A kind of welding method of copper chromium on-load switch assemblyTechnical field
The invention belongs to contact material of vacuum switch field, be specifically related to a kind of welding method of copper chromium on-load switch assembly.
Background technology
Integral electric contact is widely used in various mesohigh breaker, is the core component of various power switch, and at present, the overall liquid sintering technology of general employing manufactures integral electric contact.A kind of peculiar part that monoblock type contact is made up of two kinds of unlike materials, its head is chromiumcopper, for arc extinguishing, afterbody is generally copper alloy QCr0.5, its Main Function possesses certain elasticity and good electric conductivity, with regard to integral electric contact, the bond strength of two kinds of material faying faces, electrical conductivity are the factors of the most critical affecting integral electric contact combination property.
Conventional silver alloy or the method for copper alloy soldering, its conductivity interface and bond strength are all less than mother metal, postwelding copper tail end annealing softening, and interface performance becomes the weak link of electrical contact, in use easily generates heat, and snaps and comes off; Another kind method is the electrical contact through liquid-phase sintering, and its boundary strength can close to strength of parent (copper tail), and electrical property reaches chromiumcopper level, but the process-cycle is long, takes material.
Original copper chromium on-load switch mainly adopts smelting technology to manufacture chromium-copper contact and is prepared into conducting rod with the copper bar of machine-shaping by vacuum brazing again.Its welding tensile strength is generally at 170-230MPa, and have direct relation with the proficiency of operating personnel, it directly affects the quality of last chrome copper, and adopts silver soldering sheet, and solder cost is probably 4 yuan/part, and cost is higher.
Summary of the invention
For solving the problem, the invention provides a kind of welding method of copper chromium on-load switch assembly, the technique of friction welding (FW) is adopted to replace vacuum brazing technique, to two kinds of metal solder of switch be formed together, then through suitable heat treatment, eliminate welding interior stress, and overall processing, can obtain than other method at the tensile strength of faying face and all more excellent monoblock type on-load switch of hardness.
The present invention is for solving the problems of the technologies described above the welding method that adopted technical scheme is a kind of copper chromium on-load switch assembly, and it comprises the following steps:
1) copper chromium contact is made: the thickness of copper layers of chrome is 5 ~ 6mm; Get the copper powder of 45% ~ 55% and the chromium powder of 55% ~ 45% by weight percentage, the particle diameter of copper powder is 250 ~ 270 orders, the particle diameter of chromium powder is 4.5 ~ 5.5 μm, copper powder in hydrogen atmosphere through 350 DEG C ~ 450 DEG C reductase 12 ~ 3h, chromium powder in High Purity Hydrogen atmosphere through 1000 DEG C ~ 1200 DEG C reductase 12 ~ 3h; Copper powder after reduction and chromium powder, respectively after crushing and screening, namely obtain copper chromium powder material through abundant mixing by described weight proportion in Vacuum mixer; Load in compacting tool set, with 3.5 ~ 4.5kg/cm2precompression compacting, leave standstill 30 ~ 50min, be then blank at 800MPa ~ 1000Mpa forming under the pressure, deviate from from mould; Blank is sintered 1.5 ~ 2.5h at 950 DEG C ~ 1050 DEG C temperature, and sintering atmosphere is reducing atmosphere or vacuum-sintering; Sintering blank is multiple pressure under 1000MPa ~ 1200Mpa pressure, improves density and intensity further; Material after multiple pressure carries out annealing in process at 900 DEG C ~ 950 DEG C temperature; After cooling, in the Ar gas shielded reaction vessel that purity is 99.995%, adopt laser instrument to carry out the process of laser rapid scanning, laser processing technique parameter is: power is 3.5 ~ 4.0kW; Spot diameter is 5.5 ~ 6.5mm; Sweep speed is 220 ~ 250mm/min;
2) corresponding machining is carried out to described copper chromium contact and copper tail, both blank areas are designed to plane contact, weldment cylindrical is cylindrical, its flatness, perpendicularity are not more than 0.2mm, the surface file of weldering front connector part or sand papering, remove oxide, then through alcohol or ether cleaning 2min ~ 2.5min, in case mix other ion or impurity; Spirality welding decorative pattern is enclosed in the circumferentially processing two adopting lathe tool will carry out at copper tail the blank area welded;
3) get out the tooling device of friction-welding machine, debugging, to corresponding technological parameter, is welded; On the rolling clamp that described copper chromium contact and copper tail are held on friction-welding machine respectively and movable clamp, aim at clamping; Described rolling clamp is rotated by power drive mechanism driven rotary axle by motor and is driven, and described movable clamp drives the piston rod of hydraulic jack to shrink by hydraulic system and is driven; Clamping element in described rolling clamp and movable clamp is clamp, is made up of phenoplasts; Clamp directly clamps the outer round surface of copper chromium contact and copper tail respectively, and the face for clamping on clamp is arc surface, can make like this, on the dispersed outer round surface acting on copper chromium contact and copper tail of clamping force, the pressure in unit are to be diminished; Adjust the corresponding rotating speed of friction-welding machine, friction pressure, fraction time, burnoff length, braking time and forge length afterwards and carry out friction welding, with rotating speed 1450rpm ~ 1500rpm, initial friction pressure 30MPa ~ 35MPa friction welding 0.8s ~ 1s; Again with rotating speed 2300rpm ~ 2500rpm, friction pressure 120MPa ~ 130MPa carries out stable friction welding 6s ~ 8s rear braking, applies the upsetting force of 200MPa ~ 210MPa, and keep upsetting force 4s during brake 0.4s ~ 0.6s;
4) remove overlap, and carry out welding quality inspection, adopt ultrasonic wave or x-ray inspection, solder bond face vertical-depth is detected with or without weld crack or lack of penetration defect; When carrying out x-ray inspection, select the little focal spot x-ray defectoscope of high energy, high-quality X-ray film and titanium silk penetrameter, exposure voltage is selected according to technical chart, and light exposure is 30 ~ 40mAmin, makes barricade with stereotype, thickness is 5 ~ 8mm, physical dimension is rectangle, uses two-layer screen method to shield: the first barricade is being placed in the face of radiogenic side near weldment, secondary shielding plate, place back to radiogenic side near weldment, described barricade hides by two side shield sides; Then irradiate weld seam with X-ray, obtain x-ray film, the egative film after exposure is craft or auto-flushing on request, has not allowed scuffing, the false defect such as water stain; Quality grade evaluation is carried out to the method that the x-ray film obtained specifies by standard according to material thickness, thus realizes the detection of butt welded seam;
5) Ageing Treatment: by through step 4) weldment after process puts into high-low temperature test chamber, and be heated to 450 ~ 460 DEG C, be incubated 7 ~ 8 hours, then cool to room temperature with the furnace, complete high-temperature aging; And then temperature is adjusted to-20 DEG C ~-10 DEG C, keep 2 hours, complete low temperature aging; Finally naturally cool to room temperature in atmosphere;
6) machining: be processed into product by designing requirement stand-by.
Preferably, described step 1) in can add the mixture of metal La and Si of 0.4% of its weight when mixed copper chromium powder material, both weight ratios are 1.5:1, and the overlapping rate of laser processing technique is 37 ~ 39%.
In above-mentioned either a program preferably, described step 2) in copper tail be copper bar; The diameter of this copper bar is 28mm ~ 32mm, and length is 38mm ~ 40mm;
In above-mentioned either a program preferably, described step 3) in the friction feed speed of friction welding be 1.4Mm/s, forge length 4mm.
In above-mentioned either a program preferably, described step 3) on clamp for the size of arc surface that clamps respectively with the circular surfaces consistent size outside copper chromium contact and copper tail.
In above-mentioned either a program preferably, described step 4) in the mechanical means of overlap car or milling remove.
In above-mentioned either a program preferably, described step 4) in carry out x-ray inspection relative sensitivity be 1.5% ~ 1.8%.
Beneficial effect of the present invention:
1. friction-welding technique welding efficiency is high, and weld strength is high, and tensile strength can reach 240-280MPa, is more suitable for continuous seepage, reduces manufacturing cost, shortens the manufacturing cycle, improves yield rate; And with welding personnel experience connect experience have nothing to do, without the need to adding solder.
2. this manufacturing approach craft controllability is strong, improves welding quality, and part quality is stablized, and meets instructions for use.
3. the present invention makes the mechanical and physical character of product and electrical property obtain more effective guarantee, while raising integrated connection intensity, also improves the electric conductivity of whole electrical contact.
4. this manufacture method welding precision is high, can weldering erosion problem greatly in welding process, and the method is practical, and result of use is good, is convenient to promote the use of.
Detailed description of the invention
Below in conjunction with detailed description of the invention, the invention will be further described.
Embodiment 1
A welding method for copper chromium on-load switch assembly, it comprises the following steps:
1) copper chromium contact is made: the thickness of copper layers of chrome is 5mm; Get the copper powder of 55% and the chromium powder of 45% by weight percentage, the particle diameter of copper powder is 270 orders, and the particle diameter of chromium powder is 4.5 μm, copper powder in hydrogen atmosphere through 450 DEG C of reductase 12 h, chromium powder in High Purity Hydrogen atmosphere through 1200 DEG C of reductase 12 h; Copper powder after reduction and chromium powder, respectively after crushing and screening, namely obtain copper chromium powder material through abundant mixing by described weight proportion in Vacuum mixer; Load in compacting tool set, with 4.5kg/cm2precompression compacting, leave standstill 30min, be then blank at 1000Mpa forming under the pressure, deviate from from mould; Blank is sintered 2.5h at 950 DEG C of temperature, and sintering atmosphere is reducing atmosphere or vacuum-sintering; Sintering blank is multiple pressure under 1000MPa pressure, improves density and intensity further; Material after multiple pressure carries out annealing in process at 950 DEG C of temperature; After cooling, in the Ar gas shielded reaction vessel that purity is 99.995%, adopt laser instrument to carry out the process of laser rapid scanning, laser processing technique parameter is: power is 3.5kW; Spot diameter is 6.5mm; Sweep speed is 220mm/min;
2) corresponding machining is carried out to described copper chromium contact and copper tail, both blank areas are designed to plane contact, weldment cylindrical is cylindrical, its flatness, perpendicularity are not more than 0.2mm, the surface file of weldering front connector part or sand papering, remove oxide, then through alcohol or ether cleaning 2.5min, in case mix other ion or impurity; Spirality welding decorative pattern is enclosed in the circumferentially processing two adopting lathe tool will carry out at copper tail the blank area welded;
3) get out the tooling device of friction-welding machine, debugging, to corresponding technological parameter, is welded; On the rolling clamp that described copper chromium contact and copper tail are held on friction-welding machine respectively and movable clamp, aim at clamping; Described rolling clamp is rotated by power drive mechanism driven rotary axle by motor and is driven, and described movable clamp drives the piston rod of hydraulic jack to shrink by hydraulic system and is driven; Clamping element in described rolling clamp and movable clamp is clamp, is made up of phenoplasts; Clamp directly clamps the outer round surface of copper chromium contact and copper tail respectively, and the face for clamping on clamp is arc surface, can make like this, on the dispersed outer round surface acting on copper chromium contact and copper tail of clamping force, the pressure in unit are to be diminished; Adjust the corresponding rotating speed of friction-welding machine, friction pressure, fraction time, burnoff length, braking time and forge length afterwards and carry out friction welding, with rotating speed 1450rpm, initial friction pressure 35MPa friction welding 0.8s; Again with rotating speed 2500rpm, friction pressure 120MPa carries out stable friction welding 8s rear braking, applies the upsetting force of 210MPa, and keep upsetting force 4s during brake 0.4s;
4) remove overlap, and carry out welding quality inspection, adopt x-ray inspection, solder bond face vertical-depth is detected with or without weld crack or lack of penetration defect; When carrying out x-ray inspection, select the little focal spot x-ray defectoscope of high energy, high-quality X-ray film and titanium silk penetrameter, exposure voltage is selected according to technical chart, and light exposure is 30mAmin, makes barricade with stereotype, thickness is 8mm, physical dimension is rectangle, uses two-layer screen method to shield: the first barricade is being placed in the face of radiogenic side near weldment, secondary shielding plate, place back to radiogenic side near weldment, described barricade hides by two side shield sides; Then irradiate weld seam with X-ray, obtain x-ray film, the egative film after exposure is craft or auto-flushing on request, has not allowed scuffing, the false defect such as water stain; Quality grade evaluation is carried out to the method that the x-ray film obtained specifies by standard according to material thickness, thus realizes the detection of butt welded seam;
5) Ageing Treatment: by through step 4) weldment after process puts into high-low temperature test chamber, and be heated to 450 DEG C, be incubated 8 hours, then cool to room temperature with the furnace, complete high-temperature aging; And then temperature is adjusted to-10 DEG C, keep 2 hours, complete low temperature aging; Finally naturally cool to room temperature in atmosphere;
6) machining: be processed into product by designing requirement stand-by.
Described step 1) in can add the mixture of metal La and Si of 0.4% of its weight when mixed copper chromium powder material, both weight ratios are 1.5:1, and the overlapping rate of laser processing technique is 39%.
Described step 2) in copper tail be copper bar; The diameter of this copper bar is 28mmmm, and length is 40mm;
Described step 3) in the friction feed speed of friction welding be 1.4Mm/s, forge length 4mm.
Described step 3) on clamp for the size of arc surface that clamps respectively with the circular surfaces consistent size outside copper chromium contact and copper tail.
Described step 4) in the mechanical means of overlap car or milling remove.
Described step 4) in carry out x-ray inspection relative sensitivity be 1.5%.
Embodiment 2
A welding method for copper chromium on-load switch assembly, it comprises the following steps:
1) copper chromium contact is made: the thickness of copper layers of chrome is 6mm; Get the copper powder of 45% and the chromium powder of 55% by weight percentage, the particle diameter of copper powder is 250 orders, and the particle diameter of chromium powder is 5.5 μm, copper powder in hydrogen atmosphere through 350 DEG C reduction 3h, chromium powder in High Purity Hydrogen atmosphere through 1000 DEG C reduction 3h; Copper powder after reduction and chromium powder, respectively after crushing and screening, namely obtain copper chromium powder material through abundant mixing by described weight proportion in Vacuum mixer; Load in compacting tool set, with 3.5kg/cm2precompression compacting, leave standstill 50min, be then blank at 800MPa forming under the pressure, deviate from from mould; Blank is sintered 1.5h at 1050 DEG C of temperature, and sintering atmosphere is reducing atmosphere or vacuum-sintering; Sintering blank is multiple pressure under 1200Mpa pressure, improves density and intensity further; Material after multiple pressure carries out annealing in process at 900 DEG C of temperature; After cooling, in the Ar gas shielded reaction vessel that purity is 99.995%, adopt laser instrument to carry out the process of laser rapid scanning, laser processing technique parameter is: power is 4.0kW; Spot diameter is 5.5mm; Sweep speed is 250mm/min;
2) corresponding machining is carried out to described copper chromium contact and copper tail, both blank areas are designed to plane contact, weldment cylindrical is cylindrical, its flatness, perpendicularity are not more than 0.2mm, the surface file of weldering front connector part or sand papering, remove oxide, then through alcohol or ether cleaning 2min, in case mix other ion or impurity; Spirality welding decorative pattern is enclosed in the circumferentially processing two adopting lathe tool will carry out at copper tail the blank area welded;
3) get out the tooling device of friction-welding machine, debugging, to corresponding technological parameter, is welded; On the rolling clamp that described copper chromium contact and copper tail are held on friction-welding machine respectively and movable clamp, aim at clamping; Described rolling clamp is rotated by power drive mechanism driven rotary axle by motor and is driven, and described movable clamp drives the piston rod of hydraulic jack to shrink by hydraulic system and is driven; Clamping element in described rolling clamp and movable clamp is clamp, is made up of phenoplasts; Clamp directly clamps the outer round surface of copper chromium contact and copper tail respectively, and the face for clamping on clamp is arc surface, can make like this, on the dispersed outer round surface acting on copper chromium contact and copper tail of clamping force, the pressure in unit are to be diminished; Adjust the corresponding rotating speed of friction-welding machine, friction pressure, fraction time, burnoff length, braking time and forge length afterwards and carry out friction welding, with rotating speed 1500rpm, initial friction pressure 30MPa friction welding 1s; Again with rotating speed 2300rpm, friction pressure 130MPa carries out stable friction welding 6s rear braking, applies the upsetting force of 200MPa, and keep upsetting force 4s during brake 0.6s;
4) remove overlap, and carry out welding quality inspection, adopt x-ray inspection, solder bond face vertical-depth is detected with or without weld crack or lack of penetration defect; When carrying out x-ray inspection, select the little focal spot x-ray defectoscope of high energy, high-quality X-ray film and titanium silk penetrameter, exposure voltage is selected according to technical chart, and light exposure is 40mAmin, makes barricade with stereotype, thickness is 5mm, physical dimension is rectangle, uses two-layer screen method to shield: the first barricade is being placed in the face of radiogenic side near weldment, secondary shielding plate, place back to radiogenic side near weldment, described barricade hides by two side shield sides; Then irradiate weld seam with X-ray, obtain x-ray film, the egative film after exposure is craft or auto-flushing on request, has not allowed scuffing, the false defect such as water stain; Quality grade evaluation is carried out to the method that the x-ray film obtained specifies by standard according to material thickness, thus realizes the detection of butt welded seam;
5) Ageing Treatment: by through step 4) weldment after process puts into high-low temperature test chamber, and be heated to 460 DEG C, be incubated 7 hours, then cool to room temperature with the furnace, complete high-temperature aging; And then temperature is adjusted to-20 DEG C, keep 2 hours, complete low temperature aging; Finally naturally cool to room temperature in atmosphere;
6) machining: be processed into product by designing requirement stand-by.
Described step 1) in can add the mixture of metal La and Si of 0.4% of its weight when mixed copper chromium powder material, both weight ratios are 1.5:1, and the overlapping rate of laser processing technique is 37%.
Described step 2) in copper tail be copper bar; The diameter of this copper bar is 32mm, and length is 38mm;
Described step 3) in the friction feed speed of friction welding be 1.4Mm/s, forge length 4mm.
Described step 3) on clamp for the size of arc surface that clamps respectively with the circular surfaces consistent size outside copper chromium contact and copper tail.
Described step 4) in the mechanical means of overlap car or milling remove.
Described step 4) in carry out x-ray inspection relative sensitivity be 1.8%.
Embodiment 3
A welding method for copper chromium on-load switch assembly, it comprises the following steps:
1) copper chromium contact is made: the thickness of copper layers of chrome is 5.5mm; Get the copper powder of 50% and the chromium powder of 50% by weight percentage, the particle diameter of copper powder is 260 orders, and the particle diameter of chromium powder is 5 μm, copper powder in hydrogen atmosphere through 400 DEG C of reductase 12 .5h, chromium powder in High Purity Hydrogen atmosphere through 1100 DEG C of reductase 12 .5h; Copper powder after reduction and chromium powder, respectively after crushing and screening, namely obtain copper chromium powder material through abundant mixing by described weight proportion in Vacuum mixer; Load in compacting tool set, with 4kg/cm2precompression compacting, leave standstill 40min, be then blank at 900MPa forming under the pressure, deviate from from mould; Blank is sintered 2h at 1000 DEG C of temperature, and sintering atmosphere is reducing atmosphere or vacuum-sintering; Sintering blank is multiple pressure under 1000MPa ~ 1200Mpa pressure, improves density and intensity further; Material after multiple pressure carries out annealing in process at 930 DEG C of temperature; After cooling, in the Ar gas shielded reaction vessel that purity is 99.995%, adopt laser instrument to carry out the process of laser rapid scanning, laser processing technique parameter is: power is 3.8kW; Spot diameter is 6mm; Sweep speed is 240mm/min;
2) corresponding machining is carried out to described copper chromium contact and copper tail, both blank areas are designed to plane contact, weldment cylindrical is cylindrical, its flatness, perpendicularity are not more than 0.2mm, the surface file of weldering front connector part or sand papering, remove oxide, then through alcohol or ether cleaning 2.3min, in case mix other ion or impurity; Spirality welding decorative pattern is enclosed in the circumferentially processing two adopting lathe tool will carry out at copper tail the blank area welded;
3) get out the tooling device of friction-welding machine, debugging, to corresponding technological parameter, is welded; On the rolling clamp that described copper chromium contact and copper tail are held on friction-welding machine respectively and movable clamp, aim at clamping; Described rolling clamp is rotated by power drive mechanism driven rotary axle by motor and is driven, and described movable clamp drives the piston rod of hydraulic jack to shrink by hydraulic system and is driven; Clamping element in described rolling clamp and movable clamp is clamp, is made up of phenoplasts; Clamp directly clamps the outer round surface of copper chromium contact and copper tail respectively, and the face for clamping on clamp is arc surface, can make like this, on the dispersed outer round surface acting on copper chromium contact and copper tail of clamping force, the pressure in unit are to be diminished; Adjust the corresponding rotating speed of friction-welding machine, friction pressure, fraction time, burnoff length, braking time and forge length afterwards and carry out friction welding, with rotating speed 1480rpm, initial friction pressure 32MPa friction welding 0.9s; Again with rotating speed 2400rpm, friction pressure 125MPa carries out stable friction welding 7s rear braking, applies the upsetting force of 205MPa, and keep upsetting force 4s during brake 0.5s;
4) remove overlap, and carry out welding quality inspection, adopt ultrasonic wave to realize the detection of butt welded seam;
5) Ageing Treatment: by through step 4) weldment after process puts into high-low temperature test chamber, and be heated to 455 DEG C, be incubated 7.5 hours, then cool to room temperature with the furnace, complete high-temperature aging; And then temperature is adjusted to-15 DEG C, keep 2 hours, complete low temperature aging; Finally naturally cool to room temperature in atmosphere;
6) machining: be processed into product by designing requirement stand-by.
Described step 1) in can add the mixture of metal La and Si of 0.4% of its weight when mixed copper chromium powder material, both weight ratios are 1.5:1, and the overlapping rate of laser processing technique is 38%.
Described step 2) in copper tail be copper bar; The diameter of this copper bar is 30mm, and length is 39mm;
Described step 3) in the friction feed speed of friction welding be 1.4Mm/s, forge length 4mm.
Described step 3) on clamp for the size of arc surface that clamps respectively with the circular surfaces consistent size outside copper chromium contact and copper tail.
Described step 4) in the mechanical means of overlap car or milling remove.
Described step 4) in carry out x-ray inspection relative sensitivity be 1.6%.
In the method for above-described embodiment, Ageing Treatment also can adopt interrupted aging process: first apply 100 ~ 200A/cm at weldment two ends2dC current; The tension of first stage applying 220 ~ 260MPa, is heated to 280 ~ 320 DEG C, insulation 1.5 ~ 2.5h; Second stage applies the tension of 180 ~ 220MPa, at temperature is 350 ~ 450 DEG C, be incubated 1.5 ~ 2.5h; The tension of phase III applying 120 ~ 130MPa, is incubated 1.5 ~ 2.5h at temperature is 350 ~ 450 DEG C.
Adopting ESEM to take pictures and line sweep to described welding point, there is not obvious hole, dense structure, the defects such as pore-free, each element even transition in the microstructure of the copper chromium on-load switch welding point that the inventive method obtains.
The copper chromium welding point obtained is welded in multiple welding experiment and is circumferentially divided into 10 pieces, do shearing test respectively, the shear strength of copper chromium welding point can reach 240 ~ 280MPa.Welding precision of the present invention meets the requirement of friction-welding machine national sector standard JB/T8086-1999, solves the weldering erosion problem easily produced in prior art.
The present invention and traditional welding, integral sintered and compared with being threaded, bonding strength and the electric conductivity of chromiumcopper and copper can be improved significantly.
The friction-welding technique welding efficiency of the inventive method is high, and weld strength is high, and tensile strength can reach 240 ~ 280MPa, is more suitable for continuous seepage, reduces manufacturing cost, shortens the manufacturing cycle, improves yield rate; And with welding personnel experience connect experience have nothing to do, without the need to adding solder.This manufacturing approach craft controllability is strong, improves welding quality, and part quality is stablized, and meets instructions for use.The present invention makes the mechanical and physical character of product and electrical property obtain more effective guarantee, while raising integrated connection intensity, also improves the electric conductivity of whole electrical contact.This manufacture method welding precision is high, can weldering erosion problem greatly in welding process, and the method is practical, and result of use is good, is convenient to promote the use of.
The above is only preferred embodiment of the present invention, and be not restriction the present invention being made to other form, any those skilled in the art may utilize the technology contents of above-mentioned announcement to be changed or be modified as the Equivalent embodiments of equivalent variations.But everyly do not depart from technical solution of the present invention content, any simple modification, equivalent variations and the remodeling done above embodiment according to technical spirit of the present invention, still belong to the protection domain of technical solution of the present invention.