Materials
Manufacturing
&
Industrial Engineering
Kesha Chandrakanth
Masters in Aerospace Engineering
University of Pisa, Italy
• To learn and function effectively in an
Aerospace organization. To constantly upgrade
my knowledge and skills by teaching and make
sure to use the best out of it.
Materials, Manufacturing
and Industrial Engineering
Engineering Materials
Structure and properties of engineering materials,
phase diagrams, heat treatment, stress-strain diagrams
for engineering materials
• Casting, Forming and Joining Processes
• Machining and Machine Tool Operations
• Metrology and Inspection
• Computer Integrated Manufacturing
• Production Planning and Control
• Inventory Control
• Operations Research
ATOMIC
STRUCTURE
Electron Magnitude 1.6×10−19 C
Atomic number (Z)
CRYSTAL STRUCTURE
Amorphous
Material
crystalline
material
Lattice and Unit Cells
Coordination number
Elemental Crystals
Compound Crystals
Line Defects
Planar
Defects
EFFECTS OF
IMPERFECTIONS
Grain formation
GRAIN SIZE
MEASUREMENT
GRAIN
STRUCTURE
Distortion and dialation of solid material
Types of
Deformation
Hysteresis
behavior
Bauschinger
effect
Multiphase
Structure
Solid
Solution
Types of Solid Solution
State of Equilibrium
Solidification
Temperature
Lever rule
Copper-nickel
system
Copper-silver
system
Lead-tin
system
Eutectic
Microstructu
re Pb-Sn
Invariant Reactions
IRON-CARBON PHASE
Fe-Fe3C
system
TTT diagram
(0.8% C
steel)
HEAT
TREATMENT
OF STEEL
Hardening of
Steel
Tempering of steel
Austempering
(Tempering of
austenite)
Martempering
Annealing
Case
Hardening
Case Carburizing
Induction
Hardening
Flame Hardening
Effect of
carbon on
steels
Alloying elements
in steels
Linearity
Tensile Strength
Yielding
Ultimate Strength
Failure
σ−ε curves
Impact
Strength
Fatigue
Strength
Creep
Hardness
Vickers test
Rockwell Test
Shore Scleroscope
Knoop Test
Hardness test and criteria
ENGINEERING
METALS
Free Cutting Steels
Low Alloy Steels
Stainless Steels
High Speed Steels
Invar
Cast Irons
Gray Cast Iron
Wrought Iron
White Cast Iron
Malleable Cast Iron
Aluminium Alloys
Copper Alloys
Magnesium Alloys
Titanium Alloys
Refractory Metals
Noble Metals
Other Non-Ferrous Alloys
CERAMICS
Types of Ceramics
Glasses
Clay Products
Refractories
Abrasive Ceramics
Cements
Advanced Ceramics
• Applications of CERAMICS
•
•
•
•
Alumina
Aluminium Nitride
Silica
Silicon Carbide
POLYMERS
Plastics
Elastomers
COMPOSITES
METAL
CASTING
Materials,
Manufacturing
and Industrial
Engineering
• Casting, Forming and Joining Processes
Different types of castings, design of patterns,
moulds and cores; solidification and cooling;
riser and gating design. Plastic deformation
and yield criteria; fundamentals of hot and
cold working processes; load estimation for
bulk (forging, rolling, extrusion, drawing) and
sheet (shearing, deep drawing, bending) metal
forming processes; principles of powder
metallurgy. Principles of welding, brazing,
soldering and adhesive bonding.
METAL CASTING
Moulding Box
Pattern
Cores
Chills
Chaplets
Sprue
Runner
Riser
ELEMENTS OF CASTING
SAND
CASTING
Pattern Making
Core Making
Moulding
Melting and Pouring
Cleaning
PATTERN
Pattern Materials
MOLDING
SAND
Pouring Basin
Skim Core
Strainer
Splash cores
Skim Bob
Sprue
Runner
Gate
Delay Screen
Pouring Time
Aspiration Effect
Gating Ratio
Cooling and Solidification
The following are the
general considerations in
the design of risers:
1.Risers should be
designed to ensure
directional solidification
of the casting,
maintaining proper
temperature gradient
within the solidifying
casting.
2. Risers should be close
to the heaviest section of
the casting, preferably on
the top or at the side and
connected to the casting
by a neck of metal called
‘gate’ for easy removal of
riser from casting during
fettling.
3. Each of thick sections
of a casting should have
its own riser.
Design of Riser
Freezing Ratio
Caine’s
Equation
Modulus Method
CASTING
METHODS
Shell
Molding
Expendable Pattern Casting
Investment
Casting
Permanent
Mold Casting
Die Casting
Slush Casting
Continuous
Casting
INSPECTION OF
CASTING
Forming
Rolling
FORGING
Precision Forging
Press Forging
Upset
Forging
Roll Forging
Swaging
EXTRUSION
Forward Extrusion
Backward Extrusion
WIRE
DRAWING
SHEET METAL FORMING
Shearing
Punching Force
Spring Back
Shearing
Operations
Drawing
Spinning
Bending
Stretch Forming
Embossing
Coining
HIGH-ENERGY RATE FORMING
Electro-Hydraulic Forming
ElectroMagnetic
Forming
POWDER
METALLURGY
JOINING
WELDING
Oxyacetylene gas
welding
Gas welding techniques
Electric Arc Welding(Arc
length)
Power Source
Characteristics
Arc Power
Welding Speed
Types of Electrodes
Electrode
Coating
Arc Blow
Duty Cycle
Inert-Gas-Shielded-Arc Welding
Submerged Arc Welding
Resistance
Welding
Resistance
Spot
Welding
Resistance
Seam
Welding
Resistance
Projection
Welding
Resistance Butt
Welding
Flash Welding
Percussion
Welding
Cold
Welding
Ultrasonic
Welding
Explosive
Welding
Diffusion
Welding
Forge
Welding
Friction
Welding
Electroslag Welding
Laser Beam
Welding
Atomic
Hydrogen
Arc Welding
Plasma Arc
Welding
BRAZING
Brazing is the metal
joining processes in
which a filler metal,
having a melting
temperature of more
than 450◦C but lower
than the melting
temperature of parent
metal, is used to fill the
joint gap with capillary
action. The filler metal
has different
composition than that
of the base metals.
Alloys of copper, sliver
and aluminium are the
most common brazing
filler metals.
Soldering is the metal joining
processes in which a filler metal,
having a melting temperature of
less than 450◦C and also lower
than the melting temperature of
parent metal, is used to fill the
joint gap with capillary action.
Strength of joint largely depends
upon the adhesive quality of the
solder which never reaches the
strength of parent metals.
Materials,
Manufacturing
and Industrial
Engineering
• Machining and Machine Tool Operations:
Mechanics of machining; basic machine
tools; single and multi-point cutting tools,
tool geometry and materials, tool life and
wear; economics of machining; principles of
non-traditional machining processes;
principles of work holding, design of jigs and
fixtures.
Machining
Machining
Chip Formation
Built Up Edge
Chip Thickness Ratio
Shear Angle
Shear Strain
Chip Velocity
Shear Velocity
Shear Strain Rate
Ernst–Merchant Analysis
Cutting Forces
Power
Consumption
CUTTING HEAT
TOOL MATERIALS
CUTTING FLUIDS
CUTTING TOOL GEOMETRY
MACHINABILITY
Tool Life
Tool Wear
Taylor’s Tool Life Equation
Surface Finish
Marks of
Feed Motion
ECONOMICS OF MACHINING
MACHINING PROCESSES
Turning
Drilling
Milling
Grinding
FINISHING
OPERATIONS
Reaming
Tapping
MODERN MACHINING PROCESSES
Abrasive-Jet Machining
AJM is fit for cutting fragile materials without damage. The
process is used for frosting glass, removing oxides from metal
surfaces, deburring, etching patterns, drilling and cutting thin
sections of metal and shaping crystalline materials.
Ultrasonic Machining
• Merits
• Ultrasonic machining is best suited for
hard and brittle materials. It is the only
way to produce economically complex
cavities without breaking the workpiece.
Tooling cost of the the process is low. It
does not involve thermal stresses.
• Demerits
• Major limitations of this process are
• Low MRR.
• 2. Limited depth of hole produced.
• 3. High tool wear.
• 4. Unable to produce sharp corners.
Applications
USM is suitable for machining shallow
die cavities and forms in hard and brittle
materials, such as hardened steel and
sintered carbides. The process is also
used for thread cutting in ceramics by
rotating the workpiece in a controlled
manner.
Electrochemical Machining
Merits
Electrochemical machining offers the following
advantages:
1. High feed rate in ECM results in high MRR comparable
with the conventional methods.
2. Metal removal rate in this process exceeds other nontraditional machining processes. It depends on ion
exchange rate, therefore, the process is used for
machining complex cavities in high-strength materials,
for example, hardened tool steel or even carbide.
3. Low voltage decreases the equilibrium machining gap
and results in a surface finish of the order of 0.4 µm
and tolerance control of the order of ±0.02 mm or
less.
4. Tool wear is almost non-existent, and the process is
suitable for machining hard materials. All types of
tools, dies and molds can be made by ECM.
5. The process involves only chemical forces; therefore,
the workpiece does not need heavy mechanical
clamping. There remains now residual stress in the
workpiece.
• Demerits The following are the limitations of
the ECM process:
1.
Sharp interior edges and corners are difficult
to produce.
2. Every new job needs a new design for tool
(cathode).
3. The design of the process variables and
selection electrolyte is a highly skilled job, and
more often trial and error method is applied.
4. Use of corrosive media as electrolytes makes
ECM difficult to handle. Chemical degradation of
electrolyte are potential hazards for
environment.
5. The process is suitable for only electrically
conductive materials.
6. Large amount of electrical power is required to
perform the process, which makes it expensive.
Applications
The process is extensively used for mass
production of turbine blades, engine
parts and nozzles. ECM permits the
machining after hardening, thus
eliminates the risk of distortion or any
other change. Fragile parts that are
otherwise difficultly machinable can be
shaped by ECM. Negligible tool wear
gives high degree of accuracy; therefore,
ECM is well-suited for mass production.
Electric-Discharge
Machining
Merits
EDM offers the following advantages:
1. Suitable for machining complex
cavities in high strength materials.
2. High orders of surface finish (3.2 µm)
and tolerance (±0.05 mm).
3. Easy for automation and mass
production.
Demerits
EDM has the following limitations:
1. Suitable for only electrically conductive
materials.
2. Inevitable taper, over-cut and corner radii.
3. Every new job needs a new design for
tool.
4. Tool wear affecting dimensional accuracy.
5. Surface finish reducing on higher MRR.
6. High specific power consumption
Applications
EDM is extensively used for producing threedimensional complex cavities to a high
degree of accuracy which are later used as
tools or die sets for production of castings,
forgings, stampings, and extrusion. These are
also used in electronic industries.
A variation of EDM is wire EDM in which a
slow-moving wire travels along a prescribed
path, cutting the workpiece, with the
discharge sparks acting like cutting teeth
(similar to contour cutting with a band saw).
This process is used to cut thick plates and
for making punches, tools, and dies from
hard metals. The wire is made of electrically
conductive materials, such as brass, copper,
tungsten.
Electron-Beam Machining
Merits
EBM offers the following advantages:
1. Specially adopted for micromachining.
2. Suitable for high-strength materials.
3. Offers high degree of automation and
mass production.
4. Extremely close tolerances.
Demerits
EBM has the following limitations:
1. Vacuum chamber restricting the size of
workpiece.
2. Time is required for evacuating the
chamber.
3. Emission of X-ray due to interaction of
electron beam with workpiece.
4. High specific energy consumption.
5. High equipment cost and need for skilled
operators.
Applications
EBM finds applications in drilling fine
holes of the order of 25–125 µm and
silting narrow cuts upto 25 µm on 0.25–
6.3 mm thick plates. EBM is used for
perforating the filters and screens in
textile and chemical industries.
Laser-Beam
Machining
Merits
LBM offers the following advantages:
1. Suitable for machining micro-holes
(up to 250 µm) and narrow slots.
2. Suitable for all materials except few.
3. Does not require vacuum.
4. Offers inherent flexibility with fiberoptic beam delivery
Demerits
LBM has the following limitations:
1. Produces usually rough surfaces and
heat affected zones.
2. High specific energy consumption.
3. Low efficiency (≈ 0.3-0.5 %).
4. Unsuitable for highly conductive and
reflective materials.
5. Hazards of lasers to the retina of eye.
Applications
LBM is extensively used for drilling
metals, non-metals and composites. It is
used to machine micro-holes in filter
screens, carburetors, fuel injection
nozzles, wire-drawing die (50 µm), etc. It
is used for marking and engraving of
parts with letters, numbers and codes.
Plasma-Arc
Machining
Merits
PAM offers the following advantages:
1. MRR higher than EDM and LBM.
2. Suitable also for electricity nonconducive materials.
3. Suitable for the plates of thickness
upto 150 mm.
Demerits
PAM has the following limitations:
1. Emission of ultraviolet and infrared
radiations.
2. Metallurgical transformations in work
surface.
3. Expensive equipment.
4. Requires skilled operators.
Applications
The process is extensively used for
profile cutting of metals such as stainless
steel, aluminium, Monel, and super alloy
plates, which are difficult to cut by
oxyfuel techniques.
JIGS AND FIXTURES
• Jigs have various reference
surfaces and points for accurate
alignment of parts and tools. The
term jig is confined to the devices
employed for holding the workpiece
and for guiding the tool in
performing the options of drilling,
reaming and tapping. For this reason,
the jig carries hardened steel bushes
or tool guides. This eliminates the
need of centering and marking
operations.
A fixture is used to fix, that is, constrain all degrees of freedom
by holding and clamping the workpiece relative to cutting tool
on the machine table at the desired position but it does not
guide the tool. Thus, a fixture serves three functions: location,
support and clamping. Fixtures are generally designed for
specific purposes of machining operations, such as milling,
turning, planing, shaping or grinding. Fixtures are also used in
welding of intricate shapes.
• Metrology and Inspection:
Materials,
Manufacturing
and Industrial
Engineering
Limits, fits and tolerances; linear and angular
measurements; comparators; gauge design;
interferometry; form and finish measurement;
alignment and testing methods; tolerance
analysis in manufacturing and assembly.
METROLOGY AND INSPECTION
LIMITS,
TOLERANCES
, AND FITS
Limit Systems
Tolerance
Systems
Fits
IS:919-1963
LINEAR MEASUREMENT
ANGULAR MEASUREMENT
GAUGE
DESIGN
INTERFEROMETRY
SURFACE MEASUREMENT
Comparison-Based Methods
In this category, the surface texture is assessed by observation
of the surface with the surface produced by same techniques.
These methods include touch inspection, visual inspection,
scratch inspection, microscope inspection, etc. These methods
involve subjective judgment.
Direct Measurement Methods
It is possible to get the numerical value of surface finish by
using stylus probe type of instruments. Fiber-based optical
profilometers scan surfaces with optical probes which send
light interference signals back to the profilometer detector via
an optical fiber.
• Computer Integrated Manufacturing:
Materials,
Manufacturing
and Industrial
Engineering
Basic concepts of CAD/CAM and their
integration tools.
COMPUTER INTEGRATED MANUFACTURING
1.Business Planning Forecasting, scheduling, material
requirement planning, invoicing and accounting.
2. Business Execution Production and process control, material
handling, testing and inspection.
CIM offers the following benefits:
1. Responsiveness to short product life cycles and dynamics of
global competition.
2. Process control resulting in consistent product quality and
uniformity.
3. Control on production, scheduling, and management of the
total manufacturing operations.
4. Improved productivity by optimum utilization of resources.
COMPUTER
INTEGRATED
MANUFACTURING
CAD offers the following benefits:
1.Increased design productivity.
2. Increased available geometric forms.
3. Improved quality of the design.
4. Improved communication
documentation.
5. Creation of manufacturing data base.
6. Design standardization.
COMPUTER
AIDED DESIGN
COMPUTER AIDED
MANUFACTURING
Computer aided manufacturing (CAM)
describes use of the computers and
computer technology to assist in all
phases of manufacturing, including
process and production planning
scheduling, manufacture, quality control,
and management.
Present day CAD/CAM systems, such as Unigraphics, Pro/E, IDEAS, CATIA, have many modules packed together and are running
on their own proprietary databases. These systems have both CAD and CAM capabilities and the geometric data from CAD can
be used in the CAM module without conversion on the same interface. This allows information transfer from the design stage
to the planning stage without re-entering the data manually on part geometry. The CAD database is directly processed by CAM
for operating and controlling the production machinery and material handling equipment as well as for performing automated
testing and inspection for product quality.
INTEGRATION OF CAD AND CAM SYSTEMS
Numerical control (NC) of machine tools is a method of automation in which functions of machine tools
are controlled by programs using letters, numbers and symbols. These programs contain precise
instructions about the manufacturing procedure as well as the movements.
NUMERICAL CONTROL
The most prominent feature of NC machine tool is that a
variety of machining operations are performed on the same
machining centre, thus eliminating the non-productive waiting
time when such operations are performed on different
machines. In addition to this, the provision of automatic tool
changing, indexing of tables, and several pallets add to the
productivity of the machining centres.
NUMERICAL
CONTROL
Machine Tools
Principle of
Operation
Coordinate Systems
Programs of NC processing equipment need a definite axis
system to specify the position of the work head w.r.t. the work
part. NC systems employ two types of axis systems, one for flat
and prismatic work parts and the other for rotational parts. Both
systems are based on Cartesian coordinate system.
Motion Control Systems
Manual NC Part
Programming
• Production Planning and Control:
Materials,
Manufacturing
and Industrial
Engineering
Forecasting models, aggregate production
planning, scheduling, materials requirement
planning.
Production
planning and
control
FORECASTING
Forecasting Errors
Aggregate planning is aimed at pre-estimating the
procurement quantity and scheduling the output over an
intermediate range by determining optimum levels of
the production rate, employment, inventory and other
controllable variables.
AGGREGATE PLANNING
DISAGGREGATION
Disaggregation is not a complex process because it involves
several steps and a variety of trade-offs that must be made
before a final item-by-item production schedule is obtained.
The most successful schemes use a hierarchical planning model
that explicitly ties together the decisions at each level of
planning in order to be internally consistent.
MATERIAL REQUIREMENT PLANNING
BREAK-EVEN
POINT
ANALYSIS
LOT SIZING RULES
ASSEMBLY LINE
BALANCING
• Inventory Control:
Materials,
Manufacturing
and Industrial
Engineering
Deterministic models; safety stock inventory
control systems.
Types of Inventory
Costs of
Inventory
Carrying Cost
Ordering Cost
Inventory Demand
Deterministic Demand
The inventory model using the assumption of constant and
known demand for the item and lead time are called
deterministic models. Here, the stock is replenished as soon as
the stock reaches the point of exhaustion. In such a situation,
there is no need to maintain any extra stock.
Probabilistic Demand
When the demand over a period is uncertain, but can be
predicted by a probability distribution, the demand is called
probabilistic demand.
Inventory Control Systems
Static Inventory System
These are single purchase decision systems for a single period
without replenishment. The inventory cost is optimized
between the cost of having and the cost of not having an item
in stock.
Dynamic Inventory System
These are multi-purchase decision systems, concerned with
consumable spares, that make replenishment decisions on an
ongoing basis over time. Majority of inventory problems belong
to this type of situation
EOQ MODELS
Objective of the EOQ models is to determine the optimal order quantity
that minimizes the total incremental cost of holding an inventory and
processing order when demand occurs at a constant rate. The optimum
level of quantity is called economic order quantity (EOQ). There are various
EOQ models for different situations, but the following two models are
relevant in the present context of study
Simple EOQ
Model
Build-Up
EOQ Model
PROBABILISTIC
INVENTORY
MODELS
Simple inventory models are based on constant demand and
supply lead time. However, in real applications, the demand can
be uncertain and lead time often varies significantly. In such
situations, the risks of stock-out can be reduced by carrying
safety or buffer stock, which requires additional funds.
Therefore, probabilistic inventory models are developed to
balance the risks and minimize the incremental costs.
SELECTIVE
APPROACHES
JUST-IN-TIME
PRODUCTION
In a just-in-time (JIT) production
system , materials are produced
only at the time when they are
needed in required quantity. For
this, the companies make
agreements with their vendors.
• Operations Research:
Materials,
Manufacturing
and Industrial
Engineering
Linear programming, simplex method,
transportation, assignment, network flow
models, simple queuing models, PERT and
CPM.
SIMPLEX
METHOD
Dantzig’s simplex method is a general procedure of iterative
nature for obtaining systematically the optimal solution to a
linear programming problem (LPP). The method is based on the
property that if objective function does not take the maximum
value in a vertex, then there is an edge starting at that vertex
along which the value of the function grows.
Problem Definition
Conditions for
Applicability
Simplex
Algorithm
The simplex method proceeds by
preparing a series of tables called
simplex tableaus
Standardization of the
Problem
Modification of Constraints
Modification of Objective Function
Obtaining the
Simplex
Tableau
Obtaining
Feasible Solution
A feasible solution is obtained by
assigning zero to all variables
except basic variables, and then
assign the values of the constraints
(bi ’s) of the variable in the identity.
Testing the
Optimality
Except when an artificial variable is included in the basis, a
simplex tableau depicts an optimal solution if all entries in the
net after opportunity cost row (∆j ) are non-positive for
maximization type problems or non-negative for minimization
type problems
Iteration: This new simplex tableau represents
the new solution which needs to be again
subjected to the optimality test in previous
manner. If the solution is not optimal, it must be
improved in the similar manner again and again
until it satisfies the condition for optimality
Improving the Solution
Degeneracy and Cycling
Infeasibility
Unboundness
No Feasible Solution
Exceptional Cases
Duality
The optimal solution of maximization type problem can
yield complete information about optimal solution of
minimization type problem, and vice versa. Then, one is
called primal, and other is called dual. Such an existence
of two interdependent problems is called duality.
Limitations of
Simplex
Method
TRANSPORTATI
ON PROBLEM
Transportation problems involve a mathematical approach that
produces optimal plan for minimizing the transportation costs of
goods and services from several supply centers to several demand
centers. Transportation problems can be solved using simplex
algorithm, but involve a large number of variables and constraints.
Therefore, separate algorithms, such as stepping-stone method,
modified distribution method, have been developed to solve
transportation problems.
ASSIGNMENT
PROBLEM
Resources possess varying abilities for performing different
jobs, therefore, the costs of performing those jobs are
different. Optimal assignment of resources for production is an
essential aspect of production planning and control. An
assignment problem can be viewed as a reduced or degenerate
form of transportation problem obtained by incorporating the
following changes:
1. Sources are the assignees and destinations are tasks.
2. Taking demand (bi) and supply (ai) as 1, (there will be only
one assignment); the units available at each origin and
units demanded at each destination are all equal to one.
3. The numbers of origins and destinations should be made
exactly equal. This makes the problem a square matrix.
The objective is to minimize the cost of production by optimal
assignments of the job to most suitable worker or machine
Routing is an important function of production
planning. Most of the effectiveness measures, such as
time, cost, distance, depend on the order of
performing a series of jobs. The jobs can be scheduled
by using priority sequencing rules whenever the
workstation becomes available for further processing.
SEQUENCING
QUEUING
THEORY
A queue is a waiting line. It is formed when arrival rate of
customers is greater than the serving rate during a period of
time. Any service system involving queuing situation has to
achieve an economic balance between the percentage
utilization of server and cost of waiting line
PERT AND CPM
Project evaluation and review technique (PERT) and critical
path method (CPM) are the network based techniques of
project scheduling. A project is a well defined task having
definable beginning and end points. It requires resources for
the completion of the interrelated constituent activities.