The method for preparing high-field Nb3Sn superconducting strand wire by adding titanium element with Nb-47Ti rod as the addition source belongs to the technical field of superconducting material preparation, and relates to a method for adding titanium element in the form of Nb-47Ti rod during the preparation process of high-field Nb3Sn strand wire.
The inner tin method Nb3Sn strand wire is mainly used in high technology fields such as thermonuclear fusion Experimental reactor (ITER), NMR, high energy physics, particle accelerator magnets, etc. In order to improve the current carrying capacity of the strand wire under high field, the third element titanium or tantalum needs to be added to the commercial Nb3Sn strand wire. Considering the cost and addition method, adding titanium element is the first choice. In the preparation process of Nb3Sn strand by inner tin method, the elements Cu, Nb and Sn are independent of each other and the design is flexible, which makes the addition method of titanium element diverse and flexible. After recent years of development, there are two more mature Ti addition methods: one is to add Ti to Sn source to form SN-Ti alloy, and the other is to replace a few niobium cores with Nb47Ti cores as independent components. The first method was developed earlier and is also seen in relevant papers and patents at home and abroad. However, due to the high production cost of Sn-Ti alloy and the hard brittleness of the larger size Ti6Sn5 particles in the alloy, the further development of this method is also limited. The addition method of Nb47Ti has low cost and good plasticity, which is an ideal method for the preparation of Nb3Sn strands. The method is still in the initial application stage, and the key technologies are mastered by some foreign superconducting material production companies as trade secrets, and the relevant papers and patents are only limited to introduction.
Ti element is added in the form of Nb47Ti, and the distribution design determines the uniformity of titanium diffusion in the heat treatment process of strand, thus determining the addition effect of Ti element. The amount of addition determines the proportion of Ti addition. In the process of processing, it is necessary to ensure the synchronous deformation of Nb47Ti core wire and niobium core wire to ensure the normal stretching of the strand, so the processing method and processing parameters determine whether the method can be successfully applied to production.
