The high uniformity of NbTi alloy bars is a prerequisite for obtaining high performance NbTi superconducting wires, and its composition uniformity directly affects the magnetic flux pinning ability and critical current density properties of superconducting wires. The traditional preparation process of NbTi alloy bars includes electrode assembly welding of Nb ingot and pressed sponge titanium, multiple vacuum consumable arc furnace melting, multiple upset forging and recrystallization heat treatment. In order to form a large number of pinning centers in NbTi alloy, in the process of processing NbTi superconducting wire using multiple heat treatment and cold processing technology to form small dispersed α-Ti precipitation phase and dislocation and other defects, the processing process is complicated, long processing cycle, high processing cost.
The invention relates to a method for preparing NbTi alloy bars by powder metallurgy, which solves the problem of adding barrier layer when assembling NbTi alloy bars prepared by the existing method, simplifies the processing technology of NbTi alloy bars, greatly reduces the manufacturing cost of NbTi alloy bars, and has broad application prospects.
The purpose is to provide a method for preparing NbTi alloy bars by powder metallurgy. Pure Ti or Nb powder with similar initial size is uniformly mixed into NbTi powder, and NbTi alloy bars are obtained after degassing and hot isostatic pressing after assembly with stainless steel envelope, so that there is no need for aging heat treatment of pinning phase during the processing of superconducting wire. The preparation cost of NbTi alloy bar is greatly reduced and the processing cycle of NbTi superconducting wire is simplified, which has a broad application prospect.
Including: S1, NbTi powder and pure Ti powder or pure Nb powder to mix and stir evenly; S2. Put NbTi powder containing pure Ti or pure Nb powder prepared in step S1 into stainless steel envelope and degassing; S3, the stainless steel sheath obtained in step S2 is subjected to hot isostatic pressing, and the outer stainless steel sheath is removed by turning to obtain NbTi alloy bars. The invention provides a method for preparing NbTi alloy bar by powder metallurgy method, which greatly reduces the preparation cost of NbTi alloy bar and simplifies the processing cycle of NbTi superconducting wire, and has broad application prospect.
