Copper-based brazing filler metal for CBN tool soldering, its preparation method and application

Abstract

This invention belongs to the field of brazing materials technology, specifically disclosing a copper-based brazing filler metal for CBN tools, its preparation method, and its application. The copper-based brazing filler metal comprises: 15.0%–20.0% manganese, 1.0%–3.0% nickel, 1.0%–1.8% chromium, 6.0%–9.0% titanium, with the balance being copper, and the total amount of impurity elements is less than 0.3%. The preparation method includes: placing metallic copper, metallic manganese, metallic nickel, metallic chromium, and metallic titanium in a vacuum medium-frequency induction furnace for melting and mixing. After the raw materials are melted and mixed evenly, a refining agent is added for refining to obtain an alloy melt; the alloy melt is then atomized in vacuum using an inert gas to obtain alloy powder; the alloy powder is mixed with a dispersant under vacuum conditions of 45–60°C to obtain copper-based alloy powder. The copper-based brazing filler metal of this invention has advantages such as high purity, high bulk density, low melting point, good wettability, higher bonding strength, and good hardness and wear resistance.

Description

Technical Field

[0001] This invention relates to the field of brazing materials technology, specifically to a copper-based brazing filler metal for CBN tool brazing and its preparation method. Background Technology

[0002] Cubic boron nitride (CBN) tools are widely used in grinding ferrous materials such as high-speed steel, tool steel, die steel, and wear-resistant cast iron, as well as titanium alloys, due to their high bonding strength, lack of dressing requirements, strong abrasive holding power, large chip space, and service life several times longer than electroplated CBN tools, while also reducing processing time by one-third. Therefore, brazed CBN tools are gradually becoming one of the main manufacturing processes for single-layer CBN tools.

[0003] Currently, brazing filler metals for CBN tools mainly fall into three categories: silver-based active filler metals, copper-based active filler metals, and nickel-based high-temperature filler metals. While silver-based active filler metals are widely used in the machining of iron-based materials or alloys, their low operating temperature, poor high-temperature stability, low hardness and wear resistance, and high material cost limit their widespread application. Nickel-based high-temperature filler metals, with their excessively high melting temperature, tendency to damage the base material, poor wettability, and poor thermal conductivity, are also not widely used in CBN tool brazing. Copper-based filler metals, represented by copper-tin-titanium active filler metals, are the most promising alternative filler metals for brazing CBN tools. They possess advantages such as good thermal conductivity, low cost, good wettability, and good mechanical properties, leading to increasingly widespread research and application. However, under high grinding temperatures and heavy loads, the high-temperature performance of copper-based filler metals remains poor, easily softening and causing abrasive grain shedding, affecting tool life, and exhibiting insufficient strength and wear resistance.

[0004] Furthermore, currently, most copper-based brazing alloy powders undergo refining processes during smelting and atomization to remove impurities. The inclusions present in the alloy powder persist into the brazing and usage processes, becoming stress concentration points that lead to cracking at the weld joint and affect tool life. There are two coating methods for copper-based brazing filler metals used in CBN tools: one is to first coat the substrate surface with a colloid, then evenly distribute the copper-based alloy powder on the colloid, followed by an ordered arrangement of CBN abrasive particles, and finally vacuum brazing to obtain a CBN tool; the other is to prepare the copper-based alloy powder into a solder paste, evenly apply it to the substrate surface, then arrange an ordered arrangement of CBN abrasive particles, and finally vacuum braze to obtain a CBN tool. Regardless of the method, better dispersibility of the brazing filler metal results in better coating uniformity, which is beneficial for improving brazing performance. However, defects such as satellite powder and capped powder generated during the atomization process of copper-based alloy powder lead to poor powder dispersibility and flowability.

[0005] Therefore, in view of the aforementioned problems still existing in copper-based brazing filler metals for CBN tools, it is necessary to develop a new type of copper-based brazing filler metal for CBN tools suitable for heavy-duty and high-temperature working conditions. Summary of the Invention

[0006] In view of the above-mentioned shortcomings, this invention provides a copper-based brazing filler metal for CBN tools, its preparation method, and its application. This invention effectively reduces the inclusion content by more than 6.0% by refining the copper alloy melt, thus improving the purity of the alloy. By dispersing the alloy powder, the powder's flowability is significantly improved, and the loose packing density is increased by more than 10.0%, ensuring more uniform and dense spreading of the powder on the colloidal surface of the matrix. The copper-based brazing filler metal designed in this invention, through the synergistic effect of Mn, Cr, and Ti elements, controls the melting point of the filler metal between 920 and 960°C, ensuring that the operating temperature of CBN tools can reach 500 to 600°C. Utilizing the main wetting effect of Ti and Cr elements, the wettability of the filler metal to the base material is further improved without increasing the brittle phase. The filler metal has higher bonding strength, better hardness, and better wear resistance, making it suitable for heavy-duty, high-temperature grinding scenarios.

[0007] To achieve the above objectives, the present invention provides a copper-based brazing filler metal for CBN tools. The copper-based brazing filler metal comprises, by mass percentage: 15.0% to 20.0% manganese, 1.0% to 3.0% nickel, 1.0% to 1.8% chromium, 6.0% to 9.0% titanium, with the balance being copper, and the total amount of impurity elements is less than 0.3%.

[0008] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned copper-based brazing filler metal for CBN tool soldering, comprising the following steps:

[0009] S1. Metallic copper, metallic manganese, metallic nickel, metallic chromium, and metallic titanium are placed in a vacuum medium-frequency induction furnace for smelting. After the raw materials are melted and mixed, a refining agent is added for refining to obtain an alloy melt. The amount of the refining agent added is 0.1% to 0.4% of the total mass of the metal raw materials.

[0010] It should be noted that the amount of refining agent added in this invention is 0.1% to 0.4% of the total mass of the raw materials. For example, if there are 100 kg of raw materials (copper, manganese, nickel, chromium and titanium), then 100 g to 400 g of refining agent needs to be added.

[0011] S2. The alloy melt is subjected to vacuum atomization treatment using an inert gas to obtain alloy powder.

[0012] Furthermore, the preparation method further includes:

[0013] S3. The alloy powder is mixed with a dispersant at 45-60°C and under vacuum to obtain copper-based alloy powder.

[0014] Further, in step S1, the melting temperature is 1150℃~1300℃, and the vacuum degree is ≤40Pa; the refining temperature is 1050℃~1200℃, and the refining time is 3~5min.

[0015] Further, in step S1, the refining agent comprises, by mass percentage, 17.0%–22.0% sodium fluoroborate, 20.0%–25.0% potassium fluorotitanate, 15.0%–25.0% cryolite, 15.0%–20.0% nano barium carbonate, and 11.0%–26.0% nano manganese carbonate.

[0016] It should be noted that this invention, based on traditional fluorotitanate and fluoroborate refining agents, adds nano-carbonates, barium carbonate, and manganese carbonate. The tiny inert bubbles generated by barium carbonate and manganese carbonate during heating, due to the zero partial pressure of hydrogen and other inclusion gases within these bubbles, while the partial pressure of gaseous inclusions in the melt is much greater than zero, easily adsorb non-metallic inclusions into the inert bubbles, greatly improving the refining agent's removal of non-metallic inclusions. The MnO in the decomposition products of manganese carbonate readily reacts with oxygen at high temperatures to generate more stable oxides, such as manganese silicate, thereby achieving deoxidation and desilication, further improving the purity of the melt. Furthermore, the presence of an inert atmosphere (carbon dioxide produced by carbonate decomposition) not only reduces the corrosion of equipment by the toxic boron trifluoride corrosive gas released during the high-temperature decomposition of traditional fluorotitanate and fluoroborate refining agents, but also accelerates the rate at which the complex salts formed by fluorotitanate and fluoroborate rise to the melt surface, reducing the melt's resting time and thus minimizing element loss.

[0017] Further, in step S2, the temperature of the vacuum atomization treatment is 1050-1150℃, the atomization rate is 4-6 kg / min, the spray angle of the atomizer is 35-45°, and the atomization pressure is 4-6 MPa.

[0018] Further, in step S3, the mass percentage of the alloy powder to the dispersant is 50-60:1, the vacuum degree is 80-200 Pa, and the mixing time is 10-20 min.

[0019] Further, in step S3, the dispersant comprises, by mass percentage, 90.0% to 97.0% acetone, 0.5% to 1.0% methyl palmitate, 2.0% to 5.0% palmitic acid, and 0.2% to 1.7% dodecanoic acid.

[0020] It should be noted that directly spreading copper-based alloy powder onto the adhesive of the substrate places higher demands on the dispersion and flowability of the powder. The poor morphology, numerous satellite and capped powders, and tendency to absorb moisture and clump in copper-based alloy powders often lead to conduit blockage and uneven distribution during the powder spreading process. The dispersant used in this invention treats the alloy powder in two ways: first, by coating the alloy powder with methyl palmitate, palmitic acid, and dodecanoic acid, electrostatic adsorption and oxidation processes between powders are reduced. This results in stronger bonding between the dispersant and the adhesive on the substrate surface, and its better thermal stability reduces powder shedding during brazing, thus increasing the solder climb height; second, the acetone in the dispersant completely evaporates during the dispersion process, leaving less than 0.08% organic matter. This trace amount of dispersed material is easily removed during brazing and will not affect the weld quality. Therefore, compared to commonly used alloy powder dispersants, lubricants, or surfactants added at levels above 0.5%, this invention achieves better alloy powder dispersion with less dispersant.

[0021] Based on the same inventive concept, the present invention also provides the application of the above-mentioned copper-based brazing filler metal for CBN tool soldering or the copper-based brazing filler metal for CBN tool soldering prepared by any of the above preparation methods, the application including the following steps:

[0022] The 80%–90% alloy powder or copper-based alloy powder is mixed with 10%–20% binder to obtain copper-based solder paste. The solder paste is evenly applied to the substrate surface, and then orderly arranged CBN abrasives are arranged on it. After vacuum brazing, a CBN tool is obtained.

[0023] Alternatively, the alloy powder or copper-based alloy powder can be uniformly distributed on a colloid on the surface of a substrate, and then orderly arranged with CBN abrasives. After vacuum brazing, a CBN tool can be obtained.

[0024] It should be noted that the aforementioned alloy powder and copper-based alloy powder are essentially both copper-based alloy powders; they are simply named differently to distinguish step S3. When the preparation method only includes steps S1 and S2, the powder bonded to / uniformly distributed on the substrate surface with the binder is the alloy powder; when the preparation method also includes step S3, the powder bonded to / uniformly distributed on the substrate surface with the binder is the copper-based alloy powder.

[0025] Further, the binder is composed of the following components: 58.0%–75.0% solvent, 8.0%–15.0% thickener, 5.0%–12.0% antioxidant, and 1.0%–5.0% activator; wherein the solvent includes butyl octyl alcohol and dimethyl sulfoxide; the thickener includes ethyl cellulose and hexyl decyl alcohol; the antioxidant is oxalic acid; and the activator includes palmitic acid and hexadecyl acetate.

[0026] The beneficial effects of this invention are:

[0027] This invention effectively reduces the inclusion content by more than 6.0% by refining the copper alloy melt, thus improving the purity of the alloy. By dispersing the alloy powder, the powder's flowability is significantly improved, and the loose packing density is increased by more than 10.0%, ensuring a more uniform and dense spread of the powder on the colloidal surface of the matrix. The copper-based brazing filler metal designed in this invention controls the melting point between 920 and 960°C by regulating the synergistic effect of Mn, Cr, and Ti elements, ensuring that the operating temperature of CBN tools can reach 500–600°C. Utilizing the primary wetting effect of Ti and Cr elements further enhances the wettability of the filler metal to the base material without increasing the brittle phase. The filler metal exhibits higher bonding strength, better hardness, and better wear resistance, making it suitable for heavy-duty, high-temperature grinding applications. Attached Figure Description

[0028] Figure 1 The particle size distribution of the alloy powder prepared in Example 1 of this invention is shown.

[0029] Figure 2 This is a scanning electron microscope image of the alloy powder prepared in Example 1 of the present invention. Detailed Implementation

[0030] To make the present invention easier to understand, specific embodiments are described below to further illustrate the invention. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical terms used below have the same meaning as understood by those skilled in the art; unless otherwise specified, the raw materials and reagents involved herein can be purchased commercially or obtained by known methods.

[0031] Example 1

[0032] S1. By mass percentage, its chemical composition includes: 15.0% Mn, 1.0% Ni, 1.0% Cr, 6.0% Ti, total impurity elements less than 0.3%, and the remainder being copper. Metallic copper, metallic manganese, metallic nickel, metallic chromium, and metallic titanium are placed in a vacuum induction furnace. Under medium-frequency induction (85–100 kW, 950–1100 Hz) and a vacuum of 20–30 Pa, the raw materials are completely melted and stirred for 7 minutes to obtain a mixed alloy melt. At 1100–1200 °C, 0.1% refining agent is added to the alloy melt, and refining is carried out for 3 minutes. The refining agent consists of 19.0% sodium fluoroborate, 23.0% potassium fluoroborate, 21.0% cryolite, 17.0% nano-barium carbonate, and 20.0% nano-manganese carbonate, resulting in a refined alloy melt.

[0033] S2. The obtained alloy melt is atomized by vacuum atomization with high-purity argon gas (purity ≥99.999%). The spray angle of the atomizer is 35-40°, the atomization pressure is 5.5-6MPa, the atomization temperature of the alloy melt is 1100-1150℃, and the atomization rate is 5-6kg / min to obtain alloy powder.

[0034] S3. At a temperature of 45–50°C, the alloy powder and dispersant are mixed to obtain dispersed copper-based alloy powder. The mass percentage of alloy powder to dispersant is 58:1, the vacuum degree is 80–100 Pa, and the mixing time is 20 min. The composition and mass percentage of the dispersant include: 95.0% acetone, 0.5% methyl palmitate, 4.0% palmitic acid, and 0.5% dodecanoic acid.

[0035] S4. Dispersed copper-based alloy powder is evenly distributed on the colloid on the surface of the matrix, and then orderly arranged CBN abrasive is arranged on it. After vacuum brazing, CBN tools are obtained.

[0036] Example 2

[0037] Example 2 uses the same atomization powder preparation process as Example 1, except that there is no alloy powder dispersion step (S3). Instead, 75.0% solvent, 12.0% thickener, 10.0% antioxidant, and 3.0% activator are mixed to obtain a binder. Using a high-speed disperser, 85.0% alloy powder and 15.0% binder are mixed evenly to obtain copper-based solder paste. The solvent has a butyl octanol:dimethyl sulfoxide mass ratio of 4:1, the thickener has a ethyl cellulose:hexyl decanol mass ratio of 3:2, and the activator has a palmitic acid:hexadecyl hexadecyl ester mass ratio of 7:3. The solder paste is evenly applied to the substrate surface, and then orderly arranged CBN abrasive particles are placed on top. After vacuum brazing, a CBN tool is obtained.

[0038] The remaining steps are the same as in Example 1.

[0039] Example 3

[0040] Example 3 is essentially the same as Example 1, except that, by mass percentage, its chemical composition includes: 20.0% Mn, 3.0% Ni, 1.8% Cr, 9.0% Ti, with total impurity elements less than 0.3%, and the remainder being copper. Furthermore, at a temperature of 1100–1200°C, 0.3% refining agent was added to the alloy melt, and refining was carried out for 3 minutes. The refining agent consisted of 22.0% sodium fluoroborate, 25.0% potassium fluoroborate, 23.0% cryolite, 15.0% nano-barium carbonate, and 15.0% nano-manganese carbonate, resulting in a refined alloy melt.

[0041] The remaining steps are the same as in Example 1.

[0042] Example 4

[0043] Example 4 is basically the same as Example 2, except that 73.0% solvent, 10.0% thickener, 12.0% antioxidant, and 5.0% activator are mixed to obtain a binder. Using a high-speed disperser, 90.0% alloy powder and 10.0% binder are mixed evenly to obtain copper-based solder paste.

[0044] The remaining steps are the same as in Example 2.

[0045] Example 5

[0046] Example 5 is basically the same as Example 1, except that the mass percentage of alloy powder to dispersant is 52:1, the vacuum degree is 80-100 Pa, and the mixing time is 20 min. The composition and mass percentage of the dispersant include: 94.5% acetone, 1.0% methyl palmitate, 3.0% palmitic acid, and 1.5% dodecanoic acid.

[0047] The remaining steps are the same as in Example 1.

[0048] Comparative Example 1

[0049] Comparative Example 1 is basically the same as Example 1, except that Comparative Example 1 does not have a melt refining process.

[0050] The remaining steps are the same as in Example 1.

[0051] Comparative Example 2

[0052] Comparative Example 2 is basically the same as Example 1, except that there is no alloy powder dispersion process in Comparative Example 2.

[0053] The remaining steps are the same as in Example 1.

[0054] Comparative Example 3

[0055] Comparative Example 3 is basically the same as Example 2, except that Comparative Example 3 is a commercial copper-tin-titanium alloy powder, whose chemical composition by mass percentage includes: 19% Sn, 10.0% Ti, less than 0.3% total impurity elements, and the remainder is copper.

[0056] The remaining steps are the same as in Example 2.

[0057] Comparative Example 4

[0058] Comparative Example 4 is a commercial copper-tin-titanium active solder paste. By mass percentage, the chemical composition of the copper-tin-titanium solder includes: 19% Sn, 10.0% Ti, less than 0.3% total impurity elements, and the remainder being copper. The solder paste is evenly applied to the substrate surface, and then orderly arranged CBN abrasive particles are placed on top. After vacuum brazing, a CBN tool is obtained.

[0059] Comparative Example 5

[0060] Comparative Example 5 is a commercially available nickel-based solder paste. By mass percentage, the chemical composition of the nickel-based solder includes: 7.0% Cr, 3.0% B, 4.5% Si, 3.0% Fe, with total impurity elements less than 0.3%, and the remainder being nickel. The solder paste was evenly applied to the substrate surface, and then orderly arranged CBN abrasive particles were placed on top. After vacuum brazing, a CBN tool was obtained.

[0061] Performance testing and results analysis:

[0062] The copper-based alloy powder prepared in Example 1 was subjected to particle size and microstructure analysis. The particle size distribution of the copper-based alloy powder is shown in the figure below. Figure 1 As shown, by Figure 1 It can be seen that the copper-based alloy powder prepared in this embodiment has a small median particle size and a relatively concentrated particle size distribution, indicating that the copper-based alloy powder prepared in this application has a low impurity content. The microstructure of the copper-based alloy powder is as follows: Figure 2 As shown, by Figure 2 This indicates that the copper-based alloy powder prepared in this application is uniformly dispersed, and that the loose packing density of the copper-based alloy powder prepared in this application is high.

[0063] The volume fraction of inclusions in the alloy powders obtained in the examples and comparative examples was tested and calculated. The calculation method for the volume fraction of inclusions is as follows:

[0064] Inclusion size is expressed as the inclusion equivalent diameter d. avg express,

[0065] In the formula, A inclusion The area of ​​a single inclusion, in μm, is obtained from image analysis software. 2 .

[0066] Average volume fraction F of inclusions avgCalculated by the following formula:

[0067]

[0068] In the formula, A field It is the area of ​​the metallographic field of view, in μm. 2 .

[0069] The melting characteristics of copper-based active brazing alloy powders obtained in some embodiments and comparative examples were tested, and the results are shown in Table 1.

[0070] Table 1. Characteristics of brazing alloy powders in some examples and comparative cases.

[0071]

[0072] As shown in Table 1, compared with the copper-based alloy powder in the comparative example, the loose bulk density of the copper-based alloy powder prepared in this invention after dispersion is lower than 4.8 g / cm³. 3 It increased to over 5.4 g / cm³. 3 The increase exceeded 12%; the Hall flow rate was significantly reduced, and a lower Hall flow rate indicates better powder flowability. Furthermore, compared to unrefined alloy powder, the volume fraction of inclusions in the refined alloy powder decreased to 0.08%, a reduction of over 27%, demonstrating a significant melt purification effect. As can be seen from the melting temperatures of the examples and comparative examples, the copper-based brazing filler metal prepared in this invention has a higher melting temperature than commercial copper-tin-titanium brazing filler metals, which is beneficial for improving the thermal stability of CBN tools during use. Compared to commercial nickel-based brazing filler metals, its melting point is lower, making it less likely to cause brazing damage to the base material.

[0073] The brazing performance of the copper-based active brazing alloy powders obtained in the examples and comparative examples was tested, and the results are shown in Table 2.

[0074] Table 2 Comparison of brazing performance of the examples and comparative examples

[0075]

[0076] As shown in Table 2, compared with the commercial copper-based brazing filler metals in Comparative Examples 3 and 4, the copper-based brazing filler metal prepared in this invention, under the synergistic effect of Ti and Cr elements, exhibits better wettability with a smaller wetting angle for CBN abrasive grains at the same content of active elements. Through melt purification, brazing dispersion, and the synergistic effect of low-content brittle phases, the brazing interface between CBN and the steel substrate prepared by the brazing filler metal of this invention is dense, with fewer stress-concentrated impurity points, thus possessing higher shear strength. Under the same grinding conditions, the number of grinding feeds before tool failure is also higher, indicating a longer tool life.

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A copper-based brazing filler metal for CBN tool soldering, characterized in that, The copper-based brazing filler metal comprises, by mass percentage: 15.0%~20.0% manganese, 1.0%~3.0% nickel, 1.0%~1.8% chromium, 6.0%~9.0% titanium, with the total amount of impurity elements less than 0.3%, and the balance being copper. The preparation method of the copper-based solder for CBN tool brazing includes the following steps: S1. Metallic copper, metallic manganese, metallic nickel, metallic chromium, and metallic titanium are placed in a vacuum medium-frequency induction furnace for smelting. After the raw materials are melted and mixed, a refining agent is added for refining to obtain an alloy melt. The amount of the refining agent added is 0.1% to 0.4% of the total mass of the metallic raw materials. S2. The alloy melt is subjected to vacuum atomization treatment with inert gas to obtain alloy powder; S3. The alloy powder is mixed with a dispersant at 45~60℃ and under vacuum to obtain copper-based alloy powder.

2. The method for preparing copper-based brazing filler metal for CBN tools according to claim 1, characterized in that, Includes the following steps: S1. Metallic copper, metallic manganese, metallic nickel, metallic chromium, and metallic titanium are placed in a vacuum medium-frequency induction furnace for smelting. After the raw materials are melted and mixed, a refining agent is added for refining to obtain an alloy melt. The amount of the refining agent added is 0.1% to 0.4% of the total mass of the metallic raw materials. S2. The alloy melt is subjected to vacuum atomization treatment using an inert gas to obtain alloy powder.

3. The method for preparing copper-based brazing filler metal for CBN tool brazing according to claim 2, characterized in that, The preparation method further includes: S3. The alloy powder is mixed with a dispersant at 45~60℃ and under vacuum to obtain copper-based alloy powder.

4. The method for preparing copper-based brazing filler metal for CBN tool brazing according to claim 2, characterized in that, In step S1, the melting temperature is 1150℃~1300℃ and the vacuum degree is ≤40Pa; the refining temperature is 1050℃~1200℃ and the refining time is 3~5min.

5. The method for preparing copper-based brazing filler metal for CBN tools according to claim 2, characterized in that, In step S1, the refining agent comprises, by mass percentage, 17.0%~22.0% sodium fluoroborate, 20.0%~25.0% potassium fluorotitanate, 15.0%~25.0% cryolite, 15.0%~20.0% nano barium carbonate, and 11.0%~26.0% nano manganese carbonate.

6. The method for preparing copper-based brazing filler metal for CBN tool brazing according to claim 2, characterized in that, In step S2, the temperature of the vacuum atomization treatment is 1050~1150℃, the atomization rate is 4~6kg / min, the spray angle of the atomizer is 35~45°, and the atomization pressure is 4~6MPa.

7. The method for preparing copper-based brazing filler metal for CBN tool soldering according to claim 3, characterized in that, In step S3, the mass percentage of the alloy powder to the dispersant is 50~60:1, the vacuum degree is 80~200Pa, and the mixing time is 10~20min.

8. The method for preparing copper-based brazing filler metal for CBN tools according to claim 3, characterized in that, In step S3, the dispersant comprises, by mass percentage, 90.0%~97.0% acetone, 0.5%~1.0% methyl palmitate, 2.0%~5.0% palmitic acid, and 0.2%~1.7% dodecanoic acid.

9. The application of a copper-based brazing filler metal for CBN tool soldering as described in claim 1 or a copper-based brazing filler metal for CBN tool soldering prepared by any of the preparation methods described in claims 2 to 8, characterized in that, The application includes the following steps: The alloy powder or the copper-based alloy powder is mixed with a binder to obtain a copper-based solder paste. The composition of the copper-based solder paste is: 80.0%~90.0% of the alloy powder or the copper-based alloy powder and 10.0%~20.0% of the binder. The solder paste is evenly applied to the surface of the substrate, and then orderly arranged CBN abrasives are arranged on it. After vacuum brazing, a CBN tool is obtained. Alternatively, the alloy powder or the copper-based alloy powder can be uniformly distributed on a colloid on the surface of a substrate, and then orderly arranged with CBN abrasives. After vacuum brazing, a CBN tool can be obtained.

10. The application according to claim 9, characterized in that, The binder, by mass percentage, comprises the following components: 58.0%~75.0% solvent, 8.0%~15.0% thickener, 5.0%~12.0% antioxidant, and 1.0%~5.0% activator; wherein the solvent includes butyl octyl alcohol and dimethyl sulfoxide; the thickener includes ethyl cellulose and hexyl decyl alcohol; the antioxidant is oxalic acid; and the activator includes palmitic acid and hexadecyl acetate.

Images