阅读说明：本技术 一种新型耐热铜合金的半连续金属铸造工艺及其应用 (Novel semi-continuous metal casting process of heat-resistant copper alloy and application thereof ) 是由 马明月 庾高峰 张航 李小阳 王聪利 吴斌 张琦 靖林 于 2020-10-20 设计创作，主要内容包括：本发明公开了一种新型耐热铜合金的半连续金属铸造工艺及其应用,该铜合金的重量百分比组成为：Ni：0.1-5.0wt％,Al：0.01-0.5wt％,Si：0.01-2.0wt％,Cr：0.01-1.0wt％,Cu：余量,该铜合金型材的制备过程为：配料—熔炼—热挤压—冷拉拔—时效处理。本发明在含有Ni、Al的铜合金材料基础上,进一步加入Si、Cr元素,采用半连续铸造平衡各金属元素之间的合理配比,提高镍硅铜合金的性能,开发出一种无Be,无Co的CuNi2SiCrAl高性能铜合金,用来替代铍钴铜系列合金,同时材料的原材料成本得到大幅下降,该发明铜合金可以应用于汽轮发电机槽楔铜合金部件。(The invention discloses a semi-continuous metal casting process of a novel heat-resistant copper alloy and application thereof, wherein the copper alloy comprises the following components in percentage by weight: ni: 0.1-5.0 wt%, Al: 0.01 to 0.5 wt%, Si: 0.01-2.0 wt%, Cr: 0.01-1.0 wt%, Cu: the balance, the preparation process of the copper alloy section bar is as follows: proportioning, smelting, hot extrusion, cold drawing and aging treatment. On the basis of a copper alloy material containing Ni and Al, Si and Cr elements are further added, reasonable proportion among all metal elements is balanced by adopting semi-continuous casting, the performance of the nickel-silicon-copper alloy is improved, and a Be-free and Co-free CuNi2SiCrAl high-performance copper alloy is developed to replace beryllium-cobalt-copper series alloy, and meanwhile, the raw material cost of the material is greatly reduced.)

1. A semi-continuous metal casting process of a novel heat-resistant copper alloy is characterized by comprising the following steps:

s1, batching: weighing Cu, Ni, Al, Si and Cr according to the component ratio, wherein the metal components comprise the following components in percentage by mass: 0.1-5.0 wt%, Al: 0.01 to 0.5 wt%, Si: 0.01-2.0 wt%, Cr: 0.01-1.0 wt%, Cu: the balance, the total content of Cu, Ni, Al, Si and Cr elements is more than 99.96 percent;

s2 smelting: smelting the metal components after proportioning by adopting semi-continuous casting, and sequentially and respectively adding the intermediate alloy into a crucible according to the melting point and the easy-oxidation burning loss degree in the smelting process to manufacture an ingot;

s3 hot extrusion: carrying out hot extrusion on the cast ingot prepared in the step S2 at the temperature of 900-950 ℃ to obtain a blank;

s4 cold drawing: carrying out primary cold drawing on the obtained blank, wherein the drawing speed is 5-8mm/min, and the drawing deformation is 15-35%;

s5 aging treatment: and (3) carrying out aging treatment on the blank subjected to cold drawing, wherein the aging treatment specifically comprises the following steps:

s5-1 low-temperature aging treatment: putting the blank after cold drawing into a vacuum atmosphere protective furnace, sealing the cover and vacuumizing to 10 DEG^-1Power is supplied to heat under MPa, the power is 35-40kW, the temperature is raised to 150-200 ℃ at the temperature rise speed of 5-10 ℃/min for low-temperature aging treatment, and the temperature is kept for 2-4 h;

s5-2 high-temperature aging treatment: continuously treating the blank after the low-temperature aging treatment, filling argon into the furnace to 0.09MPa, then increasing the heating power to 45-50kW, heating the blank to the set temperature of 400-600 ℃ along with the furnace at the heating rate of 10-15 ℃/min, and preserving the heat for 4-8 h;

s5-3 ultra-low temperature aging treatment: and (3) continuously treating the blank subjected to the high-temperature aging treatment, closing the vacuum atmosphere protection furnace, discharging the blank from the furnace for cooling when the temperature in the furnace is reduced to be below 150 ℃, transferring the blank into a low-temperature chamber precooled to be 5-10 ℃ for ultralow-temperature aging treatment, wherein the treatment time is 1-3 h.

2. The semi-continuous metal casting process of a novel heat-resistant copper alloy as claimed in claim 1, wherein the novel heat-resistant copper alloy is a Be-and Co-free CuNi2SiCrAl high performance copper alloy, and the atomic percentage ratio of Si to Cr is: Si/Cr is more than 1.0 and less than 4.0.

3. The semi-continuous metal casting process of the novel heat-resistant copper alloy as claimed in claim 1, wherein the step S2 of smelting comprises the following steps:

s2-1: placing a first graphite crucible (2) and a second graphite crucible (3) in a vacuum bin (1), sequentially placing an industrial nickel plate, an electrolytic copper plate and an aluminum plate which are cut into long strips at the bottom of the first graphite crucible (2), opening a vacuum valve (6), vacuumizing to 2-6Pa, heating to 1200 ℃, smelting for 3 hours, and continuously mechanically stirring by using a graphite rod in the smelting process;

s2-2: adding Si into a first graphite crucible (2) in the form of Cu-15% Si intermediate alloy, raising the temperature to 1350-;

s2-3: and the smelted alloy solution is introduced into the crystallizer (8) from the second graphite crucible (3) through the electromagnetic stirrer (7) downwards, when the melt flows into the crystallizer (8) by 80-85%, the cooling device (9) is opened to start downwards continuous casting, the downwards introduction speed is changed from slow to fast and finally adjusted to 50-70mm/min, and when the volume of the melt in the second graphite crucible (3) is less than 25%, the downwards introduction speed is reduced to 25-35mm/min until the end.

4. The semi-continuous metal casting process of the novel heat-resistant copper alloy as claimed in claim 3, wherein the specific steps of adding Cr in the step S2-2 are as follows: a wire feeding device (5) is arranged on one side of the vacuum chamber (1), a Cu-40% Cr alloy wire (51) is arranged on the wire feeding device (5), and the vacuum is continuously pumped to 1.5 multiplied by 10^-3Pa, and then adjusting the position of the electron beam gun (4) to simultaneously position the electron beam (41) at the center of the second graphite crucible (3) and electromagnetically stirAnd (2) directly above the inlet of the stirrer (7), adjusting the Cu-40% Cr alloy wire (51) to enable the tail end of the Cu-40% Cr alloy wire to be positioned below an electron beam (41), wherein the wire feeding speed is 3-6mm/s, the wire feeding angle is 45-50 degrees, the height of the Cu-40% Cr alloy wire (51) from the second graphite crucible (3) is 8-12mm, the electron beam current is set to be 25-35mA, the focusing current is set to be 850mA, the accelerating voltage is set to be 60KV, and the beam current rising and falling period is set to be 0.5 s.

5. The semi-continuous metal casting process of a novel heat-resistant copper alloy according to claim 3, wherein the down-drawing continuous casting in the step S2-3 uses a Cu-Ni-Si alloy down-drawing continuous casting device.

6. The semi-continuous metal casting process of the novel heat-resistant copper alloy as claimed in claim 1, wherein a composite lubricant is used in the cold drawing process of step S4, the components and the mass ratio of the components are water, base lubricant oil, lime powder, antioxidant, metal deactivator and antirust agent is 5: 25: 10: 0.2: 1: 0.5, the base lubricant oil is 40 wt% of beef tallow and 60 wt% of methyl palmitate, the antioxidant is zinc dialkyl dithiophosphate, the metal deactivator is thiadiazole, and the antirust agent is zinc sulfate.

7. Use of the novel heat resistant copper alloy prepared according to the process of any one of claims 1 to 6, characterized in that the novel heat resistant copper alloy is mechanically processed and applied to copper alloy parts in slot wedges of turbonators for a treatment time of 1 to 3 hours.

8. The use of the novel heat-resistant copper alloy according to claim 7, wherein the surface of the turbonator slot wedge is coated with a plating layer of the novel heat-resistant copper alloy, or the turbonator slot wedge is formed by rolling the novel heat-resistant copper alloy.

Technical Field

The invention relates to the technical field of copper alloy manufacturing and processing, in particular to a novel semi-continuous metal casting process of a heat-resistant copper alloy and application thereof.

Background

With the rapid increase of the demand of electric power, the design of large-capacity generator sets is more and more emphasized, but some key parts such as a generator rotor slot wedge copper alloy mainly depend on an inlet, a generator rotor is the most key core component in a turbo generator set, when the turbo generator set works, a turbo generator rotor generates huge centrifugal force during high-speed operation, and simultaneously, under the action of a magnetic field generated by rotor current, large induced current can be generated on the surface of the rotor, the current can generate high temperature when passing through the rotor slot wedge copper alloy, cracks are generated under the overlapping action of shutdown and creep deformation, and the cracks can be promoted to be further developed, so that the slot wedge alloy is broken to generate slot wedge flying, the generator set with hundred million yuan of value can be exploded, and serious casualty accidents can be caused.

At present, alloys such as CuCo2BeZr, CuNi2Be and the like widely used by slot wedges reach the level of similar imported products in performance, but the Be element is toxic, trace steam generated in the processes of casting and heat treatment can generate great toxic action on human bodies and environment, and the research of the Be-free alloy to replace the Be alloy has been already called internationally.

Therefore, the slot wedge alloy with excellent performance for the motor needs to Be independently developed to replace an imported material, the slot wedge copper alloy is processed and molded and is installed in the slot wedge so as to compress a large number of copper wires longitudinally and transversely arranged on a generator rotor, the wires are prevented from flying off outwards, the high temperature resistance is strong, the creep strength and the fatigue strength of the slot wedge alloy are not reduced, the risk is reduced, and meanwhile, a proper amount of other elements are used for partially or completely replacing Be to develop a low-Be alloy or a non-Be alloy.

Disclosure of Invention

In order to solve the technical problems, the invention provides a novel semi-continuous metal casting process of heat-resistant copper alloy and application thereof.

The technical scheme of the invention is as follows: a semi-continuous metal casting process of novel heat-resistant copper alloy comprises the following steps:

s1, batching: weighing Cu, Ni, Al, Si and Cr according to the component ratio, wherein the metal components comprise the following components in percentage by mass: 0.1-5.0 wt%, Al: 0.01 to 0.5 wt%, Si: 0.01-2.0 wt%, Cr: 0.01-1.0 wt%, Cu: the balance, the total content of Cu, Ni, Al, Si and Cr elements is more than 99.96 percent;

s2 smelting: smelting the metal components after proportioning by adopting semi-continuous casting, and sequentially and respectively adding the intermediate alloy into a crucible according to the melting point and the easy-oxidation burning loss degree in the smelting process to manufacture an ingot with the diameter of 200;

s3 hot extrusion: carrying out hot extrusion on the cast ingot prepared in the step S2 at the temperature of 900-950 ℃ to obtain a blank before deformation;

s4 cold drawing: carrying out primary cold drawing on the obtained blank, wherein the drawing speed is 5-8mm/min, and the drawing deformation is 15-35%;

s5 aging treatment: and (3) carrying out aging treatment on the blank subjected to cold drawing, wherein the aging treatment specifically comprises the following steps:

s5-1 low-temperature aging treatment: putting the blank after cold drawing into a vacuum atmosphere protective furnace, sealing the cover and vacuumizing to 10 DEG^{- 1}Power is supplied to heat under MPa, the power is 35-40kW, the temperature is raised to 150-200 ℃ at the temperature rise speed of 5-10 ℃/min for low-temperature aging treatment, and the temperature is kept for 2-4 h;

s5-2 high-temperature aging treatment: continuously treating the blank after the low-temperature aging treatment, filling argon into the furnace to 0.09MPa, then increasing the heating power to 45-50kW, heating the blank to the set temperature of 400-600 ℃ along with the furnace at the heating rate of 10-15 ℃/min, and preserving the heat for 4-8 h;

s5-3 ultra-low temperature aging treatment: and (3) continuously treating the blank subjected to the high-temperature aging treatment, closing the vacuum atmosphere protection furnace, discharging the blank from the furnace for cooling when the temperature in the furnace is reduced to be below 150 ℃, transferring the blank into a low-temperature chamber precooled to 5-10 ℃ for ultralow-temperature aging treatment for 1-3h, improving the performance of the copper alloy and avoiding surface defects.

Further, the novel heat-resistant copper alloy is a Be-free and Co-free CuNi2SiCrAl high-performance copper alloy, and the atomic percentage ratio of Si to Cr is as follows: Si/Cr is more than 1.0 and less than 4.0, so that the condition that the content of one element is too large or too small is avoided.

Further, the smelting in the step S2 specifically includes:

s2-1: preparing materials according to the component proportion of the alloy, placing a first graphite crucible and a second graphite crucible in a vacuum bin, sequentially placing an industrial nickel plate, an electrolytic copper plate and an aluminum plate which are cut into long strips at the bottom of the first graphite crucible (2), opening a vacuum valve, vacuumizing to 2-6Pa, heating to 1200 ℃ and smelting for 3 hours, and continuously mechanically stirring by using a graphite rod in the smelting process;

s2-2: adding Si into a first graphite crucible in the form of Cu-15% Si intermediate alloy, raising the temperature to 1350-;

s2-3: and (3) introducing the smelted alloy solution into the crystallizer from the graphite crucible through an electromagnetic stirrer, opening a cooling device to start down continuous casting when the melt flows into the crystallizer by 80-85%, wherein the down-drawing speed is changed from slow to fast and is finally adjusted to 50-70mm/min, and reducing the down-drawing speed to 25-35mm/min until the melt volume in the second graphite crucible is lower than 25%.

Further, the specific step of adding Cr in step S2-2 is: one side of the vacuum chamber is provided with a wire feeding device, the wire feeding device is provided with Cu-40% Cr alloy wires, and the vacuum pumping is continued until the wire feeding device is vacuumized to 1.5 multiplied by 10^-3Pa, then adjusting the position of an electron beam gun to enable the electron beam to be simultaneously positioned at the center of the second graphite crucible and right above an inlet of the electromagnetic stirrer, adjusting the wire to be positioned below the electron beam spot, wherein the wire feeding speed is 3-6mm/s, the wire feeding angle is 45-50 degrees, the height of the wire from the second graphite crucible is 8-12mm, setting the electron beam current to be 25-35mA, the focusing current to be 850mA, the accelerating voltage to be 60KV, the rising and falling period of the beam current to be 0.5s, and the higher melting point of Cr element is easy to damage the internal structure if the melting time is overlong, so that the wire quickly reaches the melting point by using the electron beam melting mode and enters the down-drawing equipment together with other molten copper alloy melts.

Further, in the step S2-3, the Cu-Ni-Si alloy down-casting equipment is used for down-casting, and no other impurities are generated in the down-casting process.

Further, a composite lubricant is used in the cold drawing process of step S4, and the components of the composite lubricant and the mass ratio of the components are water: basic lubricating oil: lime powder: antioxidant: metal deactivators: antirust agent 5: 25: 10: 0.2: 1: 0.5, the base lubricating oil is 40 wt% of beef tallow and 60 wt% of methyl palmitate, the antioxidant is zinc dialkyl dithiophosphate, the metal deactivator is thiadiazole, the antirust agent is zinc sulfate, the components are uniformly dispersed, an adsorption film for preventing adhesion and reducing abrasion can be formed, the recoating capability is realized under the condition that the film is broken, and the lubricating oil has good lubricity and conductivity.

Preferably, the novel heat-resistant copper alloy prepared by the process is applied to a copper alloy part in a slot wedge of a turbonator after being machined.

Further, the surface of the slot wedge of the turbonator is coated with the coating of the novel heat-resistant copper alloy, or the slot wedge of the turbonator is formed by rolling the novel heat-resistant copper alloy.

The invention has the beneficial effects that:

1. the novel heat-resistant copper alloy CuNi2SiCrAl saves expensive cobalt resources, reduces the application cost of materials in the field, has the performance close to CuCo2BeZr, can replace the CuCo2Be series alloys which are widely used before, does not add Be element, and does not generate Be steam to cause environmental pollution and personal injury. Meanwhile, the preparation process combining electron beam melting and down-drawing continuous casting is adopted, so that the melting temperature is high, the down-drawing speed is adjustable, and the melting efficiency and the product quality are improved.

2. The preparation process of the invention combines electron beam melting and down-drawing continuous casting, and Cr element with higher melting point is melted through electron beam fuses, and the interaction among the elements is utilized to refine the structure and promote the dispersion and precipitation of the second phase, and simultaneously the mechanical properties of the nickel and the copper are further improved, particularly the high-temperature mechanical properties are obviously improved, and the electrical properties are also kept at a higher level.

3. The novel heat-resistant copper alloy CuNi2SiCrAl has higher high-temperature softening resistance, can be used for slot wedge copper alloy parts of a turbonator, prolongs the service life of a turbonator rotor, and avoids creep deformation and microcrack caused by high-temperature softening.

Drawings

FIG. 1 is a process flow diagram of the manufacturing process of the present invention;

FIG. 2 is a schematic structural diagram of the melting device of step S2 of the present invention;

FIG. 3 is a photograph of a metallographic structure of a sample in example 1 of the present invention;

FIG. 4 is a photograph of a metallographic structure obtained in example 3 of the present invention;

FIG. 5 is a schematic diagram of the step S4 cold-drawing structure of the present invention;

FIG. 6 is a schematic cross-sectional view of the step S4 of cold drawing A-A according to the present invention.

The device comprises a vacuum bin 1, a first graphite crucible 2, a second graphite crucible 3, an electron beam gun 4, an electron beam 41, a wire feeder 5, a 51-Cu-40% Cr alloy wire, a vacuum valve 6, an electromagnetic stirrer 7, a crystallizer 8 and a cooling device 9.

Detailed Description

Example 1

As shown in fig. 1, a semi-continuous metal casting process of a novel heat-resistant copper alloy, which is a Be-free and Co-free CuNi2SiCrAl high-performance copper alloy, includes the following steps:

s1, batching: weighing Cu, Ni, Si, Cr and Al according to the component ratio, wherein Ni: 2.17 wt%, Al: 0.09 wt%, Si: 0.28 wt%, Cr: 0.22 wt%, Cu: the balance, wherein the total content of Cu, Ni, Al, Si and Cr elements is 99.98 percent, and the atomic percentage ratio of Si to Cr is as follows: Si/Cr 1.27;

s2 smelting: as shown in fig. 2, the metal components after being mixed are smelted by adopting semi-continuous casting, and the intermediate alloy is respectively added into a crucible according to the melting point and the easy-to-oxidize burning loss degree in the smelting process to manufacture an ingot with the diameter of 200, and the method specifically comprises the following steps:

s2-1: placing a first graphite crucible 2 and a second graphite crucible 3 in a vacuum bin 1, sequentially placing an industrial nickel plate, an electrolytic copper plate and an aluminum plate which are cut into long strips at the bottom of the first graphite crucible 2, opening a vacuum valve 6, vacuumizing to 2Pa, heating to 1200 ℃, smelting for 3h, and continuously mechanically stirring by using a graphite rod in the smelting process;

s2-2: adding Si into a first graphite crucible 2 in a Cu-15% Si intermediate alloy mode, adding Cr into the first graphite crucible 2 in a Cu-40% Cr intermediate alloy mode, raising the temperature to 1400 ℃, continuing to smelt for 1.5h, then opening a partition plate between the first graphite crucible 2 and a second graphite crucible 3, enabling the melt to enter the second graphite crucible 3, and starting to cast;

s2-3: the smelted alloy solution is led into a crystallizer 8 from a second graphite crucible 3 through an electromagnetic stirrer 7, when the melt flows into the crystallizer 8 by 80%, a cooling device 9 is opened to start down continuous casting, the down drawing speed is changed from slow to fast and finally adjusted to 60mm/min, and when the volume of the melt in the second graphite crucible 3 is 24%, the down drawing speed is reduced to 30mm/min until the end;

s3 hot extrusion: hot extruding the cast ingot prepared in the step S2 at 950 ℃ to obtain a blank before deformation;

s4 cold drawing: as shown in fig. 5 and 6, the obtained blank is subjected to primary cold drawing, the drawing speed is 7mm/min, the drawing deformation is 27%, and a deformed slot wedge blank is obtained;

s5 aging treatment: and (3) carrying out aging treatment on the blank subjected to cold drawing, and specifically comprising the following steps:

s5-1 low-temperature aging treatment: putting the blank after cold drawing into a vacuum atmosphere protective furnace, sealing the cover and vacuumizing to 10 DEG^{- 1}The mixture is heated by power transmission under the condition of MPa, the power is 35kW, the mixture is heated to 180 ℃ at the heating rate of 6 ℃/min for low-temperature aging treatment, and the heat is preserved for 3 hours;

s5-2 high-temperature aging treatment: continuously treating the blank subjected to low-temperature aging treatment, filling argon into the furnace to 0.09MPa, then increasing the heating power to 45kW, heating the blank to 450 ℃ along with the furnace at the heating rate of 12 ℃/min, and preserving the heat for 5 hours;

s5-3 ultra-low temperature aging treatment: and (3) continuously treating the blank subjected to the high-temperature aging treatment, closing the vacuum atmosphere protection furnace, discharging the blank from the furnace for cooling when the temperature in the furnace is reduced to be below 150 ℃, transferring the blank into a low-temperature chamber precooled to 7.5 ℃ for ultralow-temperature aging treatment, wherein the treatment time is 2.5 hours.

According to the application of the novel heat-resistant copper alloy prepared by the process, the novel heat-resistant copper alloy is applied to a copper alloy part in a slot wedge of a turbonator after being machined, the surface of the slot wedge of the turbonator is coated with a plating layer of the novel heat-resistant copper alloy, or the slot wedge of the turbonator is formed by rolling the novel heat-resistant copper alloy.

Example 2

This embodiment is substantially the same as embodiment 1 except that:

s1, batching: weighing Cu, Ni, Si, Cr and Al according to the component ratio, wherein Ni: 2.68 wt%, Al: 0.18 wt%, Si: 0.44 wt%, Cr: 0.40 wt%, Cu: the balance, wherein the total content of Cu, Ni, Al, Si and Cr elements is 99.97%, and the atomic percentage ratio of Si to Cr is as follows: Si/Cr ═ 1.1.

Example 3

This embodiment is substantially the same as embodiment 1 except that:

s1, batching: weighing Cu, Ni, Si, Cr and Al according to the component ratio, wherein Ni: 3.51 wt%, Al: 0.22 wt%, Si: 0.86 wt%, Cr: 0.53 wt%, Cu: the balance, wherein the total content of Cu, Ni, Al, Si and Cr elements is 99.98 percent, and the atomic percentage ratio of Si to Cr is as follows: Si/Cr is 1.62.

Example 4

This embodiment is substantially the same as embodiment 1 except that:

s1, batching: weighing Cu, Ni, Si, Cr and Al according to the component ratio, wherein Ni: 4.12 wt%, Al: 0.25 wt%, Si: 1.51 wt%, Cr: 0.64 wt%, Cu: the balance, wherein the total content of Cu, Ni, Al, Si and Cr elements is 99.97%, and the atomic percentage ratio of Si to Cr is as follows: Si/Cr 2.35.

Example 5

This embodiment is substantially the same as embodiment 1 except that:

s1, batching: weighing Cu, Ni, Si, Cr and Al according to the component ratio, wherein Ni: 4.79 wt%, Al: 0.27 wt%, Si: 1.93 wt%, Cr: 0.82 wt%, Cu: the balance, wherein the total content of Cu, Ni, Al, Si and Cr elements is 99.99 percent, and the atomic percentage ratio of Si to Cr is as follows: Si/Cr 2.35.

Example 6

This embodiment is substantially the same as embodiment 3, except that this embodiment also provides an apparatus for melting in step S2:

as shown in fig. 2, a first graphite crucible 2 and a second graphite crucible 3 are placed at the bottom of a vacuum chamber 1, a communicating opening is arranged between the first graphite crucible 2 and the second graphite crucible 3, a partition plate for controlling the communication of the first graphite crucible and the second graphite crucible is arranged at the opening, a wire feeding device 5 is arranged on one side wall of the vacuum chamber 1 corresponding to the position of the second graphite crucible 3, a Cu-40% Cr alloy wire 51 is arranged on the wire feeding device 5, an electron beam gun 4 for smelting the Cu-40% Cr alloy wire 51 is arranged right above the second graphite crucible 3, so that an electron beam 41 emitted by the electron beam gun 4 is positioned right above an inlet of an electromagnetic stirrer 7, an electromagnetic stirrer 7 is arranged at the bottom of the second graphite crucible 3, the electromagnetic stirrer 7 penetrates through the bottom of the vacuum chamber 1 and is connected with a crystallizer 8, and a cooling device 9 is connected below the crystallizer 8.

S2 smelting: the smelting device is used for smelting by adopting semi-continuous casting to manufacture the ingot with the diameter of 200, and the method comprises the following specific steps:

s2-1: placing a first graphite crucible 2 and a second graphite crucible 3 in a vacuum bin 1, sequentially placing an industrial nickel plate, an electrolytic copper plate and an aluminum plate which are cut into long strips at the bottom of the first graphite crucible 2, opening a vacuum valve 6, vacuumizing to 6Pa, heating to 1200 ℃, smelting for 3h, and continuously mechanically stirring by using a graphite rod in the smelting process;

s2-2: adding Si into a first graphite crucible 2 in the form of Cu-15% Si intermediate alloy, raising the temperature to 1400 ℃, continuing to smelt for 1.5h, then opening a partition plate between the first graphite crucible 2 and a second graphite crucible 3, enabling a part of melt to enter the second graphite crucible 3, keeping the liquid level height at 45mm, continuing to vacuumize to 1.5 multiplied by 10^-3Pa, then adjusting the position of an electron beam gun 4 to enable an electron beam 41 to be positioned right above an inlet of an electromagnetic stirrer 7 at the center of a second graphite crucible 3, adjusting the wire feeding speed of a Cu-40% Cr alloy wire 51 to enable the tail end of the Cu-40% Cr alloy wire to be positioned below the electron beam 41 all the time, the wire feeding speed is 3mm/s, the wire feeding angle is 45 degrees, the height of the Cu-40% Cr alloy wire 51 from the second graphite crucible 3 is 10mm, setting an electron beam current of 30mA, a focusing current of 850mA, an accelerating voltage of 60KV and a beam current rising and falling period of 0.5s, continuously adding the Cu-40% Cr alloy wire 51 into the second graphite crucible 2, and melting the Cu-40% Cr alloy wire 51 by utilizing the electron beam 41,

starting casting;

s2-3: the smelted alloy melt and the melted Cu-40% Cr alloy wire 51 are mixed together and are led into a crystallizer 8 from a second graphite crucible 3 through an electromagnetic stirrer 7, when the melt flows into the crystallizer 8 by 80%, a cooling device 9 is opened to start down continuous casting, Cu-Ni-Si alloy down continuous casting equipment is used for the down continuous casting, the down speed is changed from slow to fast and is finally adjusted to 60mm/min, and when the volume of the melt in the second graphite crucible 3 is 22%, the down speed is reduced to 30mm/min until the end.

Example 7

This embodiment is substantially the same as embodiment 6 except that:

s4 cold drawing: as shown in fig. 5 and 6, the obtained blank is subjected to primary cold drawing, the drawing speed is 7mm/min, the drawing deformation is 27%, a composite lubricant is used in the cold drawing process, and the components of the composite lubricant and the mass ratio of the components are water: basic lubricating oil: lime powder: antioxidant: metal deactivators: antirust agent 5: 25: 10: 0.2: 1: 0.5, 40 wt% of butter and 60 wt% of methyl palmitate are taken as basic lubricating oil, zinc dialkyl dithiophosphate is taken as antioxidant, thiadiazole is taken as metal deactivator, and zinc sulfate is taken as antirust agent, so that the deformed slot wedge blank is obtained.

Examples of the experiments

1. The slot wedges made of the new heat-resistant copper alloys of examples 1-7 and a sample of the alloy slot wedge of a comparative example were used for the performance parameter tests, the test methods are as follows:

testing the tensile strength and the elongation of the novel heat-resistant copper alloy on a tensile testing machine according to the GB/T17737.308-2018 test on the tensile strength and the elongation of metal;

testing the yield strength of the novel heat-resistant copper alloy on a metal yield strength testing machine according to the GB/T2039-2012 test method for uniaxial tensile creep of metal materials;

testing the softening temperature of the novel heat-resistant copper alloy in an annealing furnace according to the standard of GB T33370-2016 (method for measuring the softening temperature of copper and copper alloy);

and performing an electric conductivity test on the electric conductivity meter according to the standard of GB/T3651-2008 metal high-temperature thermal conductivity coefficient measuring method.

The test results are shown in tables 1 and 2:

TABLE 1 copper alloy compositions and Property measurements of examples 1-5

TABLE 2 copper alloy property test results of examples 3, 6-7

As can be seen from the data in Table 1, the distribution ratio of different element components has a large influence on the tensile strength and the yield strength, wherein the ratio of the element components in example 3 has the largest influence on the tensile strength and the yield strength; the blending ratio of different element components also has certain influence on the softening temperature of the novel heat-resistant copper alloy, wherein the blending ratio of the element components in example 5 is optimal, and the softening temperature is highest, which shows that the softening temperature is increased when the content of elements except copper is increased; in addition, the elongation and conductivity tested in examples 1-5 did not change much, indicating that the distribution ratio of the different elements had less effect on elongation and conductivity; comparing the performance of the copper alloy obtained by the conventional means and the metal component proportion in the prior art, the performances of the copper alloy in the examples 1-5 are better than those of the copper alloy in the comparative example except that the conductivity is slightly lower, so that the element component proportion in the example 3 is optimal, and the prepared novel heat-resistant copper alloy has the best performance.

As can be seen from the data in table 1, when the process method of melting in step S2 is changed and the conventional melting process is replaced with the electron beam melting of the Cu-40% Cr alloy in the same other process flows, it can be found that the performance parameters of the copper alloy obtained in example 6, except for the elongation, are all better than those of example 3, which indicates that the performance of the copper alloy can be improved to some extent by melting the Cu-40% Cr alloy with the electron beam; it is understood from comparative examples 6 to 7 that the elongation and softening temperature of the copper alloy in example 7 are improved without affecting other properties when the composition of the composite lubricant in the cold drawing of step S4 is changed in the same manner as in the other processes.

2. As shown in fig. 3 and 4, the novel heat-resistant copper alloys prepared in examples 1 and 3 were selected for metallographic examination, and it can be seen that, after aging treatment, alloy elements of solid solutions were precipitated, and the concentration of solid solution elements in the matrix was reduced, so that the electrical conductivity of the alloys was improved; meanwhile, along with the precipitation of a large amount of second phases, the strength of the alloy is improved; in addition, it can be seen that the copper alloy of example 3 has a uniform structure and no aggregation of the second phase, which is a main factor of the excellent performance of the alloy.