Non-Traditional Machining Processes
Types of electrical machining processes
Electrochemical deburring, electrochemical grinding, electrochemical milling frontal, electrochemical milling side wall, electrochemical polishing, shaped tube electrolytic machining.
Types of thermal machining processes
Electron-beam machining, electrical-discharge grinding, electrical-discharge machining finishing, electrical-discharge machining roughing, laser-beam machining, and plasma-beam machining.
Examples of hybrid machining systems
Abrasive machining and electrochemical machining, waterjet cutting and wire EDM, electrochemical machining and electrical discharge machining, laser cutting and punching of sheet metal.
Types of mechanical machine processes
Abrasive-flow machining, low-stress grinding, ultrasonic machining.
Nontraditional machining processes
Are non-mechanical means of material removal.
Removal of Material (not chips)
Chemical machining (CM), electrochemical machining (ECM), electrochemical grinding (ECG), electrical-discharge machining (EDM), wire electrical-discharge machining, laser beam machining (LBM), water-jet machining (WJM), abrasive water-jet machining, abrasive-jet machining (AJM).
Types of advanced machining process as
Chemical machining, Electrochemical machining, electrochemical grinding, electrical-discharge machining, and wire electrical-discharge machining.
Types of Advanced machining
Chemical machining, electrical-discharge machining, electron-beam machining, laser machining, electrochemical machining.
Types of chemical machining processes
Chemical machining, photochemical machining, and electropolishing.
Types of chemical machining
Chemical milling, wet etching, chemical blanking, photochemical blanking.
Electrochemical grinding
Combines electrochemical machining and conventional grinding. The abrasive material on the wheel has a couple of functions. Less than 5% is removed by the abrasives. Suitable for applications similar to those for milling, grinding, and sawing.
Characteristics of electrochemical machining, ECM
Complex shapes with deep cavities, highest rate of material removal among other nontraditional processes, expensive tooling and equipment, high power consumption, medium to high production quantity.
Characteristics of Wire electrical-discharge machining
Contour cutting of flat or curved surfaces, expensive equipment.
Advantages of waterjet machining
Cuts can be started at any location without the need for pre-drilled holes. No heat is produced. No deflection of the rest of the workpiece takes place. Little wetting of the workpiece takes place. The burr produced is minimal. It is an environmentally safe manufacturing operation.
Characteristics of water-jet machining, WJM
Cutting all types of nonmetallic materials, suitable for contour cutting of flexible materials, no thermal damage, noisy.
Characteristics of laser-beam machining, LBM
Cutting and hole making on thin materials, heat- zone, does not require a vacuum, expensive equipment, consumes much energy.
Characteristic of electron-beam machining, EBM
Cutting and hole making on thin materials, very small holes and slots, heat-affected zone, requires a vacuum, expensive equipment.
Characteristics of electrochemical grinding, ECG
Cutting off and sharpening hard materials, such as tungsten-carbide tools, also used as a honing process, higher removal rate than grinding.
Characteristics of abrasive-jet machining, AJM
Cutting, slotting, deburring, etching, and cleaning of metallic and nonmetallic materials; tends to round off sharp edges; can be hazardous
Types of rough cutting
Flame cutting, snagging such as course grinding, and sawing.
Laser microjet
Has a focusing lines, a laser, window, a water chamber, and a nozzle. The laser is guided by water stream.
Electron-beam machining
Has a high-voltage cable, cathode grid, anode, optical viewing system, electron stream, magnetic lens, deflection coils, a viewing port to the vacuum chamber and work piece that is on the worktable, there is a high vacuum pump.
Types of finishing processes
Honing, barrel finishing, electrochemical grinding, grinding, electropolishing, polishing, lapping, superfinishing.
Types of forming
Hot rolling, forging, extruding, cold rolling, cold drawing, roller burnishing.
Abrasive-jet machining
In this type of machining, abrasive particle is propelled at the workpiece surface by a high-velocity jet of dry air, nitrogen, or carbon dioxide. The result is a concentrated force that removes the material.
Electrical-discharge machining
Is based on the erosion of metals by spark discharges. The Dielectric fluid has three functions. The electrodes are usually made up of graphite and are subject to wear.
Chemical machining
Is based on the fact that chemicals can attack and etch most material, removing a small amounts. Carried out by chemical dissolution using reagents or etchants, such as acid and alkaline solutions.
Electrochemical machining
Need to have an electrolyte, anode (+ve) and a cathode (-ve). Depends on the high flow rate of the electrolyte in the tool workpiece gap.
Summary of lecture 21
Nontraditional machining process utilizes chemical, electrochemical, electrical, and high-energy-beams sources of energy. The mechanical properties of the workpiece material is not significant for these types of processes,. Chemical and electoral methods are suitable particularly for hard materials and complex shapes. High-energy-beat machining processes basically utilize laser beams, electron beams, and plasma beams. WJM, AWJM., and AJM processes can be used for cutting as well as deburring operations. Hybrid machining processes offer possibilities for more efficient production of complex parts.
Photochemical blanking
Photographic techniques are used to produce a mask. Chemical machining then follows to produce the blanks.
Types of machining
Planing, shaping, milling, broaching, reaming, turning, boring, drilling.
Types of casting
Sand casting, permanent mold casting, investment casting, die casting.
Masking
Selective attack by the chemical reagant on different areas of the workpiece surface is accomplished by removable layers of the material.
Chemical milling
Shallow cavities are produced on plates, sheets, forgings, and extrusions, generally for the overall reduction of weight.
Characteristics of chemical machining, CM
Shallow removal on large flat or curved surfaces, blanking of thin sheets, low tooling and equipment cost, suitable for low-production runs.
Types of shaped electrolytic Machining operation
Shaped-tube electrolytic machining and electrolytic trepanning.
Characteristics of electrical-discharge machining, EDM
Shaping and cutting complex parts made of hard materials, some surface damage may result, also used as a grinding and cutting process, expensive tooling and equipment.
Characteristics of abrasive water-jet machining, AWJM
Single layer or multilayer cutting of metallic and nonmetallic materials.
Laserbeam machining
The energy source here is a laser, which focuses optical energy on the surface of the workpiece. The highly focused, high density energy source melts and evaporates portions of the workpiece.
Advanced machining processes
The major type of non-traditional machining processes.
Abrasive wet-jet machining
The water-jet contains abrasive particles, which greatly increase the material removal rate.
Important considerations of hybrid machining systems
The workpiece material and its manufacturing characteristics, compatibility of processing parameters across a different processes, cycle times of each individual operation and their synchronization, safety and other considerations.
Waterjet machining
This machining has a fluid supply, a mixer and filter, a pump, an intensifier, an accumulator, a hydraulic unit, controls, a valve, and a sapphire nozzle that the waterjet comes out of towards the workpiece. Under the workpiece is a drain,
Characteristic of laser microjet
Water-jet guided laser uses a 25 to 100 mm diameter stream to mill or cut, large depth of field, little thermal damage from laser machining.
Types of conventional machining processes
Turning and surface grinding.
Wet Etching
When chemical milling is used to fabricate micro electric devices.
Use of nontraditional machining processes
When mechanical methods are not satisfactory, economical, nor even possible due to high strength of work piece material, high hardness of work piece material, workpiece material is too brittle, work piece is too flexible or slender, the part has a complex shape, special surface finish and dimensional tolerance, non-acceptable temperature rise and residual stresses.
Types of electrical-discharge machining
Wire electrical-discharge machining.
Chemical Blanking
used for parts that are otherwise typically produced by mechanical blanking presses from thin plates and foil material. With mechanical presses, vibrations, backlash, and part distortion will make smaller parts difficult to produce
