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C-103 (Nb-10Hf-1Ti) alloy is a low-strength niobium alloy with good high-temperature strength, excellent formability and welding performance. It is widely used in rocket thrusters and other fields. It is an extremely Wide range of niobium alloys. This alloy developed in our country is used in bicomponent liquid rocket engines, and uses niobium silicide high-temperature anti-oxidation protective coating, and the working temperature can reach 1200~1300℃.

This alloy achieves solid solution strengthening by adding Hf, Ti and Zr alloy elements, among which Zr has a significant strengthening effect, and Hf and trace amounts of W mainly improve high-temperature properties.

Adding a small amount of titanium to the alloy can not only improve the processing performance of the alloy, but also improve the oxidation resistance. The interstitial impurities C, N, H, and O elements have a great influence on the mechanical properties of the alloy. When the oxygen content exceeds 0.1%, it will make subsequent cold working more difficult. In addition, the oxidation resistance of the alloy will deteriorate when it is above 450℃. Therefore, care should be taken to avoid thermal oxidation during thermal processing. Inert gas protection or vacuum equipment is usually used. When used at high temperature, in order to prevent oxidation, the metal surface is usually coated with a silicide anti-oxidation protective coating. Fe-Cr alloy silicide coating was prepared on the surface of C-103 alloy using slurry coating and vacuum diffusion technology. It was observed that the microstructure of the coating was a three-layer structure, with the outer layer being NbSi2 phase and the inner layer being Nb5Si3 and Nb3Si. Low silicide, the middle layer is composed of Fe-Cr alloy niobium silicide phase and NbSi2. Research results show that the coating provides good short-term protection for the substrate against high-temperature oxidation in air at 1100 and 1300℃, and the presence of the coating also increases the tensile strength of the alloy.

C-103 niobium alloy ingots are prepared using the electron beam secondary remelting method, and are then machined, clad, and hot extruded into slabs, and then cold rolled into thin plates. For smaller components or propellers, rods are generally processed directly. To manufacture a complete larger combustion chamber, rods with larger diameters are required, or the rod conical die reverse extrusion forming process can be effectively used. Improve component output and yield.

Good formability and stable reliability make C-103 niobium alloy have excellent cost performance and further promote its application in the aerospace field.