The experiment of function of cutting of cutting tool of CVD diamond thick film studies

05µm; Cutting tool of apparent excel hard alloy, PCBN cutting tool mixes wearability of the cutting tool when composite material of cutting difficult treatment and service life PCD cutting tool. Material of thick film of diamond of 1 foreword CVD pledges for Quan Jing diamond of simple much any crystalline substance, have hardness tall, coefficient of thermal conductivity big, coefficient of friction the good physical machinery performance such as small, isotropy, it made up for natural diamond already rare be short of the inadequacy such as costly, anisotropy, overcame grain of diamond of artificial synthesis single crystal again at the same time petty, get together brilliant diamond (interface of film of diamond of poorer, CVD combines PCD) chemical thermal stability intensity is low blemish, it is the good stuff of production cutting cutting tool. Be in abroad, cutting tool of CVD diamond thick film already was entered commercialize applied phase. In home, the research development to this kind of cutting tool and industrialization process also are accelerated ceaselessly. Can foreknow, the application of cutting tool of CVD diamond thick film will be right mechanical manufacturing industry (especially automobile manufacturing industry) generation is active and far-reaching influence. The thick film of diamond of CVD of function characteristic hardness of cutting tool of thick film of 2 CVD diamond is material of diamond of simple much any crystalline substance, carbolic atom is united in wedlock with SP3 covalent bond, its hardness is close to natural diamond, prep above uses cobaltic bond get together brilliant diamond (PCD) . The brilliant granuality size of wearability CVD diamond is different from PCD to the influence of wearability. The grain size of PCD cutting tool is larger, wearability is better, relatively advantageous to rough machining; Ask to workpiece surface quality more expensive precision work needs to choose fine grain PCD, but cutting tool durability is reduced somewhat. The wearability of CVD diamond does not depend on size of its brilliant granuality, big grain and little grain material have identical wearability (taller than PCD 2 ～ 10 times) , this is very advantageous to finish machining. The pensile key of coefficient of friction as a result of diamond surface has chemical laziness by hydrogenous saturation, accordingly surface of polish of cutting tool of CVD diamond thick film has extremely low coefficient of friction (0.

06 ～ 0.

1) , can drop cutting temperature effectively. The thermal conductance prep above of thermal conductance diamond is all other material. The thermal conductance of CVD diamond is 8 ～ 20W/cmK, the thermal conductance of outclass silver (4.

29W/cmK) . The tall thermal conductance of cutting tool of CVD diamond thick film is helpful for the quantity of heat of cutting blade conducting, because cutting tool is calorific,can avoid and produce phenomenon sticking a knife, improve cutting tool service life thereby, the fire damage that reduces workpiece and heat are out of shape. The thermal stability outclass of diamond of thermal stability CVD gets together in the complex below high temperature high pressure brilliant diamond (PCD) . Because agglomeration needs, the metal that has catalysis was mixed in PCD (the) that be like cobalt, begin oxidation namely when 600 ℃ commonly, graphitization happens to invert when 700 ℃ . And CVD diamond needs 700 ℃ above to just begin oxidation in air, the thermal stability in vacuum or inert gase can amount to 1200 ℃ above. The thermal stability with extremely tall cutting tool of CVD diamond thick film and chemical stability can improve its cutting performance greatly, especially comfortable the new-style composite material that processes tall wear-resisting at be below taller cutting temperature. Single crystal diamond, get together the applied limits that the different function characteristic of brilliant diamond, CVD diamond decided them differs somewhat. Except rupture outside tenacity, the other function of CVD diamond all excel PCD, the applied range of two kinds of cutting tool is basic and same, but PCD cutting tool suits rough machining, semifinishing machining and cutting to pound bigger treatment circumstance more, and cutting tool of CVD diamond thick film has an advantage more when finish machining and successive cutting. By treatment material: GFRP cutting condition: Ap=0.

33mm, f=0.

1mm/r, v=80m/min, dry cutting pursues diamond of the CVD when 1 turning GFRP, PCBN, YG8 of 3 kinds of cutting tool wear away state contrast is machined material: Grain of aluminium radical SiCp enhances composite material (matrix ZL109, siCp20% , granuality arranges 35µm) cutting condition: Ap=0.

3mm, f=0.

1mm/r, v=76m/min, dry cutting pursues 2 turning are aluminous base SiCp grain enhances composite material (of cutting tool of thick film of diamond of the CVD when granuality 35µm) wear away the state is machined material: Grain of aluminium radical SiCp enhances composite material (matrix ZL109, siCp20% , granuality arranges 28µm) cutting condition: Ap=0.

3mm, f=0.

1mm/r, v=70m/min, dry cutting pursues 3 turning aluminium base SiCp grain enhances composite material (diamond of the CVD when granuality 28µm) , PCD, PCBN3 is planted of cutting tool wear away function of the nicety that purpose of test of test of cutting of cutting tool of thick film of diamond of state contrast 3 CVD and purpose of conditional cutting experiment are cutting tool of thick film of research CVD diamond, superprecision and. Cutting experiment is in factory of some spaceflight industry and college of Beijing grain industry to undertake respectively. The experiment is the Shaublin125 that Switzerland makes accurate lathe with the machine tool; The bit of car of thick film of 4 CVD diamond that the experiment uses uses ply for 0.

The CVD diamond thick film of 6mm solders to go up in hard alloy cutter hub, bit total ply is 1.

6mm, detect below microscope of 600 times all-purpose tool bit, cutting blade level off is smooth, intact. Test result and analysis use razor blade of car of thick film of diamond of a CVD to machine duralumin alloy (LY12) . Cutting dosage is: 6µm of ～ of cutting deepness Ap=5, feed F=0.

01mm/r, cutting speed V=120m/min. Cutting test result: By Ra=0 of treatment surface surface roughness.

Function of 05µm(machine tool and use fixed number of years is right those who machine exterior quality is farther rise have certain limitation) , show lathe tool of CVD diamond thick film can be used at accurate cutting to machine, have the possibility that replaces lathe tool of diamond of natural single crystal to be used at exceeding accurate cutting. With other razor blade of car of thick film of 3 CVD diamond parts cutting 3 kinds of composite material: Phenolic aldehyde is plastic base fibre glass enhances composite material (the aluminium that GFRP) , granuality is 35µm and 28µm respectively base SiCp grain enhances composite material. Bit geometry angle is: G=0 ° , a=6 ° , kr=75 ° , kr=15 ° ; R=0 of radius of circular arc of point of a knife.

3 ～ 0.

35mm. Use microscope of J19 all-purpose tool to detect face of the knife after cutting tool wears away bandwidth spends VB, the cutting of as phyletic as other lathe tool wears away the state undertakes contrast. Detect the result sees a picture respectively 1 ～ pursues 3. By the graph 1 visible, use CVD diamond, PCBN, hard metal respectively (YG8) phenolic aldehyde of cutting of 3 kinds of cutting tool is plastic base fibre glass enhances composite material (when GFRP) material, if wear away with face of the knife after cutting tool width VB=0.

15mm serves as grind blunt standard, the service life of YG8 lathe tool is 30 minutes only; PCBN lathe tool is ground after using 50 minutes blunt; And lathe tool of CVD diamond thick film is in cutting after 50 minutes hind knife face wears away width VB is only 0.

06mm. By the graph 2 visible, the difficult treatment material in turning model -- grain of aluminium radical SiCp (when granuality makes an appointment with 35µm) to enhance composite material, cutting of lathe tool of CVD diamond thick film after 30 minutes hind knife face wears away width VB is only 0.

075mm left and right sides, its wearability and service life all greatly prep above hard alloy (YG8) cutting tool and PCBN cutting tool. By the graph 3 visible, plant with CVD diamond, PCD, PCBN3 respectively the aluminium that granuality of lathe tool cutting makes an appointment with 25µm base when SiCp grain enhances composite material, PCBN cutting tool is in cutting is ground after 5 minutes blunt; Turning of PCD cutting tool after 36 minutes ever since knife face wears away width VB=0.

12mm, adjacent already grind blunt; And right now of lathe tool of CVD diamond thick film hind knife face wears away width VB is only 0.

08mm. Test result makes clear: The wearability of cutting tool of CVD diamond thick film is best, take second place of PCD cutting tool, PCBN cutting tool is opposite the poorest. The cutting test result that afore-mentioned cutting test results and other document give out is more adjacent. The place on put together is narrated, cutting tool of CVD diamond thick film is in treatment of half nicety, accurate cutting, have the wearability with exceed strong cutting tool better than PCD, PCBN and longer service life. In addition, because CVD diamond has low coefficient of friction and tall thermal conductance, allow to use taller cutting rate and do not send the quantity of heat with harmful generation to accumulate, because cutting tool of this CVD diamond also applies to treatment of high speed cutting. Alloy of duralumin of cutting of cutting tool of thick film of diamond of 4 conclusion CVD (when LY12) , can realize Ra0.

The exterior surface roughness of 05µm, accordingly this cutting tool applies to accurate cutting to machine and replace natural diamond cutting tool to be used at exceeding accurate cutting to machine likely. Phenolic aldehyde of cutting of cutting tool of CVD diamond thick film is plastic base cutting tool of apparent excel hard alloy, PCBN cutting tool mixes the cutting function such as the wearability when fibre glass enhances SiCp of composite material, aluminium radical to enhance the difficult treatment material such as composite material, service life PCD cutting tool. Cutting tool of CVD diamond thick film has superior cutting performance, in exceed hard cutting domain to have wide applied perspective. CNC Milling