electrochemical+micromachining+(emm)

A

Seminar on

Electrochemical Micromachining

(EMM)

Presented by

Todkar Mahesh S.

M.Tech-I

Manufacturing Engineering

Under the Guidance of

Dr. A Venugopal

Non-Traditional Machining

Need :

• To machine newly developed metals and non-metals

• To machine complex part geometries• To machine complex part geometries

• To avoid surface damage

Classification of Non-traditional

Machining Processes

This classification is carried out depending on nature

of energy used for material removal:

Mechanical Thermo- Chemical Electro-Mechanical Thermo-

electric

Chemical Electro-

chemical

• USM

• AJM

• WJM

• AWJM

• EDM

• EBM

• LBM

• PAM

• CHM

• PCM

• ECG

• EJD

• ECM

Electrochemical Machining (ECM)

• Reverse of electroplating

• Work material must be a conductor

• Material removal by anodic dissolution

• Electrical energy + chemical energy• Electrical energy + chemical energy


Advantages over other Non-conventional

Machining:

• No thermal and mechanical stresses on the workpiece• No thermal and mechanical stresses on the workpiece

• No heat-affected layer on workpiece

• No tool wear

• Higher machining rate

• Better precision

• Controlled material removal

• Wider range of materials can be machined

• Utilized for removal and patterning of metal films and foils


Applications:

• Die sinking

• Profiling and contouring• Profiling and contouring

• Trepanning

• Micro-machining

Electrochemical Micro-machining (EMM)

Micromachining:

• Material removal of small dimensions

• Ranges from several microns to millimeters

• For production of miniaturized parts and components• For production of miniaturized parts and components

Why Micromachining?

• Difficulties in machining of miniature components and parts

with conventional machining techniques

• Requirement of precision manufacturing


Electrochemical Micro-machining:

When electrochemical machining process is applied to

micro-machining range (i.e. from 0.1 μm to 1 mm) formicro-machining range (i.e. from 0.1 μm to 1 mm) for

manufacturing ultra-precision shapes, it is called

electrochemical micromachining(EMM).


Fundamental Observations:

• Very small inter-electrode gap

• Rate of dissolution (machining) depends on• Rate of dissolution (machining) depends on

1. Atomic weight ‘a’

2. Valance ‘v’ of ion produced

3. Machining current ‘I’

4. Time for which current passes

• Shape of electrode remains unaltered


Metal Removal Method:

MRR =

Where, = current density,

= metal dissolution efficiency,

F = Faraday’s constant,

= Density of material,

= Valance of ion,

= Atomic weight of ion.

Constant

for

particular

operation


MRR depends on:

• Anodic reaction and Current efficiency(�),

• Mass transport effects,

) and

�),

• Mass transport effects,

• Current distribution() and Shape evolution.


Influence of various process characteristics:

• Nature of power supply and Machining pulse

1. DC supply1. DC supply

2. Pulse DC supply

• Inter-electrode gap

• Electrolyte type, Concentration and Flow

1. Passivity Electrolyte

2. Non-Passivity Electrolyte

• Size, shape and material of the Tool:


Sub-systems for EMM Setup:

• Mechanical

machine setup:

Main machine body

Work holding device

Tool-feeding block



• Electrical power and control System:



• Electrolyte flow

system:

Job


• Experimental EMM setup:


Specifications of EMM setup:

• Mechanical structure details:

Base: (300 * 200 * 30) mmBase: (300 * 200 * 30) mm

Vertical column: (300 * 50 * 20) mm

Main Driving screw: Φ10 * 150L, 40 TPI, 50 mm thread

Main screw nut: (25 * 50 * 40) mm, 40 TPI

Main machining chamber: (100 * 200 * 80) mm³

Bearing: 10mm bore, 10 mm Thick



• Stepper Motor Specifications:

Step angle: 1.8°Step angle: 1.8°

Step angle accuracy: 5%

Holding torque: 40 N-cm

Detent torque: 4 N-cm

Weight: 0.5 kg



• Pump Specifications:

Power: 0.125 HP/ 0.09 kWPower: 0.125 HP/ 0.09 kW

Type: Centrifugal

AC: 240 V

Impeller Material: Teflon



• Microprocessor:

8085 Intel®8085 Intel®

• Tool Specifications:

Platinum, Φ 250 μm


Applications of EMM for Micro fabrication:

• Nozzle plate for Ink Jet Printer Head

• Production of High Accuracy Holes• Production of High Accuracy Holes

• 3D Micromachining


Recent Development in EMM:

• Micro Electrochemical Milling

• Wire Electrochemical Machining• Wire Electrochemical Machining

• Solid Electrochemical Machining

• Oxide film laser lithography (OFLL)

• Micro and Nanometer scaled surface structuring

• Laser electrochemical micro machining (LECMM)


Conclusion:

EMM setup

• Successfully utilized• Successfully utilized

• Fulfill the requirement and the need of Micromachining

operations

Areas of modifications:

• Inter-electrode gap control feature

• Precise control of machining parameters

Thank you.

Any Questions?

electrochemical+micromachining+(emm)

Technology

machining pulse1

machining current i4

tomicromachining range

tpimain machining chamber

mechanicalmachine setup

conductor material removal

density of material

vimpeller material