Machine the diamond that composite material uses metallic radical

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The aluminium that gets treatment 20%SiCp with PCD cutting tool base composite material metal base the function of composite material and treatment method composite material are by two plant or the material with different component of chemistry of two kinds of above, via material of artificial complex heterogeneous. This kind of material maintained the characteristic of data of single group share already, make each learn from others's strong points to offset his weakness between group share again, cooperate with each other, form the character that actors or actress Wu Yuan has stuff. Composite material is mixed by matrix photograph add wild phase to comprise. Former it is main component, have cohere effect; Latter has the effect that heightens hardness, intensity, stiffness and wearability. And in light the metallic matrix of qualitative, tenacity (multi-purpose aluminium or aluminium alloy) in join horniness grain to enhance material (wait like SiC, AlN, Al2O3) and the metal that makes base composite material, have density small, smaller than intensity and taller than stretch model quantity, hot coefficient of expansion, high temperature resistant as good as fatigue resistance, wearability and fight Zhen Xingjiang, and preparation craft is simple wait for an advantage, already used widely at present so wait for wear-resisting spare parts and machinery, metallurgy, bearing, traffic to carry at car engine cylinder bushing, piston, the industrial department such as chemical industry, building and aerospace. But the processability of composite material differs metallic radical, although developed many new treatment methods at present, wait for a method like treatment of electric spark treatment, laser beam machining and high-pressured water efflux, but by compare at equipment costly with treatment quality not advanced reason, so traditional machining (include: Car, auger, mill, strong, bore with a reamer, boring and grind etc) the main measure that still is current treatment. Diamond is the best material on the world, its are microscopical hardness can amount to 10000HV, wearability is wonderful, cutting blade is very sharp, blade ministry surface roughness is worth small, attrition factor is low, it is good to fight cohere sex, thermal conductance is tall, when cutting not easy sticky knife and generation accumulate bits tumour, it is good that with its treatment composite material has metallic radical to life of tall, cutting tool grows work efficiency and machine quality wait for a characteristic, reason application is the widest. If plan institute is shown to use PCD (get together brilliant making synthetic diamond) the aluminium that cutting tool getting machines 20 ％ SiCP base the applied example of pump case of composite material helix. Characteristic of processability of composite material cutting connects metallic radical ordinary people the metal base composite material vest in " difficult treatment material " , when be being machined actually, it is formed short cut bits, and matrix is aluminium alloy commonly, cutting temperature is low, reason cutting processability is very good; Basically be the grain that joins inside its the hardness that enhances material is very tall, if the hardness of SiC is as high as 3000-3500HV. Horniness particle size distribution is in matrix, like be just as emery wheel to wear bead mediumly, meet be ground to be being blown since the cutting blade of cutting tool and pound action, make cutting blade wears away very quickly. The hardness of horniness grain heals the dimension of tall, grain heals the amount of big, grain heals much, criterion cutting tool wears away more fast. Accordingly, undertake very hard machining with traditional hard alloy cutting tool, very low or cutting tool life is essential cannot use. Japanese scholar ever used hard alloy cutting tool (the A390 that brand K10) turning contains silicon quantity to be 16%-18% passes in all brilliant silicon aluminium alloy and cast-iron, same cutting condition lays former cutting tool cutting is in a few minutes before cutting tool on after knife face generation grinds bead badly to wear away and invalidation, its life is not worth the 1/3 with cast-iron cutting. Will be changed by cutting material SiC brilliant must enhance aluminium alloy, the result is cutting tool wears away aluminium alloy of taller than cutting silicon is gotten even quickly much. If use treatment of cutting tool of coating hard alloy, medium horniness grain still meets composite material wear coat very quickly wear and expand quickly hard alloy matrix is medium and make cutting tool invalidation. Diamond is the known the best material on the world, use a proof actually, it is to machine metallic radical the material of optimal cutting tool of composite material. Machine metallic radical with diamond composite material, its cutting speed can amount to 800~1000m/min, cutting tool life can compare hard alloy tall severalfold, even a few times, and numerical value of treatment surface surface roughness is little, can amount to Ra0.

025-0.

012µm. Because,this is diamond not only hardness is tall (can amount to 10000HV) , wearability is good, can hold sharp cutting blade for long, blade ministry surface roughness is worth small, and chafe factor is low, it is good to fight cohere sex, thermal conductance is tall, when cutting not easy sticky knife and generation accumulate bits tumour, quality of cause treatment surface is far also be close friends than other cutting tool. The breed that chooses diamond correctly gets together brilliant diamond and hard alloy are compound bit (PCD/CC)PCD/CC is to machine metallic radical composite material uses a kind of the most extensive diamond. It is to be on the hard alloy matrix with intensity and better tenacity, in its surface agglomeration or suppress 0.

5-1mm gets together thickly brilliant diamond PCD and into. The bending strength of this kind of compound razor blade and hard alloy are basic and identical, and the hardness of working surface is close to whole to get together brilliant diamond PCD, and solderability is good, it is easy to be ground again, cost is low. Get together typically brilliant diamond and hard alloy are compound bit is flat shape or piece shape, like that after wants appearance and size into bit place with Laser Cutting. PCD/CC commonly used solder or machine place means, make a car, auger, mill, strong, bore with a reamer, boring and curium wait for all sorts of cutting cutting tool. The function of PCD/CC and size of diamond grain dimension are concerned. The PCD razor blade that De Beers company produces has 002, 010 mix a few kinds 025, the average size of grain is 2µm, 10µm and 25µm respectively. Grain dimension heals big, of diamond bulk gather degree increase, make wearability has healed, cutting tool life heals tall, but the point quality of cutting blade is a bit poor, make high accuracy cutting tool hard. Contrary, fine grain cutting tool, the radius of point blunt circle of cutting blade (the 1-2) of general PCD cutting tool, treatment surface quality is good. Get together at present consequently the grain of brilliant is refined ceaselessly, already had 1 , have 0 even.

The fine brilliant under 5 . For this, the life that should consider cutting tool integratedly and treatment surface quality choose appropriate grade get together brilliant diamond and hard alloy are compound bit. Diamond of CVD diamond CVD is the pure diamond material of a kind of tall anti-wear properties, do not contain bond, it is in low pressure (<0.

Of the preparation below 1MPa) . CVD diamond has two kinds of forms: CVD filmy coating (CD) and CVD thick film (TFD) . CD is to use deposit of CVD (chemical gas phase) craft, in hard alloy matrix (commonly used K kind alloy) on deposit a ply is small it is 10~30µm) normally at 50µm(, become by the velar shape diamond that much brilliant comprises. Use make clear, cutting tool of CD diamond coating does not suit to be versed in with Wu Jia metallic radical composite material, because the horniness grain in composite material is inside very short time,grind with respect to the coating of surface of meeting general cutting tool wear. TFD is deposit ply can amount to 3-5mm without underlay diamond thick film, what become thick film cut definite figure again according to need is small, like that after solder fashions compound razor blade or cutting tool on hard alloy. TFD has very good integral performance, it does not have the defect of natural diamond anisotropy, by at without metallic bond, matter content is low, purity is close to 100 ％ , reason hardness and thermal conductance are taller than PCD, attrition factor is minorrer, chemical stability is better, machine metallic radical with its the performance of composite material is quite good. What show the cutting tool wear curve when to use PCD and TFD two kinds of diamond process data of 40% SiCP A356MMC. The cutting requirement that the graph adopts when 2 experiments is: Cutting speed 400m/min, feed is 0.

05mm/r, back penetration of a cutting tool is measured (cutting deepness) 0.

5mm, add cutting juice. By the graph 2 in knowable, metal of treatment 40% SiCP base composite material, the effect of TFD of diamond of use thick film is best; PCD025 take second place, the service life lowest of PCD002 cutting tool. Watch 1 use for what De Beers company recommends get together razor blade of SYNDITE 025 of brilliant diamond grade machines metallic radical the cutting parameter when composite material. Consider to make clear, as cutting speed rise and of feed decrease, ra of numerical value of treatment surface surface roughness will decrease, and quantity of back penetration of a cutting tool is not being shown to the influence of Ra. When reason finish machining, cutting speed should take a list 1 in greater numerical value, feed takes small cost. Machine metallic radical with diamond composite material, can do cutting, also but wet cutting. But the thermal stability because of diamond is low, when 700-800 ℃ it carbonization (namely graphitization) , make cutting tool life is reduced quickly. If use cutting liquid wet cutting, can make cutting thermal drop small, make cutting tool life increases. But answer before cutting tool cuts work pouring till cutting fluid ends till cutting, cutting fluid must furnish continuously, cannot intermittence, cause cutting tool damaged or collapse blade easily otherwise. Manage together, still should avoid midway to jockey as far as possible in cutting process or commutation cutting dosage. Conclusion diamond is to machine metallic radical the material of optimal cutting tool of composite material. Metal of treatment 40% SiCP base composite material, the effect of TFD of diamond of use thick film is best; PCD take second place; Size of diamond grain dimension has immediate effect to quality of the life of cutting tool and treatment surface. Grain dimension heals big, diamond wearability has healed, cutting tool life heals tall, but treatment surface quality is a bit poor; Conversely, fine grain cutting tool has better treatment surface quality; Cutting speed and feed have immediate effect to machining exterior surface roughness. Cutting rate heals high with feed more small, ra of numerical value of treatment surface surface roughness will decrease, and quantity of back penetration of a cutting tool is not being shown to the influence of Ra. CNC Milling