TOOL DESIGN PARAMETERS

FOR

NON-CONVENTIONAL MACHINIG

PROCESSES

1

INTRODUCTON TO NCM PROCESSES

Remove material by various techniques such as Chemical, Electrical,

Mechanical, Thermal energy or combination of these energies.

Does not use sharp cutting tools.

Material removal may occur with chip formation or even no chip

formation may take place. ex: AJM and ECM.

There may not be a physical tool present. ex: LBM

The tool need not be harder than the work piece material. ex: EDM

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3

ULTRA SONIC MACHINING (USM)

4

Abrasive - Boron carbide, aluminium oxide and

silicon carbide

Grit size(d0) - 15 – 150 µm

Frequency of vibration (f) -19 – 25 kHz

Amplitude of vibration (a) -15 - 50 µm

Tool material - Soft steel titanium alloy

Wear ratio - Tungsten 1.5:1 and glass 100:1

Gap overcut - 0.02-0.1 mm

PHYSICAL PARAMETERS

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The tool material employed in USM should be tough and ductile. Low-carbon steel

and stainless steels give superior performance.

However, metals like aluminium, give very short life.

Metal have high fatigue strengths and low acoustic losses and they should be easily

brazed or soldered.

The metal used to construct horn are titanium, stainless steel, heat treated steel and

Aluminium.

The tool which attached to the end of the horn is exact inverse replica of object to

be manufactured.

TOOL MATERIALS

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In USM instead of tool the horn plays an important role. Hence the design of horn

must be correct so, it can transfer the vibration to tool.

HORN DESIGN FOR USM

Exponential shape Stepped shapeConical shape

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a) To amplify the vibration of the tool to the level

required for effective machining.

b) Mean of transmitting the vibrational energy

from the transducer to the workpiece.

c) Important aspect of horn design is the

calculation of the resonant length which should

be in multiple

of half the wave length of the system.

PRINCIPAL FUNCTION

This is a waveguide focussing device with a cross-sectional area which

decreases from the input (transducer) end to the output (tool) end.

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Literature Reviews

There has been various research in Horn and tool designing of UCM Process on various aspect of

the tool such as Tool material, tool shape and size etc. Here Some research paper has been

discussed regarding tool design.

Paper 1 Author Objective Conclusion

Ultrasonic horn design

for ultrasonic

machining

technologies

M. Nad’a To find dynamical

properties of different

geometrical shapes of

ultrasonic horns are

presented in this

paper.

The dynamical analysis of the

various geometrical shapes of

Sonotrode or Horn as one of the most

important elements of the Ultrasonic

machining system .

The main dynamic characteristics i:e

Natural Frequency and Amplification

factors of Horn in the Resonant state

were depend on Slenderness ratio,

shape parameter function, shape

function. Which are found by the use

of Finite Element Method.

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Paper 2 Author Objective Conclusion

Design of tool holders

for ultrasonic

machining

using FEM

K.H.W. Seah,

Y.S. Wong and

L.C. Lee

To find the Length of

the Horn Using FEM

Method.

Through this research paper the

length of various types of horn

can be obtained. The length of

the Horn is most Important thing

in USM.

1. Exponential shape

L=𝑐

𝑓[1 +

𝑙𝑛𝑁

2𝜋²

C= (𝐸

𝑑)

*C, wave speed. F, Natural frequency. E, young’s modulus

N, diameter ratio D1/D2 (D1 input end, D2 output end)

d. Density of horn material

2. Stepped shape

L= c/2f

Amplitude ratio = (D1/D2)²

3. Conical shape

L= Exponential shape * 1.1

Horn length calculation

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Paper 3 Author Objective Conclusion

Development of

Design and

Manufacturing Support

Tool for

Optimization of

Ultrasonic Machining

(USM) and Rotary

USM

Morteza Sadegh

Amalnik,

Mohammad

Rasoul Najafi

The concept and

development of an

expert system (ES)

for hard and

brittle material

manufacturing tools.

The design of tool and horn play an

important role in providing a

resonance state in USM and

MRR.

By the development of an Expert

System i:e derived from Artificial

Intelligence (AI), it is easy to design

a tool of required shape and size. By

entering required data in the expert

system.

It can further improved by joining

Expert System with CNC Machine.

Expert system is developed to

estimate machining time and cost,

penetration rate and productivity for

different design hole on different

materials such as glass, composite,

stone,

graphite and ceramic for USM and

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Paper 3 Author Objective Conclusion

Expert system is developed to

estimate machining time and cost,

penetration rate and productivity for

different design hole on different

materials such as glass, composite,

stone,

graphite and ceramic for USM and

RUSM with less than 30 seconds

Contd…

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ELECTRO-CHEMICAL MACHINING (ECM)

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Working gap - 0.1 mm to 2 mm

Overcut - 0.2 mm to 3 mm

Feed rate - 0.5 mm/min to 15 mm/min

Electrode material - Copper, brass,

bronze

Surface roughness - Ra 0.2 to 1.5 μm

Process Parameters

Power Supply

Type - direct current

Voltage - 2 to 35 V

Current - 50 to 40,000 A

Current density - 0.1 A/mm2 to 5 A/mm2

Electrolyte

Material - NaCl and NaNO3

Temperature – 20 °C – 50 °C

Flow rate - 20 lpm per 100 A current

Pressure - 0.5 to 20 bar

Dilution - 100 g/l to 500 g/l

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TOOL AND TOOL FEED SYSTEM

Use of anti-corrosive material for tool and fixtures, for a

long period of time to Operate in Corrosive environment

of electrolyte.

High thermal conductivity and high electrical

conductivity of tool material.

Easy machining of the tool material.

Tool material, Aluminium, Brass, Bronze, Copper,

carbon, stainless steel and monel.

Area on the tool with no action must be insulated.

Use of non-corrosive and electrically non-conducting

material for making fixtures is recommended.

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Paper 1 Author Objective Conclusion

Design of ECM Tool

Electrode with

Controlled

Conductive Area

Ratio for Holes with

Complex Internal

Features

Dahai Mi Wataru

Natsu

To design

Electrochemical

machining (ECM)

tool electrode with

controlled

conductive area for

the machining of

holes with given

complex internal

features.

(1) When tool electrode with

uniformly distributed helical

conductive area is considered, it is

found that the machining depth

increases rapidly with the increase of

conductive area ratio when its value

is lower than 20%, while the

machining depth reaches the

maximum and remains almost no

change in accordance with the

conductive area ratio when it’s over

50%.

Literature Reviews

17

Paper 1 Author Objective Conclusion

(2)Since the machining capability of tool electrode is

determined by conductive area ratio distribution and

conductive area ratio can be mathematically

determined by the pitch of the conductive area, the

desired inner feature of the hole can be shaped by

controlling the pitch distribution along tool electrode

surface.

(3) A prototype of tool electrode was designed and

fabricated for a given internal feature, and the

verification experiment was carried out. The results

show that the simulation and experimental results are

generally in well accordance with the given complex

internal feature. Therefore, it is proved that for a hole

with given internal feature, a corresponding tool

electrode can be designed using proposed method.

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Paper 2 Author Objective Conclusion

An integrated

approach for tool

design in ECM

V.K. Jain

K. P. Rajurkar

To design the ECM

Tool by different

methods such as ,

cos 𝜃 method, complex

variable approach,

empirical and

homographic

approach, finite

difference method,

finite element

technique,

(1) The use of the finite element

technique in predicting the anode

shape obtained, metal removal,

current density, temperature etc. in

ecru using simple and complex

shaped tools. The correlation

between limited amount of

experimental data and theoretical

results is quite good.

(2) cos 𝜃 method is not recommended, especially when complex shaped workpieces are to be analysed.

(3) complex variable approach is not advisable for use when a high degree of precision is desired. Since, its accuracy depends on the skill of the operatorand

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Paper 2 Author Objective Conclusion

(2) cos 𝜃 method is not

recommended, especially when

complex shaped workpieces are to be

analysed.

(3) complex variable approach is not

advisable for use when a high degree

of precision is desired. Since, its

accuracy depends on the skill of the

operator

and

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References

[1]. Nptel.ac.in

[2]. K.H.W. Seah, Y.S. Wong and L.C. Lee, Design of tool holders for ultrasonic machining

using FEM, Journal of Materials Processing Technology, 37 (1993) 801 816.

[3]. M. Nad’a, Ultrasonic horn design for ultrasonic machining technologies,

Applied and Computational Mechanics 4 (2010) 79–88.

[4]. Morteza Sadegh Amalnik, Mohammad Rasoul Najafi, Development of Design and Manufacturing

Support Tool for Optimization of Ultrasonic Machining (USM) and Rotary USM, Journal of Modern

Processes in Manufacturing and Production, Vol. 3, No. 2, Spring 2014

[5]. V.K. Jain and P.C. Pandey, Finite element approach to the two dimensional analysis of electrochemical

machining, PRECISION ENGINEERING (1980) 23-27.

[6]. V.K. Jain and P.C. Pandey, Tooling design for ECM, PRECISION ENGINEERING (1980) 195-203.

[7]. V. K. Jain and K. P. Rajurkar, An integrated approach for tool design in ECM, Butterworth-Heinemann

APRIL 1991 VOL 13 NO 2, 111-123.