CN102211218B - Diamond coated cutter and application thereof in processing of fiber composite material - Google Patents

Abstract

The invention relates to a diamond coated cutter, which comprises a drill tip, an edge part and a handle part, and is characterized in that: (1) a substrate material is a hard alloy with less than 6 mass percent of Co; (2) the drill tip and the edge part of the cutter are coated with a diamond coating; (3) the head part of the cutter has a drilling and milling integrated structure, the apex angle of the drill tip is double apex angles of 135 degrees and 90 degrees or a disc angle of 5 to 10 degrees, and the thickness of the coated diamond coating is 10 to 30mu m. The coated cutter is manufactured by the following steps of: (1) selecting an appropriate hard alloy substrate material; (2) forming the cutter; (3) pretreating a cutter coating; and (4) preparing the diamond coating on the drill top and the edge part of the cutter through hot filament chemical vapor deposition (CVD). The phenomena of burrs and obvious surface layer peeling when the coated cutter processes a fiber composite material are avoided.

Description

Diamond-coated tools and the application in fibrous composite processing thereof

Technical field

The present invention relates to a kind of diamond-coated tools and application thereof, the invention provides or rather a kind of cutter for composite processings such as carbon fiber or glass fibres, belong to machining manufacturing technology field.

Background technology

Composite is the product of material science high speed development in recent years, very large application space is arranged, and can carry out Design and manufacture according to the requirement of service condition, to satisfy various specific uses, thereby improved greatly the usefulness of engineering structure, become novel engineering material in a kind of present age.The composite that the modern project structure is used can be divided into this three major types of resin-based, Metal Substrate and ceramic base according to the type of matrix material.Carbon fibre composite is more typical a kind of polymer matrix composites, its phosphorus content is generally all more than 90%, specific strength is high, specific modulus is high, can be used for producing light weight and intensity is high, layer is thin and member that rigidity is large, and anti-fatigue performance is good, thermal coefficient of expansion is little, and good stability of the dimension has wide practical use in Aeronautics and Astronautics industry.For needing to carry out secondary operations after the complex-shaped parts moulding, but the very difficult processing of composite such as carbon fiber, glass fibre are mainly reflected in the hardness height, interlaminar shear strength is low and the aspect such as poor thermal conductivity.

Then, because the mechanical property of fibrous composite is anisotropy, interlaminar strength is lower, the defective such as under the effect of cutting force, produce easily layering during cutting, tear, and the cut-out that carbon fiber can not be flattened causes cutting effect not good.The composite chip forming procedure is the complex process that matrix destroys and fibrous fracture is interweaved, because fibrous fracture and matrix are sheared, and the friction between smear metal and rake face, rear knife face and the machined surface and to produce a large amount of smear metals hot.At finished surface, carbon fiber is removed in the mode of brittle fracture, can only take away seldom by the heat that produces in the processing, make the material plasticity distortion difficult, poor radiation easily produces heat and stops up under the high temperature, thereby cause the carbon fibre composite surface to produce carbonization phenomenon, affect machined surface quality.Heat in metal cutting mainly passes to cutter and workpiece, causes the cutter Fast Wearing, and many cutters all are difficult to finish the cutting overall process of composite element, affects working (machining) efficiency and workpiece precision.

Generally speaking, produce easily two kinds of defectives in the cutting process of the composites such as carbon fiber, glass fibre: a kind of is the otch damage, mainly be notching edge near easy generation outlet layering, tear, the defectives such as burr, wire drawing; The 2nd, the interlayer layering mainly refers to the separation that carbon fibre composite occurs between layers, thereby makes the composite inner tissue become loose, thereby has reduced component strength and other performances.

Can the processing difficult problem of fibrous composite solve, and is directly connected to the application of this material, and cutter is the principal element of restriction cutting technology.The helical edges Integral alloy or the high-speed steel slotting cutter that generally use at present, continuous long cutting edge is so that cutting edge is not sharp, finally caused the processing effect that the process tool cutting ability is poor, working (machining) efficiency is low, cutter life is short, and continuous long cutting edge makes easily finished surface the defective processing phenomenons such as burr, layering, peeling occur.Selecting rational cutter material and cutter structure is the key that solves a composite processing difficult problem.

Summary of the invention

The object of the present invention is to provide a kind of diamond-coated tools and application thereof, the diamond-coated tools that provides is intended to improve the cutting ability of the composites such as carbon fiber, glass fibre and the diamond-coated tools of working (machining) efficiency, the layering that occurs in the multiple material processing can fine solution recited above, tear, the defectives such as burr, wire drawing, interlayer layering, and processing life-span of obviously improving cutter.And because the structural design of uniqueness of the present invention, can be used for carbon fiber or glass fiber compound material sheet material hollow out, mill the continuous processing of the techniques such as limit, boring.Diamond-coated tools provided by the invention comprises apex point, blade and shank as shown in Figure 1, it is characterized in that:

(1) cutter apex point and blade carry out the processing of pure diamond coating, and diamond coatings has and the duplicate characteristic of nature diamond, comprises high rigidity, high strength, resistance to chemical attack, high thermal conductivity coefficient, and low-friction coefficient.These characteristics all are conducive to improve the performance of cutter.Can keep sharp in process of apex point and blade, improve processing effect, increase the service life.

(2) the cutter head mills integrative-structure for boring, can realize holing and the continuous processing of milling, and the apex point position at cutter top, according to the machining composite material sheet metal thickness with add the different of clamping in man-hour situation, structure is different:

For thicker sheet material, perhaps clamping rigidity is situation preferably, and the apex point drift angle is 135 ° and 90 ° of common apex point forms in Double Tops angle;

For thinner sheet material, or the relatively poor situation of clamping rigidity, drift angle is for negative, namely with the apex point form of 5～10 ° of Pan Jiao.

The phenomenons such as burr, layering, exit fiber tearing when special apex point design can reduce composite boring.Help to reduce and disperse cutting force, the crudy in Effective Raise hole.

The cutting edge of the blade that (3) links to each other with apex point consists of cutting unit by the symmetrical staggered helicla flute of left-right rotary, left and right sides groove number equates, groove is several to be changed to some extent according to cutter sword footpath difference, diameter is larger, the sword number is more, 10～12 ° of rake face angles, and fluting directly forms, 18～25 ° of rear knife face angles, relief angle cutting edge fluting directly grinds.

Can realize that by the available diamond-coated tools of the present invention brill mills continuous processing, when the pierced process of processing part, directly drill through the hole at composite board, then carry out milling, simultaneously, when the processed complex part, available same cutter is processed continuously, finish boring, hollow out, mill the multiple processing technologys such as limit and need not tool changing, improved working (machining) efficiency and machining accuracy.

The present invention carries out the diamond coatings processing at cutter apex point and blade surface, is adding man-hour, can keep for more time the sharp of cutting edge, obviously improves processing effect, and tool life reduces tool change time, improves working (machining) efficiency, cuts down finished cost.

The apex point of common drill bit is designed to bore the 120 ° of double cutting drills in angle, is prone to the exit fiber tearing in the composite bore process, special apex point design of the present invention, the phenomenons such as burr, layering, exit fiber tearing in the time of can reducing composite boring.Help to reduce and disperse cutting force, the crudy in Effective Raise hole.

Plain cutter only has the continuous cutting edge of a direction, causes when processing carbon fibers/fiberglass composite, and the defective phenomenons such as layering, burr, flange appear in otch, and cutter life is lower simultaneously.Tradition goldfish scale milling cutter cutting edge is pointed shape, cutting edge length, and shown in Fig. 4 (b), cutting scheme is that the wedge angle of cutting edge reaches the cutting purpose with break of CFRP, may have fiber in the working angles and be drawn out, and comparatively significantly burr occurs.Cutting edge of the present invention has left-handed and the dextrorotation cutting edge, head axes along helicla flute directional profile figure shown in Fig. 4 (a), cutting edge all is with positive rake angle, cutting edge is by interrupted rectilinear(-al), whole cutting blade is comprised of a series of triangular cutting edges by a bit of straight line, when Milling Process, left-handed, the cutting edge conversion cutting direction of dextrorotation, when a tooth cutting force departs from machined surface, the cutting force of another tooth is towards machined surface, and under certain machined parameters, the left-right rotary intersection is carried out, cutting edge can be with the direct section of cutting of fiber, establishment sheet deformation, burr appears in machined surface, the fiber layering, the defective phenomenons such as top layer flange.From the technological angle of diamond coatings, straight line edge more is conducive to the growth of coating than the wedge angle cutting edge of traditional goldfish scale milling cutter.

The present invention, traditional goldfish scale milling cutter and common helical edges milling cutter processing carbon fibre composite effect contrast figure are shown in picture group 5.

Description of drawings

Fig. 1 is the structural representation of diamond-coated tools provided by the invention.

Fig. 2 is the top view of the described process tool of Fig. 1.

Fig. 3 is the three-dimensional close up view of the described process tool apex point of Fig. 1 and blade.

Fig. 4 (a) be process tool head axes shown in Figure 1 along the profile of helicla flute direction, Fig. 4 (b) is that the goldfish scale milling cutter axis is along the helicla flute directional profile.

Fig. 5 is advanced composite material (ACM) process tool, goldfish scale milling cutter and common skew cutting cutter processing carbon fibre composite figure, (a) is the effect that coated cutting tool shown in Figure 1 is processed carbon fibre composite; (b) be the effect of Knife for removing fish scales processing carbon fibre composite; (c) be the effect of common helical tooth blade processing carbon fibre composite.

Fig. 6 is the Raman spectrogram of diamond-coated tools provided by the invention.

The specific embodiment

Preparation process below by accompanying drawing and diamond-coated tools improves with significant further to illustrate substantive distinguishing features of the present invention.

The making ofembodiment 1 diamond-coated tools

Step 1: select suitable carbide matrix material

Because coating process is carrying out more than 800 ℃, so copper plates cutter and high-speed steel tool all can not be used diamond coatings, and selected matrix material should be carbide alloy.Before coating process, select suitable carbide matrix material to carry out surface treatment, the adhesive force of coating result and diamond film there is material impact.Because the existence meeting of Co brings negative effect to adamantine film forming, therefore should select the quality percentage composition of Co to be controlled in 6%, the grain size of cemented carbide base material and material is between 1 to 3 μ m.

Step 2: the processing and forming of carrying out cutter

The diamond-coated tools that is applicable to fibrous composite processing provided by the invention, comprise apex point, blade and shank, its the first architectural feature is that the cutter head mills integrative-structure for boring, can realize holing and the continuous processing of milling, for thicker sheet material, perhaps clamping rigidity is situation preferably, and the apex point drift angle is 135 ° and 90 ° of common apex point forms in Double Tops angle; The cutting edge of the blade that links to each other with apex point consists of cutting unit by the symmetrical staggered helicla flute of left-right rotary, and left and right sides groove number equates that groove is several to be changed to some extent according to cutter sword footpath difference, and diameter is larger, and the sword number is more; 10～12 ° of rake face angles, fluting directly forms, 18～25 ° of rear knife face angles, relief angle cutting edge fluting directly grinds.

The diamond-coated tools that provides, its the second structure is characterized in that the cutter that provides comprises apex point, blade and shank, the cutter head mills integrative-structure for boring, can realize holing and the continuous processing of milling, for thinner sheet material, or the relatively poor situation of clamping rigidity, drift angle is for negative, namely with the apex point form of 5～10 ° of Pan Jiao; The cutting edge of the blade that links to each other with apex point consists of cutting unit by the symmetrical staggered helicla flute of left-right rotary, and left and right sides groove number equates that groove is several to be changed to some extent according to cutter sword footpath difference, and diameter is larger, and the sword number is more; 10～12 ° of rake face angles, fluting directly forms, 18～25 ° of rear knife face angles, relief angle cutting edge fluting directly grinds.

Step 3: the preliminary treatment of cutter coat

Cobalt process to be removed through special process in the apex point of cutter and blade (position that needs coating) surface, and the surface forms micropore, is easy to the combination with diamond coatings, improves the adhesion of matrix material and diamond coatings.Described special process is to use hydrogen peroxide to corrode, and forms micropore on the carbide matrix material surface, cleans in ultrasonic wave, dries with ethanolic solution again.

Step 4: the coating of diamond coatings

Hard alloy cutter is placed on the anchor clamps, place reaction cavity, utilize heated filament CVD to prepare diamond coatings at cutter apex point and blade top layer, produce atomic carbon after decomposing ionization in the carbon containing source of the gas vacuum cavity at high temperature, again be bonded to the diamond crystal phase structure on the depositing base surface, and form gradually the diamond coatings of crystallization, different according to tool diameter, coating layer thickness is between 10-30 μ m.It is because of overweight coating that coating layer thickness is controlled at more than the following 10 μ m of 30 μ m, and it is large that the residual stress in the coating becomes, and coating easily comes off from cemented carbide substrate surfaces, the too thin effect that does not have coating.

Hot-wire temperature 1800-2000 ℃, substrate temperature is controlled at 800-1000 ℃, in the mixed-gas environment of methane and hydrogen, and CH₄Concentration expressed in percentage by volume is 8%-13%, CH₄/ H₂Volume ratio is 0.2-0.3, and reaction pressure is 0.16-10kPa.

Embodiment 2

In the processing of carbon fibre composite, diamond-coated tools has obvious advantage, especially more with present use PCD (polycrystalline diamond) cutter is compared, diamond-coated drill can bore more hole in process of production, and advantage is more obvious in the process of glass fiber compound material.The diamond coatings milling cutter also is widely used in the cutting carbon fibre composite, has reduced processing cost, and has reduced the layering between the composite bed.This mainly is because the CVD coating process can be at drill bit and the milling cutter surface coating of all complicated shapes.And mostly the PCD cutter that uses at present is the PCD template is welded to and goes in the cutter groove, and preparation process is longer, and is more to the shape restriction of cutter, and cost is also relatively high.PCD cutter price is 3 to 5 times of other coated cutting tool, is 10 times of non-coated tool.

The laser Raman spectroscopy of diamond-coated tools provided by the invention shows, at 1331cm^-1Point appears comparatively significantly in annex and high peak is the peak value that is caused by adamantine SP3 mixed track, and at 1550 ± 150cm^-1Scope obvious spike does not appear, illustrate that the peak value that is caused by mixed tracks such as SP2 such as graphite or amorphous carbon is not obvious.Fig. 6 is the Laser Roman spectroscopic analysis of composition figure of diamond-coated tools of the present invention, and as can be seen from Figure, diamond coatings purity is higher.

Fig. 2 is the top view of cutter, can find out also that from figure the brill of cutter mills integrative-structure, and the centre is the sword type of drill bit, is the sword type of milling cutter on every side.

Head axes is prolonged helicla flute directional profile figure in Fig. 4 (a) cutter of the present invention, cutting edge is comprised of the triangle shape sword of a bit of straight line, cutting scheme and scissors are similar, the cutting edge conversion cutting direction of left-handed, dextrorotation, when the processing fiber material, directly fiber is cut off the formation of the layering of establishment burr; Be from Fig. 4 (b) be common goldfish scale milling cutter axis along helicla flute directional profile figure, cutting scheme be the wedge angle of cutting edge with break of CFRP, might have fiber and be drawn out, burr appears.

5 (a) figure is machining design sketch of the present invention, does not substantially have burr phenomena, does not also have comparatively significantly top layer skin effect phenomenon; 5 (b) figure is traditional goldfish scale milling cutter processing effect figure and since processing mechanism be the blade tip of blade with break of CFRP, the part is prone to comparatively significantly burr; 5 (c) figure is common helical edges milling cutter processing effect figure, and burr is more, is prone to layering and skin effect phenomenon.

Claims (9)

1. diamond-coated tools comprises apex point, blade and shank:

1. matrix material is that the quality percentage composition of Co is to be lower than 6% carbide alloy;

2. the apex point of cutter and blade are that diamond coatings applies; It is characterized in that

1. the head of cutter mills integrative-structure for boring, and the apex point drift angle is that 135 ° and 90 ° of Double Tops angles or drift angle are 5-10 ° of Pan Jiao;

The cutting edge of the blade that 2. links to each other with apex point consists of cutting unit by the symmetrical staggered helicla flute of left-right rotary, and left and right sides groove number equates.

2. by coated cutting tool claimed in claim 1, it is characterized in that the diamond coatings thickness that applies is 10-30 μ m.

3. by coated cutting tool claimed in claim 1, it is characterized in that described spiral fluted groove is several different and change according to cutter sword footpath, diameter is larger, the sword number is more.

4. by coated cutting tool claimed in claim 1, it is characterized in that the centre that described brill mills integrative-structure is the sword type of drill bit, be the sword type of milling cutter on every side.

5. make the method such as each described coated cutting tool among the claim 1-4, it is characterized in that making step comprises:

(1) selects suitable carbide matrix material;

(2) carry out the processing and forming of cutter;

(3) preliminary treatment of cutter coat;

(4) utilize heated filament CVD at cutter apex point and blade surface preparation diamond coatings.

6. by preparation method claimed in claim 5, it is characterized in that:

(1) carbide matrix material described in the step 1 selects the quality percentage composition of Co to be controlled in 6%, and grain size is between the 1-3 μ m;

(2) 10-12 ° of rake face angle during processing and forming in the step 2, fluting directly forms, 18-25 ° of rear knife face angle, relief angle sword face fluting directly grinds;

(3) preliminary treatment of step 3 coating refers to use hydrogen peroxide to corrode, and forms micropore on the carbide matrix material surface, cleans in ultrasonic wave, dries with ethanolic solution again;

(4) the temperature 1800-2000 of step 4 heated filament CVD ℃, the coating that the temperature of hard alloy substrate is controlled at 800-1000 ℃ of coating is to carry out in the mist of methane and hydrogen.

7. by preparation method claimed in claim 6, the volume ratio that it is characterized in that the CH4/H2 of step 4 is 0.2-0.3, and reaction pressure is 0.16-10kPa.

8. by the application of each described coated cutting tool among the claim 1-4, it is characterized in that for carbon fiber or glass fiber compound material sheet material hollow out, mill limit or boring.

9. by application claimed in claim 8, it is characterized in that the apex point drift angle is the processing that 135 ° and 90 ° of Double Tops corner structures are applicable to heavy-gauge sheeting; Drift angle is the processing that 5 ° of-10 ° of Pan Jiao are applicable to light sheet.

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