High-performance metal resin composite binding agent, grinding wheel with high-performance metal resin composite binding agent and preparation method

Abstract

The invention discloses a high-performance metal resin composite binder, and relates to the technical field of grinding tools, the binder comprises thermosetting polyimide resin and thermoplastic polysulfone resin; the grinding wheel comprises the following raw materials in percentage by volume: 10-50% of super-hard abrasive, 5-30% of thermosetting polyimide resin, 5-30% of thermoplastic polysulfone resin and 20-60% of low-melting-point copper pre-alloyed powder. The prepared grinding wheel has the advantages of being high in forming temperature matching degree, good in interface compatibility, good in heat resistance and formability and the like, and micro-nano-scale stable dispersion regulation and control of the microstructure of a grinding tool grinding unit can be achieved according to the grinding requirement; the grinding wheel has obvious advantages when being used for processing the surfaces of hard and brittle workpieces and products which are difficult to grind, such as monocrystalline silicon, silicon carbide, sapphire, glass ceramics and hard alloy cutters, and high grinding efficiency and high workpiece surface precision are realized.

Description

Technical Field

[0001] The invention relates to the technical field of grinding tools, and in particular to a high-performance metal-resin composite binder and a grinding wheel thereof and a preparation method thereof. Background Art

[0002] Superhard abrasives are experiencing a transition from the "single type" era to the "composite type" era. The application potential of composite superhard abrasives in industries with hard-to-grind hard and brittle materials such as single crystal silicon, silicon carbide, sapphire, microcrystalline glass, and carbide tools is also becoming increasingly apparent, especially in the semiconductor processing industry. Among them, metal-resin composite bond superhard abrasives have obvious advantages in grinding the surfaces of hard-to-grind hard and brittle workpieces and products with their excellent dimensional accuracy, durability, surface accuracy, heat dissipation performance, and self-sharpening properties, and are expected to solve the current processing limitations of hard, brittle, and hard-to-grind materials.

[0003] However, due to the poor compatibility, wettability, thermal expansion coefficient and molding temperature matching between metal particles and resin particles, the microstructure after compounding is uneven, not refined, and poorly densified, which will lead to irregular changes in the performance of the grinding wheel and poor product stability and performance. In addition, the traditional "weak" interface physical anchoring effect is bound to fail to meet the needs of high efficiency and long life. Therefore, the coordination and unification of the interaction regulation between metal / resin components, interface compatibility, resin heat resistance, etc. will inevitably become the key factor in the breakthrough of grinding wheel performance.

[0004] In the prior art, such as a rubber-embedded resin-bonded diamond grinding wheel and a preparation method thereof (CN118721049A), a self-lubricating abrasive tool and a preparation method thereof (CN101758463A), and a composition, use, and a solution to mixed powder leakage for resin-bonded abrasive tools (CN106808377A), it is proposed that the binder can be selected from polyimide resin and polysulfone resin, etc., and related metal fillers are added, but these diamond grinding wheels only sinter the resin binder component, and the added metal component is not sintered and used as a filler. The prepared abrasive tool is a resin-bonded grinding wheel, which has limited strength and low durability. In addition, the traditional phenolic resin and bismaleimide resin currently have a high mismatch problem in heat resistance and molding temperature with the metal component, and the high-temperature casting and wettability of the traditional thermosetting resin are difficult to coordinate, which will seriously affect the improvement of product performance, such as dimensional accuracy, durability, product stability, etc.

[0005] Therefore, in view of the problems of compatibility, wettability, castability, poor matching of thermal expansion coefficient and molding temperature in traditional metal resin binder systems, providing a high-performance metal resin composite binder and its grinding wheel and preparation method is a technical problem that urgently needs to be solved in this field. Summary of the invention

[0006] The purpose of the present invention is to provide a high-performance metal-resin composite binder and a grinding wheel and a preparation method thereof in view of the deficiencies in the above-mentioned prior art. The composite binder of the present invention has a high molding temperature matching degree and good interface compatibility. It has the good heat resistance, strength, dimensional stability, durability, and abrasive grain holding property of the metal binder, and the self-sharpening property, high grinding efficiency, and low grinding force of the resin binder. It can also adjust the microstructure of the grinding unit of the abrasive tool to micro-nano-level refinement and stable dispersion according to the grinding requirements.

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

[0008] A high-performance metal-resin composite binder, the binder comprising a thermosetting polyimide resin and a thermoplastic polysulfone resin;

[0009] Wherein, the volume ratio of the thermosetting polyimide resin to the thermoplastic polysulfone resin is 5-30:5-30.

[0010] The binder used in the present invention does not flow during vacuum hot pressing and sintering, the processing temperature window matches the processing temperature of the metal pre-alloyed powder, and can wet the pre-alloyed powder and the abrasive.

[0011] Preferably, the processing temperature window of the thermosetting polyimide resin is 300-400°C;

[0012] The processing temperature window of the thermoplastic polysulfone resin is 350-400° C., and the particle size range is 5-50 μm.

[0013] On the one hand, the present invention utilizes the polyimide resin melt-cured at 300-350° C. to ensure the wettability of the polyimide to the polysulfone resin particles and the diamond, as well as the temperature difference between the processing temperature windows of the thermosetting resin and the thermoplastic resin, to regulate the castability; on the other hand, the controllability of the processing window temperature of the thermosetting polyimide resin is utilized to regulate its casting and curing efficiency, so that the high-temperature imide curing is performed above the processing window temperature (350-380° C.), thereby ensuring the high temperature resistance of the polyimide resin in the stage of heating and sintering the metal component; in addition, the presence of the cured resin component during the high-temperature sintering of the metal hinders the complete melting and casting of the metal component, thereby ensuring the skeleton strength of the metal component and improving the self-sharpening of the metal-resin composite bond grinding tool.

[0014] The thermoplastic polysulfone resin of the present invention has good compatibility with thermosetting polyimide, and can be used to regulate the mechanical properties and molding casting properties of the composite binder under the condition that the molding temperature and the use temperature are matched, thereby optimizing the final performance of the mold.

[0015] Preferably, the thermosetting polyimide resin is obtained by reacting an aromatic dibasic acid anhydride, a diamine and an active end-capping agent in a polar solvent.

[0016] The invention adopts a norbornene-terminated polyimide with a small molecular weight, high crosslinking density and good bonding strength, and a large number of polar functional groups on the surface provide it with good interface compatibility and wetting ability, while a large number of aromatic rings and thioketone group structures in the molecular structure of thermoplastic polysulfone resin powder make the resin powder have good casting performance, reduce molding defects, and improve the impact resistance of the composite binder. The invention solves the problems of poor heat resistance of phenolic resin and bismaleimide resin liquid and resin powder, poor matching degree of processing temperature, difficult control of molding process, and high-temperature processing casting.

[0017] Preferably, the molar ratio of the diamine, the aromatic dibasic acid anhydride and the active end-capping agent is (n+1):n:2, wherein n is an integer of 2≤n≤8;

[0018] The aromatic dibasic acid anhydride includes any one of pyromellitic anhydride (PMDA) and biphenyltetracarboxylic anhydride (BPDA);

[0019] The diamine includes any one of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-diaminodiphenyl ether (ODA) and 3,3'-diaminodiphenyl sulfone (DDS);

[0020] The active end-capping agent includes any one of an acetylene end-capping agent (phenylacetylene, 4-phenylacetylene aniline), an imide end-capping agent (phthalic anhydride, 3,4-diaminophthalic anhydride), an acid anhydride end-capping agent (maleic anhydride, hexafluorodianhydride) and an aromatic amine end-capping agent (4-aminobenzoic acid, 4,4'-diaminodiphenylmethane);

[0021] The polar solvent includes any one of N,N-dimethylacetamide DMAc, N,N-dimethylformamide DMF, N-methylpyrrolidone (NMP) and dimethyl sulfoxide (DMSO); the mass proportion of the polar solvent is 82-93% of the total mass, preferably 85%;

[0022] Preferably, the precipitant is also included, which is at least one of methanol, acetone, anhydrous ethanol, isopropyl alcohol (IPA), water, ethyl acetate, n-butanol, ether, n-hexane, etc.

[0023] The reaction conditions are: reaction at 150-180° C. for 2-6 hours, preferably at 160° C. for 2 hours.

[0024] Preferably, the thermosetting polyimide resin is pre-cured before use, specifically, the temperature is raised to 200-300°C at 100-150°C and 5°C / min in a vacuum furnace, and the temperature is kept for 2-6h to remove the residual high-temperature small molecule solvent inside the prepared polyimide molding powder, so that the interface wettability and compatibility of the polyimide are improved, and the curing is more completely guaranteed to ensure the heat resistance of the polyimide resin. At the same time, the removal of small molecules and the improvement of the curing cross-linking degree help to improve the brittleness of the polyimide resin, so that the self-sharpening and strength of the abrasive tool are guaranteed.

[0025] Preferably, the thermoplastic polysulfone resin powder is characterized in that the molecular structure is composed of an aromatic ring and a thioketone group, and has excellent high temperature resistance, chemical stability and mechanical properties.

[0026] A grinding wheel, the raw material of which includes the high-performance metal-resin composite binder mentioned above.

[0027] Preferably, the raw materials include the following raw materials in volume percentage: 10-50% superhard abrasive, 5-30% thermosetting polyimide resin, 5-30% thermoplastic polysulfone resin and 20-60% low melting point copper pre-alloy powder.

[0028] Preferably, the thermosetting polyimide resin and the thermoplastic polysulfone resin are sieved through a 200-300 mesh sieve.

[0029] The grinding wheel of the present invention firstly utilizes resin, alloy powder and abrasive with fine particle size, and adopts a heterogeneous time-space "liquid-like phase" composite molding method to prepare a grinding tool with high uniformity of microstructure uniformity and abrasive distribution uniformity, and transforms the original micron-level phase structure into a micro-nano-level refined phase structure; but at the same time, the refinement of the structure is bound to cause an increase in the phase interface between the grinding tool abrasive, filler and binder, and the traditional "weak" interface physical anchoring effect is bound to fail to meet the requirements of high efficiency and long life. Therefore, the present invention utilizes thermosetting polyimide resin with high interface adhesion to improve the interface interaction of the metal-resin composite binder, and at the same time adds high-temperature resistant polysulfone resin powder to adjust the flowability and mechanical properties, so that the grinding tool prepared by the metal-resin composite binder has good sharpness and wear resistance.

[0030] Preferably, the superhard abrasive comprises any one of artificial diamond, silicon carbide and cubic boron nitride;

[0031] The metal mass percentages in the low-melting-point copper prealloy powder are: 50-95% copper, 1-90% tin, 1-90% phosphorus, 0.1-0.5% boron, 0.01-0.5% bismuth and 0.01-2% lanthanum oxide.

[0032] Preferably, the low melting point copper pre-alloy powder is mainly composed of CuSn and CuP alloys. In order to improve its compatibility with resin binders and diamonds, a very small amount of boron (B), bismuth (Bi), lanthanum oxide (La 2 O 3 ) and other trace elements and rare earth oxides; the presence of trace metal elements, on the one hand, can reduce the sintering temperature of the alloy components, improve the sintering density of the alloy components, and improve the matching of the sintering temperature with the resin curing temperature and temperature resistance; on the other hand, it can promote the cross-linking of thermosetting resins, improve the fluidity and processability of resins, improve the thermal stability and antioxidant properties of resins, greatly improve the holding force of the binder on diamonds, thereby improving the durability of the grinding wheel.

[0033] According to the above-mentioned method for preparing a grinding wheel, the following steps are included:

[0034] (1) Weigh raw materials according to volume percentage: superhard abrasive, thermosetting polyimide resin, thermoplastic polysulfone resin and low melting point copper pre-alloy powder for later use;

[0035] (2) mixing the low-melting-point copper pre-alloy powder, the thermosetting polyimide resin and the thermoplastic polysulfone resin, adding the wetted superhard abrasive, and mixing to obtain a premix;

[0036] (3) The premix is ​​subjected to vacuum hot pressing and sintering in a mold to obtain a grinding wheel.

[0037] Preferably, the low melting point copper pre-alloyed powder in step (2) is ball milled for 1-3 hours before mixing;

[0038] The wetting agent is a silane coupling agent, and the added amount is 1-3% of the mass of the superhard abrasive.

[0039] Preferably, the vacuum hot pressing sintering step in step (3) is:

[0040] In the first stage, the temperature of the premix is ​​raised from room temperature to 380°C at a heating rate of 10-30°C / min, while applying a pressure of 5MPa;

[0041] Second stage insulation: insulation at 380℃ for 20-40min, pressure adjusted to 5-10MPa;

[0042] Three-stage metal sintering: heating from 380°C to 460-500°C within 10 minutes at a heating rate of 8-12°C / min, followed by keeping warm for 2-10 minutes, and a pressure of 6-10MPa.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The preparation method of the composite binder and the grinding wheel thereof of the present invention is simple and energy-saving, taking into account the good heat resistance, strength, dimensional stability, durability, and abrasive grain holding property of the metal binder, and having the self-sharpening property, high grinding efficiency, and small grinding force of the resin binder; the microstructure of the grinding unit of the abrasive tool can be refined to the micro-nano level and stably dispersed and regulated according to the grinding requirements, thereby ensuring the stability of the abrasive tool product; at the same time, it has obvious advantages in processing the surfaces of hard-to-grind hard and brittle workpieces and products such as single crystal silicon, silicon carbide, sapphire, microcrystalline glass, and cemented carbide tools, thereby achieving high grinding efficiency and high workpiece surface accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. The drawings in this description are only embodiments of the present invention.

[0046] Figure 1 This is a scanning electron microscope image of the grinding wheel of Example 1 of the present invention magnified 8000 times;

[0047] Figure 2 This is a scanning electron microscope image of the grinding wheel of Example 1 of the present invention magnified 100 times. DETAILED DESCRIPTION

[0048] Embodiments of the present invention are described below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but are not to be construed as limiting the present invention.

[0049] Raw materials and sources:

[0050] The preparation method of the thermosetting polyimide resin is as follows: a diamine monomer 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), an aromatic dibasic acid anhydride monomer (pyromellitic anhydride PMDA) and an active end-capping agent nadic anhydride (NA) are weighed in a molar ratio of 6:5:2, and a mixed solution with a mass concentration of 15% is prepared in a polar DMAc solvent, and then the mixture is reacted at 160° C. for 2 hours, and then the heating is stopped, and the reaction system is cooled to room temperature, and anhydrous ethanol is used as a precipitant and a detergent to precipitate and wash the reaction product for 5 times, and then the product is collected by filtration, and the product is heated to 270° C. at 100° C. and a heating rate of 5° C. / min in a vacuum furnace, and the temperature is kept for 4 hours to remove the residual small molecule solvent inside and complete the imidization, and finally a yellow powdery end-capped polyimide oligomer is obtained by grinding, and the processing temperature window is 340-380° C., and the end-capped polyimide oligomer is used for preparation of grinding wheels in Examples 1 and 2;

[0051] The process route is as follows:

[0052]

[0053] The preparation method of the thermosetting polyimide resin is as follows: a diamine monomer (4,4'-diaminodiphenyl ether (ODA)), an aromatic dibasic acid anhydride monomer (biphenyltetracarboxylic acid dianhydride BPDA) and an active end-capping agent nadic anhydride (NA) are weighed in a molar ratio of 9:8:2 and configured into a mixed solution with a mass concentration of 15% in a polar DMAc solvent, and then reacted at 160°C for 2h, and then the heating is stopped, and the reaction system is cooled to room temperature, anhydrous ethanol is used as a precipitant and a detergent, and the reaction product is precipitated and washed 5 times, and then the product is collected by filtration, and the product is heated to 280°C at 100°C in a vacuum furnace at a heating rate of 5°C / min, and kept warm for 4h to remove the residual small molecule solvent inside and complete the imidization, and finally a yellow powdery end-capped polyimide oligomer is obtained by grinding, and the processing temperature window is 340-380°C, which is used for the preparation of grinding wheels in Examples 3 and 4;

[0054] The process route is as follows:

[0055]

[0056] Thermoplastic polysulfone resin was purchased from Guangdong Youju New Materials Polysulfone series resin PSU: processing temperature window is 350-400℃, particle size range is 5-50μm;

[0057] Example 1

[0058] The present invention provides a grinding wheel, and the preparation method specifically comprises the following steps:

[0059] (1) Weigh the raw materials by volume percentage: low melting point copper pre-alloy powder: (CuSn20) 20%, (CuP7) 10%, (B) 0.3%, (Bi) 0.1%, (La 2 O 3 ) 0.1%, thermosetting polyimide resin powder 10%, thermoplastic polysulfone resin powder 9.5%, artificial diamond 50%, for standby use;

[0060] (2) First, the low melting point copper pre-alloyed powder is ball-milled (using a steel ball with a diameter of 5 mm) for 1 hour and mixed, and then the thermosetting high-compatible polyimide resin powder and the thermoplastic polysulfone resin powder are added and mixed, and then the artificial diamond wetted with 2% silane coupling agent KH550 is added and mixed to obtain a premix;

[0061] (3) After assembling the mold, the premix is ​​filled and sintered in one step on a vacuum hot press sintering machine; the sintering temperature range is 0-380°C / 30min in the first stage, and the pressure is 5MPa; the second stage is 380°C / 30min, 460°C / 10min, and the pressure is 6MPa. The grinding wheel block is an integrally formed ring with an inner diameter of 150mm, an outer diameter of 180mm, and a thickness of 15mm; the scanning electron microscope microstructure of the prepared grinding wheel is shown in FIG. Figure 1 and 2 , as can be seen from the figure: the internal organizational structure of the grinding wheel, the interface between the thermosetting resin component, the thermoplastic resin component, the metal component and the diamond is well bonded, there is no gap, and the continuity is good, indicating that the compatibility between the components is good, there is no phase separation, the interface wettability of the resin relative diamond and the metal phase is good, the bonding strength is high, and the compatibility is good, which strengthens the strength and dimensional stability of the grinding wheel; it can be seen under low magnification that the distribution of the grinding wheel abrasive diamond is uniform and stable, without defects, and the product stability is high. Therefore, the composite bond grinding wheel prepared by the present invention takes into account the good heat resistance, strength, dimensional stability, durability, and abrasive grain holding property of the metal bond, and has the self-sharpening property, high grinding efficiency and small grinding force of the resin bond, which ensures the stability of the abrasive product and provides a guarantee for achieving high grinding efficiency and high workpiece surface accuracy.

[0062] A 1mm groove is made on the side of a 150mm diameter copper substrate, and the annular grinding wheel block is bonded to the copper substrate using a high-strength adhesive, and then the grinding wheel is sharpened after correction.

[0063] Example 2

[0064] The present invention provides a grinding wheel, and the preparation method specifically comprises the following steps:

[0065] (1) Weigh the raw materials by volume percentage: low melting point copper pre-alloy powder: (CuSn20) 22%, (CuP7) 9%, (B) 0.3%, (Bi) 0.1%, (La 2 O 3 ) 0.1%, highly compatible polyimide resin powder 12%, thermoplastic polysulfone resin powder 6.5%, artificial diamond 50%, for standby use;

[0066] (2) firstly, the low melting point copper pre-alloy powder is ball-milled for 1 hour and mixed, then the thermosetting high-compatible polyimide resin powder and the thermoplastic polysulfone resin powder are added and mixed, and then the artificial diamond wetted with 2% silane coupling agent KH550 is added and mixed to obtain a premix;

[0067] (3) After assembling the mold, fill the premix and perform one-time sintering on a vacuum hot press sintering machine; the sintering temperature range is 0-380°C / 30min in the first stage, and the pressure is 5MPa; the second stage is 380°C / 30min, 460°C / 10min, and the pressure is 6MPa. The grinding wheel block is an integrally molded ring with an inner diameter of 150mm, an outer diameter of 180mm, and a thickness of 15mm;

[0068] A 1mm groove is made on the side of a 150mm diameter copper substrate, and the annular grinding wheel block is bonded to the copper substrate using a high-strength adhesive, and then the grinding wheel is sharpened after correction.

[0069] Example 3

[0070] The present invention provides a grinding wheel, and the preparation method specifically comprises the following steps:

[0071] (1) Weigh the raw materials by volume percentage: low melting point copper pre-alloy powder: (CuSn20) 57%, (CuP7) 1.2%, (B) 0.5%, (Bi) 0.5%, (La 2 O 3 ) 0.8%, highly compatible polyimide resin powder 5%, thermoplastic polysulfone resin powder 5%, artificial diamond 30%, for standby use;

[0072] (2) firstly, the low melting point copper pre-alloy powder is ball-milled for 1 hour and mixed, then the thermosetting high-compatible polyimide resin powder and the thermoplastic polysulfone resin powder are added and mixed, and then the artificial diamond wetted with 2% silane coupling agent KH550 is added and mixed to obtain a premix;

[0073] (3) After assembling the mold, fill the premix and perform one-time sintering on a vacuum hot press sintering machine; the sintering temperature range is 0-380°C / 30min in the first stage, and the pressure is 5MPa; the second stage is 380°C / 30min, 460°C / 10min, and the pressure is 6MPa. The grinding wheel block is an integrally molded ring with an inner diameter of 150mm, an outer diameter of 180mm, and a thickness of 15mm;

[0074] A 1mm groove is made on the side of a 150mm diameter copper substrate, and the annular grinding wheel block is bonded to the copper substrate using a high-strength adhesive, and then the grinding wheel is sharpened after correction.

[0075] Example 4

[0076] The present invention provides a grinding wheel, and the preparation method specifically comprises the following steps:

[0077] (1) Weigh the raw materials by volume percentage: low melting point copper pre-alloy powder: (CuSn20) 10%, (CuP7) 9.4%, (B) 0.1%, (Bi) 0.1%, (La 2 O 3) 0.4%, highly compatible polyimide resin powder 30%, thermoplastic polysulfone resin powder 20%, artificial diamond 30%, for standby use;

[0078] (2) firstly, the low melting point copper pre-alloy powder is ball-milled for 1 hour and mixed, then the thermosetting high-compatible polyimide resin powder and the thermoplastic polysulfone resin powder are added and mixed, and then the artificial diamond wetted with 2% silane coupling agent KH550 is added and mixed to obtain a premix;

[0079] (3) After assembling the mold, fill the premix and perform one-time sintering on a vacuum hot press sintering machine; the sintering temperature range is 0-380°C / 30min in the first stage, and the pressure is 5MPa; the second stage is 380°C / 30min, 460°C / 10min, and the pressure is 6MPa. The grinding wheel block is an integrally molded ring with an inner diameter of 150mm, an outer diameter of 180mm, and a thickness of 15mm;

[0080] A 1mm groove is made on the side of a 150mm diameter copper substrate, and the annular grinding wheel block is bonded to the copper substrate using a high-strength adhesive, and then the grinding wheel is sharpened after correction.

[0081] Comparative Example 1

[0082] The resin component is replaced by a single thermosetting polyimide resin, and the rest is exactly the same as in Example 1.

[0083] Comparative Example 2

[0084] The resin component is replaced by a single thermoplastic polysulfone resin, and the rest is exactly the same as in Example 1.

[0085] Comparative Example 3

[0086] No trace elements such as boron, bismuth and lanthanum oxide were added to the low melting point copper pre-alloy powder, and the rest was exactly the same as in Example 1.

[0087] The grinding wheels of the embodiments and comparative examples were used in cemented carbide grinding experiments. The experimental items were carried out on a CNC cylindrical grinding test machine with a linear speed of 18 m / s. The grinding material was a cemented carbide block. Three groups of parallel tests were carried out for each embodiment and comparative example. The specific conclusions are shown in Table 1:

[0088] Table 1 Experimental results of grinding wheel carbide grinding of embodiments and comparative examples

[0089]

[0090]

[0091] It can be seen from the above that the number of processed pieces in the embodiment is much higher than that in the comparative example, indicating that the durability of the embodiment is significantly better than that in the comparative example; the processing current of the embodiment is not much different from that of the comparative example, indicating that the self-sharpening properties of the embodiment and the comparative example are both good, and the grinding machine of the embodiment has no obvious vibration, indicating that the self-sharpening and uniform stability of the grinding wheel in the embodiment are also good. Specifically, compared with comparative examples 1 and 2, the performance of the grinding wheel of the embodiment is not as good as that of the grinding wheel prepared by compounding the two-component resin and the metal component; compared with comparative example 3, it can be found that the addition of trace elements such as boron, bismuth, and lanthanum oxide can return the dressing frequency of the embodiment to normal, and the durability of the grinding wheel has also changed from wear to better, indicating that the above trace elements can effectively improve the cross-linking of the resin component and the sintering performance of the metal component, so as to increase the overall life and dimensional stability of the grinding wheel. Therefore, the present invention develops a new type of highly compatible thermosetting polyimide resin molding powder and composites it with a high temperature resistant thermoplastic polysulfone resin, and simultaneously introduces trace elements such as boron, bismuth, and lanthanum oxide to synergistically improve the composite properties of the alloy and the resin.

[0092] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-performance metal-resin composite binder, characterized in that: The binder includes a thermosetting polyimide resin and a thermoplastic polysulfone resin; Wherein, the volume ratio of the thermosetting polyimide resin to the thermoplastic polysulfone resin is 5-30:5-30.

2. A high-performance metal-resin composite binder according to claim 1, characterized in that: The processing temperature window of the thermosetting polyimide resin is 300-400°C; The processing temperature window of the thermoplastic polysulfone resin is 350-400° C., and the particle size range is 5-50 μm.

3. A high-performance metal-resin composite binder according to claim 1, characterized in that: The thermosetting polyimide resin is obtained by reacting aromatic dibasic acid anhydride, diamine and active end-capping agent in a polar solvent.

4. A high-performance metal-resin composite binder according to claim 3, characterized in that: The molar ratio of the diamine, the aromatic dibasic acid anhydride and the active end-capping agent is (n+1):n:2, wherein n is an integer of 2≤n≤8; The aromatic dibasic acid anhydride includes any one of pyromellitic anhydride and biphenyltetracarboxylic anhydride; The diamine includes any one of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-diaminodiphenyl ether, and 3,3'-diaminodiphenyl sulfone; The active end-capping agent includes any one of an acetylene end-capping agent, an imide end-capping agent, an anhydride end-capping agent and an aromatic amine end-capping agent; The polar solvent includes any one of N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone and dimethyl sulfoxide; The reaction conditions are: reacting at 150-180° C. for 2-6 hours.

5. A grinding wheel, characterized in that: The raw materials include the high-performance metal-resin composite binder according to any one of claims 1 to 4.

6. A grinding wheel according to claim 5, characterized in that: The raw materials include the following raw materials in volume percentage: 10-50% of superhard abrasive, 5-30% of thermosetting polyimide resin, 5-30% of thermoplastic polysulfone resin and 20-60% of low melting point copper pre-alloy powder.

7. A grinding wheel according to claim 6, characterized in that: The super-hard abrasive includes any one of artificial diamond, silicon carbide and cubic boron nitride; The metal mass percentages in the low-melting-point copper prealloy powder are: 50-95% copper, 1-90% tin, 1-90% phosphorus, 0.1-0.5% boron, 0.01-0.5% bismuth and 0.01-2% lanthanum oxide.

8. A method for preparing a grinding wheel according to any one of claims 5 to 7, characterized in that: The following steps are involved: (1) Weigh raw materials according to volume percentage: superhard abrasive, thermosetting polyimide resin, thermoplastic polysulfone resin and low melting point copper pre-alloy powder for later use; (2) mixing the low-melting-point copper pre-alloy powder, the thermosetting polyimide resin and the thermoplastic polysulfone resin, adding the wetted superhard abrasive, and mixing to obtain a premix; (3) The premix is ​​subjected to vacuum hot pressing and sintering in a mold to obtain a grinding wheel.

9. The method for preparing a grinding wheel according to claim 8, characterized in that: The low melting point copper pre-alloyed powder in step (2) is ball milled for 1-3 hours before being mixed; The wetting agent is a silane coupling agent, and the added amount is 2% of the mass of the superhard abrasive.

10. The method for preparing a grinding wheel according to claim 8, characterized in that: The steps of vacuum hot pressing sintering in step (3) are: In the first stage, the temperature of the premix is ​​raised from room temperature to 380°C at a heating rate of 10-30°C / min, while applying a pressure of 5MPa; Second stage insulation: insulation at 380℃ for 20-40min, pressure adjusted to 5-10MPa; Three-stage metal sintering: heating from 380°C to 460-500°C within 10 minutes at a heating rate of 8-12°C / min, followed by keeping warm for 2-10 minutes, and a pressure of 6-10MPa.

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