In NbTiTa alloy, the melting point of Ta element is as high as 3017℃, the density is as high as 16.60g/cm3, the melting point of Nb element is as high as 2469℃, the density is as high as 8.57g/cm3, while the melting point of active metal Ti is only 1668℃, the density is only 4.50g/cm3, and the melting point and density of the three elements are very different. It is very easy to produce tantalum and niobium non-frit in vacuum consumable arc melting, and the preparation technology of ingot is very difficult. When preparing titanium alloys containing refractory elements, the usual way is to first prepare the intermediate alloy by powder metallurgy or melting, and then prepare titanium alloys containing refractory elements. However, it is difficult to control the impurity elements, the purity of the material is poor, and the finished product is high. On the one hand, because the melting point of Ta element is much higher than that of Ti element, the risk of tantalum not frit in the intermediate alloy is greater. On the other hand, due to the high content of Ta and Nb in the alloy, when the proportion of intermediate alloy chips is too large, it is easy to fall off in the smelting process, and the metallurgical risk is large.
Niobium-zirconium alloy powder and its preparation method, using niobium hydride powder and zirconium hydride powder as raw materials, preparing mixed powder, controlling the content ratio of niobium element to zirconium element and oxygen to carbon ratio in the mixed powder, fully mixing and then loading into the ball mill for mechanical alloying treatment, and then pressing the powder to form, sintering under high temperature and vacuum stage, and then hydrogenating the alloy strip. The alloy strip after hydrogenation is crushed and screened by a ball mill, and the hydrogen of the powder is removed at a certain temperature. The alloy powder is screened and graded according to the requirements of the product after the impurity removal. The preparation method of niobium-zirconium alloy powder in this application is adopted. Since the raw materials are all niobium hydride powder and zirconium hydride powder, the mixed powder can be mixed evenly when preparing the mixed powder, and the element content is easy to control, avoiding the alloying process of pure niobium and pure zirconium metal through high temperature melting. Because the alloying process is completed by melting and diffusion, the diffusion process is slow. Therefore, the distribution of alloying elements is not uniform. At the same time, the technical scheme in this application, through the high temperature stage sintering of the pressed powder, can make the gas impurities more fully released during the sintering process, the prepared niobium-zirconium alloy powder has a uniform distribution of zirconium elements, and the content of gas impurities is low, which is suitable for the thermal spraying repair of the failed target or the direct preparation of niobium-zirconium alloy target by hot pressing.
