Non Traditional Machining

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  • Topic: Machining, Electrical discharge machining, Water
  • Pages : 16 (1870 words )
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  • Published : April 1, 2013
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Manufacturing Technology
MEC205
Non Traditional machining processes

Water jet machining

Electro chemical machining

Turbine blade

EDM

EDM products

Chemical machining

Product from water jet machining
Chemical machining structure

Introduction
Machining is a broad term to describe removal of material from a workpiece.

1. Machining categories:
– Cutting involves single-point or multipoint cutting
tools, each with a clearly defined geometry.

2. Abrasive processes: such as grinding.
3. Nontraditional machining: utilizing electrical,
chemical, and optical sources of energy.

Need of non traditional machining processes:
Motivations in Aerospace and Electronics Industries
1. To machine new (harder, stronger & tougher) materials
difficult or impossible to machine conventionally
2. For unusual & complex geometries that cannot easily
machined conventionally

3. To achieve stringent surface (finish & texture) requirements not possible with conventional machining

Classification of non traditional machining
processes

1. Mechanical Energy Processes
2. Electrochemical Machining Processes
3. Thermal Energy Processes
4. Chemical Machining

Classification of non traditional machining
processes
1. Mechanical - Erosion of work material by a high velocity
stream of abrasives and/or fluid

– Ultrasonic machining, Water jet cutting (WJC), Abrasive
water jet cutting (AWJC) and Abrasive jet machining (AJM)
2. Electrical - Electrochemical energy: to remove material


Electrochemical

machining

(ECM),

Electrochemical

deburring (ECD) and Electrochemical grinding (ECG)

Classification of non traditional machining
processes
3. Thermal - Thermal energy applied to small portion of
work surface, removing by fusion and/or vaporization

– Electric Discharge Machining (EDM), Wire EDM, Electron
Beam, Laser Beam, Arc Cutting
4. Chemical - chemical etchants selectively - using a
mask - remove a portion of a workpart
– Chemical Milling, Blanking, Engraving and Photochemical
Machining

1.Mechanical energy processes:
Ultrasonic machining:

USM

Metal removal in USM

USM systems:
B

A

C

20-40

kHz, )

E

D

USM system
1. Power supply:
•The power supply is a sine-wave generator
•The user can control over both the frequency and power of the generated signal.
•It converts low-frequency (50/60 Hz) power to high-frequency (10-15 kHz)

power
•Supply to the transducer for conversion into mechanical motion.

2. Transducer:

Transducers are used in USM to convert the supplied energy to mechanical motion.
3. Tool holder:
•Its function is to increase the tool vibration amplitude and to match the vibrator to the acoustic load.
•Monel and titanium have good acoustic properties and are often used together with stainless steel, which is cheaper
4. Tools:
Tools should be constructed from relatively ductile materials. The harder the tool material, the faster its wear rate.

5. Abrasive:
•The criteria for selection of an abrasive for a particular

application include hardness, usable life, cost, and particle size.
•Diamond is the fastest abrasive, but is not practical because of its cost.
•Boron carbide is economical and yields good machining

rates.
•Silicon carbide and aluminum oxide are also widely used

2.Mechanical energy processes:
Water jet machining/cutting:

Stainless steel plate (50 mm thick)
machined with AWJ

Water Jet Cutting (WJC)
• Uses high pressure, high velocity
stream of water directed at work
surface for cutting

Water jet cutting.
True cold cutting process – no HAZ,
mechanical stresses or operator and
environmental hazards

WJC Applications
• Usually automated by CNC or
industrial robots to manipulate
nozzle along desired trajectory
• Used to cut narrow slits in flat stock
such as plastic, textiles, composites,
floor tile, carpet, leather, and
cardboard
• Not suitable for brittle...
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