Los ntawm kev sim tshuaj xyuas cov cuab yeej xaiv,ua haujlwm
parameters and tool angles, the best solution for mirror surface ua haujlwm of copper alloy shaped grooves is finally arrived at, providing a theoretical basis and research foundation for improving the surface ua haujlwm quality of copper alloy parts.
With the improvement of the use performance of scientific and technological products and the growth of the use cycle, manufacturing enterprises have put forward higher requirements for the dimensional accuracy, geometric tolerance and surface roughness of product parts. In ultra-precision ua haujlwm, in order to ensure the roughness of the parts, most of them use grinding processing technology. However, copper alloy is a non-ferrous metal, and the material characteristics of non-ferrous metal determine that grinding processing is not suitable, and turning processing by lathe is appropriate. By analyzing the causes of the formation of surface roughness and combining with the actual processing experience, a set of turning methods to improve the surface roughness of the parts is summarized.
2Tshooj qauv tshuaj xyuas
A model of copper alloy material parts structure as shown in Figure 1, according to the design requirements, V-shaped groove and the inner circle coaxiality requirements φ0.01mm, surface roughness value Ra = 0.2μm. material for brass H62, the material has good mechanical properties, good plasticity, good turning performance, but there are sticky tool. The current existing ua haujlwm capacity of the factory makes the surface roughness value Ra of the part reach 0.8μm, which cannot meet the design requirements. Therefore, the processing technology of V-groove needs to be studied in depth to explore a suitable processing method to meet the production requirements.
Daim duab 1 Cov tooj liab hlau ib feem
3Kev daws teeb meem
3.1 Mirror ua haujlwm technology turning and forming
(1) Tool The tool material currently used in the factory is mainly cemented carbide. Cemented carbide is made of tungsten-cobalt class (WC), tungsten-cobalt-titanium (WC-TiC), tungsten-titanium-tantalum (niobium) cobalt (WC-TiC-TaC) and other refractory metal carbides, which are pressed and sintered by powder metallurgical methods with metal binder Co (cobalt) or Ni (nickel). Cemented carbide has high hardness, wear resistance, better strength and toughness, heat resistance, corrosion resistance and a series of excellent properties, can be used for processing non-ferrous metals. It can be used for rough ua haujlwm when processing copper alloy V-groove.
In the field of non-ferrous metal mirror processing, diamond tools are one of the more commonly used. Diamond tools have the advantages of extremely high hardness and wear resistance, low friction coefficient, high elastic modulus, high thermal conductivity and low thermal expansion coefficient, as well as low affinity with non-ferrous metals, and not easy to produce chip tumors. In addition, due to the diamond elastic modulus, cutting cutting edge sharp, edge deformation is small, the non-ferrous metal extrusion deformation of the cutting is small, can make the cutting process in a small deformation to complete, so you can improve the quality of surface processing. Diamond tools mainly have: thin film coated tools, thick film diamond welding tools, diamond sintered tools and single crystal diamond tools. The copper alloy V-groove with an angle of 60° needs to be studied for the selection of tool angle in order to avoid interference during ua haujlwm. Considering the ua haujlwm cost as well as the test convenience, the machine clamp tool is used. As shown in Figure 2 and Figure 3, 35° and 45° inserts were used, and two types of fixtures were tested.
Daim duab. 2 35 ° ntxig daim duab. 3 45 ° ntxig rau
(2) Machining parameters Machining parameters directly affect the surface roughness. In mirror ua haujlwm, the spindle speed will become the main factor affecting the surface roughness when the tool feed is reduced below a certain value. When the spindle speed is kept constant, the surface roughness increases rapidly when the turning depth is less than a certain value, while when it is greater than this value, the surface roughness shows an approximately linear increasing trend. The most appropriate depth of cut needs to be found for a particular material. Therefore, different process parameters need to be selected for experimental verification.
3.2 Machining ntawm V-grooves siv daim ntaub log polishing tshuab
Tam sim no lub Hoobkas ua cov txheej txheem ua lub ntsej muag V-puab zawj, qhov ntxhib saum npoo tuaj yeem ncav cuag Ra = 0.8Î¼m. txhawm rau ua kom qhov ntxhib qhov ntxhib tus nqi ntawm Ra = 0.2Î¼m, nws tuaj yeem txhuam, nrog daim ntaub log, ntshav txhuam cov tooj dag.
Ntaub log polishing, yog ua los ntawm daim ntaub rau hauv lub log hom siv los txhuam. Lub zog ntawm lub log polishing yog txiav txim siab los ntawm qhov deb ntawm txoj kab suture, qhov me me nyob deb li cas ntawm txoj kab suture, siab dua qhov nyuaj ntawm lub log polishing. Polishing log tuaj yeem faib ua cov ntaub tsis-xaws tag nrho log, cua txias cua daim ntaub log thiab stitched yam. Cov ntaub tsis-xaws tag nrho cov log feem ntau yog ua los ntawm cov ntaub zoo paj rwb, tsim nyog rau polishing txoj haujlwm zoo, lossis rau cov haujlwm me me ua kom zoo. Cov cua txias hauv daim ntaub log nrog 45º kaum txoj kab txiav txoj hauv kev, yog lub ntsej muag zoo li lub ntsej muag, nruab nrab yog nruab nrog cov hlau hlau, nrog cov yam ntxwv ntawm qhov cua nkag thiab cua sov tso tawm, haum rau polishing cov haujlwm loj. Stitching yam feem ntau yog ua los ntawm cov ntaub ntxhib ntxhib ntxhib ntxhib ntxhib, thiab cov ntaub zoo, thiab lwm yam, cov kab sib dhos tuaj yeem ua lub ntsej muag sib luag, hom kauv thiab daim ntawv tawg ncaj, tsim rau polishing ntau plating thiab cov duab ntawm cov haujlwm yooj yim. Polishing tooj liab alloy, feem ntau siv daim ntaub log ncig qhov nrawm ntawm 22 ~ 30m / s, rau txoj kev tshawb fawb no ntawm lub nplhaib coj ua V-puab qhov zawj, qhov tshwj xeeb ua tsis tau yuav tsum tau sim.
3.3 Electrolyte plasma polishing
(1) electrolyte plasma polishing tshawb fawb Plasma polishing yog cov haujlwm ua haujlwm thiab cov kua dej ua kom huv hauv cov hlau sib cais sib cais ions adsorbed rau ntawm qhov chaw ua haujlwm, cov khoom ua haujlwm tsoo los ntawm kev cuam tshuam ntawm tam sim no kom tshem tawm qhov thaiv, cov dej ntws tam sim no, ntu thiab sib npaug tas li hloov pauv, qhov saum npoo ntawm ntu yog maj mam nce qib. Cov thev naus laus zis tuaj yeem txhim kho qhov zoo ntawm qhov chaw.
(2) Qhov cuam tshuam rau Plasma polishing, yam uas cuam tshuam rau qhov zoo ntawm cov nplaim polishing yog: daws qhov kub, ua lub sijhawm, daws cov ntsiab lus, dhia tob, daws cov dej ntws, thiab lwm yam. raws li yam cuam tshuam cuam tshuam. Lub nplhaib V-groove qhov loj ntawm qhov kev tawm tsam no yog me me, yuav tsum tau teeb tsa kho, thiab txhawm rau kom ntseeg tau tias qhov sib xws ntawm tag nrho ib feem polishing, kuj yuav tsum tau hloov kho ntxiv raws li cov cuab yeej, tig cov khoom, yog li tag nrho cov lus qhia ntawm lub nplhaib tau txhuam hauv qhov chaw.
4 Txiav txim siab cov txheej txheem ua
Qhov kev zov me nyuam saum toj no feem ntau yog kawm cov cuab yeej, nws cov txheej txheem ua haujlwm tuaj yeem raug xaiv los ntawm lub tshuab cuab yeej, cov txheej txheem yooj yim dua. Txoj haujlwm ob ntawm daim ntaub ua lub log, tuaj yeem xa mus rau kev paub tsawg dua, thiab ntu V-puab qhov zawj me me, tsis yooj yim rau clamp ua. Cov txheej txheem peb ntawm cov tshuab polishing ntshav yog thev naus laus zis ntau dua, lub tuam txhab cov cuab yeej siv tau tag nrho, tab sis cov txheej txheem los xyuas kom zoo ib yam ntawm tag nrho cov nplhaib polishing, muaj teeb meem nyuaj teeb tsa ntau lawm. Thiab qhov xav tau rau cov lej ntau ntawm kev ntsuas ntawm qhov ntsuas ntawm polishing. Kev txheeb xyuas dav dav xaus qhov kev xaiv ib qho tau txais.
The main purpose of this study is to make the surface roughness value Ra of copper alloy V-groove reach 0.2μm mirror effect. In the field of mirror surface processing of non-ferrous metals, diamond tools have better characteristics. During the implementation of the project, the more advanced mirror surface turning technology in the industry was investigated, researched and analyzed together with tool manufacturers, and customized suitable tools for processing tests. The ua haujlwm test was carried out mainly in terms of tool feed, spindle speed, depth of cut and programmed ua haujlwm method. Combined with the part material brass H62 and the mirror ua haujlwm theory, the optimal parameters were found to achieve the mirror ua haujlwm effect with the surface roughness value Ra=0.2μm of the part, and the batch production was verified according to the explored parameters.
4.1 Mirror ua haujlwm tool research
According to the ua haujlwm scheme, the mirror ua haujlwm tool is investigated. The surface roughness of the part ua haujlwm is influenced by the ua haujlwm parameters, the main and sub-deflection angles of the turning tool, and the material and structure of the tool is also an important influencing factor.
The cutting edge of PCD (polycrystalline diamond) material consists of many microscopic crystals, and the tool with ultra-microscopic particles helps to reduce the surface roughness value of the part during the ua haujlwm process.
The V-groove angle of this attacked part is 60º. In order to avoid ua haujlwm interference and to meet the test of multiple ua haujlwm methods, MVVNN symmetric toolholder was selected, and machine clamping tool was used considering the ua haujlwm cost as well as the test convenience.
After research and analysis, Kyocera's ultra-fine grain PCD diamond inserts were selected for the ua haujlwm test. The insert model is VBMT110301NE KPD001 with a tip angle of 35º and tip R=0.1mm, as shown in Figure 4.
a) Sab xub ntiag ntawm Kyocera ntxig b) Sab sab ntawm Kyocera ntxig
Daim duab 4 Kyocera hniav
Superfine PCD diamond ensures tip strength, wear resistance, chipping resistance (toughness), and sharpness for stable, long-life ua haujlwm.
4.2 Machining Tests
According to the relevant ua haujlwm parameters affecting the surface roughness, group tests are conducted, mainly from the programmed ua haujlwm method, spindle speed, feed and depth of cut.
(1) Common ua haujlwm methods for factory ua haujlwm of V-groove type parts The common programming and ua haujlwm methods for ua haujlwm V-grooves in the workshop are the walking track type and the direct ua haujlwm by forming tool. Forming knife direct ua haujlwm has the characteristics of high processing efficiency, but the surface roughness of the machined parts is poor, and easy to damage the tool. Walking track ua haujlwm has the characteristics of consistent surface of parts, less axial force on parts, and can effectively ensure the coaxiality of parts. Therefore, this test programming processing method uses the walking track type.
(2) group test 1 first consider the protection of the diamond tool in the initial determination of ua haujlwm parameters test, first ua haujlwm cylindrical surface to feel the appropriate ua haujlwm parameters. Machining cylindrical surface, as shown in Figure 5, has reached the mirror effect. 2 according to the initial determination of ua haujlwm parameters for the test ua haujlwm of parts. In the test ua haujlwm process, in the thickness of the larger cylindrical processing V-shaped groove, when the part thickness size reduced to 0.8mm, there is a knife ua haujlwm trace problem, as shown in Figure 6. The preliminary analysis concluded that the vibration was caused by the thin wall thickness at the edge of the part. Therefore, the back draft and feed were gradually reduced and the speed was increased in the subsequent tests.3 After the improvements were made according to the problems that appeared above, the machined surface of the V-groove was greatly improved, but there were still spots, as shown in Figure 7.
Daim duab 5 Machining cylindrical nto
Fig. 6 Tool ua haujlwm marks
Daim duab 7 Qhov chaw me me
After analyzing the ua haujlwm path and parameters, and considering that the diamond tip is worn during rough ua haujlwm, the carbide tool is selected for rough ua haujlwm by re-calibrating the programming. Reserve 5mm ua haujlwm allowance, then use diamond tool for finishing, choose spindle speed 1200r/min, feed f=0.03mm/r, for ua haujlwm test. The surface of the V-groove of the part is smooth without spots, the tool marks are even, and the mirror effect is achieved (see Figure 8). The consistency of batch ua haujlwm is good, and the surface roughness value reaches Ra=0.0638μm by the surface roughness instrument, as shown in Figure 9, which meets the requirements.
Daim duab 8 Daim iav
Daim duab 9 Roughness daim ntawv qhia tshuaj xyuas
Los ntawm cov saum toj nomultiple part ua haujlwm tests
, the surface roughness of the part is greatly influenced by the tool and ua haujlwm parameters. In the verification, the V-groove structure is continuously optimized, and the combination of tool and ua haujlwm parameters is improved, and finally the surface of V-groove achieves the mirror effect. And the dimensional accuracy of the part is stable and the surface quality is consistent in batch ua haujlwm, which achieves the target of the attack. By using super fine PCD diamond tools and MVVNN symmetric shanks, the mirror surface ua haujlwm parameters were determined through experimental research, and the parameters and ua haujlwm ideas can be extended to other parts that need to achieve the mirror surface effect to effectively improve the quality of the parts.