rakshit sahu,manufacturing

8/7/2019 rakshit sahu,manufacturing

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TERM PAPER

TOPIC- CUTTING TOOL TECHNOLOGY

SUMITTED TO SUMITTED BY:

MS. SANDHYA SINGH RAKSHIT SAHU

ROLL NO.-RK4006A03REG.NO.-11006227


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(ACKNOWLEDGEMENT)

If practical knowledge carves and sharps the carrier of a person, practical experience polishes

it and adds luster and brilliance to it. Here, we found this golden chance to acknowledge all

those people who had blessed, encouraged and supported us technically and morally throughall the phases of our term paper. We take this opportunity to express our profound sense of

gratitude. We thank all mighty God for giving us this valuable opportunity to express to all

those who helped in successful completion of this term paper.

Before we get into thick of the things I would like to add a few heartfelt words for the

people who were part of this term paper in numerous ways. We reserve heartiest gratitude to

who has been very supportive and encouraging throughout this term paper. He guides us for

having given us an opportunity to undertake the term paper and providing us with feedback

and influenced the development of this term paper. We gratefully acknowledge invaluable

note of our term paper guide MS. SANDHYA SINGH and to all teachers who besides

helping us in this term paper, guided and encouraged us along each step.

We express heartfelt thanks to our friends for their morale and support and kind

corporation during this course of formulation of this project work who directly or indirectly

helps us to complete this term paper. Last but not least, my sincere regards are reserved for

our family and friends who have always encouraged and blessed us with their best. Specially

thanks to my elder brothers who always encourage me to do your best.

RAKSHIT SAHU


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CONTENTS:

Introduction

Cutting tool technology

Tool life

Taylor tool life equation

Tool material

Types of tool materials

Tool geometry

Cutting tools

Latest technology

Safety

Future scope


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CUTTING TOOL TECHNOLOGY

1. Tool life

2. Tool Materials3. Tool Geometry

4. Cutting fluids

1. Tool life

Three modes of failure

o Premature Failure

o Fracture failure -Cutting force becomes excessive and/or dynamic, leading to

brittle fracture

o Thermal failure -Cutting temperature is too high for the tool material

Gradual

o Wear Gradual failure

Tool wear: Gradual failure

o Flank wear -flank (side of tool)

o Crater wear -top rake face

o Notch wear


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o Nose radius wear

Crater and Flank Wear

Selection of cutting tool materials is very important

What properties should cutting tools have

Hardness at elevated temperatures

Toughness so that impact forces on the tool can be taken

Wear resistance

Chemical stability

Types of tool materials

o Carbon + medium alloy steel

o High speed steel (HSS)

o Cast cobalt alloys

o Carbides

o Coated tools

o Ceramics

o Cubic boron nitride

o invented by GE in 1969

o Silicon nitride

o Diamond


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CUTTING TOOL TECHNOLOGY

Three possible failure modes of cutting tool

Fracture failure: due to excessive force, failed suddenly in a brittle pattern

Temperature failure: due to high temperature at tool tip, failed gradually in a ductile

pattern

Gradual wear: most commonly seen, similar to temperature effect

Gradual wear occurs at two principal locations: crater wear and flank wear

Crater wear: formed a concave section on the rake face of the tool due to the sliding of the

chips

Flank wear: formed a rough surface on the flank face due to the constant abrasion

between newly created work surface and flank face

WHAT IS TOOL LIFE?

It is defined as the length of cutting time that the tool is performing satisfactorily.

Tool life is a function of time, and the wear-out curve is similar to a creep test curve.

For flank wear: quantitative analysis and qualitative analysis.


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TAYLOR TOOL LIFE EQUATION (QUANTITATIVE)

Developed in 1900 by F. W. Taylor

vTn = C

Where v = cutting speed, ft/min

T = tool life, min

n depends on tool material

C depends on workpiece and cutting conditions

A modified tool life equation: vTn = C (Tnref)

= Where Tnref is a reference value for C (1 minute)

In the tool life prediction, one needs to know n and C first.

The entire equation becomes vTconstant = constant [once v is known, then T can becalculated]

Tool life prediction (qualitative analyses): complete failure of cutting edge, visual

inspection of flank face, fingernail test across cutting edge by operator, change in sound


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emitting during cutting, chip shape change, increased power consumption, longer cutting

time, etc.

TOOL MATERIALS

Three important properties for tool materials

toughness

Hot hardness (Rc > 60)

Wear resistance (including chemical reaction)

Surface treatment on plain carbon steels: hydrogen embrittlement, nitrogen embrittlement,

and carburization

TYPES OF TOOL MATERIAL

o High-speed steels (HSS): highly alloyed tool steel capable of maintaining

hardness at elevated temperatures.

o two types of HSS: T-grades (12 20% tungsten) and M-grades (6% tungsten and 5%

molybdenum)


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o Cemented carbides: hard tool materials manufactured through powder metallurgy

methods, consists of tungsten carbide (WC) and cobalt (Co), titanium carbide (TiC) and

Co, or tantalum carbide (TaC) and Co.

o Cermets: combinations of titanium carbide (TiC) and titanium nitride (TiN) with

nickel and/or molybdenum as binders.

o Coated carbides: cemented carbides coated with thin layers of wear-resistant material

such as titanium carbide, titanium nitride, and/or aluminum oxide. (including chromium

carbide, zirconium nitride, and diamond)

TOOL GEOMETRY

Single-point tool: end relief angle, side relief angle, side cutting edge angle, nose radius,

end cutting edge angle

Chip breakers: force chip to curl and fracture

Effects of tool material on geometry

Cutting fluids two types: coolants (water base) and lubricants (oil base with S, Cl, P)

Coolants are used for high cutting speeds and heat generation

Lubricants are used for low cutting speeds with high pressure


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Three categories of cutting fluids: cutting oils, emulsified oils, chemical and semi-

chemical fluids

Cutting oils are generated from petroleum , animal, marine, and vegetable origin.

Emulsified oils are mixtures of mineral oil and water (suspension)

Chemical fluids are chemicals in water solution.

CUTTING TOOLS

The proper holder maintained under all of the correct standards is still only as good as the

cutting tool it contains. A quality tool is determined by three primary factors:

1. Materials (substrates)

2. Geometry

3. Coatings

MATERIALSThe best designs and coatings in the world are of little value if they are not applied to the

appropriate substrates. Using an end mill with a subpar substrate is like using a front door

made from cardboard on a new house. From a distance it looks the same, but a closer look

will reveal the obvious flaws that make it unsuitable for its intended purpose.

Carbide Grain Classification Grain Size [microns]


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Fine Micro-grain Carbide 1.0 ~ 1.3

extra-fine Micro-grain Carbide 0.5 ~ 0.9

Ultra-fine Micro-grain Carbide 0.3 ~ 0.5

Nano-series Micro-grain Carbide 0.1 ~ 0.3

CUTTING TOOL (MACHINING)

A "numerical controlled machining cell machinist" monitors a B-1B aircraft part being

manufactured.

A cutting tool has one or more sharp cutting edges and is made of a material that is harder

than the work material. The cutting edge serves to separate chip from the parent work

material. Connected to the cutting edge are the two surfaces of the tool

The rake face; andThe flank.

The rake face which directs the flow of newly formed chip, is oriented at a certain angle is

called the rake angle "". It is measured relative to the plane perpendicular to the work

surface. The rake angle can be positive or negative. The flank of the tool provides a clearance

between the tool and the newly formed work surface, thus protecting the surface from

abrasion, which would degrade the finish. This angle between the work surface and the flank

surface is called the relief angle. There are two basic types of cutting tools Single point tool; and


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Multiple-cutting-edge tool.

A single point tool has one cutting edge and is used for turning, boreing and planing. Duringmachining, the point of the tool penetrates below the original work surface of the workpart.

The point is sometimes rounded to a certain radius, called the nose radius.

Multiple-cutting-edge tools have more than one cutting edge and usually achieve their motion

relative to the workpart by rotating. Drilling and milling uses rotating multiple-cutting-edge

tools. Although the shapes of these tools are different from a single-point tool, many elements

of tool geometry are similar.

CUTTING CONDITIONS

Relative motion is required between the tool and work to perform a machining operation. The

primary motion is accomplished at a certain cutting speed. In addition, the tool must be

moved laterally across the work. This is a much slower motion, called the feed. The

remaining dimension of the cut is the penetration of the cutting tool below the original work

surface, called the depth of cut. Collectively, speed, feed, and depth of cut are called the

cutting conditions. They form the three dimensions of the machining process, and for certain

operations, their product can be used to obtain the material removal rate for the process


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where

the material removal rate in mm3/s, (in3/s),

the cutting speed in m/s, (ft/min),

the feed in mm, (in),

the depth of cut in mm, (in).

Note: All units must be converted to the corresponding decimal (or USCU) units.

Machining operations usually divide into two categories, distinguished by purpose and

cutting conditions:

Roughing cuts, and

Finishing cuts.

Roughing cuts are used to remove large amount of material from the starting workpart as

rapidly as possible, in order to produce a shape close to the desired form, but leaving some

material on the piece for a subsequent finishing operation. Finishing cuts are used to complete

the part and achieve the final dimension, tolerances, and surface finish. In production

machining jobs, one or more roughing cuts are usually performed on the work, followed by

one or two finishing cuts. Roughing operations are done at high feeds and depths feeds of .

04-1.25 mm/rev (0.015-0.050 in/rev) and depths of 2.5-20 mm (0.100-0.750 in) are typical.

Finishing operations are carried out at low feeds and depths - feeds of 0.0125-0.04 mm/rev

(0.0005-0.0015 in/rev) and depths of 0.75-2.0 mm (0.030-0.075 in) are typical. Cutting

speeds are lower in roughing than in finishing.

A cutting fluid is often applied to the machining operation to cool and lubricate the cutting

tool. Determining whether a cutting fluid should be used, and, if so, choosing the proper

cutting fluid, is usually included within the scope of cutting condition.

STAGES IN METAL CUTTINGRoughing cuts are used to remove large amount of material from the starting workpart as

quickly as possible, in order to produce a shape close to the desired form, but leaving some

material on the piece for a subsequent finishing operation. Finishing cuts are used to complete

the part and achieve the final dimension, tolerances, and surface finish. In production

machining jobs, one or more roughing cuts are usually performed on the work, followed by

one or two finishing cuts. Roughing operations are done at high feeds and depths feeds of .

04-1.25 mm/rev (0.015-0.050 in/rev) and depths of 2.5-20 mm (0.100-0.750 in) are typical.


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Finishing operations are carried out at low feeds and depths - feeds of 0.125-0.4 mm/rev

(0.005-0.015 in/rev) and depths of 0.75-2.0 mm (0.030-0.075 in) are typical. Cutting speeds

are lower in roughing than in finishing.

A cutting fluid is often applied to the machining operation to cool and lubricate the cutting

tool. Determining whether a cutting fluid should be used, and, if so, choosing the proper

cutting fluid, is usually included within the scope of cutting condition.

Today other forms of metal cutting are becoming increasingly popular. An example of this is

water jet cutting. Water jet cutting involves pressurized water in excess of 90,000 PSI and is

able to cut metal and have a finished product. This process, is called cold cutting, and it

increases efficiency as opposed to laser and plasma cutting.

LATEST TECHNOLOGIES

1. Mold making technology:

Machine tools

CAD/CAM

Cutting tools

2. Sarin technology

3. Emerging technology

4. Glass scratch removal technology


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SHARP AND CUTTING TOOL SAFETY

Now a days safety drives are organized by companies. They consider it a prime necessity and

utmost goal that all the workers of the company should work in healthy and safe environment.No compromise is undertaken where safety is concerned. Safe equipments are being used

which follow all the safety norms with authorized guarantee. Manufacturers of quality

equipments are given orders even if there cost is bit high.

Hand-held sharp and cutting tools are frequently used in the workplace. The tools range from

scissors, razors, saws, and knives to pruners, chisels, and snips. While these tools are very

different and can be used for a wide variety of jobs, they have some common hazards and

safety precautions. Horseplay should be forbidden around sharp and cutting tools.


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Sharp and cutting tools can cause cuts and puncture wounds, if theyre not handled properly.

Workers should be trained in the tool manufacturers directions for proper use, including how

to inspect, maintain, and sharpen the tool. For some tools, workers must wear personal

protective equipment such as safety glasses and well-fitting gloves.

In order to choose the right tool for the job, workers should consider not only the job task but

the type, hardness, and size of the material on which theyll be working. Substituting the

wrong tool for the job can lead to an accident or injury. Workers should use only quality tools

that are sharp and in good condition. If a tool is broken, dull or damaged, it should be tagged

as such and taken out of service.

The most important rule to remember about using sharp and cutting tools is to ALWAYS cut

away from the body and face. When cutting with one hand, workers should know where their

other hand is. If a sharp tool is dropped, workers should be taught not to try to catch it but

allow it to fall, making sure that their legs and feet are out of the way.

The safe way to work with a sharp or cutting tool is to concentrate on the task at hand,

making straight, even cuts without rocking, prying or twisting the tool. Hammering or

applying excessive force or pressure to sharp and cutting tools can cause them to slip. Keep in

mind, that some materials or outdoor conditions can also make tools slippery.

Workers need to be careful when transporting and storing sharp tools. Workers should be

instructed not to carry a sharp tool in their pocket; to use a sheath, belt or apron; and when

there is a pause in work, to hold the tool at their sides but a safe distance from their body.

When walking with a sharp tool, the tool should be carried with the blade down and away

from the body. When climbing with a sharp tool, tool belts or buckets with hand lines should

be used so workers can have both hands to grip the ladder. When passing a sharp or cutting

tool to another worker, tools should be passed with the hand first and the blade down; they

should never be tossed from one worker to another.


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When not in use, sharp or cutting tools should be stored in a sturdy tool box or on a tool rack

with the sharp edges suitably covered. Otherwise, they should be placed near the back of

work benches to keep handles or blades from extending over the edge.

FUTURE SCOPE:-

The technologies that we are using for cutting tools today are already outdated. The

ideas of the next generation of machine tools, cutting tools etc. have already gone

through research and development and are in production.

The technology is even changing rapidly and come at a price that is measurable and

when that measure is justified, it is time to make investment.

With new cutting tool technologies, companies can focus on time, cost, reduction, shortening

lead times and in many instances break even point of their cutting tool investment within

hourstoday, a high proportion of machining processes are conducted with coolants. In this

way, the work piece, tool and machine tool are cooled, friction processes are reduced, and the

manufactured chips are removed from the cutting area. Unfortunately, coolants are dangerous


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to the environment and human health. Moreover, the disposal costs for used coolants are set

to soar. Therefore, the movement towards green manufacturing cutting operations will be one

of the most important challenges in the near future. Decreasing the costs of the cutting

process and the associated reduction of environmental pollution by dry machining is the main

key to remain competitive and profitable.

In this contribution, results are presented to introduce dry machining of synchronizing cones

for automotive applications. Different CVD/PVD commercial coatings were investigated in

preliminary investigations for their suitability in dry-machining the specific austenitic steel. It

will be shown that coating systems (like hard/soft double layers) exhibit a great potential for

such operations, even under a minimal lubricant system. Furthermore, several parameter

studies were carried out towards accuracy to size, work piece morphology and process

stability. In a last step, field tests were done performed on these results.

RFERENECES:

1. Manufacturing science, H.P.GROVER,

2. Tool design and technology, P.N RAO

Links and bookmarks:

www.springer.com

www.ctemag.com
http://www.springer.com/http://www.ctemag.com/http://www.springer.com/http://www.ctemag.com/


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kimth2.softarchive.net

www.productionmachining.com

www.macraesbluebook.com
http://www.productionmachining.com/http://www.productionmachining.com/http://www.macraesbluebook.com/http://www.productionmachining.com/http://www.macraesbluebook.com/

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rakshit sahu,manufacturing