With the advancement and development of aerospace technology, the requirements for engine performance (such as combustion efficiency, payload, and on-orbit operating life) continue to increase, which requires further improvement of the specific impulse performance of the engine, so that the temperature of the combustion chamber body is getting higher and higher. The higher the temperature, the higher the requirements for the temperature and mechanical properties of the materials used in the engine body. Compared with other types of high-temperature alloys, niobium alloys have the advantages of low density, high specific strength, good cold forming and welding performance, and can be processed into thin-walled and complex-shaped parts. Therefore, niobium alloys have been widely used in the aerospace field. But at the same time, there are inevitably some unavoidable problems:
1) Most of the niobium alloys currently used are low-strength and medium-strength niobium alloys. In order to meet the upgrade and replacement of engine body materials, it is necessary to conduct in-depth research on the high-temperature strengthening mechanism and toughening mechanism of high-strength niobium alloys. A new generation of niobium alloy materials with higher strength, higher strength and toughness or higher strength and plasticity provides theoretical support.
2) As the use temperature increases and the life span requirements increase, the current high-temperature anti-oxidation protective coating technology is difficult to meet these requirements. In order to meet the requirements of the higher temperature service environment for the new generation of higher strength or toughness niobium alloy materials, it is also necessary to develop a matching long-life protective coating with higher service temperature and better oxidation resistance.
3) Although niobium alloy is the lightest metal among high melting point metals, its density is still slightly heavier compared with the development of aerospace engineering. Because the lightweight of niobium alloys is of great significance for improving the specific impulse of aerospace engines, further extending the voyage distance, and increasing the payload of spacecraft. Therefore, the development of low-density niobium alloys and the thinning and lightweighting of high-strength and tough niobium alloys are also an important direction for the future development of aerospace engineering.
Therefore, in order to meet the increasing demand for high performance of aerospace engines, niobium alloys, which are commonly used materials for engine thrust chambers, need to continuously improve and solve their own problems, and further develop new types of niobium alloys with higher strength, higher toughness and light weight. As well as higher-temperature, long-life high-temperature anti-oxidation protective coatings, thereby further promoting better applications of niobium alloys in the aerospace field.