Lect1 Small

7/25/2019 Lect1 Small

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Manufacturing Engineering and Technology Assiut Univ.-Mech. Eng. dept Lecture-1

Definition of "Manufacturing"• "Manufacturing" is a process for converting ideas

and market or customer needs into artifacts;

Includes design, procurement, test,finance, human resources, marketing,etc.

• manufacturing is the conversion of rawmaterials into useful products

– Main Focus of This Course




Little "m" manufacturing is all about

• Creating shapes b various means and assemblingthese shapes into a useful product

• !he processes used to transform raw material intofinished products

• phsical product alwas has a shape – Function – Aesthetics

• !hese shapes are created b a wide variet of

processes• #tudents must remember that these processes e$istonl in the conte$t of the larger Manufacturingprocess




Manufacturing

C u s t om er

n e e d

s

People, money, machines and automation

Societal pressures, o!ernment regulations,

company plans and policies, etc

manufacturing

a#

material

%roducts




Material!ransformation

%rocesses " a #

M a t e r i a

l A s s e

m b

l y

P r o d u c

t s

Machines and Automation

Materials Science, Statics, Dynamics, Thermodynamics, Fluiddynamics

The manufacturing Process




TABLE 1.2 Shapes and Some Common Methods of Production

Shapes and Production Method




FIGURE 1.4 An outline of engineering materials

$ngineering Materials




FIGURE 1.6 Various methods of making a simple part: (a) casting or powder metallurgy, (b)

forging or upsetting, (c) etrusion, (d) machining, (e) !oining two pieces"

Production Methods for a Simple

Part




Fundamentals of manufacturing %

Manufacturing Concepts• !he method chosen depends on the material

and the shape and properties re&uired

• Formability• Machinability• &ardenability

• Castability• Compactability• Sinterability

• 'eldability




'hy is Manufacturing (mportant)• Impact on econom

– Ma*or #ealth creation engines – ross Domestic Product – *obs

• Most decisions made during design are

impacted b production'manufacturingprocesses

• Critical (ecisions'!rade)offs – function !s cost !s schedule

• Choose materials• Choose process+es

– Cost determined by the material and theprocesses used to create the shape




Some functional parameters

affected by production processes

• Mechanical properties *#trength, +ardness,ati&ue, (uctilit, -esistance to environment

• !olerances• #urface finish• -esistance to corrosion and abrasion•

/lectrical properties• !hermal %roperties• ppearance'surface finish




Commercially A!ailable

Materials

#$%&' "*Material Available as

$luminum

Copper and brass

Magnesium

Steels and stainless steels

Precious metals+inc

Plastics

'lastomers

Ceramics (alumina)

lass

raphite

P, -, %, #, ., S, /

P, f, %, #, ., s, /

P, %, #, w, S, /

P, %, #, ., S, /

P, -, %, t, ., /P, -, 0, ., /

P, f, %, #, w

P, b, #

p, %, #, s

P, %, #, ., s

P, %, #, ., s Note: P, plate or sheet1 -, foil1 %, bar1 #, tubing1 ., wire1 S,

structural shapes1 /, ingots for casting" &owercase letter

indicates limited a2ailability" Most of these materials are also

a2ailable in powder form"




Manufacturing Process

Capabilities-igure "3Manufacturing

process capabilitiesfor minimum partdimensions" Source:4" $" Schey,

Introduction to Manufacturing Processes (5d ed")"

Mcraw67ill, *89"




Dimensional Tolerance

-igure " 0imensional tolerance capabilities of 2arious manufacturing processes"




Dimensional Tolerance and

Surface Finish-igure "; <elationship between relati2emanufacturing cost and dimensional tolerance"

-igure "= <elati2e production time, as a function of surfacefinish produced by 2arious manufacturing processes" Source:$merican Machinist" See also -ig" 5;"33"




$-amples of eneral

Function.Process elationships

• Cast metals tend to be brittle• orging adds strength along flow lines• Machining is cost effective for small lot si0es

• Casting, forging and e$trusion have highsetup costs but low production costs

• +eat treatments affect hardness, strength,corrosion resistance and fatigue properties

• Machining results in lots of scrap *the bu tofl ratio




/uy to Fly atio

!he weight of the purchased raw materialdivided b the weight of the final part

Process /uy to fly ratio

Machining 1.1 ) 23+ot closed die forging 1.4)1.2

#heet metal forming 1.1)1.42

/$trusion 1.1)1.5

%ermanent mold casting 1.3)1.4%owder metallurg 1.3)1.32




Critical Fact

• 6ou cannot design an hardware withouttaking into account the production processused to make that product

• Manufacturing considerations must beincluded in the design as earl as possible




'hat is Manufacturing %

Dimensions

• %roduct Creative Characteristics *+ow newproducts differ from previous ones

• %roduct #i0e *phsical dimension• %roduct Comple$it'#ophistication• #cale• Material low

• (egree of utomation• 7rgani0ation




Product Creati!e Characteristics

• +ow new products differ from previous ones

– Selection design +Lego houses – Configuration design +automobiles – Parametric design +portable generators – edesign +0e# 1C – 2riginal design +the original 1C, the Space

Shuttle




Product Si3e +physical dimension

• individual device on a computer chip• computer chip• television• n automobile

• 8av cruiser




0umber of parts.amount of

electronics.intelligence

• nail• !9

• car or truck• ::: aircraft• satellite• Mars soourner

• C%< chip *2 millioncomponents




Scale

• 8umber of people and disciplines involved – Artisan – arage machine shop

– eneral Motors, Arlington Plant – /oeing Commercial Aircraft – $ngineering firms #ho ma4e bridges, chemical

plants or dams




Material Flo#

• +ow the work is organi0ed on the shop floor – Discrete parts +traditional *ob shop – Cellular +0e# machine shops – Semicontinuous

– Continuous flo# +bottle ma4ing – Process +chemical industry and oil refineries




Degree of Automation

• +ow much automation e$ists on the shop floor – Manual – Machine assisted

– Computer controlled % islands of automation – Computer integrated manufacturing




Company 2rgani3ation

• +ow the enterprises organi0e to produce – Traditional – Lean – Agile

– 0e-t eneration

Lect1 Small

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