The miniature milling machine in imperceptible treatment, small cutting tool wears away the experimental research that reachs cutting power

7% , n is more than 80%) . To small way the knife that carry mill undertook mechanical character is analysed, wear away through cutting tool the experiment analysed small way coating of hard alloy TiAlN reachs those who be not coating milling cutter to wear away mechanism. Studied cutting dosage through the experiment of 2A12 of groovy mill duralumin finally (quantity of penetration of a cutting tool of main shaft rotate speed, back and every tine feed) the influence to imperceptible milling force, the thorough research that is mechanism of imperceptible milling cutting laid a foundation. The 1 foreword development as science and technology, be in in recent years IT, medical apparatus and instruments and communication domain, people is right small small-sized part (be like: Array of accelerometer of miniature sensor, miniature, small lens) demand increases increasingly. The addition of this kind of demand promoted the development of imperceptible processing technique. In a variety of current imperceptible processing technique, system of personal computer cable (Micro Electro Mechanical System, MEMS) is one of mainstream technologies all the time. Because MEMS technology derives technology of Yu Wei electron, its main treatment object is expected to go up in silicon base material by limitation, and the geometrical appearance of workpiece basically is simple 2 dimension appearance, only consequently the batch in circuit of large scale integration makes waiting for a respect just is economy. Imperceptible cutting processing technique, especially the complement that imperceptible milling regards MEMS as the technology, get treatment object material and geometrical figure scarcely as a result of its restrict and get the attention of researcher, becoming the newly emerging force in imperceptible processing technique. In current imperceptible milling treatment, miniature spare parts is mostly in groovy dimension exceed the treatment on accurate machine tool to come out. As a result of these groovy dimension exceeding accurate machine tool basically is the nicety that is used at part of high accuracy large size originally / superprecision, in the miniature hardware producer of small lot the face appears lack flexible, cost the tall, the sources of energy that waste and space and miniature spare parts unworthily, can sponsor technically 2000 for national science foundation of this United States " micron and intermediate measure machinery are made " symposium, discussed the treatment method of spare parts of accurate and three-dimensional miniature and facility. Now, a lot of foreign scholars had begun the research of small Bench Machine Tool to work. The scholastic Y of national university of Korea head Er.

B.

The person such as Bang developed milling machine of miniature of a 5 axes (328mm of × of 294mm × 220mm, have 3 linear platform, 2 rotate platform, main shaft is) of air turbine main shaft, machined thin wall of a few miniature with this miniature milling machine (ply 25µm, tall 650µm) and small pillar (320µm) of × of 30µm × 30µm, showed very good process capability. The M of lab of Japanese machinist Cheng.

The person such as Tanaka developed to be able to go to the lavatory system of mobile micro computer bed. This covers a system by lathe of a miniature (30mm) of × of 30mm × 25mm, milling machine of a miniature (102mm) of × of 170mm × 170mm, punching machine of a miniature (composition of 170mm) of × of 111mm × 66mm. In miniature CCD microscope auxiliary fall to hold calorie of work by arm of a miniature, use this to cover a system already successful treatment gave a diameter for 0.

The ball bearing of 9mm. Home concerns the research report of imperceptible milling technology to still see rarely, the system of milling machine of vertical of 3 axes linkage makes the miniature precision that the article introduced institute of project of nicety of Harbin Institute of Technology to develop and the treatment example that is accepted by user satisfaction, built system of numerical control of NC built-in PC open mode, developed an interface friendly control software is compositive video collects module; to undertake mechanical analysis to small way milling cutter, study its oscillatory, stress and be out of shape diagnostic; wears away through cutting tool the experiment analysed milling cutter of small way of coating of TiAlN hard alloy and blame coating wear away the test that mechanism; passes 2Al2 of groovy mill duralumin studied cutting dosage is right the influence of imperceptible milling force, the thorough research that is imperceptible milling craft laid a foundation. 2 miniature nicety milling machine of vertical of 3 axes linkage and treatment example 2.

The small means that 3 axes milling machine and place use the structure of milling machine of 1 miniature nicety and the miniature nicety that parameter develops carries milling cutter. Overall over all dimension is the machine tool 290mm of × of 300mm × 300mm, by the following 5 parts composition: PMAC8 axis motion controls card, operation of the interpolation that finish, the real time task such as positional control. Labour controls engine system, offer systematic initialization, code process designing, the blame such as parameter management task of real time sex. Accurate workbench, by the pottery and porcelain that suppress report drive of supersonic and linear electric machinery. Main shaft of air turbine high speed, offer for small way milling cutter highest 160, the rotate speed of 000r/min. CCD video collects a system, pair of knives go to the lavatory after be being used at magnifying small way milling cutter and small little work and position of cutting of real time observation. High speed main shaft and parameter of platform of accept rice fixed position see a table 1. Express 1 accept rice to locate platform and rice of accept of parameter of high speed main shaft locate 28N of retentivity of static state of 200mm/s of the oldest rate repeats platform journey 60mm fixed position precision 0.

25µm coder precision 0.

1µm main shaft is highest rotate speed 160, 000r/min is the biggest 140nl/min2 of wastage of air of radial and jumpy 1µm.

System of 2 numerical control develops systematic pattern to choose the development as computer technology, PC of numerical control system is changed is the main avenue that implements system of open mode numerical control, system of current open mode numerical control basically has 3 kinds of pattern: System of numerical control of PC built-in NC open mode. Interface of part of PC of this kind of system is open, but NC part remains traditional system, the user still cannot enter control system core, and the structure is complex the price is high. Be based on the system of open mode numerical control of software. This kind of mode uses the numerical control system of complete software form to realize the function of NC hardware. But because be put in the operating system oneness of real time sex, standard and systematic stability problem, still be in initial exploration phase at present, still arrive without application among actual production. System of numerical control of NC built-in PC open mode. Insert athletic control plate in this kind of system PC standard inserts groove in, by motion control card realizes the real time such as compensation of interpolation operation, motion to control a function, PC implementation blame controls a function in real time. Used this kind of pattern the MTC2000 of company of Indramat of the PMAC2NC system of American DeltaTau company, PA8000 system of German PA company, Germany. Below this kind of mode, the control system that the user can leave to develop a need by oneself in the operating system, flexibility good, function is strong, OK share substantial computer natural resources. In view of above the comparison of 3 kinds of mode, the small small-sized and accurate milling machine in article chooses the 3rd kind of mode. The PMAC8 axis campaign that because the system uses firm of American Delta Tau,software of numerical control system develops controls card, the function is powerful, dan Jiquan English operates those who make user need longer to groom the variable instruction adroitness with rich to its ability is used, developed the Chinese with friendly interface technically to control software for this. The operation was followed in software design the train of thought with handy, equitable distribution. Collect a system to have another independent application program as a result of CCD video additionally, need to be opened alone when treatment, the need in machining a process is being controlled switch makes a round trip between system and video system, very no-go, collect video so system also at the same time compositive in controlling software, while convenient operation personnel is controlling a machine tool, observation machines condition. Software, main component is control software 3 functions module: The program operates module, of machine program of the main user that finish call, check and carry out automatically. Main control module, editor of setting of the initialization of the main system that finish, each parameter, program and hand use the function such as the operation. Systematic condition shows module in real time, finish command position, real to each main shaft position, follow the real time of effective rate shows sum of errors, and the real time video presentation that machines to imperceptible milling. The adjustment of systematic adjustment and treatment example in numerical control system in the process special the make a present of before using integral depart to type PID adjusts and chafe. The key of integral separation process is a scale link P and departure of integral link I, scale P should let effective be become with reducing deviation; quickly only when error is bigger error is small arrive after certain level, throw integral I again with eliminating stable state error finally. The make a present of before attrition can be mixed to mechanical attrition obstruction hang down to lopsided rise to shift to an earlier date compensatory action. After systematic adjustment rank jump answer and parabola answers a curve, can see positional control is not had exceed tone, the system can locate well and truly quickly, follow the error is fluctuant between ± 24cts (1cts=0.

1µm) , follow the error is minor. This system showed good treatment performance in the small chamfer treatment of some film workpiece. Treatment is a diameter with cutting tool 0.

Crop of 15mm hard alloy establishs milling cutter, workpiece is 3J21 stretch alloy. This workpiece is workpiece of one film miniature, velar thick 65µm, the demand exceeds wide 150µm in the treatment on film, deepness > the small chamfer of 55µm. The enlarge after filmy workpiece treatment is finished the flank of 200 times, bottom land is thick it is 6µm only, the material purify rate on filmy ply direction is 90.

7% , surface roughness of bottom land surface 0.

365µm, batch machines n prep above 80% , obtain satisfactory treatment result. The mechanical character of milling cutter of small way of 3 hard alloy and wear away mechanism 3.

The stress that milling cutter of mechanical and characteristic analysis bears the weight of reachs milling cutter of 1 small way its are out of shape to cutting tool the stability in cutting process and cutting tool life have very big effect, study its vibration, stress and metabolic feature are right cutting practice has direct sense very much, because this article is used finite the mechanical character to small way milling cutter has yuan of method analysis, if the geometrical parameter that the experiment chooses cutting tool and material attribute are expressed 2, 3 are shown. Helix angle of the horn after expressing blade of parameter of geometry of milling cutter of 2 small way to count the part before blade diameter knife is long 20.

30 ° express 12 ° of 5mm1mm5 ° the model of Yangshi of density of material of material attribute cutting tool of milling cutter of 3 small way measures Poisson to compare K30 hard alloy 14.

108kPa0 of × of 7 × 10-6kg/mm36.

The natural frequency that 3nextpage expresses milling cutter of 4 small way is first-order natural frequency 2 rank natural frequency 3 rank natural frequency 4 rank natural frequency 42, 017Hz42, 061Hz109, 587Hz122, 656Hz mode analysis establishs milling cutter to undertake three-dimensional substance builds a model to miniature double blade above all, guide next general and finite yuan of software package is medium undertake mode is analysed. Differentiate in all reseau is unit 24, 795, before the Lansuosifa that uses cent piece undertakes analytic getting 4 rank natural frequency and vibration shape. Natural frequency sees a table 4, can see one, 2 rank natural frequency is adjacent, belong to mode concentrated area; 3, 4 rank differ bigger, and 3 rank with one, 2 rank natural frequency differs bigger. This 4 rank the vibration shape of mode is to bend model, did not appear turn round and adjustable. The working rotate speed of the pneumatic turbine main shaft that the system chooses is in 110, 000 ～ 160, between 000r/min, cutting tool is provided for the catling, the outside force frequency that get is in about 3, 600 ～ 5, between 400Hz, differ with first-order natural frequency an amount class, won't produce resonance phenomenon. The crucial factor with so jumpy radial of influence point of a knife depends on the circumgyrate precision of main shaft, it has bigger effect to machining the exterior quality after. Stress is out of shape analytic milling treatment is a complex cutting process, if the choice brings to bear on in place of point of a knife,center load to be able to differ with actual condition very far. Document adopted the method of the to load on the line, cutting force data perhaps emulates computation to get through experience formula, be hard to express actual cutting position likewise. The article to be close to with actual cutting state as far as possible, adopted the method of the to load on the face, and bring to bear on cutting force is the real data that the experiment measures. Cutting force is measured it is Kistler9251A nicety with the instrument 3 to the appearance that measure power, obtain Fy of force of radial load Fx, feed and axial force Fz3 well and truly cutting force of direction. Be in respectively near point of a knife before knife face, advocate hind knife face and deputy hind knife face intercept a zonule, before knife face intercept area of a small rectangle, hind the triangular area with knife face small intercept, retrospective cutting tool wears away method of intercept of this kind of area proving in the experiment is correct) , after having these 3 area reseau fractionize, to load is applied to carry on one's shoulder or back on node, get be out of shape the cloud and stress cloud. From be out of shape the cloud sees, the biggest be out of shape for 1.

44µm, inside the range that influences in 10µm of point of a knife centrally, but of cutting tool be out of shape entirely is not concentrated concentration in position of point of a knife, distributing however inside 50µm limits. Can be in order to see the greatest stress from stress cloud 14.

2GPa appears in deputy hind on knife face, is not position of point of a knife, be apart from point of a knife about 0.

1µm, stress of place of point of a knife is lesser under photograph comparing. Before there also is a stress to center an area on knife face, area of concentration of these two stress is one of causes that cause damaged of point of a knife. Advocate hind knife face and deputy hind area of knife face stress presents approximate triangle, this and the cutting tool from the back wear away the result that the experiment gets is consistent, proved the rationality of to load means thereby. The condition getting power when cutting of high speed of miniature milling cutter is complex, belong to periodic sexual intercourse to change load, the action of fatigue stress nots allow to ignore, still remain in the research of this respect thorough. 3.

Milling cutter of 2 small way wears away mechanism analysis experiment uses a diameter respectively 0.

5mm, milling cutter of coating of TiAlN of hard alloy of K30 fine grained and 2Al2 of duralumin of milling of blame coating milling cutter, observe cutting tool wear away form, to raise cutting tool durability, improvement machines quality to provide a basis. The experiment sees a table with cutting parameter 5. 2Al2 of experimental data duralumin belongs to high strenth aluminium, spot welding performance is good, commonly used will make tall laden part, its chemistry component sees a table 6. Express 5 cutting tool to wear away the experiment carries penetration of a cutting tool on the back to measure side penetration of a cutting tool to measure cutting tool to imagine kind of the refrigeration that extend a capacity with speed of feed of rotate speed of cutting parameter main shaft 140, 00r/min2mm/s40µm200µm12mm sky cold watch chromium of zinc of manganese of silicon of magnesian iron of copper of watch of chemical composition of 6 duralumin 2Al2 is aluminous 0.

9%1.

8%0.

5%0.

5%0.

9%0.

25%0.

2Al2 of duralumin of milling of milling cutter of small way of hard alloy of coating of TiAlN of 1% the others from scanning electron microscope (SEM) photograph and X ray can when chart analysis can see 2Al2 of duralumin of milling of milling cutter of coating small way basically wear away the form is: Coating falls off, diffuse wear away and damaged of point of a knife. With groovy dimension milling cutter wear away to basically happen after knife face is different, of small way milling cutter wear away damaged basically happens around point of a knife. Coating falls off. Because process of high speed cutting is medium, the temperature change with cutting tool and workpiece contact frequent area makes arose between coating and cutting tool matrix high frequency hand in heated stress, because this is in,around knife face appeared coating falls off phenomenon. Diffuse wear away. When high speed milling, the acuteness attrition of cutting contact area makes cutting tool is mixed happen to diffuse each other below solid state be been in by the chemical element of treatment material, changed the composition structure with original material thereby, this makes cutting tool surface layer becomes flimsy, quickened cutting tool to wear away. Wear away to diffuse typically. From can chart analysis can see Ti element has decreased greatly, the element such as Cu, Fe, Cr still appeared on cutting tool, explain coating has fallen off, the element on workpiece also had diffused on small way milling cutter. Damaged of point of a knife. Because imperceptible milling is medium edge part diameter is small, intensity of point of a knife is low, the amount of back penetration of a cutting tool of imperceptible milling is very small at the same time, cutting ply and point radius are in same amount step is smaller even, cutting basically is centrally near point of a knife area, damaged of point of a knife is so apparent, office of point of a knife appears clear round part and damaged trace, this is small way milling cutter and groovy milling cutter wear away the main reason with different type. Did not observe abrasive wears away apparently in the process of 2Al2 of duralumin of milling of milling cutter of small way of hard alloy of use TiAlN coating, stick receive wear away with oxidation. 2Al2 of duralumin of milling of milling cutter of small way of blame coating hard alloy uses a diameter 0.

5mm, milling cutter of small way of K30 hard alloy falls in identical cutting parameter (2Al2 of duralumin of treatment of milling of 5) seeing a table. Mix by SEM can chart analysis sees, when be not 2Al2 of duralumin of milling of milling cutter of small way of coating hard alloy, mix besides damaged of point of a knife diffuse wear away besides, a main different point is stuck namely receive a phenomenon serious. Additional, because lost the protection of Al2O3 oxidation film, damaged of point of a knife relatively TiAlN coating milling cutter is more serious. From can chart analysis looks, w is occupied 91.

2% , co is 8.

57% , al is 0.

16% , the existence of Al element proved to diffuse tatty exists. Show advocate deputy hind knife face has diffuse apparently wear away phenomenon. The experiment of force of 4 imperceptible milling studies cutting process is medium, the change of cutting force machines the effect with the direct or indirect existence such as degenerative layer to be being mixed by surface roughness of the dimension of treatment workpiece and appearance precision, surface. Additional, diameter of the milling cutter in imperceptible milling the wave motion of force of low, cutting causes small, strength very easily the damaged of small way milling cutter breaks off even. Because current imperceptible milling mechanism considers to still be in primary level, the parameter of methodological research cutting that passes a test changes to milling force regular influence makes one of main research technique. 4.

The influence cutting force to imperceptible milling force follows S of rotate speed of 1 main shaft the metabolic curve of S, can see: When 2Al2 of groovy mill duralumin, as the current that after cutting strength pool efforts and each component of force appear to increase first, the addition of main shaft rotate speed reduces. In 2 archives 121, when 800r/min, cutting force reachs maximum. Through frequency domain the analysis can see 2 archives rotate speed falls, not only cutting muscularity, and the interference signal of generation also increases apparently, and fall in high main shaft rotate speed, cutting force and interference signal are reduced somewhat, answer to choose bigger main shaft rotate speed as far as possible when imperceptible milling so. The abscissa is on behalf of the value: 1 files shows 109, 500r/min, 2 archives are 121, 800r/min, 3 archives 135, 000r/min, 4 archives are 146, 100r/min, 5 archives are 159, 500r/min. 4.

Penetration of a cutting tool of different to the influence of imperceptible milling force back measures Ap of quantity of 2 backs penetration of a cutting tool the metabolic curve of next imperceptible milling force. Each cutting component of force and join forces appear as the addition of Ap go out to increase first next small are reduced, the current that increases quickly again finally. Analysis of cutting force frequency domain reachs signal of force of the cutting when increasing 30µm by 10µm when Ap and interference signal increase;50 ～ 60µm somewhat paragraph with 30µm paragraph photograph comparing change is not apparent; disturbs signal to begin to increase when Ap>70µm. From raise treatment efficiency and the angle that assure to machine quality to set out, ap should be elected it is under 50µm, but the dot of cutting force peak value when escape 30µm. 4.

Fz is opposite feed of 3 every tine the affects cutting force to follow Fz change curve of imperceptible milling force. Can see each component of force and join forces present addition trend, the radial load in 3 component of force Fx is the biggest and in Fz<0.

Increase when 3µm rapid, tend later gently. Through spectrum the analysis reachs, as the addition of Fz, 6 what exist from beginning to end in the experiment, the interference signal of 100Hz is in Fz>0.

Begin to decrease when 5µm, but accompany what disturb signal as other frequency to increase at the same time. Imperceptible milling regards 5 conclusion as imperceptible processing technique medium newly emerging force is getting of people take seriously. The equipment of imperceptible milling treatment that manufactures in article and wear away to cutting tool the thorough research that mechanism and the analysis that influencing factor has milling power are imperceptible milling mechanism laid a foundation. Built nicety of a miniature milling machine of vertical of 3 axes linkage, total size is 290mm of × of 300mm × 300mm, developed Chinese to control software, used this miniature milling machine to realize the batch treatment in small chamfer of the milling on film of miniature flexibility alloy successfully, small chamfer is in rate of purify of the material on velar thick direction 90.

7% , treatment n prep above 80% . Use finite yuan of method is mechanical to small way milling cutter character undertakes an analysis, got small way milling cutter before 4 rank natural frequency and vibration shape; measure Kistler the data of force of actual measurement cutting that power instrument measures is on face of knife of around of part of point of a knife after having the to load on the face, observation stress and be out of shape cloud atlas discovers the biggest be out of shape happen around point of a knife inside 10µm limits, advocate hind and deputy hind knife face presents an approximate triangle, confirmed the rationality of the to load on face of divisional on around knife face region. Wear away to basically happen after with groovy dimension milling cutter differ on knife face, small way of TiAlN hard alloy establishs milling cutter wear away to the form falls off besides coating and diffuse outside wearing away, a marked characteristic is damaged of point of a knife serious. Because amount of penetration of a cutting tool of imperceptible milling back is small,this is, be in with point radius same amount step is smaller even, intensity of place of point of a knife is weaker those who cause. Small way of blame coating hard alloy establishs milling cutter and photograph of TiAlN coating milling cutter to compare besides damaged of point of a knife more serious besides, stick receive a phenomenon apparent. 2Al2 of groovy mill duralumin discovers, fx takes the radial load in 3 component of force of imperceptible milling force from beginning to end main position; as main shaft rotate speed rise, cutting force presents the current that after going out to increase first, reduces, in 120, fz is opposite Ap of quantity of penetration of a cutting tool of back of; of occurrence peak value of 000r/min left and right sides and every tine feed cutting power influence is remarkable, as the addition of Ap, cutting force is had after increasing first when small reduce the phenomenal; that increases again next to increase when Fz, 6 what exist from beginning to end, the interference signal of 100Hz is in Fz>0.

Begin to reduce when 5µm, but increase what accompanying other frequency to disturb signal at the same time apparently. So, below the premise that assures to machine quality, machine efficiency to rise, imperceptible milling ought to choose high main shaft rotate speed as far as possible when duralumin 2Al2, ap chooses to be under 50µm but should keep away from the peak value area of 30µm, fz choosing is in 0.

3µm left and right sides is more appropriate. CNC Milling