 ℃ for a long time. As a result, the mechanical properties are greatly reduced, resulting in serious burning loss failure of hot end parts and reduced service life. Therefore, it is necessary to improve its high-temperature oxidation resistance. At the same time, with niobium alloy hot end parts service temperature.
Too high temperature will lead to too fast loss of oxidation resistance ablative coating and decrease of mechanical properties of niobium alloy. Therefore, in view of the complex and changeable corrosion environment and oxygen-rich high temperature combustion flow and solid rocket engine.
In the dynamic oxidation environment of particle flow erosion, the thermal protection of niobium alloy should be carried out from two aspects of oxidation ablative resistance and heat insulation resistance.
