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In the late 1950s, people developed a strong interest in nuclear power, aviation and space flight, and began to develop related niobium alloys. Since the 1960s, the development of commercial traditional niobium-based alloys has begun. Around 1970, foreign development of medium- and low-strength niobium alloys was relatively mature. The niobium alloys that have been used or trial-produced in rocket nozzles or thrust chambers mainly include C-103, SCb-291, C-129Y, FS85, etc. . Among them, C-103 alloy has excellent processing and welding properties. Although its room temperature strength is low, its overall performance is good, especially its high temperature strength, which can meet the working conditions of the nozzle. SCb-291 alloy has better plasticity and higher high temperature strength. C-129Y alloy also has good plasticity and weldability, but lower creep strength. FS85 alloy has high creep strength, medium plasticity and good welding performance. In terms of comprehensive properties, Cb-752 and D43 alloys have high high-temperature strength, moderate plasticity, and good processing and welding properties, so they can be selected for rocket nozzles. However, niobium alloys also have a fatal weakness, which is that they are easily oxidized at high temperatures in the atmosphere. That is, “pest” oxidation phenomenon easily occurs at around 600℃. It is necessary to prepare an anti-oxidation protective coating on its surface to meet the needs of aerospace engines. High temperature requirements for thrust chambers.

In the 1970s, people began to study high-strength niobium alloys. The main strengthening methods were still solid solution strengthening or dispersion strengthening. During this period, both the former Soviet Union and the United States conducted a lot of research on the development of high-strength niobium alloys. Our country is still in a blank in the research field of this kind of materials. With the continuous development of new models of aerospace products and the need for upgrading, higher requirements have been put forward for the specific impulse and weight reduction of orbit control/attitude control liquid engines. Consider starting from the weight reduction of the base material, thereby developing the density Low density niobium alloys below 8g/cm3.

In aerospace, the most widely used alloy in the United States is C-103 alloy, which has an operating temperature of 1200 to 1400°C, followed by PWC-11, Nb-1Zr, SCb-291, FS85 and other alloys. The coating mostly adopts silicide system, such as R512A (Si-20Cr-5Ti) and R512E (Si-20Cr-20Fe). The most widely used alloy in Russia is the 5ΒΜЦ alloy, which is used at a temperature of 1200-1650°C and is usually coated with molybdenum silicide (MoSi2). The most commonly used alloys in my country are C-103 and Nb521. At present, the refractory metal material thrust chamber of orbit control/attitude control engines has formed a “two-generation” series of products. Among them, the “first generation” is niobium-hafnium alloy (ie C-103) and “815” coating system, and the “second generation” is niobium-tungsten alloy (ie Nb521) and “056” coating system.