Emerging Cutting Tool Materials for Improving

Performance of Machining DEPARTMENT OF MECHANICAL ENGINEERING

HALDIA INSTITUTE OF TECHNOLOGY,HALDIA

PURBA MEDINIPUR-721657,WEST BENGAL

2016-2017

HALDIA INSTITUTE OF technology

Submitted by.SUJAY KUMAR PATARRegistration no.161030410026 of 2016-17Roll no.10312416004M.Tech ME sem-1

What Do We Use To Cut A Apple ?

Which Tool ?

Knife is Harder_(material property) Knife is Sharper_(design) It is used to cut, with easei.e. Approach Angle_(technique orMechanism)

What Do We Use To Cut Steel or Cast Iron orStainless Steel?

Tungsten Carbide – Since it’s harder than most of the materials. Diamond is hardest than all other materials

Introduction

Machining is accomplished by cutting tools. Cutting tools undergo high force and temperature and temperature

gradient. Tool life

Two aspects of design 1) Tool Materials2)Tool Geometry

Cutting fluids

Machining is the process of removing unwanted materials from work piece. The major drawback of this process is loss of material in the form of chips.

Material removal process

Conventional

Cutting Axisymmetric cutting

Pismatic cutting

AbrasiveBonded cutting

Loose cutting

Un-conventional

CHEMICAL AND ELECTRO-CHEMICAL

ENERGY BASED PROCESSES

THERMAL ENERGY BASED

PROCESSES

ELECTRICAL ENERGY BASED

PROCESSESMECHANICAL

ENERGY BASED PROCESSES

Turning*Drilling*BoringMilling*SawingShaping

Grinding*HoningSuper finishing

Lapping

Tool as index of progress of civilizationRough estimation of time(in year)

Cultural stages

Types of tools

1,000,000800,000100,00050,0008,000 B.C5,500 B.C3,000 B.C1,400 B.C

Pre-Palaeolkthic

Lower-Palaeolithic

Middle –Paleolithic

Upper PalaeoithicMesolithic

NeolithicBronze AgeIron Age

StonesStones with chopping toolsTransinding bending of ancient tool typesBades,files fine flakesAgricultural implementations & animal domesticationUse of bronze elementsUses of metal and beginning of modern cutting tools.

Increase in productivity(MRR) with progress of cutting tool materials

What is Common in this Process?

TurningMilling

DrillingGrinding

Cutting tool considerations…

Tool life Three modes of failure Premature Failure Fracture failure -Cutting force becomes excessive and/or dynamic, leading to brittle fracture Thermal failure -Cutting temperature is too high for the tool

material Gradual Wear Gradual failure.

Tool wear: Gradual failure Flank wear -flank (side of tool) Crater wear -top rake face Notch wear Nose radius wear

Manufacturing TechnologyMachining requirements

The blank and the cutting tool are properly mounted (in fixtures) and moved in a powerfuldevice called machine tool enabling gradual removal of layer of material from the worksurface resulting in its desired dimensions and surface finish. Additionally someenvironment called cutting fluid is generally used to ease machining by cooling andlubrication.

The Balance of Properties of cutting tool

Hot hardness of the different commonly used tool materials

Silent properties of cutting tool materials

Hot hardness Toughness and strength Wear resistance Thermal conductivity Low coefficient of thermal expansion Weldability

1)Carbon Steels

It is the oldest of tool material. The carbon content is 0.6~1.5% with small quantities of silicon,

chromium, manganese, and vanadium to refine grain size. Maximum hardness is about HRC 62.

This material has low wear resistance and low hot hardness. The use of these materials now is verylimited.

1)HSS

HSS

T type C%-0.75W%-18Cr%-4V%1

M type

C%-0.8W%-4

Mo%-8,V%-1.2Cr%-5

18-4-1

2)Carbide tools

4)Coated carbide#Cemented Carbide− are composed primarily of carbon mixed with tungsten, tantalum and titanium powdersand bonded by cobalt in a sintering process.− have excellent red hardness capabilities.− can remove large amounts of materials in a short period of time.− are capable of CS 3−4 times greater than HSS cutting tools.

Machining by coted carbide inserts

5)High performance ceramic (HPC)tools1)Zerconia toughened alumina2)Whisker reinforced ceramic3)Metal toughed alumina.

Comparison of important properties of ceramic and tungsten carbide

5)Cermet's=cer(ceramic)+met(metal)The favourable cermets include TiC ,TiN,TiCN

6)CBN

Diamond

Polycrystalline Diamond ( PCD )

unique PCD also suffers from some limitations like : • High tool cost • Presence of binder, cobalt, which reduces wear resistance and

thermal stability • Complex tool shapes like in-built chip breaker cannot be made • Size restriction, particularly in making very small diameter tools

The above mentioned limitations of polycrystalline diamond tools have been almost overcome by developing Diamond coated tools.

Diamond coated carbide tools

• Free from binder, higher hardness, resistance to heat and wear more than PCD and properties close to natural diamond

• Highly pure, dense and free from single crystal cleavage • Permits wider range of size and shape of tools and can be deposited

on any shape of the tool including rotary tools • Relatively less expensive

Future PossibilitiesFrom the above discussion it is evident that continuous interest is there for developing new cutting tool materials to meet the challenge of aerospace age.The following ideas appear t have some relevance to possible new material concepts:1.Thermo mechanical treatments2.Industry point of view cost and time benefits.2.Internal oxidations to produce small (10 nm) hard particle3.Multi phase material with each phase interconnected produced.4.Directional solidification of cast tool materials ,and casting technique.5.Continues and extended application of the composite concept- It is seen that there are many existing new possibilities for future improvement of cutting tool material capability.

THANK YOU