Manufacturing Technology II(ME-202)

Overview of

Manufacturing

Processes

Dr. Chaitanya Sharma

PhD. IIT Roorkee

WHAT IS MANUFACTURING?

• The word manufacture is derived from two Latin wordsmanus (hand) and factus (make); the combinationliterally means “made by hand”.

• “Made by hand” accurately described the fabricationmethods that were used when the English word“manufacture” was first coined around 1567 A.D.

• Most modern manufacturing operations areaccomplished by mechanized and automated equipmentthat is supervised by human workers

• It encompasses: Design of the product, Raw materialselection, choosing the sequence of processes formaking items.

Is Manufacturing Important?

• Making things has been an essential human

activity since before recorded history.

• Today, the term manufacturing is used for this

activity.

• Manufacturing is important to most of developed

and developing nations in two ways:

– Technologically

– Economically

Manufacturing: Technological

• Application of physical and chemical processesto alter the geometry, properties, and/orappearance of a starting material to makeparts or products

Technological Importance

• Technology - the application of science to

provide society and its members with those

things that are needed or desired.

• Technology provides the products that help our

society and its members live better.

• What do these products have in common?

– They are all manufactured.

• Manufacturing is the essential factor that

makes technology possible.

Manufacturing - Economical

• Transformation of materials into items ofgreater value by one or more processingand/or assembly operations

Economic Importance

• Manufacturing has the important function ofadding value to products i.e. marketable price.

• In general, higher the standard of living, higheris the level of manufacturing activity in acountry.

U.S. Economy

Sector: %GDP

Agriculture and natural resources 5

Construction and public utilities 5

Manufacturing 15

Service industries 75

100

Economic Importance of Manufacturing

Importance of manufacturing to national economies.

Global Labor Rates

Manufacturing Industries

• Industry consists of enterprises and organizationsthat produce or supply goods and services.

• Industries can be classified as:

1. Primary industries - cultivate and exploit naturalresources, e.g., agriculture, mining

2. Secondary industries - take the outputs ofprimary industries and convert them intoconsumer and capital goods e.g. aerospace,automobile

3. Tertiary industries - service sector e.g. Banking,Insurance

Specific Industries in Each Category

• Some specific examples of primary, secondary and tertiary industries

Manufacturing Industries

• Secondary industries include manufacturing,construction, and electric power generation.

• Manufacturing includes several industries whoseproducts are not covered in this book; e.g., apparel,beverages, chemicals, and food processing.

• For our purposes, manufacturing means productionof components/hardware e.g.

– Nuts and bolts, forgings, cars, airplanes, digitalcomputers, plastic parts, and ceramic products

Manufactured Products

• Final products divide into two major classes:

1. Consumer goods - products purchased directly by

consumers

– Cars, clothes, TVs, tennis rackets

2. Capital goods - those purchased by companies to

produce goods and/or provide services

– Aircraft, computers, communication equipment,

medical apparatus, trucks, machine tools,

construction equipment

Production Quantity Q

• The quantity of products Q made by a factory hasan important influence on the way its people,facilities, and procedures are organized.

• Annual quantities can be classified into three ranges:

Production type Quantity

Low production Job production 1-to 100

Medium production Batch production 100 to 10000

High production Mass production 10000 to millions

Product Variety P

• Product variety P refers to different product types ormodels produced in the plant.

• Different products have different features.

– They are intended for different markets

– Some have more parts than others

• The number of different product types made each yearin a factory can be counted.

•When the number of producttypes made in the factory ishigh, this indicates highproduct variety.

Manufacturing Capability

• A manufacturing plant consists of processes andsystems (and people) to transform a certain limitedrange of materials into products of increased value

• The three building blocks - materials, processes, andsystems - are the subject of modern manufacturing.

• Manufacturing capability includes:

1. Technological processing capability

2. Physical product limitations

3. Production capacity

1. Technological Processing Capability

• It means set of available manufacturing processes in the plant (or company) to make products.

• Certain manufacturing processes are suited to certain materials, so by specializing in certain processes, the plant is also specializing in certain materials.

• Includes not only the physical processes, but also the expertise of the plant personnel

• In simple term technological processing capability can be understood from following examples:

– A machine shop cannot roll steel

– A steel mill cannot build cars

2. Physical Product Limitations

• Given a plant with a certain set of processes, thereare size and weight limitations on the parts orproducts that can be made in the plant.

• Product size and weight affect:

– Production equipment

– Material handling equipment

• Production, material handling equipment, and plantsize must be planned for products that lie within acertain size and weight range

3. Production Capacity

• Defined as the maximum quantity that a plant canproduce in a given time period (e.g., month oryear) under assumed operating conditions

• Operating conditions refer to number of shiftsper week, hours per shift, direct labor manninglevels in the plant, and so on

• Usually measured in terms of output units, such astons of steel or number of cars produced by theplant.

– Also called plant capacity

History of Manufacturing(Until 1700)

History of Manufacturing (1700-1960)

History of Manufacturing (1960-2000s)

How Many Manufactured Components In Products?

• Products around us consist of numerous individual pieces that shall be built and assembled:

• Single components products :nail, bolt, fork, coat hanger, etc.

• Assembled products :ball point pens, automobiles, washing m/c

1. Clip, pin : one part

2. Lawn mower :300 parts

3. Grand piano :12,000 parts

4. Automobile :15,000 parts

5. Boeing 747-400: 6 million parts

How Many Materials In Products?

• A product requires use of many materials with desirable properties to make different parts.

Range of Materials & Processes in a Tractor

John Deere (Model 8430) tractor, with detailed illustration of its dieselengine, showing the variety of materials and processes incorporated.

Materials In An Automotive Engine

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Materials & Processes In All-Aluminum Automobile

The aluminum body structure, showing various componentsmade by extrusion, sheet forming, and casting processes.

Fig: Examples of the wide

variety of materials and

geometries for paper clips.

Some for consideration:

• Functional requirements.

• What material propertiesare required?

• What manufacturingattributes are required?

• Would the material andprocessing strategychange if the desiredquantity was 10,000 vs. 1million per day?

Example:1Manufacturing Paper Clip

Example:1Manufacturing Paper Clip

General considerations:1. What type of material? Metallic or non metallic?2. If metal what kind of metal?3. If the material is wire then what should be its diameter?4. Should it be round or have some other x-section?5. Is the wire’s surface finish & appearance important? What should it

be its roughness?6. How would you take a piece of wire & shape it into a paper clip?7. Would you do it by hand? If not , what kind of machine should you

design or purchase to make paper clips?8. If, as the owner of a company, you were given an order for 100 parts

vs for a million parts, would your approach to mfg be different?Functional and Service Requirement:1. Clamping force, Permissible plastic deformation, corrosion etc.2. Relation between mechanical properties (stiffness) & wire diameter.3. What should be the yield strength of wires? (If too low, clip will

bend permanently.)4. Life, customer satisfaction

Material Selection1. Material selection requires knowledge of function and service

requirements of the product.2. Therefore, choosing materials that are commercially available.3. Corrosion resistance must also be consideredStyle & Appearance,1. Metallic or plastic? What shape (round or else)?2. Surface finish, surface finishProduction Requirements:

1. How to shape (hand or machine)? Batch quantity

2. Bending without cracking or breaking?

3. Is wire cut easily without causing excessive wear on tooling?

4. Are edges on the wire smooth (burs not desire)?5. What is the most economical method of mfg this part at the

desired production rate?

Example:1Manufacturing Paper Clip

Example:2MANUFACTURING of LIGHT BULB

Some informations:

1. 60W bulb has thin Wire (0.045 mm dia)

2. 1% decrease in wire diameter,shortens bulb life by 25%.

3. Filament is heated to 2200 to 30000C.

4. Requires inert environment/ vacuum.

5. Bulb vacuumed or filled with N2 orArgon Moisture causes 0.5mblackened spot.

6. Production Rate >1000/Min.

Example 2: Steps In Making incandescent Light Bulbs

Fig a Components of a common

incandescent light bulb.

Fig b Manufacturing steps

in making an incandescent

light bulb

Example 3:Baseball Bat Cross-sections

Fig: X-sections of baseball bats

Top portion is made ofaluminum while bottomportion is made ofcomposite material

Example 4: Sunglasses Mold

• An excellent example of machining complexity and use computer in manufacturing.

(a) Computer model of thesunglass as designed andviewed on the monitor.

(b) Machine the die cavity using a CNC milling machine

(c) Final product

Change In Materials

• Materials used undergone changes throughout historydue to periodic material shortages and the cost ofappropriate raw materials. e.g. U.S. Pennies.

Time Period Materials Used

1793-1837 100% copper1837-1857 95% copper, 5% tin and zinc1857-1863 88% copper, 12% nickel1864-1962 95% copper, 5% tin and zinc1943(WW II year) Steel, plated with zinc1962-1982 95% copper, 5% zinc1982-present 97.5% zinc, plated with copper

Materials in Manufacturing

• Most engineering materials can be classified intoone of three basic categories:

1. Metals

2. Ceramics

3. Polymers

• Their chemistries are different, and theirmechanical and physical properties are different.

• These differences affect the manufacturingprocesses that can be used to produce productsfrom them

Methods of Manufacture

FIG: Various methods of making a simple part:(a) casting or powder metallurgy, (b) forging or upsetting,(b) (c) extrusion, (d) machining, (e) joining two pieces.

• A product can be made using from many materials and various methods

Chart For Selecting Shapes & Manufacturing Process

Scales in Manufacturing

FIG: Illustration of therange of common sizes ofparts and the capabilitiesof manufacturing processesin producing these parts.

Manufacturing Characteristics of Alloys

Applicability of Manufacturing Processes to Materials

Selection of Manufacturing Process

• Type of basic manufacturing process mainly depends on:

1. Type of the Work Material

2. Nature (i.e. ductile or brittle) and its Hardness

3. Melting Temperature of the Work Material

4. Production Volume or Batch Size of the Production

• Basic nature of the manufacturing process affects the

1. Cost

2. Properties and

3. Characteristics of the Final Product

Application Range of ManufacturingProcesses According to Melting Tempof Materials & Batch Size

Manufacturing Attributes of Manufacturing Processes

How to Select Processes

Some guidelines for selection of basic manufacturing process:

[A] According to the Batch Size:

• Smaller batch size requires flexible manufacturingprocesses like machining, which can produce variety ofgeometrical features. (up to 500 products).

1. Larger batch size allows use of primary forming anddeforming processes so as to offset the relatively highcosts of machine tools and tooling.

Primary forming processes from 75 onwards.

Deforming processes more than 1000.

Classification of Manufacturing Processes

• All the Manufacturing Processes can be Put into Basic SIX Categories according to their Nature:

1. Primary Forming Processes [Additive or Accretion]

2. Material Removal or Machining [Subtractive]

3. Deforming Processes [Formative]

4. Joining or Fabrication or Consolidation [Assembling]

5. Finishing and Surface Treatment Processes

6. Bulk Property Enhancing Processes [Heat Treatment]

• All These SIX Categories can be Sub-divided into TWO Sub-categories

1. Conventional

2. Unconventional or Advanced

Manufacturing Processes

Two basic types:

1. Processing operations - transform a workmaterial from one state of completion to amore advanced state

– Operations that change the geometry,properties, or appearance of the startingmaterial

2. Assembly operations - join two or morecomponents to create a new entity

Processing Operations

• Alters a material’s shape, physical properties, orappearance in order to add value

• Three categories of processing operations:

– Shaping operations - alter the geometry of thestarting work material

– Property-enhancing operations - improve physicalproperties without changing shape

– Surface processing operations - clean, treat,coat, or deposit material on surface of work

Shaping Processes

Basically there are four shaping processes:

1. Solidification processes - starting material is a heated liquid or semifluid

2. Particulate processing - starting material consists of powders

3. Deformation processes - starting material is a ductile solid (commonly metal)

4. Material removal processes - starting material is a ductile or brittle solid

Solidification Processes

• Starting material is heated sufficiently totransform it into a liquid or highly plasticstate.

• Casting process at left and casting product atright.

Particulate Processing

• (1) Starting materials are metal or ceramicpowders, which are (2) pressed and (3)sintered .

Deformation Processes

• Starting workpart is shaped by application offorces that exceed the yield strength of thematerial

• Examples: (a) forging and (b) extrusion

Material Removal Processes

• Excess material removed from the starting piece so what remains is the desired geometry

• Examples: (a) turning, (b) drilling, and (c) milling

Property Enhancing Processes

Processes that improve mechanical or physicalproperties of work material.

• Examples:

– Heat treatment of metals and glasses

– Sintering of powdered metals and ceramics

• Part shape is not altered, except unintentionally

– Example: unintentional warping of a heat treatedpart

A batch of silicon wafers enters a furnace heated to1000°C (1800°F) during fabrication of integrated circuitsunder clean room conditions (photo courtesy of IntelCorporation).

Surface Processing Operations

• Cleaning - chemical and mechanical processesto remove dirt, oil, and other surfacecontaminants

• Surface treatments - mechanical working suchas sand blasting, and physical processes likediffusion

• Coating and thin film deposition - coatingexterior surface of the workpart. Examples:

– Electroplating

– Physical vapor deposition

– Painting

Photomicrograph ofthe cross section ofmultiple coatings oftitanium nitride andaluminum oxide on acemented carbidesubstrate (photocourtesy ofKennametal Inc.).

Assembly Operations

• Two or more separate parts are joined to form a new entity.

• Types of assembly operations:

1. Joining processes – create a permanent joint

• Welding, brazing, soldering, adhesive bonding

2. Mechanical assembly – fastening by mechanicalmethods

• Threaded fasteners (screws, bolts and nuts); press fitting, expansion fits

Two weldersperform arc weldingon a large steel pipesection (photocourtesy of LincolnElectric Company).

Automated dispensingof adhesive ontocomponent parts priorto assembly (photocourtesy of EFD,Inc.).

Production Machines and Tooling

• Manufacturing operations are accomplished using machinery and tooling (and people).

• Types of production machines:– Machine tools - power-driven machines used

to operate cutting tools previously operated manually

– Other production equipment:• Presses• Forge hammers,• Plastic injection molding machines

Production Systems

• People, equipment, and procedures used for thematerials and processes that constitute a firm'smanufacturing operations .

• A manufacturing firm must have systems andprocedures to efficiently accomplish itsproduction

• Two categories of production systems:

– Production facilities

– Manufacturing support systems

• People make the systems work

Production Facilities

• The factory, production equipment, and material handling systems.

• Includes the way the equipment is arranged in the factory - the plant layout

• Equipment usually organized into logical groupings, called manufacturing systems. Examples:– Automated production line

– Machine cell consisting of an industrial robot and two machine tools

• Production facilities "touch" the product

Machine cell consisting of two horizontal machiningcenters supplied by an in-line pallet shuttle.

Facilities vs Product Quantities

• A company designs its manufacturing systemsand organizes its factories to serve theparticular mission of each plant.

• Certain types of production facilities arerecognized as most appropriate for a giventype of manufacturing:1. Low production – 1 to 100

2. Medium production – 100 to 10,000

3. High production – 10,000 to >1,000,000

Low Production

• Job shop is the term used for this type of production facility

• A job shop makes low quantities of specialized and customized products– Products are typically complex, e.g., space capsules,

prototype aircraft, special machinery

– Equipment in a job shop is general purpose

– Labor force is highly skilled

– Designed for maximum flexibility

©2010 John Wiley &

Sons, Inc. M P

Groover,

Fixed-Position Plant Layout

Medium Production

• Two different types of facility, depending on product variety:

• Batch production– Suited to medium and hard product variety

– Setups required between batches

• Cellular manufacturing– Suited to soft product variety

– Worker cells organized to process parts without setups between different part styles

Process Plant Layout

Cellular Plant Layout

High Production

• Often referred to as mass production– High demand for product

– Manufacturing system dedicated to the production of that product

• Two categories of mass production: 1. Quantity production

2. Flow line production

Quantity Production

• Mass production of single parts on singlemachine or small numbers of machines

• Typically involves standard machines equippedwith special tooling

• Equipment is dedicated full-time to theproduction of one part or product type

• Typical layouts used in quantity production areprocess layout and cellular layout

Flow Line Production

• Multiple machines or workstations arranged insequence, e.g., production lines

• Product is complex– Requires multiple processing and/or assembly

operations

• Work units are physically moved through thesequence to complete the product

• Workstations and equipment are designedspecifically for the product to maximizeefficiency

©2010 John Wiley &

Sons, Inc. M P

Groover,

Product Plant Layout

Assembly workers on anengine assembly line(photo courtesy of FordMotor Company).

Manufacturing Support Systems

• A company must organize itself to design theprocesses and equipment, plan and controlproduction, and satisfy product qualityrequirements– Accomplished by manufacturing support systems

• The people and procedures by which a company managesits production operations

• Typical departments:– Manufacturing engineering, Production planning and

control, Quality control

©2010 John Wiley &

Sons, Inc. M P

Groover,

Trends in Manufacturing

• Lean production and Six Sigma

• Globalization and outsourcing

• Environmentally conscious manufacturing

• Microfabrication and Nanotechnology

©2010 John Wiley &

Sons, Inc. M P

Groover,

Lean Production and Six Sigma

• Lean production– Doing more work with fewer resources, yet

achieving higher quality in the final product

– Underlying objective: elimination of waste in manufacturing

• Six Sigma– Quality-focused program that utilizes

worker teams to accomplish projects aimed at improving an organization’s organizational performance

©2010 John Wiley &

Sons, Inc. M P

Groover,

Globalization

The recognition that we have an international economy in which barriers once established by national boundaries have been reduced

• This has enabled the freer flow of goods and services, capital, technology, and people among regions and countries

• Once underdeveloped countries such as China, India, and Mexico have developed their manufacturing infrastructures and technologies so

©2010 John Wiley &

Sons, Inc. M P

Groover,

Outsourcing

Use of outside contractors to perform work that was traditionally accomplished in-house

• Local outsourcing– Jobs remain in the U.S.

• Outsourcing to foreign countries– Offshore outsourcing - production in China

and other overseas locations

– Near-shore outsourcing - production in Canada, Mexico, and Central America

©2010 John Wiley &

Sons, Inc. M P

Groover,

Environmentally Conscious Manufacturing

Determining the most efficient use of materials and natural resources in production, and minimizing the negative consequences on the environment

• Associated terms: green manufacturing, cleaner production, sustainable manufacturing

• Basic approaches:1. Design products that minimize

environmental impact2. Design processes that are environmentally

friendly

Manufacturing Processes: Casting

Figure I.7a Schematic illustration of various

casting processes

Manufacturing Processes: Forming and Shaping

Figure I.7b Schematic illustration of various bulk deformation processes

Manufacturing Processes: Forming and Shaping

Figure I.7c Schematic illustration of various sheet metal

forming processes

Manufacturing Processes: Machining

Figure 1.7e Schematic illustrations

of various machining and finishing

processes.

Manufacturing Processes: Joining

Figure I.7f Schematic illustration of various joining processes

Additive Processes

• Processes

– Rapid Prototyping

• Very flexible to part shape;

usually limited in material

choices; slow rates; fully automated

– Advanced Composites Processes

• Combination of additive and net

shape processes

– Microelectronics Processes

• Physical and chemical vapor

deposition processes and

coating methods

– Joining & Assembly

• Broad category includes welding,

adhesives, and mechanical

assembly

Laser Cutting

Figure I.8 Cutting sheet metal with a

laser beam. Source: Courtesy of

Rofin-Sinar, Inc. and Manufacturing

Engineering Magazine, Society of

Manufacturing Engineers

Hip Replacement

Figure 1.9 Components of a total

hip replacement. Source: Courtesy

of Zimmer, Inc.

Manufacturing of Hip Replacement

Figure 1.10 (a) Manufacturing steps in the production of a roll-

formed and machined total hip replacement stem; (b)

Manufacturing steps in the production of a forged stem. Hip

stems can also be produced by investment casting, metal injection

molding, insert injection molding, and assorted other processes.

Microscopic Components

Figure I.11 (a) Microscopic gears with dust mite. Source:

Courtesy Sandia National Laboratory; (b) A movable

micromirror component of a light sensor. Source: Courtesy

of Richard Mueller, University of California at Berkeley.

Salt and Pepper Shakers

Figure I.12 A salt and pepper mill

set. The two metal pieces (at the

bottom) for the pepper mill are made

by powder-metallurgy techniques.

Source: Reproduced with

permission from Success Stories on

P/M Parts, Metal Powder Industries

Federation, Princeton, NJ, 1998.

Automated welding of automobiles

Figure I.13 Automated

spot welding of

automobile bodies in a

mass production line.

Source: Courtesy of

Ford Motor Company.