A high strength niobium alloy reinforced by scandium and tantalum is prepared through the steps of batching, mixing, pressing and hot pressing sintering. The new idea of introducing scandium and tantalum into the alloy as beneficial alloying elements, meanwhile, niobium reduces the content of aluminum in the alloy and ensures the alloy has good plasticity and toughness. By means of hot-pressing sintering, low-cost high-strength alloy materials with high strength and wear resistance were obtained. By adding lanthanum and praseodymium elements, the microstructure of the alloy is refined, the strength of the alloy is further enhanced, and the alloy keeps good mechanical properties at room temperature and high temperature.
In the development of aviation and space industry, the development of advanced materials is very important for the progress of aviation and space technology. In order to save energy and reduce pollution, aviation and aerospace structural materials are required not only to withstand high temperature but also to have high specific strength and stiffness. Nickel-niobium alloy is considered as one of the potential candidate materials for high-temperature light alloy due to its high melting point, high specific strength and modulus, low creep rate, relatively small density, good thermal conductivity and high temperature oxidation resistance. However, the poor ductility at room temperature and high temperature strength of niobium alloys limit their wide application. At present, there are many methods for the synthesis and preparation of niobium intermetallic compounds and their alloys, such as alloy melting, plasma sintering, combustion synthesis, mechanical alloying and hot isostatic pressing. However, these methods more or less have some shortcomings.
The microstructure of ni-Ag intermetallic compounds is very stable, and the formation energy is high, up to 82kJ/mol. In the development of niobium alloy, alloying and composite technology have always been the two most important means to improve the microstructure and properties of niobium alloy. In fact, people have not stopped exploring the influence of metal elements on the microstructure and properties of niobium alloy. However, the influence of metal elements on the strength and plasticity of niobium alloy and its mechanism are still unclear and controversial.
