this topic comes under manufacturing engineering or particularly machine tools.it gives brief information on non conventional machining which includes total six no of machines.
3. • Abrasive jet machining (AJM)
By Rushikesh Urunkar JJMCOE
4. Abrasive materials
Aluminum oxide
Silicon carbide
Dolomite (calcium magnesium carbonate)
Sodium bicarbonate
Glass beads
Size of abrasive
Around 25µm
Medium
Air or co2
Velocity -150 to 300m/sec
Pressure 2 to 8kg/cm²
Nozzle – WC with orifice .05-0.2mm³
Nozzle tip distance 0.25-15mm
By Rushikesh Urunkar JJMCOE
5. Work material
Hard and brittle materials like glass, ceramics, mica etc
Machining operations
Drilling, cutting, debarring, cleaning
By Rushikesh Urunkar JJMCOE
8. Advantages of AJM
Ability to cut intricate hole shapes in hard and brittle materials
Ability to cut fragile and heat sensitive materials without damage
because there is no heating of working surface
Low capital cost
Machining of semiconductors
Limitations of AJM
Slow material removal rate
Low accuracy (0.1mm) due to stray cutting (taper effect)
Embedding of the abrasive in the w/p surface may occur while
m/cing softer materials
Abrasive powder can not be refuse
unwanted waste material, especially material that
is regularly thrown away from a house, factory, etc.:By Rushikesh Urunkar JJMCOE
9. Taper is also a problem
Abrasive powder can not be reused
Machining accuracy is relatively poorer
It is not suitable for machining ductile materials
There is always a danger of abrasive particles getting
embedded in the work material, hence cleaning needs to
be necessarily done after the operation
By Rushikesh Urunkar JJMCOE
10. • Applications :
Cutting slots, thin sections, contouring, drilling, deburring
and for producing intricate shapes in hard and brittle
materials
It is often used for cleaning and polishing of plastics ,
nylon and teflon components
Frosting of the interior surface of the glass tubes
Etching of markings on glass cylinders etc
Machining of semiconductors
By Rushikesh Urunkar JJMCOE
13. Small Spark gap is about 0.01-0.50mm and spark
frequency 200-500 KHz
The electric current is varied within a wide range from .5
to 400amp at 40-300V dc
The dielectric fluid is pumped through the tool or w/p at a
pressure of 2kg/cm²
Material removal rate(max) 5000mm³/min
Specific power consumption 2-10W/mm³/min
By Rushikesh Urunkar JJMCOE
14. Tool material
Brass, copper, graphite, copper tungsten, tungsten carbide
Dielectric fluid
Hydrocarbon oils, kerosene liquid paraffin, silicon oils,
aqueous solution of ethylene glycol
Materials that can be machined
All conducting metals and alloys
By Rushikesh Urunkar JJMCOE
15. Advantages
The process can be applied to all electrically conducting
metals and alloys irrespective of their melting points,
hardness, toughness or brittleness
Time of machining is less than conventional machining
No mechanical stress is present in the process
Fragile and slender w/ps can be machined without
distortion
Hard and corrosion resistant surfaces, essentially needed
for die making, can be developed
By Rushikesh Urunkar JJMCOE
16. Limitations
Machining times are too long
Excessive tool wear
High specific power consumption
Machining heats the w/p considerably and hence causes
change in surface and metallurgical properties
Profile m/cing of complex contours is not possible at
required tolerances
By Rushikesh Urunkar JJMCOE
17. Applications
The EDM provides economic advantage for making
stamping tools, wire drawing and extrusion dies, header
dies, forging dies, intricate mould cavities etc
It has been extremely used for m/cing of exotic materials
used in aerospace industry, refractory metal, hard carbide
and hardenable steels
Typical EDM applications include
fine cutting with thread shaped electrode (wire cutting
EDM)
Drilling of micro-holes
Thread cutting
Helical profile milling
Curved hole drilling
By Rushikesh Urunkar JJMCOE
20. ECM is the controlled removal of metal by anodic
dissolution in an electrolytic medium in which the w/p is
the anode and a shaped tool or electrode is the cathode
Tool material
Cupper, brass or steel
Power supply
Constant voltage DC supply
Voltage 5-30V dc
Current 50-40000 Amp
By Rushikesh Urunkar JJMCOE
21. Electrolyte
Sodium chloride (common salt)
Sodium nitrate
Material removal rate
1600mm³/min
Specific power consumption
7 W/mm³/min (around 150 times more in comparison to
conventional methods )
By Rushikesh Urunkar JJMCOE
22. Advantages of ECM
The machined work surface is free of stresses
Burr- free surface
Reduced tool wear
No cutting forces are involved in the process
No thermal damage
Used for machining difficult to machine materials and
complex shaped parts
Any good electrically conducting material can be
machined
High surface finish of order of 0.1 to 2.0 microns
Very thin sections, such as sheet metals can be easily
m/ned without any damage or distortion
By Rushikesh Urunkar JJMCOE
23. Disadvantages of ECM
Non-conducting materials can not be machined
high specific power consumption
High initial and working cost
Large floor space is required
Designing and fabrication of tools is relatively more difficult
Extremely fine corner radii, say less than 0.2mm, can not be
produce
Specially designed fixtures are required to hold the w/p in
position, because it may be displaced due to the pressure of the
inflowing electrolyte
Corrosion and rusting of w/p, m/c tool, fixture etc by
electrolyte is a constant menance
By Rushikesh Urunkar JJMCOE
24. Applications
Machining of hard to machine and heat resistant materials
Machining of blind holes and pockets, such as in forging
dies
Machining of complicated profiles, such as of jet engine
blades, turbine blades, turbine wheels etc
Drilling small deep holes, such as in nozzle
Machining of cavities and holes of irregular shapes
Deburring of parts
By Rushikesh Urunkar JJMCOE
26. Laser Beam Machining (LBM)
LBM – is a machining process in which the work material
is melted and vaporized by means of an intense,
monochromatic beam of light called the laser
The heat produced in the small area where the laser beam
strikes can melt almost any of the known material
Light Amplification by Stimulated Emission of Radiation
By Rushikesh Urunkar JJMCOE
31. Material removal technique
Heating, melting and vaporization
Tool material
Laser beams in wavelength range of 0.4-0.6 µm
Power density
As high as 107 W/mm²
Output energy of laser and its pulse duration
20J, 1milli second
Peak power
20 KW
Specific power consumption
1000 W/mm³/min
By Rushikesh Urunkar JJMCOE
32. Material removal rate
5mm³/min
Material of work piece
All materials except those with high thermal conductivity
and high reflectivity
By Rushikesh Urunkar JJMCOE
33. Materials :
Almost all materials can be cut/drilled with laser (steel
and steel alloys(including those coated with lead, tin, zinc,
nickel, paint or plastic), titanium, tantalum, nickel)
Non metals which can be cut are – pvc, reinforced plastic,
leather, wood, rubber, wool and cotton,
Inorganic materials like glass, ceramics, asbestos, mica,
stone, alumina and graphite can also be cut or drilled
Dynamic balancing of precision rotating components,
such as of watches
By Rushikesh Urunkar JJMCOE
34. Applications
Machining very small holes and cutting complex
profiles in thin, hard material like ceramics and
tungsten.
Application includes sheet metal trimming, blanking
and resistor trimming
Drilling micro holes (up to 250µm)
Cutting or engraving patterns on thin films
The laser beam is effectively used in welding and heat
treatment of material
By Rushikesh Urunkar JJMCOE
36. There is direct contact b/w tool (laser) and w/p
Machining of any material including non-metals is possible,
irrespective of their hardness and brittleness
Welding, drilling and cutting of areas not readily accessible
are possible
There is no tool wear problem
Soft materials like rubber and plastics can m/cned
Extremely small holes can be m/cned i.e drilling micro holes
(up to 250 µm)
Cutting very narrow slots
can be effectively used for welding of dissimilar metal as well
Advantages :
By Rushikesh Urunkar JJMCOE
37. High capital investment needed
Highly skilled operator are needed
Very large power consumption
Low material removal rate
The process is limited to thin sheet plates(depth limitation)
and where a very small amount of metal removal is
involved
Can not be effectively used to m/c highly heat conductive
and reflective materials
The machined holes are not round and straight
Certain materials like fiber-glass reinforced materials,
phenolics, vinyls etc. cannot be worked by laser as these
materials burn, char and bubble
Disadvantages :
By Rushikesh Urunkar JJMCOE
38. Life of the flash lamp is short
Effectively safety procedures are required
By Rushikesh Urunkar JJMCOE
40. USM, Impact grinding or Ultrasonic grinding
Tapered shank
By Rushikesh Urunkar JJMCOE
41. Material removal mechanism :
complex mechanism involving both fracture and plastic
deformation by impact of grains due to vibrating tool
Tool material :
Soft steel (generally used), monel metal or stainless steel
Monel is a group of nickel alloys, primarily composed of
nickel (up to 67%) and copper, with small amounts of
iron, manganese, carbon, and silicon. Stronger than pure
nickel, Monel alloys are resistant to corrosion by many
agents, including rapidly flowing seawater.
By Rushikesh Urunkar JJMCOE
42. Abrasive :
Silicon carbide, Aluminium oxide, boron carbide or diamond
dust (size:200 to 2000 grit 1000 for finishing)
This process is suitable only for hard and brittle materials like
carbide, glass, ceramics, silicon, precious stones, germanium,
titanium, tungsten, tool steel, die steel, etc
Medium :
Slurry of water with 30-60% by volume of the abrasives
Power :
0.2-2.5KW
Vibrating frequency and amplitude :
15 to 30 kHz as vibrating frequency
0.01 to 0.06 mm as amplitude of vibration
By Rushikesh Urunkar JJMCOE
43. Cutting rate :
1. Grain size of abrasive
2. Abrasive material
3. Concentration of slurry
4. Amplitude of vibration
5. Frequency
6. Decreases with ratio W/P hard. to tool hard.
Cooling System :
A refrigerating cooling system is used to cool the abrasive
slurry to a temp 5-6˚c
By Rushikesh Urunkar JJMCOE
44. Extremely hard and brittle materials can be easily machined
In machining operations likes drilling, grinding, profiling and
milling operations on all materials both conducting and non
conducting
The operation is noiseless
The machined workpieces are free of stresses
Very high degree of surface finish is obtained
Metal removal cast is low
Operation of the equipment is quite safe
Advantages
By Rushikesh Urunkar JJMCOE
45. Low metal removal rate
High rate of tool wear
Hole depth to diameter ratio of 10:1
The cost of tool is also high
Power consumption is quite high
Difficulties are encountered in machining softer
materials
In order to maintain an efficient cutting action, the slurry
may have to be replaced periodically
The size of the cavity that can be machined is limited
This process does not suit to heavy metal removal
Limitations :
By Rushikesh Urunkar JJMCOE
46. Applications :
This process is suitable only for hard and brittle materials
like carbide, glass, ceramics, silicon, precious stones,
germanium, titanium, tungsten, tool steel, die steel, etc
Holes as small as 0.1 mm can be drilled as well as large
holes can be made.
It is mainly used for drilling, grinding, profiling, coining
and threading operations on all materials both conducting
and non conducting
Tool and die making , especially wire drawing dies,
extrusion dies and forging dies
By Rushikesh Urunkar JJMCOE
47. Available in portable 20 W to heavy machines 2000 W
Stomatology : Enabling a dentist to drill a hole of any
shape on teeth without creating any pain
Coining operations for materials such as glass, ceramics
etc
Threading by appropriate rotating and translating the
workpiece or tool.
By Rushikesh Urunkar JJMCOE
48. Water jet machining (WJM)
High-pressure water
Orifice
Abrasive
Focusing tube
Cover
By Rushikesh Urunkar JJMCOE
49. Material removal mechanism :
High velocity jet made to impinge on workpiece. Jet
pierces the work material and performs desired action.
Water under pressure from Hydraulic accumulator is passed
through orifice of nozzle to increase its velocity.
In another type of machine abrasive particles added in high
stream of water jet. (Hydrodynamic Abrasive Jet Machine)
Orifice of nozzle : Dia. is usually varies from 0.08 to 0.5
Exit Velocity : 920 m/s
Materials :
Relatively softer and non metallic materials like paper
boards, wood, plastics, asbestos, rubber, fibreglass, leather.
All type of ferrous and non ferrous metals and alloys.By Rushikesh Urunkar JJMCOE
50. Abrasives :
Silica, Aluminium oxide and garnet
Grit Sizes : 60, 80, 100 and 120
• Focusing Tube – WC – 0.8 to 2.4 mm
• Pressure – 2500 to 4000 bar
• Abrasive – garnet and olivine - #125 to #60
• Abrasive flow - 0.1 to 1.0 Kg/min
• Stand off distance – 1 to 2 mm
• Machine Impact Angle – 60o to 900
• Traverse Speed – 100 mm/min to 5 m/min
• Depth of Cut – 1 mm to 250 mm
Parameters :
By Rushikesh Urunkar JJMCOE
51. Almost no heat generated on your part
There is no tool changing
Fast setup and programming
Better edge finish
No mechanical stresses
both metal and non-metallic materials
Are very safe
Environmentally friendly
Advantages :
By Rushikesh Urunkar JJMCOE
52. Limitations :
Water jet technology cuts slower than laser or other cutting
process
Reducing material processing productivity
Higher entry cost than the other cutting machines
Abrasive material used for cutting harder materials tends to
be quite expensive.
By Rushikesh Urunkar JJMCOE