Metal and Nonmetal Use in Automobiles Figure I

Metal and Non-metal Use in Automobiles Figure I. 1 Some of the metallic and nonmetallic materials used in a typical automobile ME 282 – Copyright Prentice-Hall

Permanent Deformation Figure 1. 5 Permanent deformation (also called plastic deformation) of a single crystal subjected to a shear stress: (a) structure before deformation; and (b) permanent deformation by slip. The b/a ratio influences the magnitude of the shear stress required to cause slip. ME 282 – Copyright Prentice-Hall

Defects in a Single-Crystal Lattice Figure 1. 8 Schematic illustration of types of defects in a single-crystal lattice: self-interstitial, vacancy, interstitial, and substitutional ME 282 – Copyright Prentice-Hall

Edge Dislocation Movement Figure 1. 10 Movement of an edge dislocation across the crystal lattice under a shear stress. Dislocations help explain why the actual strength of metals is much lower than that predicted by theory. ME 282 – Copyright Prentice-Hall ?

Solidification of Molten Metal Figure 1. 11 Schematic illustration of the stages during solidification of molten metal; each small square represents a unit cell. (a) Nucleation of crystals at random sites in the molten metal; note that the crystallographic orientation of each site is different. (b) and (c) Growth of crystals as solidification continues. (d) Solidified metal, showing individual grains and grain boundaries; note the different angles at which neighboring grains meet each other. ME 282 – Copyright Prentice-Hall

Recovery, Recrystallization, and Grain Growth Effects Figure 1. 14 Schematic illustration of the effects of recovery, recrystallization, and grain growth on mechanical properties and on the shape and size of grains. Note the formation of small new grains during recrystallization. ME 282 – Copyright Prentice-Hall

Relative Mechanical Properties of Materials ME 282 – Copyright Prentice-Hall

Loading and Unloading of Tensile-test Specimen Figure 2. 3 Schematic illustration of the loading and the unloading of a tensile-test specimen. Note that, during unloading, the curve follows a path parallel to the original elastic slope. ME 282 – Copyright Prentice-Hall

Power Law Constitutive Model where K = strength coefficient n = strain hardening exponent ME 282 – Copyright Prentice-Hall

Temperature Effects on Stress-strain Curves Figure 2. 7 Typical effects of temperature on stress-strain curves. Note that temperature affects the modulus of elasticity, the yield stress, the ultimate tensile strength, and the toughness (area under the curve) of materials. ME 282 – Copyright Prentice-Hall

Effect of Strain Rate on Tensile Strength of Al Figure 2. 8 The effect of strain rate on the ultimate tensile strength for aluminum. Note that, as the temperature increases, the slopes of the curves increase; thus, strength becomes more and more sensitive to strain rate as temperature increases. Source: After J. H. Holloman ME 282 – Copyright Prentice-Hall

Cooling of Metals Figure 4. 4 (a) Cooling curve for the solidification of pure metals. Note that freezing takes place at a constant temperature; during freezing, the latent heat of solidification is given off. (b) Change in density during the cooling of pure metals. ME 282 – Copyright Prentice-Hall

Iron-iron Carbide Phase Diagram Figure 4. 8 The iron-iron carbide phase diagram. Because of the importance of steel as an engineering material, this diagram is one of the most important of all phase diagrams. ME 282 – Copyright Prentice-Hall

Effect of Time and Temperature on Yield Stress Figure 4. 22 The effect of aging time and temperature on the yield stress of 2014 -T 4 aluminum alloy. Note that, for each temperature, there is an optimal aging time for maximum strength. ME 282 – Copyright Prentice-Hall

Outline of Heat Treatment Processes for Surface Hardening

Mechanical Properties of Steel as a Function of Tempering Temperature Figure 4. 25 Mechanical properties of oilquenched 4340 steel as a function of tempering temperature. ME 282 – Copyright Prentice-Hall

Cost of Wrought Metals and Plastics vs. Carbon Steel ME 282 – Copyright Prentice-Hall

What happens to plastics as you move from condition(a) to (d)? Chains Polymer Figure 7. 5 Schematic illustration of polymer chains. (a) Linear structure – thermoplastics such as acrylics, nylons, polyethylene, and polyvinyl chloride have linear structures. (b) Branched structure, such as in polyethylene. (c) Cross-linked structure – many rubbers or elastomers have this structure, and the vulcanization of rubber produces this structure. (d) Network structure, which is basically highly cross-linked – examples are thermosetting plastics, such as expoxies and phenolics. ME 282 – Copyright Polymers become stronger and less ductile with more cross linking. Prentice-Hall

Ceramic Types and Characteristics ME 282 – Copyright Prentice-Hall

Boeing 757 -200 Figure 9. 1 Application of advanced composite materials in Boeing 757 -200 commercial aircraft. Source: Courtesy of Boeing Commercial Airplane Company. ME 282 – Copyright Prentice-Hall

Metal-Matrix Composite Materials and Applications ME 282 – Copyright Prentice-Hall

Casting Design and Fluidity Test Figure 10. 8 Schematic illustration of a typical riser-gated casting. Risers serve as reservoirs, supplying molten metal to the casting as it shrinks during solidification. Figure 10. 9 A test method for fluidity using a spiral mold. The fluidity index is the length of the solidified metal in the spiral passage. The greater the length of the solidified metal, the greater is its fluidity. ME 282 – Copyright Prentice-Hall

Alloy Solidification Figure 10. 4 Schematic illustration of alloy solidification and temperature distribution in the solidifying metal. Note the formation of dendrites in the mushy zone. ME 282 – Copyright Prentice-Hall

Solidification Contraction or Expansion ME 282 – Copyright Prentice-Hall

Expendable-Pattern Casting Process Figure 11. 11 Schematic illustration of the expendable-pattern casting process, also known as lost-foam or evaporative casting.

Investment Casting Process Figure 11. 13 Schematic illustration of investment casting (lost-wax) process. Castings by this method can be made with very fine detail and from a variety of metals. Source: Courtesy of Steel Founder’s Society of America. ME 282 – Copyright Prentice-Hall

Effects of Hot Rolling Figure 13. 6 Changes in the grain structure of cast or of large-grain wrought metals during hot rolling. Hot rolling is an effective way to reduce grain size in metals for improved strength and ductility. Cast structures of ingots or continuous castings are converted to a wrought structure by hot working.

Shape Rolling of an H-section part Figure 13. 12 Steps in the shape rolling of an H-section part. Various other structural sections, such as channels and I-beams, also are rolled by this kind of process. ME 282 – Copyright Prentice-Hall

Forged Components Figure 14. 1 (a) Schematic illustration of the steps involved in forging a knife. (b) Landinggear components for the C 5 A and C 5 B transport aircraft, made by forging. (c) General view of a 445 MN (50, 000 ton) hydraulic press. Source: (a) Courtesy of the Mundial LLC. (b and c) Courtesy of Wyman-Gordon Company. ME 282 – Copyright Prentice-Hall

Microstructure as a Function of Manufacturing Method Figure 14. 2 Schematic illustration of a part made by three different processes showing grain flow. (a) Casting by the processes described in Chapter 11. (b) Machining form a blank, described in Part IV of this book, and (c) forging. Each process has its own advantages and limitations regarding external and internal characteristics, material properties, dimensional accuracy, surface finish, and the economics of production. Source: Courtesy of Forging Industry Association. ME 282 – Copyright Prentice-Hall

Extrusions and Products Made from Extrusions Figure 15. 2 Extrusions and examples of products made by sectioning off extrusions. Source: Courtesy of Kaiser Aluminum. ME 282 – Copyright Prentice-Hall

Extrusion Temperature Ranges ME 282 – Copyright Prentice-Hall

Process Variables in Wire Drawing Figure 15. 18 Process variables in wire drawing. The die angle, the reduction in crosssectional area per pass, the speed of drawing, the temperature, and the lubrication all affect the drawing force, F. ME 282 – Copyright Prentice-Hall

Characteristics of Sheet-Metal Forming Processes ME 282 – Copyright Prentice-Hall

Deformation and Tearing in Sheet Metal During Forming Figure 16. 15 The deformation of the grid pattern and the tearing of sheet metal during forming. The major and minor axes of the circles are used to determine the coordinates on the forming-limit diagram in Fig. 16. 14 b. Source: After S. P. Keeler. ME 282 – Copyright Prentice-Hall

Springback in Bending Figure 16. 19 Springback in bending. The part tends to recover elastically after bending, and its bend radius becomes larger. Under certain conditions, it is possible for the final bend angle to be smaller than the original angle (negative springback). ME 282 – Copyright Prentice-Hall

Parts Made by Powder-Metallurgy (b) (c) (a) Figure 17. 1 (a) Examples of typical parts made by powder-metallurgy processes. (b) Upper trip lever for a commercial sprinkler made by P/M. This part is made of an unleaded brass alloy; it replaces a die-cast part with a 60% savings. (c) Main-bearing metal-powder caps for 3. 8 and 3. 1 liter General Motors automotive engines. Source: (a) and (b) Reproduced with permission from Success Stories on P/M Parts, 1998. Metal Powder Industries Federation, Princeton, New Jersey, 1998. (c) Courtesy of Zenith Sintered Products, Inc. , Milwaukee, ME 282 – Copyright Wisconsin. Prentice-Hall

Density as a Function of Pressure and the Effects of Density on Other Properties Figure 17. 10 (a) Density of copper- and ironpowder compacts as a function of compacting pressure. Density greatly influences the mechanical and physical properties of P/M parts. (b) Effect of density on tensile strength, elongation, and electrical conductivity of copper powder. Source: (a) After F. V. Lenel, (b) IACS: International Annealed Copper Standard (for electrical conductivity). ME 282 – Copyright Prentice-Hall

Sintering Time and Temperature for Metals ME 282 – Copyright Prentice-Hall

Comparison of Properties of Wrought and Equivalent P/M Metals ME 282 – Copyright Prentice-Hall

Extruder Schematic Figure 19. 2 (a) Schematic illustration of a typical screw extruder. (b) Geometry of an extruder screw. Complex shapes can be extruded with relatively simple and inexpensive dies. ME 282 – Copyright Prentice-Hall

Production of Plastic Film and Bags (b) Figure 19. 5 (a) Schematic illustration of the production of thin film and plastic bags from tube – first produced by an extruder and then blown by air. (b) A blown-film operation. This process is well developed, producing inexpensive and very large quantities of plastic film and shopping bags. Source: Courtesy of Windmoeller & Hoelscher. ME 282 – Copyright Prentice-Hall

Parts Made by Rapid-Prototyping (c) (a) (b) Figure 20. 1 Examples of parts made by rapid-prototyping processes: (a) selection of parts from fused-deposition modeling; (b) stereolithography model of cellular phone; and (c) selection of parts form three-dimensional printing. Source: Courtesy of Stratasys, Inc. , (b) and (c) Courtesy of 3 D Systems, Inc. ME 282 – Copyright Prentice-Hall

Fused-Deposition-Modeling Figure 20. 3 (a) Schematic illustration of the fused-deposition-modeling process. (b) The FDM 5000, a fused-deposition-modeling machine. Source: Courtesy of Stratysis, Inc. ME 282 – Copyright Prentice-Hall

Common Machining Operations Figure 21. 1 Some examples of common machining operations. ME 282 – Copyright Prentice-Hall

Two-Dimensional Cutting Process Figure 21. 3 Schematic illustration of a two-dimensional cutting process, also called orthogonal cutting: (a) Orthogonal cutting with a well-defined shear plane, also known as the Merchant Model. Note that the tool shape, depth of cut, to, and the cutting speed, V, are all independent variables, (b) Orthogonal cutting without a well-defined shear plane. ME 282 – Copyright Prentice-Hall

Tool-life Curves Figure 21. 17 Tool-life curves for a variety of cutting-tool materials. The negative inverse of the slope of these curves is the exponent n in the Taylor tool-life equation and C is the cutting speed at T = 1 min, ranging from about 200 to 10, 000 ft. /min in this figure. ME 282 – Copyright Prentice-Hall

Feed Marks on a Turned Surface roughness: Figure 21. 23 Schematic illustration of feed marks on a surface being turned (exaggerated). ME 282 – Copyright Prentice-Hall

Hardness of Cutting Tool Materials as a Function of Temperature Figure 22. 1 The hardness of various cutting-tool materials as a function of temperature (hot hardness). The wide range in each group of materials is due to the variety of tool compositions and treatments available for that group. ME 282 – Copyright Prentice-Hall

General Properties of Tool Materials ME 282 – Copyright Prentice-Hall

Inserts and Toolholders Figure 22. 2 Typical carbide inserts with various shapes and chip-breaker features: Round inserts are also available, as can be seen in Figs. 22. 3 c and 22. 4. The holes in the inserts are standardized for interchangeability in toolholders. Source: Courtesy of Kyocera Engineered Ceramics, Inc. Figure 22. 3 Methods of mounting inserts on toolholders: (a) clamping and (b) wing lockpins. (c) Examples of inserts mounted with threadless lockpins, which are secured with side screws. Source: Courtesy of Valenite. ME 282 – Copyright Prentice-Hall

General Recommendations for Turning Operations ME 282 – Copyright Prentice-Hall

Range of Surface Roughnesses in Machining Processes Figure 23. 13 The range of surface roughnesses obtained in various machining processes. Note the wide range within each group, especially in turning and boring. ME 282 – Copyright Prentice-Hall

Range of Dimensional Tolerances in Machining as a Function of Workpiece Size Figure 23. 14 Range of dimensional tolerances obtained in various machining processes as a function of workpiece size. Note that there is an order os magnitude difference between small and large workpieces. ME 282 – Copyright Prentice-Hall

Milling Cutters and Milling Operations Figure 24. 2 Some basic types of milling cutters and milling operations. (a) Peripheral milling. (b) Face milling. (c) End milling. (d) Ball-end mill with indexable coated-carbide inserts machining a cavity in a die block. (e) Milling a sculptured surface with an end mill, using a five-axis numerical control machine. Source: (d) Courtesy of Iscar. (e) Courtesy of The Ingersoll Milling Machine Co. ME 282 – Copyright Prentice-Hall

Summary of Peripheral Milling Parameters and Formulas ME 282 – Copyright Prentice-Hall

Face-Milling Cutter Figure 24. 7 Terminology for a face-milling cutter. ME 282 – Copyright Prentice-Hall

Horizontal-Spindle Machining Center Figure 25. 2 A horizontal-spindle machining center equipped with an automatic tool changer. Tool magazines can store up to 200 cutting tools of various functions and sizes. Source: Courtesy of Cincinnati Milacron, Inc. ME 282 – Copyright Prentice-Hall

Machining Centers Figure 25. 4 (a) Schematic illustration of the top view of a horizontal-spindle machining center showing the pallet pool, set-up station for a pallet, pallet carrier, and an active pallet in operation (shown directly below the spindle of the machine). (b) Schematic illustration of two machining centers with a common pallet pool. Various other pallet arrangements are possible in such systems. Source: Courtesy of Hitachi Seiki Co. , Ltd. ME 282 – Copyright Prentice-Hall

Chatter Marks on Surface of Turned Part Figure 25. 13 Chatter marks (right of center of photograph) on surface of a turned part. Source: Courtesy of General Electric Company. ME 282 – Copyright Prentice-Hall

Bonded Abrasives Used in Abrasive-Machining Processes Figure 25. 1 A variety of bonded abrasives used in abrasivemachining processes. Source: Courtesy of Norton Company. ME 282 – Copyright Prentice-Hall

Chemical Milling Figure 27. 2 (a) Missile skin-panel section contoured by chemical milling to improve the stiffness-to-weight ratio of the part. (b) Weight reduction of space-launch vehicles by the chemical milling of aluminum-alloy plates. These panels are chemically milled after the plates first have been formed into shape by a process such as roll forming or stretch forming. The design of the chemically machined rib patterns can be modified readily at minimal cost. ME 282 – Copyright Prentice-Hall

Stepped Cavities Produced by EDM Process Figure 27. 11 Stepped cavities produced with a square electrode by the EDM process. The workpiece moves in the two principle horizontal directions (x – y), and its motion is synchronized with the downward movement of the electrode to produce these cavities. Also shown is a round electrode capable of producing round or elliptical cavities. Source: Courtesy of AGIE USA Ltd. ME 282 – Copyright Prentice-Hall

Nonmetallic Parts Made by Water-Jet Cutting Enlargement of Fig. 27. 16 c. Examples of various nonmetallic parts produced by the water-jet cutting process. Source: Courtesy of Possis Corporation ME 282 – Copyright Prentice-Hall

Fabrication of Integrated Circuits Figure 28. 2 Outline of the general fabrication sequence for integrated circuits. ME 282 – Copyright Prentice-Hall

Circuit Board Structures and Features Figure 28. 29 Printed circuit board structures and design features. ME 282 – Copyright Prentice-Hall

Example: Surface Micromachining of a Hinge (a) (b) Figure 29. 6 (a) SEM image of a deployed micromirror. (b) Detail of the micromirror hinge. Source: Courtesy of Sandia National Laboratories. ME 282 – Copyright Prentice-Hall

Fusion Welding Processes ME 282 – Copyright Prentice-Hall

Weld Bead Comparison (a) (b) Figure 30. 14 Comparison of the size of weld beads: (a) laser-beam or electronbeam welding, and (b) tungsten-arc welding. Source: American Welding Society, Welding Handbook (8 th ed. ), 1991. ME 282 – Copyright Prentice-Hall

Ultrasonic Welding Figure 31. 2 (a) Components of an ultrasonic welding machine for making lap welds. The lateral vibrations of the tool tip cause plastic deformation and bonding at the interface of the workpieces. (b) Ultrasonic seam welding using a roller as the sonotrode. ME 282 – Copyright Prentice-Hall

Friction Stir Welding Figure 31. 5 The principle of the friction stir welding process. Alluminum-alloy plates up to 75 mm (3 in. ) thick have been welded by this process. ME 282 – Copyright Prentice-Hall