Exceed coating of strong cutting tool

  • Time:
  • Click:258
  • source:SHNMIN CNC Machining
By CVD diamond and PVD cubic metre in deposit of cutting tool surface nitrogen changes boron (CBN) comprises exceed hard scumble layer to have applied latent capacity extremely, the flexibility phase that because these two kinds are in all material,the coating of functional sex wear-resisting with highest hardness and parameter of cutting tool geometry design is united in wedlock, can satisfy the special requirement that gives treatment job, make efficient treatment politic (like high speed cutting) get more effective execution, its are as a result produce through decreasing time strengthens competitive dominant position with production cost. Accordingly, coating of development general coating and the innovation that the advantage posture that transcends hard cutting material combines cutting tool is crucial. In the meantime, these two kinds exceed coating of strong cutting tool falling to have good performance with interrupted cutting condition continuously. The comparison of the result of a few tests that the article gave out to concern CBN and diamond coating and different development phase. According to ISO513 standard, exceed material of strong cutting tool to include to get together nitrogen of brilliant cubic metre changes boron (diamond of PCBN) He Jujing (PCD) . By what exceed hard data to make industrial cutting tool production value is 4 billion dollar about. If the graph is shown 1 times, drive the main trend that exceeds progress of material of strong cutting tool to reflect in two respects: Use as the material of point of a knife of cutting tool and use as the wear-resisting coating that besmears Fu has matrix face at the knife, the purpose is to make cutting tool acquires stronger function and higher geometrical design flexible. Nevertheless, the research unlike of CBN of natural to be not material makes progress in that way to the research of diamond fast. Graph the research that 1 exceed coating of strong cutting tool makes progress (by time sort) express 1 summary the advantage that exceeds cutting tool of hard wear-resisting coating. For example, compare with PCBN cutting tool or photograph of PCD cutting tool, exceed hard coating cutting tool to be mixed through be being ground again again coating, can reduce cutting tool cost. The dominant position that expresses the advantage coating cutting tool that 1 exceed hard coating cutting tool (with not photograph of coating cutting tool is compared) the advantage that exceeds strong cutting tool (compare with photograph of other cutting tool) the advantage of coating cutting tool (compare with photograph of cutting tool of PCD cutting tool) long hardness of cutting tool life is tall (heat, need not cool diffuse without binder the applied diamond of a problem diamond is kind of natural pure crystal be out of shape carbon, its atom structure is covalent bond connective face heart is cubic. Diamond has the physical character that special rate jumps over, be like the hot conductivity with extremely highest hardness, tall nature and exceedingly good insulation property. Because diamond has exceedingly good wearability and chemical stability to be not iron material, because this suits very much,apply at cutting to machine as cutting tool material. In the past, diamond aborning basically uses as abrasive or cutting blade. 20 centuries second half period, apply mediumly in auto industry as material of light qualitative alloy increasing, diamond cutting tool is shown increasingly in the importance of cutting domain. The demand that increases increasingly to diamond is brought about be necessary to synthesize diamond artificially in order to replace (compensatory) diamond of natural single crystal (MCD) . Have the thermodynamic force way of diamond of two kinds of artificial synthesis: One kind is baric the high temperature high pressure that is 1700 ℃ for 6GPa, temperature synthesizes a law (HPHT); is pressure another kind the low-pressure synthesis law that is 1000 ℃ for 10OhPa, temperature. 1955, general Electric company uses high temperature high pressure to synthesize a law to synthesized diamond to gain revolutionary headway artificially. 70 time metaphase, PCD comes out as material of a kind of compound cutting tool. The bond that use cobalt combines diamond grain together and PCD is formed, can use as the material of integral point of a knife that solders to go up at cutter hub. Replace PCD to be in with CVD diamond research PCD material while, deposit of benefit chemically gas phase (the low-pressure synthesis that CVD) coating craft realized diamond. 1975, russia scientist first time is before on blame diamond matrix deposit gave layer of CVD diamond Chu. This craft makes diamond gets marked improvement as the function of cutting tool material. Its can divide knife of CVD diamond coating to be mixed for thick film cutting tool filmy cutting tool. When cutting tool of thick film of preparation CVD diamond, give ply to be the diamond thick film of hundreds of micron in the deposit on matrix above all, use next stimulate cent of beam of light to cut figuration to be small, solder to go up to cutter hub. Differ with this, cutting tool of CVD diamond film is the diamond film with a few deep micron with a kind of mixed pattern direct deposit arrives already on the cutting tool of figuration. Because do not use metallic bond, the hardness of cutting tool of CVD diamond coating, wearability and high temperature resistant function excel PCD cutting tool. In addition, diamond coating cutting tool also has very large dominant position on the flexibility that parameter of cutting tool geometry designs. 1993, commercialized diamond coating but dislocation razor blade appears on the market first. Nowadays, already had the coat of diamond cutting tool of various special design. Besides the standard that basically makes by cubic grain beyond microcrystalline diamond film, returned preparation to go out by Balasi film of diamond of accept rice grain and by micron and Na Mijing bead film layer is besmeared alternately of Fu multilayer diamond is filmy. In addition, microcrystalline diamond coating also is developing the systematism that is located in diamond brilliant face surface of blade of cutting tool cutting surely and in analytic research. Cutting tool: VCGT160412; Cutting dosage: F=0.

1mm, vc=600m/min, ap=1mm; Cooling fluid: 5% graphs 2 mix with cutting tool of CVD diamond coating not when the circle outside cast-iron workpiece of AlSi20 of turning of cutting tool of coating hard alloy, knife face wears away after the relation CVD diamond that takes width and cutting length is like a graph as coating of cutting tool wear-resisting 2 are shown, machining tall caustic over- in all brilliant when aluminum-silicon alloy, cutting tool of hard alloy of coating of diamond of accept rice grain and not photograph of cutting tool of coating hard alloy is compared, cutting tool life rose 20 multiple, reduced data of purify unit volume to expend thereby but cost of dislocation razor blade. In addition, because diamond coating cutting tool won't produce the tumor that accumulate bits, because this and photograph of cutting tool of common hard alloy are compared, after treatment go up surface roughness improves an appearance apparently. The development of coating of CBN cutting tool on one hand, already had deposit of all sorts of physical gas phase (PVD) and plasma quicken deposit of chemical gas phase (PACVD) craft applies successfully at CBN coating preparation. Normally, limitation of deposit CBN coating ply is in 500nm less than, this is main because the CBN coating interior of heavy panel exists,bigger remains presses stress, adhesiveness to differ and long-term stability is lacked below ambient conditions. On the other hand, on the matrix do not have silicon related to applied technology development CBN coating remains challenge of a technology. Nevertheless, the husband Lang that is located in German Braunschweig city and cost surface project and filmy institute (IST) excogitated the means that obtains thicker CBN coating, this method is based on with B4C coating and BCN gradient coating compound, the adhesiveness of system of factory CBN coating and stability are improved below the circumstance that stress reduces without materiality. The husband Lang that is located in Dresden and institute of the porcelain that expend contented and agglomeration technology (IKTS) was offerred in silicon matrix, also be at the same time on razor blade of hard alloy cutting the CBN coating plan that deposit ply is more than 2ΜM, carry out successfully below the temperature under 600 ℃ by IST, run an institute in machine tool of Berlin technology university and factory (IWF) experiments through attrition and turning experiment undertook analytic study. The matrix of WC-CoCBN(Si of function coating sort that expresses all sorts of 2 coating) CBN(WC-Co matrix) diamond (WC-Co matrix) TiN(WC-Co matrix) TiAlN(WC-Co matrix) the biggest ply - 2.

52>3>3>3 small hardness 2560 ～ of 8 ～ 6080 ～ of 6555 ～ 3022 ～ of 10025 ～ 28 diamond pyramid hardness [HV0.

2500 ～ of 01]800 ～ 2800 ～ of ～ of 5800 ～ 5500- 2400 bounce [650500 ～ of GPa]550 ～ 5501050300330 ～ of 550500 ～ 350 wearability [M3m-1N-110-15]n/a ～ 0.

4 ～ 0.

75 ～ of 6-5 ～ 7 coefficient of friction [- ] N/a0.

40.

4<<0.

70.

6 nick experiment [the hardness of the CBN coating system that 35-50>25 is matrix with hard alloy is 20 ～ of N]-18 ～ of standard TIN coating 2 times much, wear-resisting comparing raises 10 times above, and the half that is TIN coating only with the coefficient of friction of conjugate material steel (2) seeing a table. These CBN coating cutting tool already were opposite hard steel of alloy steel, temper by dipping in water, nodular cast iron and nickel base the turning of super alloy got succeeding examining in treatment. The system of coating of turning experiment CBN of diamond coating cutting tool is to use granuality measure normally matrix serves as after polish of the smallest K10 brand hard alloy, tu Futai is atomic above preexistence layer in order to enhance adhesiveness, mix in deposit B4C coating next BCN gradient coating, besmear in surface layer finally Fu CBN coating. Nevertheless, the coating system with the most advanced ibid is to use thick coating of TiN or TiAlN to replace Ti atomic layer, better adhesiveness is had in order to make between matrix and CBN coating system. Graph 3 for standard TiN coating, increased (the TiN of B4C-RCN-)CBN surface layer and TiAlN coating are in the cutting tool life when hard steel of turning temper by dipping in water is comparative. If the graph is shown 3 times, through be on TiN foundation coating deposit is additional CBN surface layer, can improve cutting tool life significantly, achieve 1OOm/min in highest cutting speed especially when, cutting tool life can be added almost to 3 times. Compare with this photograph, the performance of TiAlN-CBN coating is better even. Add from 80m/min when cutting speed to 100m/min when, the life of TiAlN-CBN coating cutting tool increases substantially, although because cutting temperature is elevatory,have possibly also,cause the cause of workpiece material bate. In the comparative test that having with the PCBN cutting tool with high price, when cutting speed is 100m/min, the life of PCBN cutting tool also is 54 minutes only, rose only 33% . Notable is, differ with has used PCBN cutting tool, the coating that CNMA geometry parameter designs but dislocation razor blade can be used (dislocation) 4, accordingly its have taller cost effectiveness. Cutting tool: Division of CNMA120408 workpiece material: 1.

2344(52HRC) ; Cutting dosage: F=0.

1 Mm, ap=0.

Of face of the knife before 5mm; does cutting tool of coating of 3B-G TiAlN-CBN of type cutting graph wear away the concern plan 3B-G that life of coating cutting tool and cutting speed differ when hard steel of temper by dipping in water of turning of process graph 3A showed TiAlN-CBN coating cutting tool (in did not besmear the TiAlN with Fu thick 2µm is mixed on the matrix of polishing 1.

The CBN) with thick 2µm is in turning treatment (Vc=80 M/min, ap=0.

Of 25mm) different level wear away process. Begin, felt of material of a few workpiece rises to protect action to cutting tool thereby in osculatory area; Accumulate bits tumour to begin to form next (graph 3D) , subsequently by purify (graph 3F) . This process is an adverse element, because of its ram not the rough surface of polishing matrix (normally coarse express and advantageous to the adhesiveness of coating, because milling effect is very good and by try out at turning) . Nevertheless, can see in graph 3F in a few small area cutting blade is penetrated, brought about graph 3G place to show the bigger damaged of cutting blade from this. Turning experiments again test and verify develops coating system has good wear-resisting performance, because not the matrix of coating falls to be able to hold to a few seconds only in so abominable treatment condition. The milling experiment of diamond coating cutting tool is pair of CBN coating systems next the function below interrupted cutting condition is evaluated. Experiment to undertake milling, lang of IKTS (husband and institute of the porcelain that expend contented and agglomeration technology) the hard alloy matrix that developed all sorts of different grain dimension and different cobaltic content technically. In the graph 4 in, through the CVD with coating of standard TiN, TiAlN and commercialization multilayer coating undertakes comparative, showed the cutting performance with TiAlN-CBN outstanding coating. For example, when feed length achieves 1800mm, of the cutting tool of 2 TiAlN-CBN coating that the experiment uses hind knife face wears away to still have 0 only.

1mm, and right now of cutting tool of pure TiAlN coating hind knife face wears away to be 2 times former about. Compare with this photograph, the function of CVD coating cutting tool and hard steel of temper by dipping in water of milling of TiN coating cutting tool should be differred more apparently. In addition, of the TiAlN-CBN coating cutting tool that graph 4B-G shows wear away the process makes clear again: When the CBN coating system of new development cuts hard steel of temper by dipping in water with Yu Xi, have enough good adhesiveness and hardness, because coating realized the sufficient protection to face of the knife before cutting tool, till reach level of differentiate of cutting tool life. If be inside the deposit antrum of IST coating equipment,installation rotates device, the cutting function of coating can rise probably further, because CBN surface layer may be right now main,deposit is in before cutting tool on knife face. Face mill; Cutting tool: SNUN150612, dc=53mm, material of Z=l; workpiece: 1.

2080(365HV62.

5) ; Do cutting; Cutting dosage: , vc=70m/min, f=0.

1mm, ap=0.

5mm, before cutting tool of coating of Ae=5mm graph 4B-G TiAlN-CBN, hind of knife face wear away face of the knife after coating cutting tool differring when hard steel of temper by dipping in water of milling of process graph 4A wears away because the relationship conclusion that carries width and cutting rate is right the special requirement that exceeds hard data and application, if make conclusions,can reach: The TiN-CBN that uses innovation and the workpiece data that TiAlN-CBN coating adjusts all sorts of differring successfully undertook cutting (turning and milling) experiment. The result makes clear, in be machined to the turning of hard steel of temper by dipping in water and milling, because be on TiN and TiAlN standard coating additional and add CBN surface layer and make cutting tool function rises significantly. With not photograph of cutting tool of coating hard alloy is compared, the life of cutting tool of CVD diamond coating rose severalfold. In addition, differ with hard alloy and PCD, cobaltic bond material is not contained in CVD diamond, accordingly its fight abrasiveness to be able to be mixed adhesiveness is more exceedingly good, the treatment with can be obtained better is expressed and quality. The article described the development tide that combines the advantage look that exceeds the wearability with good stuff of strong cutting tool and cutting tool coating, center at be the system of multilayer and compound coating of surface layer with CBN to the research of CBN coating at present; And the research of CVD diamond coating basically is aimed at coating of pure single crystal or much brilliant diamond mainly. CNC Milling CNC Machining