CN1785587A - Preparation method of Cu/Ta/Cu composite tube - Google Patents

Abstract

A technology for manufacturing the composite Cu/Ta/Cu pipe includes such steps as assembling the nested Cu/Ta/Cu body, die pressing at 600-650 deg.C to become Cu/Ta/Cu pipe, straightening, cooling, and removing head and tail. It has high metallurgical adhesion.

Description

A kind of preparation method of Cu/Ta/Cu multiple tube

Technical field

A kind of preparation method of Cu/Ta/Cu multiple tube, Sn method Nb in relating to ₃The preparation method of the multiple tube of the adding usefulness of needed Ta barrier layer in final composite blank when Sn superconduction strand prepares.

Technical background

Multicore Nb ₃Sn superconduction strand is to make one of optimal high field super material of the above superconducting magnet of 10T.Sn method technology prepares this strand and is subjected to people in recent years and pays much attention in adopting, and it has not only overcome needs the shortcoming of repeatedly annealing among the bronze method preparation technology, and superconductivity is more excellent more than the latter.In interior Sn method technology, at first prepare multicore Cu/Nb complex (subgroup unit) with Sn core, again that 19 (or 37 or 61) root is such subgroup unit boundling is packed into and is constituted final blank in the Cu/Ta/Cu multiple tube that contains the Ta layer, processes this final blank then and carry out Nb to required composite strands 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.Ta layer in the strand be to prevent that Sn pollutes the outer pure Cu district that the superconduction strand is played stabilization of Ta floor in the heat treatment process, so the adding of Ta barrier layer is one of key technology of strand preparation as desirable barrier material.

How to make that Ta layer and Cu are combined in the Cu/Ta/Cu multiple tube, make that the Ta layer is difficult for breaking in the composite strands processing, and the thickness that can effectively control the Ta floor and the Ta floor thickness in Cu district outward, make composite pipe at interior Sn method Nb ₃The control that helps long line processing and Cu ratio in the preparation of Sn composite strands is very important.

Summary of the invention

Purpose of the present invention is exactly to have excellent metallurgical between Ta layer and the Cu and combine in order to prepare, make that the Ta layer is difficult for breaking in the composite strands processing subsequently, and can control the thickness in the outer Cu district of the thickness of Ta floor and Ta floor, help that long line is processed and the preparation method of the Cu/Ta/Cu multiple tube that contains the Ta layer of the control of Cu ratio.

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

A kind of preparation method of Cu/Ta/Cu multiple tube is characterised in that its preparation process is:

(a) with after the shell Cu that processes pipe, Ta pipe and the pickling of liner Cu pipe, dehydration, the oven dry; Be assembled into Cu/Ta/Cu superpacket body successively in order, there is Cu sheet cap seal at the two ends up and down of compound jacket; Adopt vacuum electron beam welding equipment that the superpacket body is carried out soldering and sealing, whole soldering and sealing process is 10 ^-3Carry out under the vacuum more than the Pa;

(b) superpacket behind the vacuum seal is enclosed within 600-650 ℃ of extruding acquisition Cu/Ta/Cu composite pipe down, extrusion ratio is controlled to be 7-11;

(c) on tube straightener for pipe, extrude tubes is aligned, removed head after the cooling, tail can obtain finished product Cu/Ta/Cu composite pipe.

The Cu/Ta/Cu multiple tube of method of the present invention preparation because this multiple tube is to adopt the hot extrusion technology to obtain, has excellent metallurgical and combines between the Ta floor between the inside and outside Cu district and Cu, the thickness in the thickness of Ta floor and inside and outside Cu district can artificially be controlled.The Ta barrier layer is difficult for breaking in composite strands process subsequently.And the thickness in the outer Cu district of the thickness of Ta floor and Ta floor can artificially be controlled, in the internal Sn method of the preparation method technology of the therefore this Cu/Ta/Cu multiple tube that contains the Ta layer the long line of composite strands process and the control of Cu ratio very favourable.The Cu/Ta/Cu 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) can reach more than the 1500m, and does not occur crack conditions substantially in the process.

Description of drawings

The preparation method's of a kind of Cu/Ta/Cu multiple tube of the present invention Cu/Ta/Cu superpacket cover installation diagram.

The specific embodiment

A kind of preparation method of Cu/Ta/Cu multiple tube, its preparation process is: adopt purity to be respectively Cu shell 9 and liner Cu pipe 10 that 99.995% and 99.95% Cu pipe is processed into required size; Purity is Ta pipe 11 (annealed state) that 99.95% Ta is processed into required size; Carry out dressing up after pickling, dehydration, the oven dry the compound jacket of Cu/Ta/Cu again, it is 99.95% Cu lid 12,13 that there is purity at the two ends up and down of compound jacket; Adopt vacuum electron beam welding equipment that the superpacket cover is carried out vacuum seal; Whole soldering and sealing process is 10 ^-3Carry out under the vacuum more than the Pa; The superpacket behind the vacuum seal is enclosed within 600-650 ℃ of extruding acquisition Cu/Ta/Cu composite pipe down, extrusion ratio is controlled to be 7-11 again; On tube straightener for pipe, extrude tubes is aligned at last, removed head after the cooling, tail can obtain finished product Cu/Ta/Cu composite pipe.

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

Example 1

At first be with purity 99.995% and 99.95% Cu pipe be processed into respectively outer through Φ 98.5mm, interior through Φ 35.5mm, high 220mm shell and outside through Φ 29.9mm, interior through Φ 20.1mm, high 220mm internal lining pipe and upper and lower Cu lid, be processed into outer with 99.95% Ta simultaneously through Φ 35.5mm, interior through the Ta of Φ 30.0mm, high 200mm pipe.Between Cu shell and internal lining pipe, have the compound jacket of Cu/Ta/Cu of Cu lid up and down with being assembled into the Ta pipe after the pickling of the above-mentioned Cu assembly that obtains and Ta pipe, dehydration and the oven dry again; The superpacket that assembles is enclosed within the vacuum electron beam welding equipment and carries 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 is after He mass-spectrometer leak test confirms that weldquality is qualified, and through Φ 35.0mm, interior through the Cu/Ta/Cu of Φ 19.0mm multiple tube, extrusion ratio is 10.7 outside being squeezed under 600 ℃.The multiple tube that extruding obtains is aligned through tube straightener for pipe, and straightening temperature～300 ℃ are cut away tubing at last and obtained finished product Cu/Ta/Cu composite pipe end to end.The Cu district outside the Ta layer thickness～0.4mm in this multiple tube, Ta floor and the ratio R of the cross-sectional area of whole tubing are 0.68.The cross section in length and breadth of metallographic observation multiple tube, the Ta layer thickness is even, has reached excellent metallurgical with inside and outside Cu district and has combined.

According to interior Sn method Nb ₃The different designs parameter of Sn strand can satisfy the designing requirement of various Ta layer thicknesses and R value by the size of adjusting compound jacket corresponding assembly.

The Cu/Ta/Cu 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 can reach more than the 1500m, does not occur crack conditions in the process substantially.The thickness of Ta barrier layer is 6-7 μ m in Φ 0.81mm composite strands, and composite strands uses HNO ₃Do not see that with the mixed liquor corrosion of water the Ta layer breaks.This composite strands is through Nb ₃After Sn generated heat treatment (total heat treatment time is about 400 hours), energy spectrum analysis showed that the outer pure Cu district of Ta floor is not subjected to the pollution of Sn.

Example 2

Each assembly material purity of compound jacket, size, preparation method, assembling and soldering and sealing situation are with example 1.Different is, in Cu/Ta/Cu composite pipe extrusion process, extrusion temperature is heightened to 650 ℃ by 600 ℃ in the example 1, and extrusion ratio is 7.The cross section is through metallographic observation in length and breadth for the Cu/Ta/Cu finished product composite pipe that is obtained, and the Ta layer thickness is even, has reached excellent metallurgical with inside and outside Cu district and has combined.The Cu/Ta/Cu composite pipe uses at interior Sn method Nb ₃The long line processing situation of Sn strand, HNO ₃Ta layer situation behind the aqueous corrosion strand, composite strands are through Nb ₃The EDAX results in the outer Cu district of Ta floor, Sn generation heat treatment (with example 1) back etc. are identical with example 1.

Example 3

The purity of compound each assembly material of jacket, preparation method, assembling, vacuum seal, extrusion temperature are equal to example 1, and the size that is compound each assembly of jacket is different: the Cu shell is outer through Φ 98.5mm, interior through Φ 44.5mm, high 220mm; Internal lining pipe is outer through Φ 41.0mm, interior through Φ 31.0mm, high 220mm; The Ta pipe is outer through Φ 44.5mm, interior through Φ 41.0mm, high 200mm.Use the Cu/Ta/Cu multiple tube of the resulting compound jacket of these assemblies through vacuum seal, hot extrusion acquisition external diameter Φ 45.0mm, internal diameter Φ 30.0mm, the tubing extrusion ratio is 7.8.At tube straightening after in the finished product multiple tube that crop truncates, Ta layer thickness～0.3mm, the Cu district that the Ta floor is outer and the ratio R of the cross-sectional area of whole tubing are 0.55.Use the cross section in length and breadth of metallographic observation finished product multiple tube, the Ta layer thickness is even, has reached excellent metallurgical with inside and outside Cu district and has combined, and the Cu/Ta/Cu composite pipe uses at interior Sn method Nb ₃The long line processing situation of Sn strand, HNO ₃Ta layer situation behind the aqueous corrosion strand, composite strands are through Nb ₃The EDAX results in the outer Cu district of Ta floor, Sn generation heat treatment (with example 1) back etc. are identical with example 1.

1,2,3,4,5,6,7,8 is weld seam in the accompanying drawing.

Claims (1)

1. the preparation method of a Cu/Ta/Cu multiple tube is characterised in that its preparation process is:

(a) with after the shell Cu that processes pipe, Ta pipe and the pickling of liner Cu pipe, dehydration, the oven dry; Be assembled into Cu/Ta/Cu superpacket body successively in order, there is Cu plate cap seal at the two ends up and down of compound jacket; Adopt vacuum electron beam welding equipment that the superpacket body is carried out vacuum seal, whole soldering and sealing process is 10 ^-3Carry out under the vacuum more than the Pa;

(b) superpacket behind the vacuum seal is enclosed within 600-650 ℃ of extruding acquisition Cu/Ta/Cu composite pipe down, extrusion ratio is controlled to be 7-11;

(c) on tube straightener for pipe, extrude tubes is aligned, removed head after the cooling, tail can obtain finished product Cu/Ta/Cu composite pipe.

Images