Abrasive Waterjet Machining

3y ago
67 Views
5 Downloads
1.10 MB
29 Pages
Last View : 6d ago
Last Download : 4m ago
Upload by : Adalynn Cowell
Transcription

Water Jet Machining &Abrasive Water Jet MachiningPeiman Mosaddegh, Ph.D.Isfahan University of TechnologyFall 2020Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

تعریف ماشینکاری با جت آب : در این روش ، آب به عنوان ابزار برش از مسیر پیوسته و کنترل شده ای از نازل با مجرای باریک و با فشار 4000 – 2000 بار خارج میشود و به قطعه کار برخورد میکند . ابزار برش ، آب خالص یا آب به همراه مواد ساینده است . فرآیند برش با آب خالص معموال برای مواد با استحکام کم مانند کاغذ ، فایبر گالس و مقوا و فرآیند برش با آب به همراه مواد ساینده ، برای مواد مستحکم مانند فلزات و آلیاژها مورد استفاده قرار میگیرد . هنگامی که نیروی موضعی ضربه سیال از مقاومت پیوندهای زیر ساختار ماده بیشتر باشد ، موجب جدایی توده ای از اتم ها یا مولکول ها از ماده گردیده و ساییدگی یا برش اتفاق می افتد . Peiman Mosaddegh – Non-traditional Machining Department of Mechanical Engineering 2

Water Jet Machining (Cutting) Uses a fine, high pressure, high velocity streamof water directed at work surface for cutting When cuttingmetals, includesabrasive particles instreamWater pressure from2000 to 4000 barWater velocity isaround 900 m/sFeed rate: 10 to6000 mm/min 3Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Intensifier توان ورودی توان خروجی P2 * Q2 P1 * Q1 P2 (Q1/Q2) *P1 P2 ((V1*A1)/(V2*A2)) *P1 V1 V2 P2 (A1/A2) *P1 با توجه به رابطه اخیر اگر فشار روغن 20 مگاپاسکال باشد ، جهت ایجاد فشار 400 مگاپاسکال برای آب ، باید سطح پیستون روغن 20 برابر سطح پیستون آب باشد Peiman Mosaddegh – Non-traditional Machining Department of Mechanical Engineering 4

HistoryDr. Norman Franz in 1950’s first studied UHP watercutting for forestry and wood cutting (pure WJ) 1979 Dr. Mohamed Hashish added abrasive particles toincrease cutting force and ability to cut hard materialsincluding steel, glass and concrete (abrasive WJ)www.flowwaterjet.com First commercial use was in automotive industry to cutglass in 1983 Soon after, adopted by aerospace industry for cuttinghigh-strength materials like Inconel, stainless steel andtitanium as well as composites like carbon fiber 5Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Pure WJM 6Fastest growing machining processOne of the most versatile machining processesCompliments other technologies such as milling,laser, EDM, and plasmaTrue cold cutting process – no HAZ (heataffected zone), mechanical stresses or operatorand environmental hazardsNot limited to machining – food industryapplicationsPeiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Pure WJM 7Pure WJ cuts soft materials , disposable diapers, tissuepapers, automotive interiorsVery thin stream (0.004-0.010” in dia.)Extremely detailed geometryVery little material loss due to cuttingCan cut thick, soft, light materials like fiberglassinsulation up to 24” thick or thin, fragile materialsVery low cutting forces and simple fixturingWater jet erodes work at kerf line into small particlesPeiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Pure WJ Cutting cont.Forced through hole injewel (preciousstone)0.07-0.5 mm in diaSapphires, Rubies with50-100 hour lifeDiamond with 800-2,000hour life, but they arepricey 8Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

WJC Nozzle9Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

WJCWJC advantages: no crushing orburning of work surface, minimummaterial loss, no environmentalpollution, and ease of automation,no heat affected zoneWJC disadvantages: Not suitablefor brittle materials (e.g., glass),high capital investment, safety,not suitable for metals and hardmaterial 10Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

WJC ApplicationsUsually automated by CNC or industrial robots to manipulate nozzle alongdesired trajectoryPrinted wiring board11Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Abrasive Jet Machining (AJM)12 High velocity stream of gas containingsmall abrasive particles (aka Sandblasting)Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

AJM Applications13Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Abrasive WJ Machining (AWJM). که از یک جت اب به همراه مواد ساینده تشکیل شده است AJM و WJM این فرایند ترکیبی از اصول از ترکیب یک جت آب با سرعت زیاد همراه ذرات ساینده برای AWJM به عبارت دیگر در فرآیند . ایجاد یک جت دوغابی شکل و برنده استفاده میشود 14Used to cut much harder materialsWater is not used directly to cut material as in Pure,instead water is used to accelerate abrasive particleswhich do the cutting80-mesh garnet (sandpaper) is typically used though 50and 120-mesh is also usedStandoff distance between mixing tube and workpart istypically 0.010-0.200” – important to keep to a minimumto keep a good surface finishPeiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Abrasive WJ Machining cont. 15Evolution of mixing tubetechnologyStandard Tungsten Carbide lasts4-6 hours (not used muchanymore)Premium Composite Carbidelasts 100-150 hoursConsumables include water,abrasive, orifice and mixing tubePeiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Tolerances 16Typically /- 0.005 inchMachines usually have repeatability of0.001 inchWJ tolerance range is good for manyapplications where critical tolerances arenot crucial to workpart designPeiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Setup17Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

When is AWJM Practical?It’s practical to use it to cut any kindof material. In abrasive waterjetcutting, there is no heat generated.This is especially useful for cuttingtool steel and other metals whereexcessive heat may change theproperties of the material. Waterjetcutting does not leave a burr or arough edge, and eliminates othermachining operations such as finishsanding and grinding. It can be easilyautomated for production use.18Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Advantages Cheaper than other processes. Cut virtually any material. (pre hardenedsteel, mild steel, copper, brass, aluminum;brittle materials like glass, ceramic, quartz,stone) Cut thin stuff, or thick stuff. Make all sorts of shapes with only one tool. No heat generated. Leaves a smooth finish, thus reducingsecondary operations. Clean cutting process without gasses or oils. Modern systems are now very easy to learn.19This part is shaped with abrasivewaterjet using one tool. Slots,radii, holes, and profile in one 2minute setup.Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Advantages (continued)20 Unlike machining or grinding, waterjet cuttingdoes not produce any dust or particles that areharmful if inhaled. The kerf width in waterjet cutting is very small,and very little material is wasted. Waterjet cutting can be easily used to produceprototype parts very efficiently. An operator canprogram the dimensions of the part into thecontrol station, and the waterjet will cut the partout exactly as programmed. This is much fasterand cheaper than drawing detailed prints of apart and then having a machinist cut the partGet nice edge quality from differentout.materials. Waterjets are much lighter than equivalent lasercutters, and when mounted on an automatedrobot. This reduces the problems of acceleratingand decelerating the robot head, as well as takingless energy.Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Disadvantages One of the main disadvantages of waterjet cutting is that a limited number of materialscan be cut economically. While it is possible to cut tool steels, and other hard materials,the cutting rate has to be greatly reduced, and the time to cut a part can be very long.Because of this, waterjet cutting can be very costly and outweigh the advantages. Another disadvantage is that very thick parts can not be cut with waterjet cutting andstill hold dimensional accuracy. If the part is too thick, the jet may dissipate some, andcause it to cut on a diagonal, or to have a wider cut at the bottom of the part than the top.It can also cause a rough wave pattern on the cut surface.21Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Disadvantages (continued) Taper is also a problem with waterjet cutting in very thick materials. Taper is when thejet exits the part at a different angle than it enters the part, and can cause dimensionalinaccuracy. Decreasing the speed of the head may reduce this, although it can still be aproblem. Stream lag caused inside corner damage to this 1-in.-thick stainless steel part. The exitpoint of the stream lags behind the entrance point, causing irregularities on the insidecorners of the part. The thicker the material is or the faster an operator tries to cut it, thegreater the stream lag and the more pronounced the damage. جت اب از باال تا پایین ضخامت ، در قطعات ضخیم قطعه منحرف میشود و در پایین قطعه عقب تر از به همین خاطر وقتی جت به کنج قطعه . بالی ان است میرسد به خاطر تفاوت در باال و پایین قطعه در کف قطعه این مشکل بوجود می اید و کنج های قطعه . خراب میشود Waterjet lag22Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Waterjets vs. Lasers Abrasive waterjets can machine manymaterials that lasers cannot. (Reflectivematerials in particular, such as Aluminum andCopper. Uniformity of material is not very importantto a waterjet. Waterjets do not heat your part. Thus thereis no thermal distortion or hardening of thematerial. Precision abrasive jet machines can obtainabout the same or higher tolerances thanlasers (especially as thickness increases). Waterjets are safer. Maintenance on the abrasive jet nozzle issimpler than that of a laser, though probablyjust as frequent.After laser cuttingAfter waterjet cutting23Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Waterjets vs. EDM Waterjets are much faster than EDM. Waterjets machine a wider variety ofmaterials (virtually any material). Uniformity of material is not veryimportant to a waterjet. Waterjets make their own pierce holes. Waterjets are capable of ignoringmaterial aberrations that would causewire EDM to lose flushing. Waterjets do not heat the surface of whatthey machine. Waterjets require less setup. Waterjets can be considered to be likesuper-fast EDM machines with lessprecision.24Waterjets are much faster than EDM.Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Waterjets vs. Other ProcessesFlame Cutting:Waterjets would make a great compliment to a flame cutting where moreprecision or higher quality is required, or for parts where heating is not good, orwhere there is a need to cut a wider range of materials.Milling:Waterjets are used a lot for complimenting or replacing millingoperations. They are used for roughing out parts prior to milling, for replacingmilling entirely, or for providing secondary machining on parts that just cameoff the mill. For this reason, many traditional machine shops are addingwaterjet capability to provide a competitive edge.Punch Press:Some stamping houses are using waterjets for fast turn-around, or for lowquantity or prototyping work. Waterjets make a great complimentary tool forpunch presses and the like because they offer a wider range of capability forsimilar parts.26Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Conclusion 27Relatively new technology has caught on quickly and isreplacing century-old methods for manufacturingUsed not only in typical machining applications, but foodand soft-goods industriesAs material and pump technology advances fastercutting rates, longer component life and tightertolerances will be achievablePaves the way for new machining processes thatembrace simplicity and have a small environmentalimpactPeiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Advanced spx#videos28Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

References cs.co.ukPeiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

با تشکر از توجه شما 30Peiman Mosaddegh – Non-traditional MachiningDepartment of Mechanical Engineering

Water Jet Machining & Abrasive Water Jet Machining Peiman Mosaddegh, Ph.D. Isfahan University of Technology Fall 2020. Peiman Mosaddegh –Non-traditional Machining Department of Mechanical Engineering راشفاب کیراب یارجم اب لزان زا یا هدش لرتنک هتسیپ ریسم زا شرب رازبا نانع هب بآ ،شر نیا رد دام هارمه هب بآ ای .

Related Documents:

KMT Waterjet pumps can be networked (a KMT Waterjet exclusive) to allow high cutting speeds for multiples of cutting heads. Abrasive Waterjet Cutting Speeds Approximate inches per Minute At 60,000 PSI (4,137 Bar) . the same or different parts, at extremely low operating costs.File Size: 567KBPage Count: 12

In Abrasive Jet Machining (AJM), abrasive particles are made to impinge on the work material at a high velocity. The jet of abrasive particles is carried by carrier gas or air. High velocity stream of abrasive is generated by converting the pressure energy of the carrier gas or air to its kinetic energy and hence high velocity jet. Nozzle directs the abrasive jet in a controlled manner onto .

Abrasive water jet can do this with quality results but, generally is too expensive compared to plasma, laser or punching. 5. Cut Geometry Abrasive waterjet cuts have straight edges with a slight amount of taper. Kerf width is controlled by the orifice/nozzle combination. Cuts in thicker materials generally require larger combinations with more abrasive usage. The kerf width can be as small as .

Chapter 296-818 WAC Abrasive Blasting _ Page 1 WAC 296-818-099 Definitions. Abrasive. A solid granular substance used in abrasive blasting operations. Abrasive blasting. The forcible application of an abrasive to a surface using either: (a) Pneumatic or hydraulic pressure; or (b) Centrifugal force. Abrasive-blasting respirator. A supplied air or a continuous flow respirator constructed with a

KMT Waterjet Systems Inc. 635 W. 12th Street r P.O. Box 231 r Baxter Springs, KS 66713 800-826-9274 r Tel.: 1-620-856-2151 r Fax: 1-620-856-5050 kmtwaterjet.com r sales#kmtwaterjet.com r kmtgenXineparts.com KMT Waterjet System Integrators More Options, Better Choices! KMT Waterjet Systems has

Abrasive jet Machining consists of 1. Gas propulsion system 2. Abrasive feeder 3. Machining Chamber 4. AJM Nozzle 5. Abrasives Gas Propulsion System Supplies clean and dry air. Air, Nitrogen and carbon dioxide to propel the abrasive particles. Gas may be supplied either from a compressor or a cylinder. In case of a compressor, air filter cum drier should be used to avoid water or oil .

Abrasive water jet machining Ultrasonic machining. Difference between grinding and milling The abrasive grains in the wheel are much smaller and more numerous than the teeth on a milling cutter. Cutting speeds in grinding are much higher than in milling. The abrasive grits in a grinding wheel are randomly oriented . A grinding wheel is self-sharpening. Particles on becoming dull either .

sigurime, financë-kontabilitet, lidership dhe menaxhim burimesh njerëzore, administrim publik, lidership, e drejta publike, e drejta e biznesit, komunikim publik dhe gazetari ekonomike). Me VKM nr. 564 datë 28.05.2009 “Për hapjen e programeve të reja të studimit “Master i Nivelit të