Method for preparing multi-element Cu-Mn-Ni-Si foil strip brazing filler metal at low cost

Abstract

The invention belongs to the technical field of brazing filler metal preparation, and particularly relates to a low-cost method for preparing multi-element Cu-Mn-Ni-Si foil strip brazing filler metal. The preparation method comprises the following steps: smelting and casting preparation raw materials of the multi-element Cu-Mn-Ni-Si series brazing filler metal to obtain a cast ingot; carrying out primary annealing on a first semi-finished product obtained by carrying out multiple times of small-deformation hot rolling on the cast ingot to obtain a second semi-finished brazing filler metal; and the second semi-finished brazing filler metal is subjected to multiple times of small-deformation cold rolling and second annealing, and the multiple times of small-deformation cold rolling and second annealing are circularly conducted till the multi-element Cu-Mn-Ni-Si foil strip brazing filler metal is obtained. The method is easy to operate, a conventional machining device is adopted, compared with a spray forming method, an atomization method and the like, the manufacturing cost of the multi-element Cu-Mn-Ni-Si series foil strip brazing filler metal is remarkably reduced, and meanwhile the method has the advantage of being wide in practicability.

Description

Technical Field

[0001] The invention belongs to the technical field of solder preparation, and in particular relates to a method for preparing a multi-element Cu-Mn-Ni-Si foil strip solder at a low cost. Background Art

[0002] Multi-component Cu-Mn-Ni-Si brazing filler metals have good fluidity, wettability, thermal strength, corrosion resistance and excellent weld mechanical properties. They can be used for brazing of carbon steel, copper alloys, stainless steel and high-temperature alloys, and are widely used in the chemical industry, aerospace and other fields.

[0003] At present, multi-component Cu-Mn-Ni-Si solders are usually used in the form of wires, foils or powders, among which foils are more commonly used, while wires and powders are less commonly used.

[0004] The addition of alloying elements such as Si (especially Si mass percentage higher than 1%), B, P, etc. in the multinary Cu-Mn-Ni-Si solder improves the welding performance of the multinary Cu-Mn-Ni-Si solder, but will significantly reduce the plasticity of the solder. Moreover, the solder is easily affected by temperature and forms a brittle phase, which further reduces the plasticity of the solder and causes the processing performance of the solder to deteriorate.

[0005] The prior art discloses the use of spray forming and atomization to prepare multi-component Cu-Mn-Ni-Si solder, but the operation steps are complicated and the processing equipment is expensive, resulting in a high preparation cost of the multi-component Cu-Mn-Ni-Si solder. Summary of the invention

[0006] The object of the present invention is to provide a method for preparing a multi-component Cu-Mn-Ni-Si foil strip solder at a low cost. The method provided by the present invention is simple to operate and uses conventional processing equipment. Compared with injection molding, atomization, etc., the production cost of the multi-component Cu-Mn-Ni-Si foil strip solder is significantly reduced, and at the same time, it has the advantage of wide practicality.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a method for preparing a multi-element Cu-Mn-Ni-Si foil solder at low cost, comprising the following steps:

[0009] The raw materials for preparing the multi-component Cu-Mn-Ni-Si brazing alloy are melted and cast to obtain an ingot;

[0010] The ingot is subjected to multiple small deformation hot rolling to obtain a first semi-finished brazing material, wherein a single roll gap reduction of the small deformation hot rolling is ≤0.3 mm;

[0011] Performing a first annealing on the first semi-finished solder to obtain a second semi-finished solder;

[0012] The second semi-finished solder is subjected to small deformation cold rolling and second annealing, the small deformation cold rolling and second annealing are cyclically performed, and the single roll gap reduction of the small deformation cold rolling is ≤0.15mm, until the multi-component Cu-Mn-Ni-Si foil solder is obtained.

[0013] Preferably, the multiple small deformation hot rolling is performed along the length direction of the ingot, the hot rolling temperature range is 0.85 to 0.95 times the solidus temperature, and the rolling rate is 30 to 60 mm / s;

[0014] A heat preservation treatment is performed between two adjacent small deformation hot rollings, wherein the temperature of the heat preservation treatment is 0.92 to 0.95 times the solidus temperature, and the heat preservation time is 8 to 15 minutes.

[0015] Preferably, the multiple small deformation hot rolling includes first hot rolling with a single roll gap reduction of ≤0.2mm to a cumulative deformation of ≥40%; then hot rolling with a single roll gap reduction of ≤0.3mm to a cumulative deformation of ≤80%; and finally hot rolling with a single roll gap reduction of ≤0.15mm to a thickness of the first semi-finished solder of 1.5 to 2mm.

[0016] Preferably, the first annealing is performed in an air atmosphere, the holding temperature of the first annealing is 0.88 to 0.92 times the solidus temperature, the holding time is 20 to 30 minutes, and the cooling method is air cooling.

[0017] Preferably, the small deformation cold rolling is performed along the length direction of the second semi-finished solder, the rolling rate is ≤25mm / s, the single roll gap reduction is 0.05-0.15mm; the cumulative deformation between two adjacent second annealings is 50-80%.

[0018] Preferably, the second annealing is vacuum annealing, the vacuum degree of the second annealing is ≤10Pa, the temperature is 0.84 to 0.88 times the solidus temperature, the holding time is 10 to 25min, the cooling method is rapid cooling to 0.4 times the solidus temperature and then furnace cooling, and the rapid cooling rate is ≥30°C / min.

[0019] Preferably, the ingot has a thickness of 15 to 25 mm, a width of 70 to 100 mm, and a length of 200 to 250 mm.

[0020] Preferably, after obtaining the ingot, before the ingot is subjected to multiple small deformation hot rolling, the ingot is also subjected to pre-treatment; the pre-treatment includes: removing shrinkage holes and milling the rolling surface of the ingot to obtain the pre-treated ingot; the thickness difference of the rolled surface of the pre-treated ingot is ≤0.3mm, and the surface roughness of the rolled surface is ≤Ra12.5.

[0021] Preferably, after obtaining the second semi-finished solder, before the second semi-finished solder is subjected to small deformation cold rolling, the second semi-finished solder is also subjected to pre-treatment to obtain the second semi-finished solder after pre-treatment, and the rolling surface thickness difference of the second semi-finished solder after pre-treatment is ≤0.2mm, and the surface roughness of the rolled surface is ≤Ra6.3.

[0022] Preferably, the thickness of the multi-element Cu-Mn-Ni-Si foil solder is 0.05 to 0.12 mm;

[0023] The multi-component Cu-Mn-Ni-Si foil solder includes Cu35NiMnSiCoFeBP, Cu40AgMnNiSiZnBP, CuAgMnNiSi or CuMnNiSi;

[0024] The mass percentage of Si element in the CuAgMnNiSi is 1-3%;

[0025] The mass percentage of Si element in the CuMnNiSi is 1-3%.

[0026] The present invention provides a method for preparing multi-component Cu-Mn-Ni-Si foil solder at low cost, comprising the following steps: melting and casting the raw materials for preparing the multi-component Cu-Mn-Ni-Si solder to obtain an ingot; performing multiple small deformation hot rolling on the ingot to obtain a first semi-finished solder, wherein the single roll gap reduction of the small deformation hot rolling is ≤0.3mm; performing a first annealing on the first semi-finished solder to obtain a second semi-finished solder; performing a small deformation cold rolling and a second annealing on the second semi-finished solder, wherein the small deformation cold rolling and the second annealing are performed in a cycle, wherein the single roll gap reduction of the small deformation cold rolling is ≤0.15mm, until the multi-component Cu-Mn-Ni-Si foil solder is obtained. The present invention controls the single roll gap reduction of the small deformation rolling by adopting multiple small deformation rolling (including hot rolling and cold rolling) and annealing, thereby greatly reducing the tendency of the solder to tear (when the single roll gap reduction is too large, it is easy to cause the ingot to break, such as Figure 2 As shown; or cause the ingot to open, such as Figure 3 As shown; or cause the edge tearing of the subsequent solder and slight tearing of the surface, such as Figure 4As shown), the solder product yield is high; at the same time, the method provided by the present invention is simple to operate, and conventional processing equipment is used, which can achieve low-cost preparation of various types of multi-element Cu-Mn-Ni-Si foil solders. Compared with injection molding, atomization, etc., it has the advantages of simple operation and wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flowchart of a method for preparing a multi-element Cu-Mn-Ni-Si foil solder at low cost provided by the present invention;

[0028] Figure 2 This is the fracture analysis diagram of the ingot during the preparation of the multi-element Cu-Mn-Ni-Si foil brazing alloy;

[0029] Figure 3 This is the ingot opening analysis diagram during the preparation of multi-element Cu-Mn-Ni-Si foil brazing alloy;

[0030] Figure 4 This is an analysis diagram of edge tearing and slight surface tearing of semi-finished products during the preparation of multi-element Cu-Mn-Ni-Si foil solder;

[0031] Figure 5 This is a tear analysis diagram of the semi-finished product surface during the preparation of multi-component Cu-Mn-Ni-Si foil solder. DETAILED DESCRIPTION

[0032] The present invention provides a method for preparing a multi-element Cu-Mn-Ni-Si foil solder at low cost, comprising the following steps:

[0033] The raw materials for preparing the multi-component Cu-Mn-Ni-Si brazing alloy are melted and cast to obtain an ingot;

[0034] The ingot is subjected to multiple small deformation hot rolling to obtain a first semi-finished brazing material, wherein a single roll gap reduction of the small deformation hot rolling is ≤0.3 mm;

[0035] Performing a first annealing on the first semi-finished solder to obtain a second semi-finished solder;

[0036] The second semi-finished solder is subjected to small deformation cold rolling and second annealing, the small deformation cold rolling and second annealing are cyclically performed, and the single roll gap reduction of the small deformation cold rolling is ≤0.15mm, until the multi-component Cu-Mn-Ni-Si foil solder is obtained.

[0037] In the present invention, unless otherwise specified, all preparation raw materials / components are commercially available products well known to those skilled in the art.

[0038] The present invention melts and casts the raw materials for preparing the multi-component Cu-Mn-Ni-Si solder to obtain an ingot. In the present invention, the multi-component Cu-Mn-Ni-Si foil solder preferably includes Cu35NiMnSiCoFeBP, Cu40AgMnNiSiZnBP, CuAgMnNiSi or CuMnNiSi. The mass percentage of Si element in the CuAgMnNiSi is preferably 1-3%. The mass percentage of Si element in the CuMnNiSi is preferably 1-3%. In a specific embodiment of the present invention, the Cu35NiMnSiCoFeBP is preferably Cu34.3-Ni29-Mn29-Co5-Fe1.2-Si1.1-B0.2-P0.2 in terms of mass percentage. The Cu40AgMnNiSiZnBP is preferably Cu42-Ag23-Mn21.5-Ni11.5-Si0.3-Zn1.3-B0.2-P0.2 in terms of mass percentage. The CuMnNiSi is preferably Cu55-Mn37.5-Ni5-Si1.5 in terms of mass percentage.

[0039] In the present invention, the raw materials for preparing the multi-element Cu-Mn-Ni-Si solder preferably include single-element raw materials, or include single-element raw materials and intermediate alloy raw materials. In the present invention, the single-element raw materials preferably include at least four of Cu, Ni, Mn, Co, Fe and Si. The purity of the Cu single substance is preferably >99.9% or preferably electrolytic Cu. The purity of the Ni single substance is preferably >99.9% or preferably electrolytic Ni. The purity of the Mn single substance is preferably >99.9% or preferably electrolytic Mn. Therefore, the purity of the Co single substance is preferably >99.9% or preferably electrolytic Co. The Fe single substance is preferably industrial pure Fe. The purity of the Si single substance is preferably >99.9%. The intermediate alloy raw material preferably includes NiB intermediate alloy and / or CuP intermediate alloy.

[0040] In the present invention, the raw materials are preferably prepared according to the mass percentage of each element in the multi-element Cu-Mn-Ni-Si foil solder, and then the smelting is performed.

[0041] In the present invention, the smelting is preferably carried out in a vacuum medium frequency induction furnace. The present invention has no special requirements for the specific implementation process of the smelting. The mold used for casting is preferably a graphite mold. The present invention controls the ingot size and cooling rate through the graphite mold, reduces the shrinkage cavity and loose part of the ingot, and the obtained ingot has a smooth surface and a uniform crystal structure, which is convenient for subsequent rolling and annealing.

[0042] In the present invention, when the casting mold is used improperly (i.e., without using a graphite mold), it is easy to cause the ingot to break (such as Figure 2At the same time, the resulting ingot structure is seriously loose, which is easy to cause the ingot to open, such as Figure 3 As shown; or cause tearing on the surface of the ingot, such as Figure 5 shown.

[0043] In the present invention, the thickness of the ingot is preferably 15-25 mm, and in the embodiment it can be 25 mm, 15 mm or 20 mm. The width of the ingot is preferably 70-120 mm, and in the embodiment it can be 90 mm, 88 mm or 70 mm, and the length is preferably 200-250 mm.

[0044] In the present invention, when the thickness of the ingot is too large, it is easy to cause the ingot to break (such as Figure 2 shown).

[0045] After obtaining the ingot, before the ingot is subjected to multiple small deformation hot rolling, the present invention preferably further comprises pre-treating the ingot; the pre-treatment comprises: removing shrinkage cavities from the ingot and milling the rolling surface to obtain the ingot after pre-treatment. The milling is preferably performed using a milling machine, and the milling is used to remove impurity defects from the ingot. The thickness difference of the rolled surface of the ingot after the pre-treatment is ≤0.3mm, preferably 0.2mm or 0.3mm, the rolled surface is free of impurities and the surface roughness of the rolled surface is ≤Ra12.5. In the present invention, when the ingot after the pre-treatment does not meet the standard of "thickness difference ≤0.3mm, surface roughness of the rolled surface ≤Ra12.5", the pre-treatment step is repeated until the ingot after the pre-treatment meets the standard of "thickness difference ≤0.3mm, surface roughness of the rolled surface ≤Ra12.5".

[0046] The present invention controls the thickness difference of the ingot after pre-treatment to be ≤0.3mm, and the surface roughness of the rolled surface to be ≤Ra12.5, which can effectively avoid the tearing of the rolled surface and even the breakage of the ingot caused by the uneven deformation of the ingot.

[0047] In the present invention, when the ingot is not pre-treated and the multiple small deformation hot rolling is directly performed, it is easy to cause slight tearing on the surface of the ingot, such as Figure 4 shown.

[0048] In the present invention, the thickness difference of the ingot after the pre-treatment is too large, which may easily cause the edge tearing of the subsequent solder. Figure 4 shown.

[0049] In an embodiment of the present invention, the thickness of the ingot after the pre-treatment may be 22 mm, 18 mm or 13 mm.

[0050] After obtaining the ingot (i.e. the ingot after pretreatment), the present invention performs multiple small deformation hot rolling on the ingot to obtain the first semi-finished brazing material, and the single roll gap reduction of the small deformation hot rolling is ≤0.3mm.

[0051] In the present invention, the multiple small deformation hot rollings are performed along the length direction of the ingot, the hot rolling temperature range is preferably 0.85 to 0.95 times the solidus temperature, the rolling rate is preferably 30 to 60 mm / s, more preferably 35 to 55 mm / s, and in the embodiments it can be 45 mm / s, 40 mm / s or 50 mm / s.

[0052] The present invention can avoid the formation of brittle phase and ensure the thermoplasticity of the ingot by controlling the hot rolling temperature range to preferably 0.85 to 0.95 times the solidus temperature. In the present invention, if the hot rolling temperature is too high or too low, it is easy to cause the ingot to open. Figure 3 As shown; at the same time, it is easy to cause slight tearing on the surface of the ingot, such as Figure 4 As shown, or cause tearing on the surface of the ingot, such as Figure 5 shown.

[0053] The present invention can avoid tearing problems caused by the tail temperature of the ingot being lower than the rolling temperature and the ingot deforming too quickly during the rolling process by controlling the rolling rate of the multiple small deformation hot rolling to preferably 30-60 mm / s.

[0054] In the present invention, a heat preservation treatment is preferably performed between two adjacent small deformation hot rollings, the temperature of the heat preservation treatment is preferably 0.92 to 0.95 times the solidus temperature, and the heat preservation time is preferably 8 to 15 minutes. The heat preservation treatment is performed in an air atmosphere.

[0055] In the present invention, the single roll gap reduction of the small deformation hot rolling is ≤0.3mm, preferably 0.15-0.3mm, more preferably 0.15-0.2mm, and in the embodiment, it can be 0.15mm, 0.2mm, 0.25mm or 0.3mm. In the present invention, if the single roll gap reduction of the small deformation hot rolling is too large, it is easy to cause the surface tearing of the ingot, such as Figure 5 shown.

[0056] In the present invention, the multiple small deformation hot rolling preferably includes firstly hot rolling with a single roll gap reduction of preferably ≤0.2mm, which can be 0.15mm or 0.2mm in the embodiment, until the cumulative deformation is preferably ≥40%, which can be 40% in the embodiment; then hot rolling with a single roll gap reduction of preferably ≤0.3mm, which can be 0.25mm or 0.3mm in the embodiment, until the cumulative deformation is preferably ≤80%, which can be 80% in the embodiment; finally hot rolling with a single roll gap reduction of preferably ≤0.15mm, which can be 0.15mm in the embodiment, until the thickness of the first semi-finished solder is preferably 1.5-2mm, which can be 1.8mm or 2.0mm in the embodiment.

[0057] In an embodiment of the present invention, the multiple small deformation hot rolling specifically includes first hot rolling with a single roll gap reduction of preferably ≤0.2mm to a cumulative deformation of preferably ≥40%, and then heat preservation treatment; then hot rolling with a single roll gap reduction of preferably ≤0.3mm to a cumulative deformation of preferably ≤80%, and then heat preservation treatment; finally, hot rolling with a single roll gap reduction of preferably ≤0.15mm to a thickness of the first semi-finished solder of preferably 1.5 to 2mm.

[0058] In the present invention, the cumulative deformation amounts in the multiple small deformation hot rolling processes are all cumulative deformation amounts compared to the ingot (i.e. the ingot after pre-treatment).

[0059] The present invention controls the hot rolling with a single roll gap reduction of ≤0.2mm to a cumulative deformation of ≥40%, thereby breaking the coarse dendrites inside the ingot, densifying the ingot structure, and improving the plasticity of the ingot. At the same time, the tendency of the ingot to tear, open and break caused by the large plasticity difference between the rolling surface and the center of the ingot during plastic deformation is greatly reduced.

[0060] The present invention controls the hot rolling with a single roll gap reduction of ≤0.3mm to a cumulative deformation of ≤80%, and finally hot rolling with a single roll gap reduction of ≤0.15mm to a thickness of the first semi-finished solder of 1.5-2mm, and preferably performs heat preservation treatment between two adjacent small deformation hot rollings. This can improve the preparation efficiency while avoiding problems such as tearing caused by excessive single variable after the solder thickness is reduced.

[0061] After obtaining the first semi-finished solder, the present invention performs a first annealing on the first semi-finished solder to obtain a second semi-finished solder.

[0062] In the present invention, the first annealing is preferably performed in an air atmosphere, the holding temperature of the first annealing is preferably 0.88 to 0.92 times the solidus temperature, the holding time is preferably 20 to 30 minutes, and in the embodiment it can be 25 minutes or 20 minutes, and the cooling method is preferably air cooling. In the present invention, the first annealing is preferably performed to eliminate the solder rolling stress and soften the solder, and air cooling is performed to avoid the formation of a brittle phase and ensure the solder plasticity.

[0063] After obtaining the second semi-finished solder, before the second semi-finished solder is subjected to small deformation cold rolling, the present invention preferably further comprises pre-treating the second semi-finished solder to obtain the second semi-finished solder after pre-treatment. In the present invention, the pre-treatment preferably comprises sanding the second semi-finished solder to remove impurities on the solder surface and cutting off 2 to 3 mm along each side (long side and wide side), which may be 2 mm or 2.5 mm in the embodiment. The sanding is preferably performed by a belt sander. The rolling surface thickness difference of the obtained second semi-finished solder after pre-treatment is preferably ≤0.2 mm, more preferably ≤0.15 mm, and the rolling surface of the obtained second semi-finished solder after pre-treatment is free of impurities and the surface roughness of the rolling surface is preferably ≤Ra6.3. The present invention can effectively avoid poor surface quality of the solder caused by uneven deformation due to uneven surface of the solder, or even tearing and breaking, by pre-treating the second semi-finished solder. The thickness of the second semi-finished solder after pre-treatment is preferably 1.4 to 1.7 mm, which may be 1.4 mm, 1.7 mm or 1.5 mm in the embodiment.

[0064] After obtaining the second semi-finished solder (i.e., the second semi-finished solder after pretreatment), the present invention performs small deformation cold rolling and second annealing on the second semi-finished solder, the small deformation cold rolling and the second annealing are performed in a cycle, and only the small deformation cold rolling is performed in the last cycle, and the single roll gap reduction of the small deformation cold rolling is ≤0.15mm, until the multi-component Cu-Mn-Ni-Si foil strip solder is obtained.

[0065] In the present invention, by way of example, the small deformation cold rolling and the second annealing cycle are specifically carried out as follows: small deformation cold rolling, second annealing, small deformation cold rolling, second annealing, ..., small deformation cold rolling, second annealing, small deformation cold rolling.

[0066] In the present invention, the small deformation cold rolling is preferably carried out by a four-roll rolling mill. The small deformation cold rolling is carried out along the length direction of the second semi-finished solder, the rolling rate is preferably ≤25mm / s, and in the embodiment, it can be 15mm / s, 20mm / s, 10mm / s or 25mm / s, the single roll gap reduction is preferably 0.05-0.15mm, and in the embodiment, it can be 0.1mm or 0.05mm; the cumulative deformation between two adjacent second annealings is preferably 50-80%.

[0067] The present invention can avoid tearing of the edge or middle of the solder due to excessive or too fast single deformation by controlling the rolling rate of the small deformation cold rolling and the single roll gap reduction.

[0068] The present invention controls the cumulative deformation between two adjacent second annealings to be preferably 50-80%, thereby reducing the number of second annealings and improving production efficiency while ensuring the quality of the solder.

[0069] In the present invention, the second annealing is vacuum annealing, the vacuum degree of the second annealing is preferably ≤10Pa, preferably ≤5Pa, the temperature is preferably 0.84 to 0.88 times the solidus temperature, the holding time is preferably 10 to 25min, and in the embodiment it can be 10min or 15min, the cooling method is preferably rapid cooling to 0.4 times the solidus temperature followed by furnace cooling, the rapid cooling rate is preferably ≥30°C / min, more preferably ≥35°C / min, further preferably 35 to 40°C / min, and in the embodiment it can be 40°C / min or 35°C / min.

[0070] The present invention preferably controls the operating conditions of the second annealing to eliminate the solder rolling stress, soften the solder, and cool quickly to avoid the formation of a brittle phase, thereby ensuring the solder plasticity.

[0071] In the present invention, the thickness of the multi-component Cu-Mn-Ni-Si foil solder is 0.05-0.12 mm, and in the embodiment, it can be 0.1 mm or 0.05 mm.

[0072] In the present invention, the composition of the multi-component Cu-Mn-Ni-Si foil solder is controllable, with low carbon and oxygen contents, wherein the oxygen content is less than 200 ppm. The deviation between the actual composition Si, B, P and the nominal composition Si, B, P does not exceed 0.06% (mass percentage).

[0073] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0074] In the following embodiments, Figure 1 The flow chart shown is for preparing multi-component Cu-Mn-Ni-Si foil solder.

[0075] Example 1

[0076] This embodiment prepares a Cu35NiMnCoFeSiBP foil strip solder with a width of 80 mm and a thickness of 0.1 mm, specifically comprising the following steps:

[0077] (1) According to the nominal composition of Cu35NiMnCoFeSiBP (in mass percentage, Cu34.4-Ni29-Mn29-Co5-Fe1.2-Si1-B0.2-P0.2) and a total weight of 3.0 kg, electrolytic copper Cu, electrolytic copper Ni, electrolytic copper Mn, electrolytic Co, industrial pure Fe, and pure Si with a purity greater than 99.9% are weighed respectively, wherein B and P elements are added in the form of NiB and CuP master alloys, respectively, the raw materials are placed in a medium frequency furnace for smelting and cast into an ingot with a width of 90 mm and a thickness of 25 mm using a high-purity graphite mold;

[0078] (2) After the shrinkage cavity of the ingot is removed, the surface of the ingot is milled by a milling machine to remove impurities and defects, thereby obtaining an ingot with a thickness of 22 mm, a thickness difference of 0.2 mm, and a surface roughness of the rolled surface ≤ Ra12.5;

[0079] (3) rolling along the length direction of the ingot, controlling the rolling rate to 45 mm / s, controlling the hot rolling temperature range to 820-880°C, first rolling to a thickness of 12 mm with a single roll gap reduction of 0.15 mm, and keeping at 880°C for 12 min after hot rolling; then rolling to a thickness of 4.5 mm with a single roll gap reduction of 0.25 mm, and keeping at 880°C for 12 min after hot rolling; then rolling to a brazing material thickness of 1.8 mm with a single roll gap reduction of 0.15 mm;

[0080] (4) Keep the brazing material at 880°C for 25 minutes and then quickly take it out and air cool it to room temperature;

[0081] (5) Use a belt sander to remove impurities on the solder surface and cut off 3 mm on each side along the edge to obtain a sheet with a thickness of 1.4 mm, a thickness difference of 0.2 mm, and a surface roughness of the rolled surface ≤ Ra6.3;

[0082] (6) Using a four-roll mill with a rolling rate of 15 mm / s, the solder is rolled to a thickness of 0.3 mm with a single roll gap reduction of 0.1 mm. The solder is then placed in a vacuum tube furnace and evacuated to below 5 Pa. After being kept at 840 °C for 10 min, the solder is cooled to 350 °C at a cooling rate of 40 °C / min and then cooled to room temperature with the furnace.

[0083] (7) A four-roll mill is used with a rolling rate of 20 mm / s, and the solder is rolled to a thickness of 0.1 mm with a single roll gap reduction of 0.05 mm. The solder is cut off at the edge to obtain a foil strip solder with a width of 80 mm and a thickness of 0.1 mm.

[0084] The Cu35NiMnCoFeSiBP foil solder obtained in this embodiment has an oxygen content of less than 200ppm, uniform solder composition, stable quality, and a deviation between the actual composition Si, B, P and the nominal composition Si, B, P of no more than 0.06% (mass percentage), and a yield rate of up to 46%.

[0085] Example 2

[0086] In this embodiment, a Cu40AgMnNiSiZnBP foil solder with a width of 80 mm and a thickness of 0.05 mm is prepared. The specific method includes the following steps:

[0087] (1) According to the nominal composition of Cu40AgMnNiSiZnBP (in mass percentage, Cu42-Ag23-Mn21.5-Ni11.5-Si0.3-Zn1.3-B0.2-P0.2) and a total weight of 2.6 kg, Ag, Cu, Ni, Mn, Zn, and Si with a purity greater than 99.9% are weighed, wherein B and P elements are added in the form of NiB and CuP master alloys, and the raw materials are placed in a medium frequency furnace for smelting and cast into an ingot with a width of 88 mm and a thickness of 20 mm using a high-purity graphite mold;

[0088] (2) After the shrinkage cavity of the ingot is removed, the surface of the ingot is milled by a milling machine to remove impurities and defects, thereby obtaining an ingot with a thickness of 18 mm, an ingot thickness difference of 0.3 mm, and a rolling surface roughness of ≤ Ra12.5;

[0089] (3) rolling along the length direction of the ingot, controlling the rolling rate to 40 mm / s, controlling the hot rolling temperature range to 670-720°C, first rolling to a thickness of 9 mm with a single roll gap reduction of 0.2 mm, and keeping at 720°C for 10 min after hot rolling; then rolling to a thickness of 3.6 mm with a single roll gap reduction of 0.3 mm, and keeping at 720°C for 10 min after hot rolling; then rolling to a brazing material thickness of 2.0 mm with a single roll gap reduction of 0.15 mm;

[0090] (4) Keep the brazing material at 720°C for 20 minutes and then quickly take it out and air cool it to room temperature;

[0091] (5) Use a belt sander to remove impurities on the solder surface and cut off 2.5 mm on each side along the edge to obtain a sheet with a thickness of 1.7 mm, a thickness difference of no more than 0.15 mm, and a surface roughness of the rolled surface not exceeding Ra6.3;

[0092] (6) A four-roll mill is used with a rolling rate of 10 mm / s, and a single roll gap reduction of 0.1 mm is used to roll the brazing material to a thickness of 1.0 mm. The brazing material is then placed in a tubular furnace and evacuated to below 5 Pa. After being kept at 670 °C for 15 min, the brazing material is cooled to 200 °C at a cooling rate of 35 °C / min and then cooled to room temperature with the furnace.

[0093] (7) A four-roll mill is used with a rolling rate of 15 mm / s, and a single roll gap reduction of 0.1 mm is used to roll the brazing material to a thickness of 0.2 mm. The brazing material is then placed in a tubular furnace and evacuated to below 5 Pa. After being kept at 670 °C for 15 min, the brazing material is cooled to 200 °C at a cooling rate of 35 °C / min and then cooled to room temperature in the furnace.

[0094] (8) A four-roll mill is used with a rolling rate of 15 mm / s. The solder is rolled to a thickness of 0.05 mm with a single roll gap reduction of 0.05 mm. The solder is then cut off at the edges to obtain a foil solder with a width of 80 mm and a thickness of 0.05 mm. The Cu40AgMnNiSiZnBP foil solder obtained in this embodiment has an oxygen content of less than 200 ppm, a uniform solder composition, and stable quality. The actual components Si, B, and P deviate from the nominal components Si, B, and P by no more than 0.06% (mass percentage), and the yield rate can reach 52%.

[0095] Example 3

[0096] In this embodiment, a Cu55-Mn37.5-Ni5-Si1.5 foil solder with a width of 64 mm and a thickness of 0.1 mm is prepared. The specific preparation method includes:

[0097] (1) Cu, Ni, Mn and Si with a purity greater than 99.9% were weighed according to the nominal composition of Cu55-Mn37.5-Ni5-Si1.5 and a total weight of 2.2 kg, the raw materials were placed in a medium frequency furnace for smelting and cast into an ingot with a width of 70 mm and a thickness of 15 mm using a high-purity graphite mold;

[0098] (2) After the shrinkage cavity of the ingot is removed, the surface of the ingot is milled by a milling machine to remove impurities and defects, thereby obtaining an ingot with a thickness of 13 mm, an ingot thickness difference of 0.2 mm, and a rolling surface roughness of ≤ Ra12.5;

[0099] (3) rolling along the length direction of the ingot, controlling the rolling rate to 50 mm / s, controlling the hot rolling temperature range to 740-800 °C, first rolling to a thickness of 6 mm with a single roll gap reduction of 0.2 mm, and keeping at 800 °C for 10 min after hot rolling; then rolling to a thickness of 3 mm with a single roll gap reduction of 0.3 mm, and keeping at 800 °C for 10 min after hot rolling; then rolling to a brazing material thickness of 1.8 mm with a single roll gap reduction of 0.15 mm;

[0100] (4) Keep the brazing material at 800°C for 20 minutes and then quickly take it out and air cool it to room temperature;

[0101] (5) Use a belt sander to remove impurities on the solder surface and cut off 2 mm on each side along the edge to obtain a sheet with a thickness of 1.5 mm, a thickness difference of no more than 0.2 mm, and a surface roughness of the rolled surface ≤ Ra6.3;

[0102] (6) A four-roll mill is used with a rolling rate of 25 mm / s, and a single roll gap reduction of 0.1 mm is used to roll the brazing material to a thickness of 0.4 mm. The brazing material is then placed in a tubular furnace and evacuated to below 5 Pa. After being kept at 750 °C for 15 min, the brazing material is cooled to 300 °C at a cooling rate of 40 °C / min and then cooled to room temperature along with the furnace.

[0103] (7) A four-roll mill is used with a rolling rate of 20 mm / s, and a single roll gap reduction of 0.05 mm is used to roll the solder to a thickness of 0.1 mm. The solder is then cut off at the edge to obtain a foil strip solder with a width of 64 mm and a thickness of 0.1 mm.

[0104] The Cu55-Mn37.5-Ni5-Si1.5 foil solder obtained in this embodiment has good cleanliness and stable quality. The Cu55-Mn37.5-Ni5-Si1.5 foil solder obtained in this embodiment has an oxygen content of less than 200 ppm, uniform solder composition, stable quality, a deviation between the actual component Si and the nominal component Si of no more than 0.06% (mass percentage), and a yield rate of up to 54%.

[0105] As can be seen from the above embodiments, the present invention can greatly reduce the tendency of solder tearing by adopting multiple small deformation cold rolling (including hot rolling and cold rolling) and annealing, and controlling the single roll gap reduction of small deformation cold rolling, so that the solder product yield is high; at the same time, the method provided by the present invention is simple to operate, and conventional processing equipment is used, which can realize the low-cost preparation of various types of multi-element Cu-Mn-Ni-Si foil solders, and has the advantages of simple operation and wide applicability compared with spray forming, atomization, etc. In addition, the method of the present invention can increase the number of rolled ingots in the same batch to further reduce costs.

[0106] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a multi-element Cu-Mn-Ni-Si foil solder at low cost, characterized in that: The following steps are involved: The raw materials for preparing the multi-component Cu-Mn-Ni-Si brazing material are melted and cast to obtain an ingot; The ingot is subjected to multiple small deformation hot rolling to obtain a first semi-finished brazing material, wherein a single roll gap reduction of the small deformation hot rolling is ≤0.3 mm; Performing a first annealing on the first semi-finished solder to obtain a second semi-finished solder; The second semi-finished solder is subjected to small deformation cold rolling and second annealing, the small deformation cold rolling and second annealing are cyclically performed, and the single roll gap reduction of the small deformation cold rolling is ≤0.15mm, until the multi-component Cu-Mn-Ni-Si foil solder is obtained.

2. The method for preparing multi-element Cu-Mn-Ni-Si foil solder at low cost according to claim 1, characterized in that: The multiple small deformation hot rolling is performed along the length direction of the ingot, the hot rolling temperature range is 0.85 to 0.95 times the solidus temperature, and the rolling rate is 30 to 60 mm / s; A heat preservation treatment is performed between two adjacent small deformation hot rollings, wherein the temperature of the heat preservation treatment is 0.92 to 0.95 times the solidus temperature, and the heat preservation time is 8 to 15 minutes.

3. The method for preparing multi-element Cu-Mn-Ni-Si foil solder at low cost according to claim 1 or 2, characterized in that: The multiple small deformation hot rolling includes first hot rolling with a single roll gap reduction of ≤0.2mm until the cumulative deformation is ≥40%; then hot rolling with a single roll gap reduction of ≤0.3mm until the cumulative deformation is ≤80%; and finally hot rolling with a single roll gap reduction of ≤0.15mm until the thickness of the first semi-finished solder is 1.5-2mm.

4. The method for preparing multi-element Cu-Mn-Ni-Si foil solder at low cost according to claim 1, characterized in that: The first annealing is performed in an air atmosphere, the holding temperature of the first annealing is 0.88 to 0.92 times the solidus temperature, the holding time is 20 to 30 minutes, and the cooling method is air cooling.

5. The method for preparing multi-element Cu-Mn-Ni-Si foil solder at low cost according to claim 1, characterized in that: The small deformation cold rolling is performed along the length direction of the second semi-finished solder, with a rolling rate of ≤25mm / s and a single roll gap reduction of 0.05-0.15mm; the cumulative deformation between two adjacent second annealings is 50-80%.

6. The method for preparing multi-element Cu-Mn-Ni-Si foil solder at low cost according to claim 1 or 5, characterized in that: The second annealing is vacuum annealing, the vacuum degree of the second annealing is ≤10Pa, the temperature is 0.84 to 0.88 times the solidus temperature, the holding time is 10 to 25min, the cooling method is rapid cooling to 0.4 times the solidus temperature and then furnace cooling, and the rapid cooling rate is ≥30°C / min.

7. The method for preparing multi-element Cu-Mn-Ni-Si foil solder at low cost according to claim 1, characterized in that: The ingot has a thickness of 15 to 25 mm, a width of 70 to 100 mm, and a length of 200 to 250 mm.

8. The method for preparing multi-element Cu-Mn-Ni-Si foil solder at low cost according to claim 1 or 7, characterized in that: After obtaining the ingot, before the ingot is subjected to multiple small deformation hot rolling, the ingot is also subjected to pre-treatment; the pre-treatment includes: removing shrinkage holes and milling the rolling surface of the ingot to obtain the pre-treated ingot; the thickness difference of the rolled surface of the pre-treated ingot is ≤0.3mm, and the surface roughness of the rolled surface is ≤Ra12.

5.

9. The method for preparing multi-element Cu-Mn-Ni-Si foil solder at low cost according to claim 1, characterized in that: After obtaining the second semi-finished solder, before the second semi-finished solder is subjected to small deformation cold rolling, the second semi-finished solder is also subjected to pre-treatment to obtain the second semi-finished solder after pre-treatment, and the thickness difference of the rolled surface of the second semi-finished solder after pre-treatment is ≤0.2mm, and the surface roughness of the rolled surface is ≤Ra6.

3.

10. The method for preparing multi-element Cu-Mn-Ni-Si foil solder at low cost according to claim 1, characterized in that: The thickness of the multi-element Cu-Mn-Ni-Si foil solder is 0.05-0.12 mm; The multi-component Cu-Mn-Ni-Si foil solder includes Cu35NiMnSiCoFeBP, Cu40AgMnNiSiZnBP, CuAgMnNiSi or CuMnNiSi; The mass percentage of Si element in the CuAgMnNiSi is 1-3%; The mass percentage of Si element in the CuMnNiSi is 1-3%.

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