Based on
niobium, adding other elements to form a binary, ternary or multi-element alloy is an energy alloy. These niobium alloys not only have the low-temperature plasticity of pure niobium, but also improve the strength, oxidation resistance and corrosion resistance of the material itself. Because niobium has good low-temperature plasticity and large solid solubility for a large number of elements, a large number of alloying elements can be added to niobium to form an energy alloy, thereby improving various properties of the material. For example, adding a certain proportion of
tungsten and
molybdenum can significantly Improve the high-temperature and low-temperature strength of the material, but excessive addition will reduce the plastic workability of the alloy. Add a certain proportion of
titanium,
zirconium, hafnium and appropriate C to form a dispersed carbide phase for precipitation strengthening. Among them,
Ti can improve the material's oxidation resistance and process performance;
Zr can improve the material's corrosion resistance to molten alkali metals; Hf Can improve the material's oxidation resistance and welding performance.
Among them, the interstitial elements have a solid solution strengthening effect, but they will increase brittleness in the order of H, N, O, C; Cr and V have the strongest room temperature solid solution strengthening effect on
Nb, and Ti and Hf have the least effect; at high temperatures, Zr and V has the strongest solid solution strengthening effect on Nb, Ti has the smallest effect, and the effects of
Mo,
W, and Hf are in the middle. It can be seen that V is the most effective alloying element, but excessive V (>20%) will make the grain boundary oxide film of the material brittle, thereby making the material brittle.
