CN1027495C

CN1027495C - Chemically bonded superabrasive

Info

Publication number: CN1027495C
Application number: CN 90109306
Authority: CN
Inventors: C·M·孙; S·H·陈
Original assignee: Norton Co
Current assignee: Saint Gobain Abrasives Inc
Priority date: 1989-11-22
Filing date: 1990-11-17
Publication date: 1995-01-25
Anticipated expiration: 2005-11-17
Also published as: CA2028415C; CN1051691A; CA2028415A1

Abstract

Superhard cutting tools such as saw blades, grinding wheels, drill bits, and the like are made by chemically bonding a superabrasive material such as diamond or CBN to a coating such as tungsten and then bonding the tungsten coating to the tool body.

Description

Chemically bonded superabrasives grit

The present invention relates to coating super-hard abrasive (material) a kind of novelty, that be used to produce improved grinding or cutting tool.The present invention also comprises the cutter of using this coating abrasive material production simultaneously.

Adhere to the diamond or the CBN(cubic boron nitride of support) etc. super-hard abrasive (material), be widely used as cutting material.Its typical application for example comprise saw, bore, polishing, grinding, grinding and polishing.

In common application, abrasive particle (material) is cemented in the suitable matrix, and is fixed in blade.The maintenance of abrasive material (material) mainly is by mechanical means, for example contains abrasive particle with matrix material.Although it is this adherence method is simple and practical, very limited.Because the exposed palpus of abrasive particle (material) is restricted, with the mechanical grip power of the matrix of avoiding having weakened containment role.Consequently, the exposed cutting rate that limited of very little abrasive particle (material).And because the wearing and tearing of matrix, its chucking power weakens, thereby abrasive particle (material) may be because of " being peeled off " loss.For example, be used for the typical case of saw blade, the average exposed degree of diamond abrasive grain (material) is less than 20% of abrasive particle B abrasive particle total height, and is worn full-sized approximately three/for the moment to it when abrasive particle (grain), and abrasive particle flies mistake because of peeling off.This saw blade is after using a period of time, and from hole that saw blade occurs as seen, about 1/3rd original abrasive particle has flown mistake it on usually.

For addressing this problem, people attempt to improve bond strength by the coating of abrasive particle always.No. 3650714 United States Patent (USP) of Farkas narrated in the diamond abrasive grain (method of the last this coating of plating of grain grain.Commercial available typical lining super hard abrasive product has the titanizing product that is used as the saw blade abrasive particle of De Beer company and the CBN abrasive particle titanizing product of General Electric Co. Limited.Concerning the super hard abrasive cutter of all metallic matrixes, but abrasive particle (grain) coating that unique commercialization is used is the titanizing product.

But, it is found that, titanizing product-be particularly useful for diamond abrasive grain, improve aspect its bond strength very ineffective.Its performance evaluation value, that is, the service life and the cutting rate that are used for the titanizing abrasive particle (grain) of saw blade do not show tangible improvement.The problem that the titanizing product is run into is that antioxygenic property is poor.As everyone knows, Ti and TiC may be oxidized under most of saw blade manufacturing states.This oxidation can be destroyed between abrasive particle and the coating material and the adhesion between coating material and the matrix.Another problem of titanizing product is the thickness of coating.Usually, the Ti of titanizing product and TiC thickness of coating are less than 1 micron.Bao coating can not prevent that coating is melted erosion by matrix material or breaks away from from abrasive particle B abrasive particle surface in making the cutter process like this.The 3rd, 757,878 and 3,757 of Wider, No. 879 United States Patent (USP)s have been narrated the method for a cladding diamond particles.But, its objective is abrasive particle (grain) clad of producing a kind of machinery, do not relate to chemical bond.

In addition, in the Chinese patent in the inventor's 1032509A, a kind of diamond and manufacture method thereof have also been disclosed.But described diamond is the assembly of a metallic support, diamond individuality.Diamond surface is coated with the coat of metal of the transition elements that can form carbide, and bonding with chemical bond.Yet this invention still has the diamond individuality to peel off and the problem of aspect such as antioxygenic property.

The super-hard abrasive (material) that the purpose of this invention is to provide a kind of chemical lining.

Another object of the present invention provides a kind of abrasive particle (material) that makes securely attached to the method on the tool matrix.

A further object of the present invention is, a kind of method at the continuous coating of super-hard abrasive (grain) lining at least 1 micron thickness is provided, so that after the cutter manufacture process, the integrality of coating still can keep.

The present invention also aims to, a kind of lining material is provided, this material is essentially inertia to the oxidation in the cutter manufacture process.

The present invention also aims to, provide the grinding or the cutting tool that use this chemical bond coating super hard abrasive, to improve the performance that cutter eliminates material.

The present invention also aims to, the cutter with chemical deposit abrasive particle (material) is provided, this abrasive particle (grain) shows abrasive particle confining force preferably, bigger abrasive particle overhang and shear action more at a high speed.These cutters comprise for example saw blade, emery wheel, milling tools, drill bit and milling tool.

Hereinafter and said in the claim " super-hard abrasive (material) " be meant natural and synthetic diamond and cubic boron nitride (CBN) particle.

Hereinafter said " chemical bond " is different from mechanical adhesion.React generation between two coupling parts in one situation of back.And in " chemical bond ", on the interface of two coupling parts chemical reaction is arranged.This reaction can be the generation of for example carbide, the generation of boride, the generation of nitride, or the solid solution that forms owing to the phase counterdiffusion between two coupling parts.

Hereinafter reach the drill bit that said in the claim " drill bit " singly is not meant the machinery knives type, but also comprise those be generally used for prospecting and petroleum industry in the drill bit of stratigraphical drilling.

According to the present invention, can produce a kind of through the metal lining, coating comprises W, the super hard abrasive of Mo or Ta, it comprises: the super hard abrasive particle with rough surface, described super-hard abrasive is selected from the category that comprises diamond and cubic boron nitride (CBN), one is actually continuous on described rough surface, and first coat of metal that combines with described surface chemistry, this first coat of metal is from comprising W, Mo, Ta, select for use in Nb and this metalloid of their alloy, with one be plated in and be actually the second continuous coat of metal on described first coat of metal, described second coat of metal comprises nickel or copper, and the gross thickness of described first and second coats of metal is in about 1-50 micrometer range.

According to the present invention, we can produce the super-hard abrasive (material) of the non-oxidizing relatively metal lining of a kind of usefulness, at least 1 micron of thickness of coating.

This coat of metal is incorporated into the abrasive particle surface securely with chemical bond.In brief, abrasive particle by lining one deck be difficult for the metal of oxidation.For example W, Ta, Mo, Nb or their alloy.Then, before making cutter or in manufacture process to lining abrasive particle heat-treat so that form very strong chemical bond between coating and the abrasive particle, for example for diamond abrasive grain (material) formation carbide coating.Tungsten is a kind of metal of lining preferably.Method roughening chemistry or machinery can be used selectively in the surface of abrasive particle before by lining, to strengthen combination subsequently.The chemical analysis of matrix must with the abrasive particle lining material compatibility of selecting for use so that in the process status that cutter is made, matrix can with lining material production chemical bond.Its result, just can with the super-hard abrasive (material) of lining firmly chemical bond in tool matrix.

Between super-hard abrasive and the coating, and the interface between coating and the matrix is generated by strong chemical bond.This is different fully by the prior art of the containment role of the machinery of matrix material with adhering to of abrasive particle basically.Lining super hard abrasive of the present invention has following advantage when being used for cutter:

Abrasive particle peel off lessly, thereby service life is longer;

2. the ledge of abrasive particle is bigger, thereby the cutting rate of cutter is higher;

3. the ledge of abrasive particle is bigger, can carry out the more cutting of high speed with less power, lower power, and caloric value is less.

Super hard abrasive through lining of the present invention can be used for the cutter that tool better eliminates performance, for example, saw blade, emery wheel, milling tools, cutting tool, drill bit and milling tool, these instrument blades generally are metals, when being used for emery wheel, milling tools, milling tool etc., its blade can be nonmetal.

Lining super hard abrasive of the present invention is particularly suitable for as the abrasive material in the drill bit, for example as the combination of the cutting tool of geometry such as circle, ellipse, sheet etc. especially, perhaps when this abrasive particle is impregnated in the actual matrix of drill bit, protrude in the surface of matrix, along with wearing away, constantly expose other abrasive particles that are incorporated into matrix.This is specially adapted to the drill bit of coring, although also can make the drill bit that is used for other hard machine-shaping similarly.

According to the present invention, at first make super-hard abrasive (material) surface become coarse with method machinery or chemistry.The not plane surface that the roughening process is produced can improve the adhesive force of abrasive particle and the lining material that uses subsequently.The improvement of this adhesive force is a large amount of uneven chemical reactivity that strengthened owing to the abrasive particle surface.The free electron quantity of lip-deep carbon also will increase, thereby the reaction between abrasive particle (grain) and the lining material also will strengthen.The uneven contact surface that makes on surface amasss increase, and this also can make abrasive particle that the mechanical adhesion of lining material is increased.

In a practical application of the present invention, at first with abrasive particle (material) roughening at random.A kind of method of roughening preferably is to manage a kind of equally distributed hair side.The method of this available machinery is for example milled together with other superhard abrasive dust; Or with the chemistry method, for example oxidation or etch reach.For example, abrasive particle (material) can be placed on the processing of at high temperature going round and round a millstone in inherent air of cylinder or the oxygen-enriched atmosphere, so that its evenly oxidation of surface.A kind of fluidized-bed chemical vapor deposition (CVD) system or a kind of converter all can be used for producing desired result effectively.Concerning chemical corrosion method, the oxidant of potassium bichromate or potassium nitrate and so on all can be selected for use.No matter use which kind of method, the loss in weight of abrasive particle in the surface roughening processing procedure (material) should be controlled at below 5% weight ratio.

Although the rough surface processing is an important step among the present invention, concerning some is used, might not be necessary.For example, in the occasion of the abrasive particle of using reduced size, for example for the polishing crosus cloth of using fine abrasive dust, the roughening treatment process can be omitted.

Surface roughening is washed and Chemical cleaning abrasive particle (material), to remove the surface contaminants that is caused by methods known in the art after handling.For example,, or in nitrogen atmosphere, heat abrasive particle, all can remove big portion surface contaminants with the inorganic acid washing abrasive particle (material) of nitric acid or hydrochloric acid solution and so on.

After the surface clean, with oxidation resistant material comparatively speaking, these materials such as W, Ta, Mo and Nb or their alloy etc. is easy to generate carbide, and generates the continuous coating of one at least 1 micron thickness with abrasive particle (material) lining.Thickness of coating can be from about 1 micron to about 50 microns, but preferably about 1 micron to about 30 microns.Such coating obviously is different from coating known in the art.For example, press the coating that narration obtained in the 3rd, 650, No. 714 United States Patent (USP)s of Farkas, far be thinner than 1 micron.This significantly difference for other commercialization the titanizing product also be the same.

On abrasive particle, plated after first kind of lining material, also can be on first coating lining second coating or other any additional coating arbitrarily.The purpose of multilayer lining is, in the cutter manufacture process and/or in the Tool in Cutting process, additional protection is provided for ground floor coating, makes it unlikely oxidized or be dissolved among the matrix material in air.Outer coating also can make and produce between abrasive particle and the matrix bond village material a kind of better metallurgical connection, to form a kind of interface that spreads combination.Concerning great majority were used, outer coating need not to comprise the element that is easy to generate carbide.For example, can come to combine with the outer coating of a kind of copper of electroless coating with certain matrix material.

In the occasion of using diamond abrasive grain (material), make between abrasive particle and the lining material by the generation temperature that the abrasive particle of lining is heated to carbide to generate carbide.And, generate the nitride bonded key in the occasion of using CBN.As a kind of suitable alloy layer, for example W-NiB is better.

Be the hot strength of the best of obtaining super hard abrasive (material), among the present invention, the about 10 μ m of the preferred first metal-plated bed thickness, the about 30 μ m of the preferred second metal-plated bed thickness.

Coating is usually with known method, and for example Wilder is the 3rd, 757, and the CVD method described in No. 878 United States Patent (USP)s is come plating.These methods are used for plating and generally do not contain anti-oxidant and easily generate the mechanical coating of the element of carbide.

Chemical bond between abrasive particle and the coating reaches by a kind of method of required final products that depends on.Like this, for example,, then form the treatment conditions of this saw blade, particularly form the required temperature of saw blade and must be enough to cause chemically combined formation if abrasive particle (material) is to be used for saw blade.On the other hand, if required final products form under the different disposal condition, and these conditions can not reduce enough chemical adhesion power, then: lining abrasive particle (material) preliminary treatment under suitable condition, for example for example about with the temperature that can generate carbide effectively in stove, 850 ℃ are carried out heat treated so that caused the formation chemical bond before abrasive particle is used for final product.

After abrasive material (material) is carried out lining, lining abrasive particle (material) can as the abrasive material of lining not, be used for the processing procedure that cutter is subsequently made.For example, when being used to make saw blade, the parent metal powder that abrasive particle (material) Ying Yujing fully mixes well is hot pressed into sheet shape then or under about 800-1000 ℃, or mixes with a kind of in conjunction with alloy.As a result, an abrasive material that has had by the coating material chemical bond and chemical bond have just been made in the saw blade of the coating material of matrix material.Briefly, all interfaces are all with the chemical bond combination.

In another embodiment of the present invention, with lining abrasive particle (material) be compacted into the very high piece material of density, for example with vibration compaction method.The abrasive particle of single granularity (being of a size of 500 microns) can reach about 55% compacting rate (all the other 45% be the hole part).If add the abrasive material (70 microns) of second kind of size again, its cun be about to the greatest extent first kind 1/7th, compacting rate can be increased to about 77%.If add the abrasive particle of the third size again, its be of a size of second kind 1/7th, the compacting rate of then whole block material can reach more than 83%.After abrasive particle (material) compacting, the piece material is infiltrated the alloy that is lower than the regression temperature of super hard abrasive with fusing point.If with diamond abrasive grain (material), for the diamond synthesis abrasive particle, according to its quality, temperature limit should be lower than about 1100 ℃, and for natural diamond abrasive particle (material), is about 1300 ℃.Because coated existence is in conjunction with the super-hard abrasive piece material of alloy phase when the compacting of easy infiltration height.As do not have this coating, then most ofly can not infiltrate such piece material in conjunction with alloy.

Volume compacting rate when as mentioned above, super hard abrasive of the present invention is used for the piece material is preferably in more than 70%.

By this embodiment, we obtain a kind of super hard abrasive-metallic composite, and for example we are referred to as the diamond-metallic composite of " diamet ".This composite has higher impact resistance because of the metal bond is arranged than polycrystalline super hard abrasive granule commonly used, and for example, the Diamet piece material that we obtain is compared with polycrystalline diamond, and when standing same impact test, its toughness is bigger.

This " Diamet " material is incorporated into the WC(tungsten carbide of sintering easily) base material, to form the blade for example be used for the drill bit that stratigraphical drilling uses.Be fixed in that this blade on the base material is in vitro to have stood test, its cutting effect can compare favourably with the drilling cutters made from the compacting briquet of " Geoset " and so on.

This method of the present invention has many advantages.Such as, it does not need with very high pressure, and make the polycrystalline process for ultra hard pellet for example PCD must use high pressure.Thereby the cost of making this composite can be significantly less than any method of prior art.The size and dimension of this material also can have more flexibility because of the restriction that is not subjected to the hyperbaric chamber.

For further specifying practical application of the present invention, below provide several embodiment:

Embodiment 1:

A kind of to be of a size of natural diamond abrasive particle (material) fluid bed CVD method lining one deck tungsten that 30/40 U.S.'s sieve mesh F.E.P.A label is D602 by the commodity of Be Beers company supply EMBS by name.Its practice is earlier this diamond abrasive grain to be impregnated in the acid solution that contains hydrofluoric acid and nitric acid about 1 minute, then with deionized water rinsing 15 minutes, washes 2 minutes with the NaDH solution of dilution, at last again with the further rinsing of deionized water again.

The abrasive particle of cleaning (material) is dried in baking oven.The diamond abrasive grain (material) of drying is placed the CVD reactor of a graphite-pipe, then, argon gas was fed reative cell about 30 minutes with the pressure of about 5 torrs.Then, changing pressure is that 0.5 torr is with evaporation moisture content, the gas that to be made up of in 1: 1: 1 ratio Ar, He, three kinds of gases of Hz with the pressure of 5 torrs feeds in the reative cell with 0.21 liter/minute flow then, simultaneously, in 16 minutes, reactor is heated to 900 ℃, is incubated 30 minutes down at 900 ℃ subsequently.Then make temperature in 3 minutes, reduce to 700 ℃, and improve pressure to 12 torr.The flow of gas is increased to and can makes the interior diamond abrasive grain (material) of reactor with air current flow, simultaneously, feeds the WF6(tungsten hexafluoride in reactor) so that tungsten is deposited on the diamond abrasive grain (material), deposit thickness reaches 11 microns in about 75 minutes.At last, only feed argon gas stream with cooling reactor to room temperature.Tungsten coating on this product is thick to be 7.75 microns.With lining abrasive particle (material) be pressed into the matrix material of making by 80%Cu-Sn alloy and 20% cemented tungsten carbide abrasive particle (material) with hot-press method, make saw blade.Once the concrete grinding stone sample that contained the flint particle with the saw blade cutting of making like this.The result shows that the loss of peeling off of abrasive particle (material) is reduced to less than 10% on the cutting surface after the test.Low like this peel off loss and under similarity condition, 40% peel off the contrast that loss becomes distinctness with what the abrasive particle that does not have coating walk abreast that test drawn.

Embodiment 2

SDA100 by name supplies the diamond synthesis abrasive particle that is of a size of F.E.P.A label D602 by De Beer company equally to a kind of commodity, as embodiment 1, and the tungsten that lining one bed thickness is about 10 microns.To spray through the abrasive particle of lining and on the matrix powder body made from tungsten carbide, form individual layer surface closely.With this assembly pre-molding, the pressure with 3500 pounds/square inch carries out hot pressing under 815 ℃ of temperature then.Hot-forming piece material is claw (dag-bone) shape.Draw group test (uniaxial tension test) with tensile sample.The result shows that the coating abrasive particle (material) that is a kind of like this geometry can bear 15000 pounds/square inch hot strength.And under same test conditions, do not have the abrasive particle (material) of coating in fact not show any hot strength.

Above-mentioned through lining abrasive particle (material) plated the electroless deposition nickel boron of about 30 micron thickness of one deck again with a kind of method that the Allied-Kelite branch company of Witco company provides again.The used solution that contains nickel-boron is buied from Witco company.The first step in the lining is, with the Niklad Alprep230 solution (buying) that is heated to 65.5 ℃, clean the tungsten surface, and diamond abrasive grain (material) was immersed in wherein 5 minutes from Witco company, then with running water rinsing diamond abrasive grain (material), until lather collapse.Again under 224 ℃, diamond abrasive grain (material) was dipped in the sensitizer of the commodity Niklad 261 by name that buys from Witco company 2 minutes.Then, with deionized water rinsing diamond abrasive grain (material).Diamond abrasive grain (material) being immersed in the catalyst of commodity Niklad 262 by name in pH value be that 1.9-3,43 ℃ descend maintenance 4 minutes again.Make catalyst be applied to diamond abrasive grain (material) surface.Then, with deionized water rinsing abrasive particle (material).The pH value is about 6 with being dipped in after treated diamond abrasive grain (material) drying, temperature is in 80 ℃ the Ni-B solution (Niklad752 solution).Nickel coating contains 3% the boron of having an appointment.Under identical experimental condition, its hot strength is 20000 pounds/square inch.

In a parallel test,, carry out same double-deck lining then with the surperficial first roughening of abrasive particle of the same type (material).The roughening on abrasive particle (material) surface is to be undertaken by the effect of milling by diadust in aqueous medium.This milling continued 24 hours, final abrasive particle (material) loss in weight about 0.7%.Under above-mentioned experimental condition, hot strength is increased to 35000 pounds/square inch.

Embodiment 3

Carry out produce the diadust through plating tungsten that is of a size of 500 microns and 60 microns with the described method of embodiment 1, vibrating compacting makes it to form compacting rate and is 80% homogeneous piece material.Then, under vacuum and 1050 ℃, this block of material infiltrated alloy with cupric, manganese and titanium, last 20 minutes, make cutting tool with this " Diamet ", and be used to cut colored hard rock rock rod, use cooling fluid during cutting.Measured its wearability, and with under similarity condition, test, other commercial PCD material of buying contrasts.The result shows that " Geoset " type PCD's of the wearability of " Diamet " and General Electric Co. Limited's supply is equally matched.Back one product is made in the diamond stability region under condition of high voltage.Same " Diamet " sample has also stood one and has contained the corrosion test that the abrasive material of mud carries out by injection.Find that its corrosion resistance can compare with the tungsten carbide billot through infiltrating of the lining that is commonly used for bit matrix." Diamet " material with so high wearability and corrosion resistance can be used for making the blade that the drill bit of drilling rock is used.And present existing drill bit generally is with PCD(such as Geoset in this field) or the tungsten carbide filler rod.

Embodiment 4

" bit body is welded in a bit body with a kind of typical soldering processes known in the art will to make " Diamet " blade use 81/2 according to embodiment 3.

Claims

1, a kind of through lining, coating comprises W, the super hard abrasive of Mo or Ta, it is characterized in that, it comprises: the super hard abrasive particle with rough surface, described super-hard abrasive is selected from the category that comprises diamond and cubic boron nitride (CBN), one is actually continuous on described rough surface, and first coat of metal that combines with described surface chemistry, this first coat of metal is from comprising W, Mo, Ta, select for use in Nb and this metalloid of their alloy, with one be plated in and be actually the second continuous coat of metal on described first coat of metal, described second coat of metal comprises nickel or copper, and the gross thickness of described first and second coats of metal is in about 1-50 micrometer range.

As the defined super hard abrasive of claim 1, it is characterized in that 2, second coat of metal on the wherein said abrasive material comprises NiB through lining.

3, as claim 1 or 2 defined super hard abrasives, it is characterized in that first coat of metal on the wherein said abrasive material is a tungsten, and second coat of metal on the described abrasive material comprises NiB through lining.

4, as each defined super hard abrasive in the claim 1 to 2, it is characterized in that about 10 microns of the first metal-plated bed thickness on the wherein said abrasive material, and about 30 microns of the second metal-plated bed thickness on the described abrasive material through lining.

5, the super hard abrasive through lining as defined in claim 3 is characterized in that, about 10 microns of the first metal-plated bed thickness on the wherein said abrasive material, and about 30 microns of the second metal-plated bed thickness on the described abrasive material.

6, a kind of through lining, coating comprises W, the super hard abrasive of Mo or Ta is used for the purposes of cutter, described super hard abrasive comprises: the super hard abrasive particle with rough surface, described super-hard abrasive is selected from the category that comprises diamond and cubic boron nitride (CBN), one is actually continuous on described rough surface, and first coat of metal that combines with described surface chemistry, this first coat of metal is from comprising W, Mo, Ta, select for use in Nb and this metalloid of their alloy, with one be plated in and be actually the second continuous coat of metal on described first coat of metal, described second coat of metal comprises nickel or copper, the gross thickness of described first and second coats of metal is in about 1-50 micrometer range, it is characterized in that, this abrasive material closely contacts with matrix, and described matrix bond is in blade.

7, purposes as claimed in claim 6 is characterized in that, wherein said blade is a metal.

8, purposes as claimed in claim 6 is characterized in that, wherein said blade is nonmetallic.

9, purposes as claimed in claim 7 is characterized in that, wherein, described cutter is saw.

10, purposes as claimed in claim 7 is characterized in that, cutter is a drill bit.

As each described purposes in the claim 6 to 10, it is characterized in that 11, described abrasive material has the volume compacting rate greater than 70%.

12, a kind of through lining, coating comprises W, the super hard abrasive of Mo or Ta is used for the purposes of cutting tool, this super hard abrasive comprises: the super hard abrasive particle with rough surface, described super-hard abrasive is selected from the category that comprises diamond and cubic boron nitride (CBN), one is actually continuous on described rough surface, and first coat of metal that combines with described surface chemistry, this first coat of metal is from comprising W, Mo, Ta, select for use in Nb and this metalloid of their alloy, with one be plated in and be actually the second continuous coat of metal on described first coat of metal, described second coat of metal comprises nickel or copper, the gross thickness of described first and second coats of metal is in about 1-50 micrometer range, it is characterized in that, described cutting tool comprises cutting members and the above-mentioned super hard abrasive through lining, and described abrasive material is the part of cutter.