Cutting tool of CVD diamond film makes technology and its application

2µm. Although domestic CVD is at present filmy,the application of coating cutting tool still is in budding condition, but grow as CVD diamond of the technology rise, CVD diamond base the size of round grain has been narrowed by 40 ～ 50µm ten even rice of a few accept, appeared thereby accept rice diamond. Be like laboratory of state of American A tribute (Argonne Nat.

The Dr of Lab) .

Gruen D.

M has grown good, surface is a quality lens face (the Namijin that exterior highest peak and lowermost peak span are 15nm) , aleatoric ply is firm stone film, and the adherent power of its coating is enough. Believe its are promoted somewhat to the application of coating cutting tool. 2, CVD diamond thick film solders thick film of diamond of cutting tool CVD solders cutting tool is solder the CVD diamond thick film with fine cut to matrix first (it is K normally kind hard alloy) on, form compound piece, cast recover to close next piece, solder 2 times to go up to cutter hub, the figure that blade wear needs and point. Workmanship flow: The → of preparation → Laser Cutting of high quality CVD diamond film solders compound a → is compound piece polishing → solders 2 times to grind → to examine to blade of the → on cutter hub. A few crucial working procedure introduce below, be like cut, solder, polishing and blade are ground etc. 1.

Hardness of diamond film of Laser Cutting CVD is not tall, electric (already had diamond of electric conduction CVD now, but its resistor rate is very old) , wearability is extremely strong, the method such as groovy machining and line cut does not agree with the cut of CVD diamond thick film. Efficient treatment method is Laser Cutting. 2.

Soldering is to show CVD diamond below vacuum condition thick film solders to go up to certain matrix, form compound piece. Between diamond and general metal but weldability extreme difference. Current, the welder of cutting tool of diamond thick film art the method that basically uses exterior metallization. Solder is the silver-colored copper alloy that contains titanium, the action of titanium is to soldering heat react with diamond film surface in the process, among generation TiC layer, make metallization of diamond film surface, rise thereby solder intensity. Solder to be K normally with matrix kind hard alloy. Below high vacuum condition, use diffusion welding to add the craft of drill rod solder, ag, Cu, Ti alloy makes intermediate layer, solder diamond thick film to go up in hard alloy matrix, solder intensity satisfies cutting to machine a requirement. 3.

Compound the purpose of a polishing polish is a surface on bit (namely before knife face) polishing becomes lens area, general requirement achieves Ra0.

1µm is the following. Can decrease to chafe with what cut bits after polish of face of the knife before cutting tool with felt, prolong cutting tool life; Return the flatness that can improve where a thing can be put to best use and sharp sex at the same time, raise the precision that cutting machines. Compound piece polishing uses special polisher. 4.

Soldering 2 times 2 times is to point to will compound piece solder to go up to cutter hub. Place is high frequency induction to solder more with equipment equipment, place is silver-colored copper solder and brazing flux with solder. Solder temperature is 650 ～ between 700 ℃ . Temperature cannot exorbitant, solder each solder side should maintain in the process clean. Reasonable choose brazing flux to be helpful for rising solder intensity and improvement are compound the weldability of a matrix and cutter hub material can. The intensity that solders 2 times generally speaking is 180 ～ 200MPa, can satisfy the requirement that cutting of diamond cutting tool machines. Additional, to improve the outward appearance of cutting tool, can use oilstone grind redundant silver-colored copper, with layer of oxidation of surface of purify of gush arenaceous law, with exterior plating Ni law or immerse with passivation fluid the combustion that prevents cutter hub is rusty. Blade grinds CVD diamond to have very tall hardness and wearability, it is very difficult that blade is ground. The blade that uses similar PCD cutting tool generally at present grinds a method. 5.

Equipment: Use special tool grinding machine, equipment manufacturer has British COBORN company, Taiwan KARMAM company, Swiss EWAG company and Beijing enlighten install a company to wait. Its are main the function includes: Straight blade grinding and circular arc grinding, circular arc grinding includes again conic hind knife face and cylindrical hind the formation of knife face and conic wait with the combination of face of the knife after cylinder. To realize these functions, ask the main movement of the machine tool includes: Machine tool main shaft (emery wheel) whirligig; The move back and forth of main shaft moves point-blank; The circumgyrate of tool carrier moves, cooperate microscope or measuring projector to aim centre of turning circle accurately, the radius of circular arc of point of a knife that gets differring. 6.

Emery wheel: Blade grinds place to be emery wheel of colophony bond diamond with emery wheel, art cent is ground for kibble, half essence and essence of life grinds blade grinding work etc. Emery wheel size range is 250 ～ 325 to W10 ～ 07. To improve point quality, still need the technology such as abrade, polish sometimes, what use size finer, it is 1 ～ 3µm even. To gain the point of high quality, use normally embed arenaceous cast-iron dish undertake abrade. 7.

Blade grinds: Blade grinds a process in, need to add cooling fluid, should notice the nap of emery wheel, use the oilstone that suit normally correctly nap emery wheel can raise blade to grind efficiency and improvement blade grinds quality. Because the anti-impact properties of CVD diamond is inferior to PCD diamond, because this has the point after the cutting tool blade of some of special requirement is ground,should fall blunt, it is commonly 0.

02 ～ 0.

03mm. 8.

Examine of circumstance of quality of cutting tool point examine to be 40 ～ with enlarge multiple normally the tool microscope of 80 times will observe. The point of common cutting tool is toothed spend ≤ 0.

02mm. Taller to precision cutting tool, after passing abrade polish, point is toothed spend ≤ 0.

005mm. Additional, process different workpiece data, also have difference to the requirement of quality of cutting tool point, blade grinds CVD diamond cutting tool to should set out from actual application circumstance, go after the point of high quality blindly, reduce manufacturing efficiency already so, raise manufacturing cost again. 3, the cutting experiment of composite material of treatment of cutting tool of CVD diamond film 1.

Machine grain of metallic radical SiC to strengthen composite material (diamond of SiCp/LY12) CVD thick film solders cutting tool is successive cutting SiCp/LY12 composite material (HV>3000, siCp place holds weight than 30% , granuality 28µm) . Cutting tool wear curve is shown 1 times like the graph. V=75m/min, f=0.

1mm/r, ap=0.

3mm pursues the VB-t curve of composite material of SiCp/LY12 of treatment of cutting tool of 1 different material (dry cut) parameter of cutting tool geometry: · YS8: G0=0 ° , a0=12 ° , kr=90 ° , re=1.

0mm, PCBN of Ls=0 ° · : G0=0 ° , a0=12 ° , kr=90 ° , re=0.

1mm, PCD of Ls=0 ° · : G0=-4 ° , a0=9 ° , re=5.

Thick film of 0mm · CVD: G0=3 ° , a0=13 ° , kr=75 ° , re=0.

6mm. From the graph 1 can see, TFD(CVD diamond thick film) when cutting tool is machining 38min hind knife face wears away VB value is about 0.

05mm, PCD cutting tool is about 0.

16mm, the wearability of thick film cutting tool is apparent cutting tool of prep above PCD. Its reason is diamond thick film be get together by what pure diamond grain comprises brilliant material, and PCD diamond is by the metal Co, Ni is served as stick those who receive an agent to be together diamond agglomeration to get together brilliant material, metallic Co makes the wear-resisting function of PCD cutting tool is reduced somewhat. Of PCBN cutting tool wear away to be gotten more quickly than PCD and cutting tool of CVD thick film much, and cutting tool of YS8 of fine grain hard alloy can be competent far from. Aborning, should thick film of actor choosing CVD or PCD cutting tool. 2.

Machine colophony radical fibre glass strengthens composite material (GFRP) graph shows the wearability curve when machining GFRP for film of diamond of PCBN, CVD and thick film 2 times. V=80m/min, f=0.

1mm/r, ap=0.

3mm pursues the VB-t curve of composite material of GFRP of treatment of cutting tool of 2 different material (dry cut) parameter of cutting tool geometry: · PCBN: G0=0 ° , a0=8 ° , kr=45 ° , re=0.

5mm, CVD of Ls=0 ° · is filmy: G0=-10 ° , a0=8 ° , re=4.

Thick film of 0mm · CVD: G0=-8 ° , a0=8 ° , kr=45 ° , re=0.

5mm, ls=0 ° from the graph 2 can see, the wearability of cutting tool of CVD thick film is best, take second place of CVD filmy cutting tool, PCBN cutting tool more take second place. The bases of GFRP is SiO2(85HRA) , power of the attrition when treatment is greater, it is dry cut, the temperature when reason is machined is higher, what can cause cover of the knife after blade of cutting tool cutting is mixed is faster wear away. GFRP material is less than the treatment difficulty of SiCp/LY12, cutting tool life is longer, 3 kinds of cutting tool that the experiment uses all but aborning application. Anyhow, no matter be cutting tool of coating of CVD diamond film, still be CVD diamond thick film solders cutting tool, if can make full use of its good performance, take its length, avoid of those short, it is very good that its apply foreground. In the meantime, the growth that should continue to raise CVD diamond film on one hand technology, make its performance more good; On the other hand, should improve the production technology of CVD diamond cutting tool, make its more apply at each domains widely. CNC Milling