Lecture 1 - Introduction to Manufacturing PDF

INTRODUCTION AND OVERVIEW OF MANUFACTURING 1. What is Manufacturing? 2. Materials in Manufacturing g 3. Manufacturing Processes ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e Manufacturing is...

INTRODUCTION AND OVERVIEW OF MANUFACTURING 1. What is Manufacturing? 2. Materials in Manufacturing g 3. Manufacturing Processes ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e Manufacturing is Important  Historicallyy  Technologically  Economically ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 1  Manufacturing - Historically Important Throughout history, human cultures that were better at making things were more successful  Making better tools meant better crafts & weapons  Better crafts allowed people to live better  Better weapons allowed them to conquer other ot e cu cultures tu es in ttimes es o of co conflict ct  To a significant degree, the history of civilization is the history of humans' ability to make things ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e Manufacturing - Technologically Important Technology - the application of science to provide societyy and its members with those things g 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 ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 2  Manufacturing - Technologically Application of physical and chemical processes to alter the geometry, properties, and/or appearance of a starting material to make parts or products  Manufacturing also includes assembly  Almost always carried out as a sequence of operations Figure 1.1 (a) M Manufacturing f t i as a technical process ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e Manufacturing - Economically Transformation of materials into items of greater value by means of one or more processing and/or assembl operations assembly  Manufacturing adds value to the material by changing its shape or properties, or by combining it with other materials Figure 1.1 (b) M Manufacturing f t i as an economic process ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 3  Manufacturing Industries - continued  For our purposes, manufacturing means production of hardware  Nuts and bolts, forgings, cars, airplanes, digital computers, plastic parts, and ceramic products ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e Materials in Manufacturing Most engineering materials can be classified into one of three basic categories: 1. Metals 2. Ceramics 3. Polymers  Their chemistries are different  Their mechanical and physical properties are dissimilar  These differences affect the manufacturing processes that can be used to produce products from them ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 4  In Addition: Composites Nonhomogeneous mixtures of the other three basic types rather than a unique category Figure 1.3 Venn diagram of three yp basic material types plus composites ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 1. Metals Usually alloys, which are composed of two or more elements, at least one of which is metallic  Two basic groups: 1. Ferrous metals - based on iron, comprises about 75% of metal tonnage in the world:  Steel = Fe-C alloy (0.02 to 2.11% C)  Cast iron = Fe-C alloy (2% to 4% C) 2. Nonferrous metals - all other metallic elements and their alloys: aluminum, copper, magnesium, nickel, silver, tin, titanium, etc. ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 5 A spectacular scene in steelmaking is charging of a basic oxygen furnace, in which molten pig iron produced in a blast furnace is poured into the BOF. Temperatures are around 1650°C (3000 ° F). ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 2. Ceramics Compounds containing metallic (or semi-metallic) and nonmetallic elements.  Typical nonmetallic elements are oxygen, nitrogen, and carbon  For processing, ceramics divide into: 1. Crystalline ceramics – includes:  Traditional ceramics, such as clay ((hydrous y aluminum silicates))  Modern ceramics, such as alumina (Al2O3) 2. Glasses – mostly based on silica (SiO2) ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 6  3. Polymers Compound formed of repeating structural units called mers, whose atoms share electrons to form very er large molec molecules les  Three categories: 1. Thermoplastic polymers - can be subjected to multiple heating and cooling cycles without altering molecular structure 2. Thermosetting polymers - molecules chemically transform (cure) into a rigid structure – cannot be reheated 3. Elastomers - shows significant elastic behavior ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 4. Composites Material consisting of two or more phases that are processed separately and then bonded together to achieve properties superior to its constituents  Phase - homogeneous mass of material, such as grains of identical unit cell structure in a solid metal  Usual structure consists of particles or fibers of one phase mixed in a second phase  Properties depend on components, physical shapes of components, and the way they are combined to form the final material ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 7  Manufacturing Processes Two basic types: 1. Processing g operations p - transform a work material from one state of completion to a more advanced state  Operations that change the geometry, properties, or appearance of the starting material 2. Assembly sse b y ope operations at o s - jo join ttwo ooor more oe components to create a new entity ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e Shaping Processes – Four Categories 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 ate a is material s a duct ductilee or o brittle b tt e solid so d ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 8  Solidification Processes Starting material is heated sufficiently to transform it into a liquid or highly plastic state  Examples: metal casting, plastic molding ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e Particulate Processing Starting materials are powders of metals or ceramics  Usually involves pressing and sintering, in which powders are first compressed and then heated to bond the individual particles ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 9  Deformation Processes Starting workpart is shaped by application of forces that exceed the yield strength of the material  Examples: (a) forging, (b) extrusion ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e Material Removal Processes Excess material removed from the starting piece so what remains is the desired geometry  Examples: machining such as turning, drilling, and milling; also grinding and nontraditional processes ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 10  High speed turning Computer numerical control Metal chips fly in a high speed turning operation performed on a computer p p numerical control turning center (photo courtesy of Cincinnati Milacron). ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 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, and adhesive bonding 2. Mechanical assembly – fastening by mechanical methods  Threaded fasteners (screws, bolts and nuts); press fitting, expansion fits ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 11  Joining Arc welding Two welders perform arc welding on a large steel pipe section (photo courtesy of Lincoln Electric Company). ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e Joining process Adhesive bonding Automated dispensing of adhesive onto component parts prior to assembly ( h t courtesy (photo t off EFD, EFD Inc.). ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 12  Assembly Car engine assembly Assembly workers on an engine assembly line (photo courtesy of Ford M t Company). Motor C ) ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e 13