Microstructure And Properties Of Vanadium-based Multicomponent Alloys

Vanadium alloy is a new type of alloy design concept that can form a simple structure.Vanadium-based alloys have the characteristics of high strength,high temperature resistance,and excellent high temperature mechanical properties.The element composition of vanadium alloys is flexible and can give play to variouscomponent elements to provide.a wide range of potential applications.According to the design concept of multi-component vanadium-based alloys,a vacuum arc melting technique was used in this dissertation to prepare quaternary alloys with low activation metal elements V,Ti,Cr,and Fe as the main elements.For V-Ti-Cr-Fe-C and V-Ti-Cr-Fe-La alloy systems,the effects of element addition,the change of element content,and heat treatment on the microstructure and properties of vanadium-based alloys have been studied.The V-Ti-Cr-Fe alloy is mainly composed of BCC phase.The V₇₀Ti₁₀Cr₅Fe₁₅ alloy has highest strength and plasticity in the V-Ti-Cr-Fe alloy system.In the element analysis diagram,the main phase of V₇₀Ti₁₀Cr₅Fe₁₅ alloy is V-based solid solution,enriched in V and Cr elements,and the other phase is Ti-Fe matrix,enriched in Ti and Fe elements.The results show that the strength and plasticity of the alloy are obviously improved by doping different elements in the selected system,and the properties are better with the increase of the adding elements.In the screened V₇₀Ti₁₀Cr₅Fe₁₅ system doped with different atomic ratios of C and La elements,adding 8 at.% C has the best effect on the strength and plasticity of the alloy.The results of elemental analysis show that the elements in the matrix are mainly V,Cr and Fe whereas C and Ti elements are enriched in ellipsoid region.After aging at 1000 ? for 5hours,the hardness and compression strength of the alloy are increased most.Among the alloys with added La,the strength and plasticity of the alloy are largely increased by adding 3 at% La.The compressive properties of the alloy are lowered after annealing at800 ? and 1000 ? for 1 h.With the increase of annealing temperature,the phase is still a BCC solid solution,and the phase structure has not changed significantly.In this dissertation,different elements are added into the V-Ti-Cr-Fe alloy to construct a V-based multi-component alloy.The addition of C and La elements improves the comprehensive mechanical properties of the alloy and provides a new idea for its application in the field of nuclear structure materials.