Manufacturing Engineering & Technology by 7xS3ef

VIEWS: 11 PAGES: 34

									Manufacturing Engineering &
       Technology
       Introduction
             Manufacturing
• Comes from Latin manu factus “made by
  hand”
• Manufacturing is concerned with making
  products. Dates back to 5000-4000 BC
TABLE 1.1 Approximate Number of Parts in Products
TABLE 1.2 Historical Development of Materials, Tools, and Manufacturing Processes
TABLE 1.2 (continued) Historical Development of Materials, Tools, and Manufacturing Processes
TABLE 1.2 (continued) Historical Development of Materials, Tools, and Manufacturing Processes
TABLE 1.2 (continued) Historical Development of Materials, Tools, and Manufacturing Processes
TABLE 1.2 (continued) Historical Development of Materials, Tools, and Manufacturing Processes
         Industrial Revolutions
• (First)Industrial revolution: England 1750s.
  Prior to this good produced in batches and
  required much manual labor in all phases of
  production
• (Second) Industrial revolution: mid-1900’s
  Solid-state electronic devices and computers
• Interchangeable parts- early 1800’s- American
  manufacturer Eli Whitney
FIGURE 1.2a Components of a common incandescent light bulb. Source: Courtesy of General Electric Company.
FIGURE 1.2b Manufacturing steps in making an incandescent light bulb. Source: Courtesy of General Electric Company.
             Product Design
• Product Design involves the creative and
  systematic prescription of the shape and
  characteristics of an artifact to achieve
  specified objectives while simultaneously
  satisfying several constraints (p.8)
• Concurrent Engineering (simultaneous
  engineering): from the earliest stages of
  product design and engineering, all relevant
  disciplines are simultaneously involved.
FIGURE 1.3 (a) Chart showing various steps involved in traditional design and manufacture of a product. Depending on the complexity of the
  product and the type of materials used, the time span between the original concept and the marketing of the product may range from a few
  months to several years. (b) Chart showing general product flow in concurrent engineering, from market analysis to marketing the product.
                                                            Source: After S. Pugh.
                 Life Cycle
• Life cycle of a product
1. Product start-up
2. Rapid growth of the product in the
   marketplace
3. Product maturity
4. Decline
         Life Cycle Engineering
Life cycle engineering requires that the entire
life of a product be considered, beginning with
the design stage and on through production,
distribution, product use, and finally recycling or
the disposal of the product.
             Computers
• CAD
• CAM
• Prototype: a physical model of an
  individual component or product
  (Rapid prototyping)
        More about Design
• Design for manufacture is a
  comprehensive approach to
  integrating the design process with
  production methods, materials,
  process planning, assembly, testing
  and quality assurance.
• Design for service: products often
  have to be disassembled to varying
  degrees in order to service and
  repair.
            Green Design
Green design and
manufacturing considers all
possible adverse environmental
impacts of materials, processes,
operations, and products, so
that they can all be taken into
account at the earliest stages of
design and production.
         Selection of Materials
• Ferrous metals: carbon, alloy, stainless, steel
• Nonferrous metals: aluminum, magnesium,
  copper, nickel, titanium…
• Plastics (polymers): Thermoplastics, thermosets,
  elastomers
• Composite materials: reinforced plastics and
  metal-matrix and ceramic-matrix composites
• Nanomaterial
• Shape-memory alloys
TABLE 1.3 General Manufacturing Characteristics of Various Materials
FIGURE 1.5 Cross sections of baseball bats made of aluminum (top two) and composite material (bottom two).
FIGURE 1.6a Schematic illustrations of various casting processes.
FIGURE 1.6b Schematic illustrations of various bulk-deformation processes.
FIGURE 1.6c Schematic illustrations of various sheet-metal-forming processes.
FIGURE 1.6d Schematic illustrations of various polymer-processing methods.
FIGURE 1.6e Schematic illustrations of various machining and finishing processes.
FIGURE 1.6f Schematic illustrations of various joining processes.
FIGURE 1.9 A saltshaker 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.
TABLE 1.4 Average Life Expectancy of Various Products
              Product Quality
Product quality (p.29) is one of the most critical
aspects of manufacturing because it directly
influences customer satisfaction. The traditional
approach of inspecting products after they are
made had largely been replaced by the
recognition that quality must be built into the
product from its initial design thought all
subsequent stages of manufacture and
assembly.
           ∑∑∑∑∑∑ (Six Sigma)
• The level of defects is identified in terms of
  standard deviation and given the symbol
  sigma (Greek letter ∑ upper case or σ lower
  case)
• Six sigma (standard deviations) allows only 3.4
  defective parts per million parts made
TABLE 1.5 Relative Cost of Repair at Various Stages of Product Development and Sale
TABLE 1.6 Typical Cost Breakdown in Manufacturing
TABLE 1.7 Approximate Relative Hourly Compensation for Workers in Manufacturing in 2006 (United States = 100)

								
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