The method of solid solution strengthening preparation of tantalum base alloy with gradient structure is as follows: 1. The tantalum powder is placed in nitriding furnace, and the tantalum powder is treated with oxynitriding; Second, the tantalum powder after oxynitriding treatment is placed in the plasma sintering furnace, and the tantalum powder after oxynitriding treatment is sintered to obtain tantalum base alloy; Third, the tantalum base alloy is placed in a vacuum annealing furnace, and the tantalum base alloy is subjected to vacuum annealing treatment. The method of the invention firstly makes the oxygen nitrogen in the tantalum powder distribute in gradient from the surface to the core through oxynitrizing treatment, and then forms the tantalum base alloy through sintering treatment, and the hardness of the tantalum base alloy also presents gradient distribution from the surface to the core. Finally, the oxygen nitrogen in the tantalum base alloy is gradually diffused from the boundary to the core through vacuum annealing treatment. It can control the mechanical properties of the material in a large range, achieve a good match between the strength and plasticity of the tantalum base alloy, and extend the service life of the material.
Refractory metals tantalum and niobium are widely used, but compared with their melting points, their potential strength properties are far from being discovered, and can not meet the increasing application needs of people. Even at low operating temperatures, due to its lack of strength, it will lead to the reduction of fatigue, wear and corrosion properties, thereby shortening the service life of zero components. At present, tantalum or tantalum alloy is widely used at home and abroad to replace gold and platinum alloy to make spinnerets for chemical fiber wet or dry and wet spinning. However, its wear resistance is poor and it is easy to scratch, resulting in deformation under a certain pressure for a long time, which increases the production cost, affects the spinning effect of spinnerets, and leads to high defects and hairline fall. Therefore, it is of great significance to improve the strength properties of tantalum alloy to meet the special production process.
At present, the main strengthening methods of tantalum alloy are solid solution strengthening and precipitation strengthening. For example, Ta-7.5W, Ta-12W, Ta-15W series alloys used for many years in aerospace and missile technology rely on solid solution strengthening of tungsten, and its strength increases with the increase of tungsten content, but the processing of tantalum tungsten series alloys is more difficult. In addition, elements such as hafnium and carbon are added on the basis of tantalum tungsten alloy, and the strength performance can be further improved through the solid solution strengthening of tungsten and hafnium and the precipitation phase strengthening of hafnium carbide, but it only reaches about 800MPa. The composition of multi-element tantalum alloy is relatively complex, and the price of added elements such as tungsten and hafnium is relatively expensive, and the processing performance of the alloy is poor. Therefore, the development and research of low-cost high-strength tantalum alloys can not only effectively save the amount of materials, but also expand the application range of tantalum alloys.
