CN1996507A - Preparing method for the Cu-based multi-core Cu/Nb compound tube - Google Patents

Abstract

This invention relates to one multi-chip Cu and Nb compound tube process method in need of Nb3Sn super conductive wire process, which comprises the following steps: firstly processing six angle Cu-Nb compound chip bar; processing Cu/Cu-Nb/Cu compound cover tube in the gap between shell Cu cover an inner Cu tube in tightly arrayed bars; sealing the cover tube two ends to get the compound tube with multiple chips with Cu base.

Description

A kind of is the preparation method of the multicore Cu/Nb multiple tube of matrix with Cu

Technical field

A kind of is the preparation method of the multicore Cu/Nb multiple tube of matrix with Cu, Sn fado core Nb in relating to ₃The preparation method of needed Cu Quito core Cu/Nb multiple tube when Sn superconduction strand prepares.

Technical background

Multicore Nb ₃Sn superconduction strand is a kind of high field super material with excellent superconductivity, is to make one of optimal superconductor of the above superconducting magnet of 10T.This strand of Sn method prepared is subjected to the great attention of developed countries such as Europe, the United States, day in adopting, and it has not only overcome needs the shortcoming of repeatedly annealing among the bronze method preparation technology, and superconductivity is than latter's excellence more.In interior Sn method technology, at first prepare Cu Quito core Cu/Nb multiple tube, be processed into Cu/Nb/Sn compound bar (subgroup unit) after inserting the Sn core, subgroup that 19 (or 37 or 61) root is such unit boundling is packed into and is constituted final blank in the Cu/Ta/Cu multiple tube, processes final blank then and carry out Nb to the composite strands of required size ₃The generation heat treatment of Sn.After Sn and Cu generated the Sn bronze in heat treatment, Sn in the bronze and Nb solid-state diffusion generated Nb ₃The Sn layer.Obviously, the required Cu Quito core Cu/Nb multiple tube of preparation subgroup unit is interior Sn fado core Nb ₃One of key technology of Sn superconduction strand preparation.

Summary of the invention

The objective of the invention is the multicore Cu/Nb multiple tube that in the Cu matrix, is embedded with hundred above Nb cores in order to prepare, distribution of Nb core and size are even in multiple tube, having excellent metallurgical with the Cu matrix combines, multiple tube internal diameter size and Cu, Nb percent by volume are controlled, the multiple tube inner wall smooth is smooth, helps follow-up composite strands and adds man-hour Nb and the preparation method of Cu Quito core Cu/Nb multiple tube of disconnected core situation do not occur.

The objective of the invention is to be achieved through the following technical solutions.

A kind of is the preparation method of the multicore Cu/Nb multiple tube of matrix with Cu, it is characterized in that its preparation process is followed successively by:

(a) with after the Nb that configures rod and the pickling of Cu pipe, dehydration, the oven dry, will be processed into hexagonal rod in the Nb rod insertion Cu pipe, fixed-length cut-off is made hexagonal Cu-Nb composite core rod;

(b) the shell Cu sleeve pipe of big caliber is in the same place with tubule footpath liner Cu pipe coaxial package, the tight boundling of hexagonal Cu-Nb composite core rod that makes is arranged in the gap that forms between shell Cu cover and the liner Cu pipe makes Cu/Cu-Nb/Cu superpacket sleeve pipe;

(c) with the two ends of the Cu/Cu-Nb/Cu superpacket sleeve pipe made with Cu lid welding cap seal, welding cap seal process is carried out under vacuum;

(d) the superpacket sleeve pipe after the soldering and sealing being pushed acquisition down at 600-650 ℃ is the multicore Cu/Nb multiple tube of matrix with Cu, and extrusion ratio is controlled to be 7-11; On the tube straightener for pipe extruded tube aligned, removed end to end, after the pickling, making finished product multicore Cu/Nb multiple tube.

The Cu/Nb multiple tube of the inventive method preparation, owing to be to adopt the hot extrusion technology to obtain, having excellent metallurgical between Nb core in the Cu matrix and the Cu combines, Cu-Nb plug when compound jacket is assembled is according to the close-packed hexagonal boundling, plug is difficult for dislocation in extrusion process, guaranteed that distribution and the size of Nb core in the Cu matrix is even, also can not change Cu, Nb percent by volume in the compound jacket; Superpacket is enclosed within and uses the high extruding pin of surface smoothness in the extruding, has guaranteed the smooth smooth of multicore Cu/Nb multiple tube inwall; The good metallurgical binding of Cu and Nb has guaranteed subsequently in the composite strands course of processing not easy fracture of Nb core in multiple tube.Multicore Cu/Nb multiple tube is used at interior Sn method Nb ₃In the long line preparation of Sn strand, the solid wire length of strand (Φ 0.81mm) surpasses 2500m, and Nb core size can reach 4 μ m, and is not prone to crack conditions in the course of processing.

Embodiment

A kind of is the preparation method of the multicore Cu/Nb multiple tube of matrix with Cu, its preparation process is followed successively by: after (a) Nb that configures rod and Cu being managed pickling, dehydration, oven dry, insert in the Cu pipe Nb rod by required Cu, Nb volume ratio and be dimensioned to hexagonal rod, such hexagonal rod is blocked the formation composite core rod by Len req.(b) with after the shell Cu that processes cover, the pickling of liner Cu pipe, dehydration, the oven dry and the composite core rod (a) be assembled into the compound jacket of Cu/Cu-Nb/Cu, the Cu-Nb plug more than hundred in compound jacket by the close-packed hexagonal boundling between shell Cu cover and liner Cu pipe.There is Cu lid cap seal at the two ends up and down of compound jacket, adopt vacuum electron beam welding equipment that the superpacket cover is carried out soldering and sealing, and whole soldering and sealing process is 10 ^-3Carry out under the vacuum more than the Pa.(c) superpacket after the soldering and sealing being enclosed within 600-650 ℃ of following extruding acquisition is the multicore Cu/Nb multiple tube of matrix with Cu, and extrusion ratio is controlled to be 7-11; (d) on the tube straightener for pipe extruded tube is being aligned, removed end to end, can obtain finished product multicore Cu/Nb multiple tube after the pickling.

Below in conjunction with example method of the present invention is described further.

Embodiment 1

With purity is to be processed into that Cu, Nb volume ratio are 1.3, opposite side is of a size of 4.5mm, length is the hexagonal composite core rod of 200mm behind 99.99% and 99.99% Cu pipe and the Nb rod compound (in the Nb rod insertion Cu pipe).Using purity is the Cu shell that 99.99% Cu pipe is processed into external diameter Φ 98.5mm, internal diameter Φ 92.0mm, high 220mm, the liner Cu pipe of external diameter Φ 27.0mm, internal diameter Φ 15.0mm, high 220mm and Cu lid up and down.Have the compound jacket of Cu/Cu-Nb/Cu of Cu lid up and down with being assembled into behind 324 Cu-Nb hexagonal sticks and the pickling of Cu assembly, the dewatered drying, 324 Cu-Nb plugs at compound jacket meta between Cu shell and internal lining pipe, by the close-packed hexagonal boundling.The compound jacket that assembles uses vacuum electron beam welding equipment to carry out soldering and sealing, and whole soldering and sealing process is 10 ^-3Carry out under the vacuum more than the Pa.Compound jacket after the soldering and sealing through hunt leak qualified after, under 600-650 ℃, be squeezed into external diameter Φ 35.0mm, the Cu/Nb multiple tube of internal diameter Φ 14.3mm, extrusion ratio～10.Multiple tube obtains finished product Cu/Nb composite pipe after aligning, the tail of decaptitating, pickling.The cross section of metallographic observation multiple tube, distribution of Nb core and size are even, have reached excellent metallurgical with the Cu matrix and have combined.

The Cu/Nb composite pipe is used at interior Sn method Nb ₃In the long line processing of Sn strand, composite strands (Φ 0.81mm) solid wire length surpasses 2500m, does not occur crack conditions in the course of processing.Nb core chi can reach about 4 μ m in Φ 0.81mm composite strands, and composite strands uses HNO ₃Do not find disconnected core situation with the mixed liquor corrosion of water.This composite strands is through Nb ₃After Sn generated heat treatment, the superconducting critical current density Jcn in the non-Cu of strand district (4.2K, 12T, 0.1 μ v/cm) reached 1000A/mm ²More than.

Embodiment 2

The assembling of the material purity of compound each assembly of jacket, plug preparation method and size, compound jacket, soldering and sealing, hot extrusion technique are with example 1, different is, the Cu of 324 hexagonal Cu/Nb composite core rods, Nb volume ratio are 1.0, composite pipe outside dimension after the extruding is that Φ 35.Omm, internal diameter size are Φ 13.0mm, extrusion ratio～11.The cross section metallographic observation results of multicore Cu/Nb multiple tube and use are at interior Sn method Nb ₃The long line processing result of Sn composite strands is identical with example 1.

Embodiment 3

The assembling of the material purity of compound each assembly of jacket, plug preparation method, compound jacket, soldering and sealing, hot extrusion technique are with example 1, the Cu/Nb hexagonal sticks opposite side that different is in the compound jacket is of a size of 6.5mm, total core number is 144, Cu, Nb volume ratio are 1.5 in the plug, composite pipe outside dimension after the extruding is Φ 45.0mm, internal diameter size is Φ 18.00mm, extrusion ratio～7.The cross section result of metallographic observation multicore Cu/Nb multiple tube and use are at interior Sn method Nb ₃The long line processing result of Sn composite strands is identical with example 1.

Claims (1)

1. be the preparation method of the multicore Cu/Nb multiple tube of matrix with Cu, it is characterized in that its preparation process is followed successively by:

(a) with after the Nb that configures rod and the pickling of Cu pipe, dehydration, the oven dry, will be processed into hexagonal rod in the Nb rod insertion Cu pipe, fixed-length cut-off is made hexagonal Cu-Nb composite core rod;

(b) the shell Cu sleeve pipe of big caliber is in the same place with tubule footpath liner Cu pipe coaxial package, the tight boundling of hexagonal Cu-Nb composite core rod that makes is arranged between shell Cu cover and the liner Cu pipe makes Cu/Cu-Nb/Cu superpacket sleeve pipe in the formed gap;

(c) with the two ends of the Cu/Cu-Nb/Cu superpacket sleeve pipe made with Cu lid welding cap seal, capping and welding process are carried out under vacuum;

(d) the superpacket sleeve pipe after the soldering and sealing being pushed acquisition down at 600-650 ℃ is the multicore Cu/Nb multiple tube of matrix with Cu, and extrusion ratio is controlled to be 7-11; On the tube straightener for pipe extruded tube aligned, removed end to end, after the pickling, making finished product multicore Cu/Nb multiple tube.