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 raw materials into useful products Main Focus of This Course
Little "m" manufacturing is all about Creating shapes by various means and assembling these shapes into a useful product The processes used to transform raw material into finished products A physical product always has a shape Function Aesthetics These shapes are created by a wide variety of processes Students must remember that these processes exist only in the context of the larger Manufacturing process
People, money, machines and automation Manufacturing Customer needs People, money, machines and automation Societal pressures, Government regulations, company plans and policies, etc manufacturing Raw material Products
The manufacturing Process Materials Science, Statics, Dynamics, Thermodynamics, Fluid dynamics Products Material Transformation Processes Assembly Raw Material Machines and Automation
Shapes and Production Method TABLE 1.2 Shapes and Some Common Methods of Production
Engineering Materials FIGURE 1.4 An outline of engineering materials
Production Methods for a Simple Part FIGURE 1.6 Various methods of making a simple part: (a) casting or powder metallurgy, (b) forging or upsetting, (c) extrusion, (d) machining, (e) joining two pieces.
Fundamentals of manufacturing - Manufacturing Concepts The method chosen depends on the material and the shape and properties required Formability Machinability Hardenability Castability Compactability Sinterability Weldability
Why is Manufacturing Important? Impact on economy Major wealth creation engines Gross Domestic Product jobs Most decisions made during design are impacted by production/manufacturing processes Critical Decisions/Trade-offs function vs cost vs schedule Choose materials Choose process(es) Cost determined by the material and the processes used to create the shape
Some functional parameters affected by production processes Mechanical properties (Strength, Hardness, Fatique, Ductility, Resistance to environment) Tolerances Surface finish Resistance to corrosion and abrasion Electrical properties Thermal Properties Appearance/surface finish
Commercially Available Materials
Manufacturing Process Capabilities Figure 40.3 Manufacturing process capabilities for minimum part dimensions. Source: J. A. Schey, Introduction to Manufacturing Processes (2d ed.). McGraw-Hill, 1987.
Dimensional Tolerance Figure 40.4 Dimensional tolerance capabilities of various manufacturing processes.
Dimensional Tolerance and Surface Finish Figure 40.5 Relationship between relative manufacturing cost and dimensional tolerance. Figure 40.6 Relative production time, as a function of surface finish produced by various manufacturing processes. Source: American Machinist. See also Fig. 25.33.
Examples of General Function/Process Relationships Cast metals tend to be brittle Forging adds strength along flow lines Machining is cost effective for small lot sizes Casting, forging and extrusion have high setup costs but low production costs Heat treatments affect hardness, strength, corrosion resistance and fatigue properties Machining results in lots of scrap (the buy to fly ratio)
Buy to Fly Ratio The weight of the purchased raw material divided by the weight of the final part Process Buy to fly ratio Machining 1.1 - 50 Hot closed die forging 1.2-1.5 Sheet metal forming 1.1-1.25 Extrusion 1.1-1.3 Permanent mold casting 1.0-1.2 Powder metallurgy 1.0-1.05
Critical Fact You cannot design any hardware without taking into account the production process used to make that product Manufacturing considerations must be included in the design as early as possible
What is Manufacturing - Dimensions Product Creative Characteristics (How new products differ from previous ones) Product Size (physical dimension) Product Complexity/Sophistication Scale Material Flow Degree of Automation Organization
Product Creative Characteristics How new products differ from previous ones Selection design (Lego houses) Configuration design (automobiles) Parametric design (portable generators) Redesign (New VCR) Original design (the original VCR, the Space Shuttle)
Product Size (physical dimension) A individual device on a computer chip A computer chip A television An automobile A Navy cruiser
Number of parts/amount of electronics/intelligence A nail A TV A car or truck A 777 aircraft A satellite Mars sojourner A CPU chip (5 million components)
Scale Number of people and disciplines involved Artisan Garage machine shop General Motors, Arlington Plant Boeing Commercial Aircraft Engineering firms who make bridges, chemical plants or dams
Material Flow How the work is organized on the shop floor Discrete parts (traditional job shop) Cellular (New machine shops) Semicontinuous Continuous flow (bottle making) Process (chemical industry and oil refineries)
Degree of Automation How much automation exists on the shop floor Manual Machine assisted Computer controlled - islands of automation Computer integrated manufacturing
Company Organization How the enterprises organize to produce Traditional Lean Agile Next Generation