Self-adaptive friction regulator as well as preparation method and application thereof

Abstract

The invention provides a self-adaptive friction regulator as well as a preparation method and application thereof. The self-adaptive friction regulator is prepared from the following raw materials in parts by weight: 30 to 55 parts of metal adhesive, 3 to 10 parts of self-lubricating filler and 35 to 60 parts of space dispersion filler. The self-adaptive friction regulator disclosed by the invention has relatively high compressive strength. The preparation method of the self-adaptive friction regulator comprises the following steps: mixing materials, forming a blank, sintering and granulating. The preparation method is simple, and industrial production is facilitated. The self-adaptive friction regulator serves as an additive to be used for producing a grinding wheel, the self-adaptive friction regulator can be broken and abraded in the grinding process, and then a grinding wheel / workpiece grinding matching pair surface interface is effectively lubricated; meanwhile, an air hole cavity gap formed after the self-adaptive friction regulator is crushed can improve the self-sharpening performance of the grinding wheel and improve the grinding efficiency of the grinding wheel, and the air hole cavity gap can also play a role in containing and discharging chips and improve the blockage of the grinding wheel.

Description

Technical Field

[0001] The invention belongs to the technical field of grinding wheel additives, and in particular is an adaptive friction regulator and a preparation method and application thereof. Background Art

[0002] Grinding wheels are also called bonded abrasives. Grinding wheels are bonded abrasives that are bonded by adhesives into a certain shape (mostly round with a through hole in the center) and have a certain strength. Grinding wheels are generally composed of abrasives, adhesives, and pores. These three parts are often called the three elements of bonded abrasives. According to the different classifications of adhesives, common ones are ceramic grinding wheels, resin grinding wheels, and rubber grinding wheels. Grinding wheels are the most widely used and widely used abrasives. When used, they rotate at high speeds and can be used for rough grinding, semi-finishing grinding, and fine grinding of the outer circle, inner circle, plane, and various surfaces of metal or non-metal workpieces, as well as grooving and cutting.

[0003] Active rail grinding is one of the important means to remove rail surface damage, repair rail profile, and extend rail service life and reliability. Active rail grinding to remove rail damage layer mainly uses high-performance resin-based grinding wheels. Under the conditions of dry grinding (no lubrication, no cooling), coarse grinding (abrasive grain size F10~F30), high load (~4000N), low operating (feed) speed (3~24km / h), high motor power (~22.5kW), and high linear speed (~50m / s), a large amount of grinding heat will be generated at the rail grinding wheel / rail grinding pair interface, which will lead to an increase in grinding temperature rise. The resin adhesive in the rail grinding wheel will experience thermal degradation due to high grinding temperature, and the wear resistance and cutting ability of the rail grinding wheel will be sharply reduced; at the same time, high grinding temperature will cause burns on the rail surface and produce a white layer structure ("pre-fatigue layer"), thereby reducing the surface quality of the ground rail and reducing the service safety of the rail.

[0004] Under dry grinding conditions, solid lubrication is an important means to regulate the grinding heat of the rail grinding wheel / rail grinding pair interface. Zhang et al. (Tribology International, 2023, 179: 108169) mixed graphite and molybdenum disulfide powders with resin binders in the form of fillers to prepare rail grinding wheels. Although this can effectively reduce grinding heat and improve the surface quality of rails, solid lubricants have the characteristics of low surface energy and easy sliding of two-dimensional layers. Excessive addition of solid lubricant fillers will cause a sharp drop in the mechanical properties and wear resistance of the grinding wheel. Zhao Jinbo et al. (Machinery Manufacturing, 2019, 48(3):56-58.) prepared self-lubricating segments by mixing fluorite (CaF2) and polyetheretherketone, and placed the self-lubricating segments symmetrically in the rail grinding wheel. Although the self-lubricating segments can effectively reduce the grinding temperature, it is difficult for the self-lubricating agglomerates to ensure the theoretical geometric position in the grinding wheel, thereby reducing the dynamic balance performance of the grinding wheel. In addition, the self-lubricating segments have problems with the interface bonding between the self-lubricating segments and the resin grinding wheel matrix, resulting in a decrease in the strength of the grinding wheel. Therefore, under extreme service conditions, the regulation of the grinding heat at the rail grinding wheel / rail grinding interface is a difficult problem that needs to be solved in rail grinding technology.

[0005] In summary, in view of the shortcomings of the current self-lubricating design of rail grinding wheels, the development of adaptive friction regulators for the rail grinding wheel / rail grinding wheel grinding pair interface, the adjustment and development of rail grinding wheel / rail interface temperature, and the improvement of the service life of the grinding wheel and the surface quality of the rail are of great significance for ensuring the efficient operation and maintenance of rails in rail transit. Summary of the invention

[0006] In view of the deficiencies of the prior art, the purpose of the present invention is to provide an adaptive friction modifier and a preparation method and application thereof; the adaptive friction modifier of the present invention has a high compressive strength; the preparation method of the present invention is simple and is conducive to industrial production. The adaptive friction modifier of the present invention is used as an additive to prepare a grinding wheel. The adaptive friction modifier can be broken and worn during the grinding process, thereby effectively lubricating the grinding wheel / workpiece grinding surface interface; at the same time, the pores and cavities formed after the adaptive friction modifier is broken can improve the self-sharpening property of the grinding wheel and improve the grinding efficiency of the grinding wheel. The pores and cavities can also play the role of chip storage and chip removal, improving the clogging of the grinding wheel.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] In a first aspect, the present invention provides an adaptive friction modifier, wherein the raw materials of the adaptive friction modifier include, by weight: 30 to 55 parts of a metal adhesive, 3 to 10 parts of a self-lubricating filler, and 35 to 60 parts of a spatially dispersed filler.

[0009] In some embodiments of the present invention, the metal adhesive is copper powder, iron powder or a mixture of the two, preferably iron powder.

[0010] In some embodiments of the present invention, the particle size of the metal adhesive is above 200 mesh, preferably 220-300 mesh.

[0011] In some embodiments of the present invention, the self-lubricating filler includes any one of graphite powder, molybdenum disulfide powder, fluorite powder, tungsten sulfide powder, etc., or a mixture of two or more thereof.

[0012] In some embodiments of the present invention, the particle size of the self-lubricating filler is above 100 mesh, preferably 120-180 mesh.

[0013] In some embodiments of the present invention, the spatial dispersion filler includes fibers and spatial fillers; preferably, the spatial dispersion filler includes 10 to 25 parts of fibers and 25 to 55 parts of spatial fillers by weight.

[0014] In some embodiments of the present invention, the fiber is any one of basalt fiber, copper fiber, steel fiber, glass fiber, etc., or a mixture of two or more thereof; preferably, the fiber has a diameter of 10 to 50 μm and a length of 0.8 to 3 mm.

[0015] In some embodiments of the present invention, the space filler is any one of chromite powder, feldspar powder, alumina, silicon dioxide, barium sulfate, etc., or a mixture of two or more thereof.

[0016] In some embodiments of the present invention, the particle size of the space filler is above 200 mesh, preferably 200-260 mesh.

[0017] In some embodiments of the present invention, the particle size of the adaptive friction modifier is 0.15 to 1.5 mm, preferably 0.25 to 1.0 mm.

[0018] In a second aspect, the present invention provides a method for preparing the adaptive friction modifier according to the first aspect, the preparation method comprising the following steps:

[0019] (1) Mixing: Mixing metal adhesive, self-lubricating filler and spatial dispersion filler;

[0020] (2) blank forming: placing the mixed material obtained in step (1) in a mold and pressing it to obtain a blank;

[0021] (3) Sintering: sintering the blank obtained in step (2) at high temperature;

[0022] (4) Granulation: The product obtained by high temperature sintering in step (3) is crushed and sieved to obtain an adaptive friction modifier.

[0023] In some embodiments of the present invention, step (1) is performed in a ball mill; preferably, the conditions for mixing in the ball mill include: a ball mill speed of 300 to 450 rpm, a ball-to-material ratio of (1 to 3):1, and a mixing time of 10 to 20 h.

[0024] In some embodiments of the present invention, in step (2), the forming pressure is 120 to 450 MPa, preferably 220 to 350 MPa; and the holding time is 1 to 3 hours, preferably 1 to 2 hours.

[0025] In some embodiments of the present invention, in step (3), the sintering temperature is 800-1200° C., the sintering time is 10-20 h, and the sintering pressure is 1.5-4 MPa.

[0026] In some embodiments of the present invention, the raw materials used for mixing in step (1) are dry raw materials, preferably raw materials that have been dried; preferably, the drying is carried out at 120-150° C. for 20-30 hours.

[0027] In some embodiments of the present invention, the crushing in step (4) is carried out in a jaw crusher or a single-cylinder cone crusher.

[0028] In some embodiments of the present invention, the screening is to first pass through a F12-F22 mesh screen, obtain the undersize material, then pass through a F46-F80 mesh screen, and then recover the oversize material.

[0029] In some embodiments of the present invention, the F12-F22 mesh sieve means that the sieve can be selected from any one of the F12 mesh sieve, the F14 mesh sieve, the F16 mesh sieve, the F20 mesh sieve, the F22 mesh sieve and the like.

[0030] In some embodiments of the present invention, F46-F80 mesh screen means that the screen can be selected from any one of F46 mesh screen, F54 mesh screen, F60 mesh screen, F70 mesh screen, F80 mesh screen and the like.

[0031] In some embodiments of the present invention, the screening is to first pass through an F16 mesh screen, obtain the undersize material, then pass through an F60 screen, and then recover the oversize material.

[0032] In a third aspect, the present invention provides an application of the adaptive friction modifier described in the first aspect and / or the preparation method described in the second aspect in the production of grinding wheels, preferably in the production of grinding wheels for rail grinding, and more preferably in the production of resin-based grinding wheels for rail grinding.

[0033] The beneficial effects of the present invention are as follows:

[0034] The adaptive friction modifier of the present invention has high compressive strength; the preparation method of the present invention is simple and is conducive to industrial production. The adaptive friction modifier of the present invention is used as an additive to prepare a grinding wheel, and the adaptive friction modifier can be broken and worn during the grinding process, thereby effectively lubricating the grinding wheel / workpiece grinding surface interface; at the same time, the pores and cavities formed after the adaptive friction modifier is broken can improve the self-sharpening property of the grinding wheel and improve the grinding efficiency of the grinding wheel. The pores and cavities can also play the role of chip storage and chip removal, and improve the clogging of the grinding wheel. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The light blue burn morphology on the surface of the rail after the rail is polished using the resin-based grinding wheel for rail polishing produced with the adaptive friction modifier of Example 1 of the present invention is shown.

[0036] Figure 2 The metallographic structure morphology of the rail section after the rail is polished by the resin-based grinding wheel for rail polishing produced by the adaptive friction modifier of Example 1 of the present invention is shown.

[0037] Figure 3 The morphology of the crushing and hole formation of the adaptive friction modifier on the surface of the grinding wheel after the rail is ground using the resin-based grinding wheel for rail grinding produced with the adaptive friction modifier of Example 1 of the present invention.

[0038] Figure 4 The ribbon-shaped wear chip morphology formed by continuous cutting of a resin-based grinding wheel for rail grinding produced using the adaptive friction modifier of Example 1 of the present invention is shown.

[0039] Figure 5 The black burn morphology on the rail surface after the rail was ground using a resin-based grinding wheel for rail grinding produced without adding any adaptive friction modifier is shown.

[0040] Figure 6 The metallographic morphology of the rail cross section after the rail was ground using a resin-based grinding wheel for rail grinding produced without adding any adaptive friction modifier is shown. DETAILED DESCRIPTION

[0041] The following examples further illustrate the technology of the present invention. These examples are for illustration and example of the present invention and are not intended to limit the scope of the present invention in any form.

[0042] Example 1

[0043] A self-adaptive friction regulator, whose raw materials include, by weight: 35 parts of copper powder, 4 parts of graphite powder, 3 parts of fluorite powder, 3 parts of basalt fiber, 12 parts of copper fiber, 8 parts of chromite powder, 17 parts of aluminum oxide powder, and 8 parts of barium sulfate powder.

[0044] Among them, copper powder is 300 mesh, graphite powder is 120 mesh, fluorite powder is 160 mesh, chromite powder is 200 mesh, alumina powder is 200 mesh, and barium sulfate powder is 260 mesh.

[0045] The diameter of the basalt fiber and the copper fiber is 10 to 20 μm, and the length is 0.8 to 1.5 mm.

[0046] The method for preparing the adaptive friction modifier comprises the following steps:

[0047] (1) Raw material pretreatment: Each raw material was placed in a vacuum drying oven at 150°C and dried for 25 h.

[0048] (2) Mixing: The raw materials pretreated in step (1) were placed in a ball mill and mixed for 15 h at a ball mill speed of 400 rpm and a ball-to-material ratio of 2:1.

[0049] (3) Pressing and forming: The mixed material obtained in step (2) is placed in a mold, and after pressing and forming at a forming pressure of 240 MPa and a holding time of 1 h, the mold is demolded to obtain a blank.

[0050] (4) Sintering: The blank obtained in step (3) is sintered at 800° C. and 1 MPa pressure for 20 h, and then cooled in the furnace to obtain a block-shaped adaptive friction modifier material.

[0051] (5) Granulation: The block friction modifier material is crushed by a jaw crusher, and then the crushed material is passed through an F16 mesh sieve, the undersize material is obtained and then passed through an F60 mesh sieve, and finally the oversize material is recovered to obtain an adaptive friction modifier with uniform particle size.

[0052] Example 2

[0053] A self-adaptive friction modifier, whose raw materials include, by weight: 40 parts of iron powder, 5 parts of graphite powder, 2 parts of molybdenum disulfide powder, 2 parts of tungsten sulfide powder, 20 parts of steel fiber, 5 parts of basalt fiber, 5 parts of feldspar powder, 8 parts of aluminum oxide powder, 10 parts of silicon dioxide powder, and 3 parts of barium sulfate powder.

[0054] Among them, iron powder is 300 mesh, graphite powder is 120 mesh, molybdenum disulfide powder is 160 mesh, tungsten sulfide powder is 160 mesh, feldspar powder is 200 mesh, alumina powder is 200 mesh, silica powder is 260 mesh, and barium sulfate powder is 260 mesh.

[0055] Among them, the diameter of basalt fiber and steel fiber is 10-20 μm and the length is 0.8-1.5 mm.

[0056] The method for preparing the adaptive friction modifier comprises the following steps:

[0057] (1) Raw material pretreatment: Each raw material was placed in a vacuum drying oven at 150°C and dried for 20 h.

[0058] (2) Mixing: The raw materials pretreated in step (1) were placed in a ball mill and mixed for 20 h at a ball mill speed of 450 rpm and a ball-to-material ratio of 2:1.

[0059] (3) Pressing and forming: The mixed material obtained in step (2) is placed in a mold, and after pressing and forming at a forming pressure of 300 MPa and a holding time of 1.5 h, the mold is demolded to obtain a blank.

[0060] (4) Sintering: The blank obtained in step (3) is sintered at 1200° C. and 3 MPa for 12 h, and then cooled in the furnace to obtain a block-shaped adaptive friction modifier material.

[0061] (5) Granulation: The block friction modifier material is crushed by a jaw crusher, and then the crushed material is passed through an F16 mesh sieve, the undersize material is obtained and then passed through an F60 mesh sieve, and finally the oversize material is recovered to obtain an adaptive friction modifier with uniform particle size.

[0062] Example 3

[0063] A self-adaptive friction regulator, whose raw materials include, by weight: 40 parts of copper powder, 5 parts of graphite powder, 4 parts of molybdenum disulfide powder, 18 parts of copper fiber, 5 parts of glass fiber, 5 parts of chromite powder, 7 parts of feldspar powder, 20 parts of aluminum oxide powder, 10 parts of silicon dioxide powder, and 3 parts of barium sulfate powder.

[0064] Among them, copper powder is 300 mesh, graphite powder is 120 mesh, molybdenum disulfide powder is 160 mesh, chromite powder is 200 mesh, feldspar powder is 200 mesh, alumina powder is 200 mesh, silica powder is 260 mesh, and barium sulfate powder is 260 mesh.

[0065] The diameter of the glass fiber and the copper fiber is 10 to 20 μm and the length is 0.8 to 1.5 mm.

[0066] The preparation method of the adaptive friction modifier is the same as that of Example 1.

[0067] Example 4

[0068] A self-adaptive friction regulator, whose raw materials include, by weight: 50 parts of iron powder, 8 parts of graphite powder, 15 parts of steel fiber, 8 parts of basalt fiber, 15 parts of aluminum oxide powder, 8 parts of silicon dioxide powder, and 5 parts of barium sulfate powder.

[0069] Among them, iron powder is 300 mesh, graphite powder is 120 mesh, alumina powder is 200 mesh, silica powder is 260 mesh, and barium sulfate powder is 260 mesh.

[0070] Among them, the diameter of basalt fiber and steel fiber is 10-20 μm and the length is 0.8-1.5 mm.

[0071] The preparation method of the adaptive friction modifier is the same as that of Example 2.

[0072] Example 5

[0073] An adaptive friction modifier, whose raw materials are the same as those in Example 4.

[0074] The method for preparing the adaptive friction modifier comprises the following steps:

[0075] (1) Raw material pretreatment: Each raw material was placed in a vacuum drying oven at 150°C and dried for 20 h.

[0076] (2) Mixing: The raw materials pretreated in step (1) were placed in a ball mill and mixed for 20 h at a ball mill speed of 450 rpm and a ball-to-material ratio of 2:1.

[0077] (3) Pressing and forming: The mixed material obtained in step (2) is placed in a mold, and after pressing and forming at a forming pressure of 220 MPa and a holding time of 3 h, the mold is demolded to obtain a blank.

[0078] (4) Sintering: The blank obtained in step (3) is sintered at 1200° C. and 3 MPa for 12 h, and then cooled in the furnace to obtain a block-shaped adaptive friction modifier material.

[0079] (5) Granulation: The block friction modifier material is crushed by a jaw crusher, and then the crushed material is passed through an F16 mesh sieve, the undersize material is obtained and then passed through an F60 mesh sieve, and finally the oversize material is recovered to obtain an adaptive friction modifier with uniform particle size.

[0080] Example 6

[0081] An adaptive friction modifier, whose raw materials are the same as those in Example 4.

[0082] The method for preparing the adaptive friction modifier comprises the following steps:

[0083] (1) Raw material pretreatment: Each raw material was placed in a vacuum drying oven at 150°C and dried for 20 h.

[0084] (2) Mixing: The raw materials pretreated in step (1) were placed in a ball mill and mixed for 20 h at a ball mill speed of 450 rpm and a ball-to-material ratio of 2:1.

[0085] (3) Pressing and forming: The mixed material obtained in step (2) is placed in a mold, and after pressing and forming at a forming pressure of 350 MPa and a holding time of 3 h, the mold is demolded to obtain a blank.

[0086] (4) Sintering: The blank obtained in step (3) is sintered at 1200° C. and 3 MPa for 12 h, and then cooled in the furnace to obtain a block-shaped adaptive friction modifier material.

[0087] (5) Granulation: The block friction modifier material is crushed by a jaw crusher, and then the crushed material is passed through an F16 mesh sieve, the undersize material is obtained and then passed through an F60 mesh sieve, and finally the oversize material is recovered to obtain an adaptive friction modifier with uniform particle size.

[0088] Example 7

[0089] A self-adaptive friction regulator, whose raw materials include, by weight: 30 parts of iron powder, 5 parts of graphite powder, 2 parts of molybdenum disulfide powder, 2 parts of tungsten sulfide powder, 20 parts of steel fiber, 5 parts of basalt fiber, 5 parts of feldspar powder, 8 parts of aluminum oxide powder, 10 parts of silicon dioxide powder, and 3 parts of barium sulfate powder.

[0090] Among them, iron powder is 300 mesh, graphite powder is 120 mesh, molybdenum disulfide powder is 160 mesh, tungsten sulfide powder is 160 mesh, feldspar powder is 200 mesh, alumina powder is 200 mesh, silica powder is 260 mesh, and barium sulfate powder is 260 mesh.

[0091] Among them, the diameter of basalt fiber and steel fiber is 10-20 μm and the length is 0.8-1.5 mm.

[0092] The preparation method of the adaptive friction modifier is the same as that of Example 2.

[0093] Example 8

[0094] A self-adaptive friction modifier, whose raw materials include, by weight: 55 parts of iron powder, 5 parts of graphite powder, 2 parts of molybdenum disulfide powder, 2 parts of tungsten sulfide powder, 20 parts of steel fiber, 5 parts of basalt fiber, 5 parts of feldspar powder, 8 parts of aluminum oxide powder, 10 parts of silicon dioxide powder, and 3 parts of barium sulfate powder.

[0095] Among them, iron powder is 300 mesh, graphite powder is 120 mesh, molybdenum disulfide powder is 160 mesh, tungsten sulfide powder is 160 mesh, feldspar powder is 200 mesh, alumina powder is 200 mesh, silica powder is 260 mesh, and barium sulfate powder is 260 mesh.

[0096] Among them, the diameter of basalt fiber and steel fiber is 10-20 μm and the length is 0.8-1.5 mm.

[0097] The preparation method of the adaptive friction modifier is the same as that of Example 2.

[0098] Example 9

[0099] A self-adaptive friction regulator, whose raw materials include, by weight: 40 parts of copper powder, 5 parts of graphite powder, 2 parts of molybdenum disulfide powder, 2 parts of tungsten sulfide powder, 20 parts of steel fiber, 5 parts of basalt fiber, 5 parts of feldspar powder, 8 parts of aluminum oxide powder, 10 parts of silicon dioxide powder, and 3 parts of barium sulfate powder.

[0100] Among them, copper powder is 300 mesh, graphite powder is 120 mesh, molybdenum disulfide powder is 160 mesh, tungsten sulfide powder is 160 mesh, feldspar powder is 200 mesh, alumina powder is 200 mesh, silica powder is 260 mesh, and barium sulfate powder is 260 mesh.

[0101] Among them, the diameter of basalt fiber and steel fiber is 10-20 μm and the length is 0.8-1.5 mm.

[0102] The preparation method of the adaptive friction modifier is the same as that of Example 2.

[0103] Example 10

[0104] An adaptive friction modifier, whose raw materials are the same as those in Example 4.

[0105] The method for preparing the adaptive friction modifier comprises the following steps:

[0106] (1) Raw material pretreatment: Each raw material was placed in a vacuum drying oven at 150°C and dried for 20 h.

[0107] (2) Mixing: The raw materials pretreated in step (1) were placed in a ball mill and mixed for 20 h at a ball mill speed of 450 rpm and a ball-to-material ratio of 2:1.

[0108] (3) Pressing and forming: The mixed material obtained in step (2) is placed in a mold, and after pressing and forming at a forming pressure of 130 MPa and a holding time of 2 h, the mold is demolded to obtain a blank.

[0109] (4) Sintering: The blank obtained in step (3) is sintered at 1200° C. and 3 MPa for 12 h, and then cooled in the furnace to obtain a block-shaped adaptive friction modifier material.

[0110] (5) Granulation: The block friction modifier material is crushed by a jaw crusher, and then the crushed material is passed through an F16 mesh sieve, the undersize material is obtained and then passed through an F60 mesh sieve, and finally the oversize material is recovered to obtain an adaptive friction modifier with uniform particle size.

[0111] Embodiment 11

[0112] An adaptive friction modifier, whose raw materials are the same as those in Example 4.

[0113] The method for preparing the adaptive friction modifier comprises the following steps:

[0114] (1) Raw material pretreatment: Each raw material was placed in a vacuum drying oven at 150°C and dried for 20 h.

[0115] (2) Mixing: The raw materials pretreated in step (1) were placed in a ball mill and mixed for 20 h at a ball mill speed of 450 rpm and a ball-to-material ratio of 2:1.

[0116] (3) Compression molding: The mixed material obtained in step (2) is placed in a mold, and after compression molding at a molding pressure of 400 MPa and a holding time of 2 h, the mold is demolded to obtain a blank.

[0117] (4) Sintering: The blank obtained in step (3) is sintered at 1200° C. and 3 MPa for 12 h, and then cooled in the furnace to obtain a block-shaped adaptive friction modifier material.

[0118] (5) Granulation: The block friction modifier material is crushed by a jaw crusher, and then the crushed material is passed through an F16 mesh sieve, the undersize material is obtained and then passed through an F60 mesh sieve, and finally the oversize material is recovered to obtain an adaptive friction modifier with uniform particle size.

[0119] The block-shaped adaptive friction modifier obtained by sintering step (4) in the above Examples 1 to 11 was subjected to a compressive strength test according to the requirements of GB / T1041-2008. The compressive strength test results of the block-shaped adaptive friction modifier of each Example are shown in Table 1.

[0120] Table 1 Performance test results of block adaptive friction modifier

[0121]

[0122] It can be seen from Table 1 that the adaptive friction modifier of the present invention has a high compressive strength, which can meet the pressure requirement (10-20 MPa) during the rail grinding wheel forming process, ensuring that the adaptive friction modifier has good shape retention during the rail grinding wheel forming process.

[0123] It can also be seen from Table 1 that the compressive strength of the adaptive friction modifier can be improved by appropriately increasing the content of the metal adhesive; however, the inventors have found that when the amount of the metal adhesive is too high, it will cause the adaptive friction modifier to be difficult to be pressed and formed during the forming process. When the amount of the metal adhesive is within the range specified by the present invention, it can ensure that the adaptive friction modifier can be pressed and formed, and can also ensure that the adaptive friction modifier has a higher compressive strength.

[0124] In addition, it can be seen from Table 1 that the pressing pressure has a great influence on the compressive strength of the adaptive friction modifier. Too low or too high a pressing pressure and too long or too short a holding time are not conducive to obtaining a higher compressive strength.

[0125] Application Examples

[0126] The self-adaptive friction modifiers prepared in Examples 1 to 11 were used to produce the resin-based grinding wheel for rail grinding, and a resin-based grinding wheel for rail grinding without any self-adaptive friction modifier was used as a blank control. The raw materials of the resin-based grinding wheel for rail grinding include, by weight: 95 parts of a mixed abrasive composed of zirconium corundum and brown corundum, 10 parts of phenolic resin powder, 5 parts of a wetting agent, 10 parts of a mineral filler, 5 parts of a reinforcing fiber, and 8 parts of a self-adaptive friction modifier.

[0127] The particle size of the mixed abrasive composed of zirconium corundum and brown corundum is F10-F24; the mass ratio of zirconium corundum to brown corundum in the mixed abrasive composed of zirconium corundum and brown corundum is 10:9.

[0128] The wetting agent is furfural.

[0129] The mineral filler is a mixture of cryolite, pyrite, calcium oxide and barium sulfate in a mass ratio of 1:1:1:1.

[0130] The particle size of the mineral filler is 70 mesh

[0131] The reinforcing fiber is glass fiber, and the diameter of the glass fiber is 8-15 μm and the length is 2-4 mm.

[0132] The method for preparing a resin-based grinding wheel for rail grinding comprises the following steps:

[0133] (1) Mixing

[0134] (1-1) adding the wetting agent to the mixed abrasive consisting of zirconium corundum and brown corundum, and fully mixing in the upper pot of a double-pot countercurrent mixer for 5 minutes to obtain a wetted abrasive;

[0135] (1-2) adding the mineral filler and reinforcing fiber to the impregnated abrasive obtained in step (1-1), stirring the mixture in the upper pot of a double-pot countercurrent mixer for 3 minutes, and pouring the mixture into the lower pot after mixing;

[0136] (1-3) adding the phenolic resin powder into the lower pot of a double-pot countercurrent mixer and mixing it thoroughly with the mixture obtained in step (1-2) for 2 minutes;

[0137] (1-4) adding the adaptive friction modifier into the lower pot of a double-pot countercurrent mixer and mixing it fully with the mixture obtained in step (1-3) for 1 minute;

[0138] (1-5) The mixed material obtained in step (1-4) is passed through a 30-mesh sieve, and the material on the sieve is passed through a F10-mesh sieve. The material under the F10-mesh sieve is the resin-based grinding wheel forming material for rail grinding.

[0139] (2) Preforming

[0140] The resin-based grinding wheel forming material for rail grinding obtained in step (1-5) was weighed, and pressed at 180° C. and 15 MPa for 60 min to obtain a resin-based grinding wheel blank for rail grinding.

[0141] (3) Silk wrapping

[0142] The resin-based grinding wheel blank for rail grinding obtained in step (2) is wound with glass fiber on the circumferential surface by a wire winding machine with a winding thickness of 5 mm to obtain a grinding wheel to be sintered.

[0143] (4) Sintering

[0144] The grinding wheel to be sintered obtained in step (3) is placed in a sintering furnace at 190° C. and continuously cured for 30 hours. After sintering, it is cooled in the furnace to obtain a resin-based grinding wheel for rail grinding.

[0145] The compressive strength test and the grinding performance test were performed on the resin-based grinding wheel for rail grinding produced by using the adaptive friction modifiers prepared by the above Examples 1 to 11 and without adding any adaptive friction modifier. The results are shown in Table 2.

[0146] Table 2 Performance test results of resin-based grinding wheels for rail grinding

[0147]

[0148]

[0149] In addition, the rails and the grinding wheel after the rails were ground using the resin-based grinding wheel for rail grinding produced by the adaptive friction modifier of Example 1 of the present invention were observed; wherein the light blue burn morphology on the surface of the rails is as follows Figure 1 As shown in Figure 2, the metallographic structure of the rail section is as follows: Figure 2 As shown in the figure, the pore morphology of the grinding wheel surface is as follows: Figure 3 As shown; the strip-shaped grinding chips formed by continuous cutting of the grinding wheel are as follows Figure 4 shown.

[0150] The rails and the grinding wheel after being ground by a resin-based grinding wheel produced without any adaptive friction modifier were observed; the black burn morphology on the rail surface is as follows Figure 5 As shown in Figure 2, the metallographic structure of the rail section is as follows: Figure 6 shown.

[0151] The results of Table 2 are combined Figures 1 to 6 It shows that the use of the adaptive friction modifier of the present invention can maintain a high compressive strength of the resin-based grinding wheel for rail grinding; at the same time, during the rail grinding process, the adaptive friction modifier in the resin-based grinding wheel for rail grinding can effectively lubricate the grinding wheel / rail interface under dry grinding state along with the wear of the adhesive, thereby greatly reducing the friction coefficient of the grinding wheel / rail interface and reducing the grinding heat. The gain effect is specifically manifested in the reduction of grinding temperature and only local blue burns on the rail surface. At a lower grinding temperature, the wear of the resin-based grinding wheel for rail grinding is reduced, and the gain effect is manifested in a significant increase in the grinding ratio. In addition, the adaptive friction modifier of the present invention is broken to form pores, which can promote the migration and discharge of grinding chips and improve the self-sharpening of the resin-based grinding wheel for rail grinding. The gain effect is specifically manifested in the increase in grinding amount and the decrease in the blockage area ratio of the resin-based grinding wheel for rail grinding. Compared with the blank control group of the resin-based grinding wheel for rail grinding without adding any adaptive friction modifier, the blockage area ratio of the resin-based grinding wheel for rail grinding has a maximum decrease of 61.4%, and the gain effect is significant. The above experimental results show that the addition of the adaptive friction modifier can ensure that the resin-based grinding wheel for rail grinding has a higher compressive strength, and at the same time can effectively lubricate the grinding wheel / rail interface, reduce the generation of grinding heat, thereby increasing the service life of the resin-based grinding wheel for rail grinding and improving the surface quality of the rail.

[0152] In summary, the above experimental results show that the adaptive friction modifier of the present invention can obtain two significant gain effects. The first is the surface friction reduction effect: during the rail grinding process, along with the wear of the resin-based grinding wheel for rail grinding, the adaptive friction modifier will be worn and broken, and the lubricating components will be released on the surface of the grinding wheel / rail grinding pair, thereby effectively lubricating the surface of the grinding wheel / rail grinding pair, regulating the interface friction and grinding heat generation, and reducing the grinding temperature. The second is the crushing, pore-forming and sharpening effect: the adaptive friction modifier will be broken during the grinding process, and then pores will be formed on the surface of the resin-based grinding wheel for rail grinding, which plays a role in accommodating the grinding debris in the contact area of ​​the grinding wheel / rail grinding pair, promoting the migration of grinding debris in the contact area, and improving the clogging and heat dissipation effect of the resin-based grinding wheel for rail grinding.

[0153] It should be noted that the above-described embodiments are only used to explain the present invention and do not constitute any limitation of the present invention. The embodiments describe the present invention and it should be understood that the words used therein are descriptive and explanatory words, rather than limiting words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention.

Claims

1. An adaptive friction modifier, characterized in that: The raw materials of the self-adaptive friction modifier include, by weight: 30 to 55 parts of metal adhesive, 3 to 10 parts of self-lubricating filler, and 35 to 60 parts of spatial dispersion filler.

2. The adaptive friction modifier according to claim 1, characterized in that The metal adhesive is any one of copper powder and iron powder or a mixture of the two; preferably, the particle size of the metal adhesive is above 200 mesh, preferably 220-300 mesh.

3. The adaptive friction modifier according to claim 1 or 2, characterized in that: The self-lubricating filler is any one of graphite powder, molybdenum disulfide powder, fluorite powder, and tungsten sulfide powder, or a mixture of two or more thereof; preferably, the particle size of the self-lubricating filler is above 100 mesh, preferably 120-180 mesh.

4. The adaptive friction modifier according to any one of claims 1 to 3, characterized in that The spatial dispersion filler includes fibers and spatial fillers; preferably, the spatial dispersion filler includes 10 to 25 parts of fibers and 25 to 55 parts of spatial fillers by weight; more preferably, The fiber is any one of basalt fiber, copper fiber, steel fiber, glass fiber, or a mixture of two or more thereof; preferably, the fiber has a diameter of 10 to 50 μm and a length of 0.8 to 3 mm; and / or The space filler is any one of chromite powder, feldspar powder, alumina, silicon dioxide, barium sulfate, or a mixture of two or more thereof; preferably, the particle size of the space filler is above 200 mesh, preferably 200-260 mesh.

5. The adaptive friction modifier according to any one of claims 1 to 4, characterized in that The particle size of the adaptive friction modifier is 0.15 to 1.5 mm, preferably 0.25 to 1.0 mm.

6. The method for preparing the adaptive friction modifier according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: (1) Mixing: Mixing metal adhesive, self-lubricating filler and spatial dispersion filler; (2) blank forming: placing the mixed material obtained in step (1) in a mold and pressing it to obtain a blank; (3) Sintering: sintering the blank obtained in step (2) at high temperature; (4) Granulation: The product obtained by high temperature sintering in step (3) is crushed and sieved to obtain an adaptive friction modifier.

7. The preparation method according to claim 6, characterized in that: The step (1) is carried out in a ball mill; preferably, the conditions for mixing in the ball mill include: a ball mill speed of 300 to 450 rpm, a ball-to-material ratio of (1 to 3):1, and a mixing time of 10 to 20 hours; And / or, in the step (2), the forming pressure is 120 to 450 MPa, preferably 220 to 350 MPa; the holding time is 1 to 3 hours, preferably 1 to 2 hours; And / or, in the step (3), the sintering temperature is 800-1200° C., the sintering time is 10-20 h, and the sintering pressure is 1.5-4 MPa.

8. The preparation method according to claim 6 or 7, characterized in that: The raw materials used for mixing in step (1) are dry raw materials, preferably raw materials that have been dried; preferably, the drying is carried out at 120-150° C. for 20-30 hours.

9. The preparation method according to any one of claims 6 to 8, characterized in that The crushing in step (4) is carried out in a jaw crusher or a single-cylinder cone crusher; And / or, the screening is first through a F12-F22 mesh screen, the undersize material is obtained, then through a F46-F80 mesh screen, and then the oversize material is recovered.

10. Use of the adaptive friction modifier according to any one of claims 1 to 5 and / or the preparation method according to any one of claims 6 to 9 in the production of grinding wheels, preferably in the production of grinding wheels for rail grinding, more preferably in the production of resin-based grinding wheels for rail grinding.

Images