İmal Kaynak Kaynak ( ingilzice ) Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Weld Joints FIGURE 12.1 Examples of welded joints. (a) Butt joint (b) Corner joint (c) T joint (d) Lap joint (e) Edge joint Method Strength Design Variability Small Parts Large Parts Tolerances Relibility Ease of Maintenance Visual Inspection Cost Arc welding 1 2 3 1 3 1 2 2 2 Resistance welding 1 2 1 1 3 3 3 3 1 Brazing 1 1 1 1 3 1 3 2 3 Bolts and nuts 1 2 3 1 2 1 1 1 3 Riveting 1 2 3 1 1 1 3 1 2 Fasteners 2 3 3 1 2 2 2 1 3 Seaming, crimping 2 2 1 3 3 1 3 1 1 Adhesive bonding 3 1 1 2 3 2 3 3 2 Note: 1, very good; 2, good; 3, poor. TABLE 12.1 Comparison of various joining methods. Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 General Summary Joining Skill Level Welding Current Distor- Cost of Process Operation Advantage Required Position Type tion * Equipment Shielded metal arc Manual Portable and ?exible High All ac, dc 1 to 2 Low Submerged arc Automatic High deposi- tion Low to medium Flat and horizontal ac, dc 1 to 2 Medium Gas metal arc Semiautomatic or automatic Works with most metals Low to high All dc 2 to 3 Medium to high Gas tung- sten arc Manual or automatic Works with most metals Low to high All ac, dc 2 to 3 Medium Flux-cored arc Semiautomatic or automatic High deposi- tion Low to high All dc 1 to 3 Medium Oxyfuel Manual Portable and ?exible High All – 2 to 4 Low Electron beam, laser beam Semiautomatic or automatic Works with most metals Medium to high All – 3 to 5 High * 1, highest; 5, lowest TABLE 12.2 General characteristics of joining processes.Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Oxyfuel Gas Welding FIGURE 12.2 Three basic types of oxyacetylene ?ames used in oxyfuel gas welding and cutting operations: (a) neutral ?ame; (b) oxidizing ?ame; (c) carburizing, or reducing, ?ame. (d) The principle of the oxyfuel gas welding operation. (a) Neutral flame (b) Oxidizing flame (c) Carburizing (reducing) flame 2100°C (3800°F) 1260°C (2300°F) Inner cone 3040 to 3300°C (5500 to 6000°F) Outer envelope Outer envelope (small and narrow) Inner cone (pointed) Acetylene feather Bright luminous inner cone Blue envelope (d) Gas mixture Welding torch Flame Solidified weld metal Molten weld metal Filler rod Base metalManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Pressure Gas Welding FIGURE 12.3 Schematic illustration of the pressure gas welding process; (a) before, and (b) after. Note the formation of a ?ash at the joint, which can later be trimmed off. C 2 H 2 + O 2 mixture Torch Flame heating of surfaces Clamp Upsetting force Torch withdrawn (a) (b)Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Heat Transfer in Welding Speci?c Energy, u Material J/mm 3 BTU/in 3 Aluminum and its alloys 2.9 41 Cast irons 7.8 112 Copper 6.1 87 Bronze (90Cu-10Sn) 4.2 59 Magnesium 2.9 42 Nickel 9.8 142 Steels 9.1-10.3 128-146 Stainless steels 9.3-9.6 133-137 Titanium 14.3 204 TABLE 12.3 Approximate speci?c energy required to melt a unit volume of commonly welded materials. Heat input Welding speed H l =e VI v v=e VI uAManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Shielded Metal Arc Welding FIGURE 12.4 (a) Schematic illustration of the shielded metal arc welding process. About one-half of all large-scale industrial welding operations use this process. (b) Schematic illustration of the shielded metal arc welding operation. Welding machine AC or DC power source and controls Electrode Electrode holder Arc Solidified slag Coating Electrode Shielding gas Base metal Arc Weld metal Work Work cable Electrode cable FIGURE 12.5 A weld zone showing the build-up sequence of individual weld beads in deep welds. 7 1 2 8 5 4 6 3Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Submerged Arc Welding FIGURE 12.6 Schematic illustration of the submerged arc welding process and equipment. Unfused ?ux is recovered and reused. Electrode-wire reel Electrode cable Voltage and current control Voltage-pickup leads (optional) Ground Wire-feed motor Unfused-flux recovery tube Flux hopper Contact tube Workpiece Weld backingManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Gas Metal Arc Welding FIGURE 12.7 (a) Gas metal arc welding process, formerly known as MIG welding (for metal inert gas). (b) Basic equipment used in gas metal arc welding operations. Shielding gas Nozzle Travel Arc Base metal Molten weld metal Solidified weld metal Wire guide and contact tube Shielding gas Solid wire electrode Current conductor Workpiece Gun Feed control Control system Gas out Gun control Gas in Wire Shielding-gas source Wire-feed drive motor 110 V supply Voltage control Contactor control (a) (b) Welding machineManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Flux-Cored Arc Welding FIGURE 12.8 Schematic illustration of the ?ux-cored arc welding process. This operation is similar to gas metal arc welding. Metal droplets covered with thin slag coating forming molten puddle Powdered metal, vapor-or gas-forming materials, deoxidizers and scavengers Insulated extension tip Current-carrying guide tube Arc Base metal Arc shield composed of vaporized and slag-forming compounds protects metal transfer through arc Solidified slag Molten slag Solidified weld metal Molten weld metalManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Electrogas & Electroslag Welding FIGURE 12.9 Schematic illustration of the electrogas welding process. Welding wire Drive rolls Electrode conduit Gas Welding gun Welding wire Water out Water in Water in Water out Moveable shoe Fixed shoe Primary shielding gas Supplementary shielding gas Gas Gas box Water Gas Oscillator FIGURE 12.10 Equipment used for electroslag welding operations. Control panel Wire reel Wire-feed drive Oscillation (optional) Molten slag Molten weld pool Retaining shoe Water in Consumable guide tube Water out Work Workpiece (ground) lead Electrode lead Power sourceManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Gas T ungsten Arc Welding FIGURE 12.11 (a) Gas tungsten arc welding process, formerly known as TIG welding (for tungsten inert gas). (b) Equipment for gas tungsten arc welding operations. Electrical conductor Tungsten electrode Shielding gas Arc Travel Filler wire Molten weld metal Gas passage Filler rod Cooling-water supply Inert-gas supply Foot pedal (optional) Workpiece Drain AC or DC welder (a) (b) Solidified weld metal TorchManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Plasma Arc Welding FIGURE 12.12 T wo types of plasma arc welding processes: (a) transferred and (b) nontransferred. Deep and narrow welds are made by this process at high welding speeds. Power supply Tungsten electrode Plasma gas Shielding gas (a) (b) – Power supply – + +Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Weld Bead Comparisons FIGURE 12.13 Comparison of the size of weld beads in (a) electron-beam or laser-beam welding with that in (b) conventional (tungsten arc) welding. Source: American Welding Society, Welding Handbook, 8th ed., 1991. (a) (b) FIGURE 12.14 Gillette Sensor razor cartridge, with laser-beam welds. Laser weldsManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Fusion Weld Characteristics FIGURE 12.15 Characteristics of a typical fusion weld zone in oxyfuel gas welding and arc welding processes. Molten weld metal Melting point of base metal Temperature at which the base-metal microstructure is affected Original temperature of base metal Temperature Original structure Heat-affected zone Fusion zone (weld metal) Base metal FIGURE 12.16 Grain structure in (a) a deep weld and (b) a shallow weld. Note that the grains in the solidi?ed weld metal are perpendicular to their interface with the base metal. (a) (b) FIGURE 12.17 (a) Weld bead on a cold-rolled nickel strip produced by a laser beam. (b) Microhardness pro?le across the weld bead. Note the lower hardness of the weld bead as compared with the base metal. Source: IIT Research Institute. (a) (b) 145 155 260 330 355 0.1 mm 1 mm 0.43 mm Hardness (HV) Heat-affected zone Melt zoneManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Fusion Defects FIGURE 12.19 Examples of various incomplete fusion in welds. FIGURE 12.18 Intergranular corrosion of a weld joint in ferritic stainless-steel welded tube, after exposure to a caustic solution. The weld line is at the center of the photograph. Source: Courtesy of Allegheny Ludlum Corp. Incomplete fusion in fillet welds. B is often termed bridging B Weld Base metal (a) (b) (c) Weld Incomplete fusion from oxide or dross at the center of a joint, especially in aluminum Incomplete fusion in a groove weld WeldManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Defects in Welded Joints FIGURE 12.20 Examples of various defects in fusion welds. (c) Good weld (b) Lack of penetration Undercut Porosity Overlap Underfill Crack Inclusions (a) Incomplete penetration Base metal FIGURE 12.19 Examples of various incomplete fusion in welds. Toe crack Underbead crack Toe crack Base metal Weld Longitudinal crack Longitudinal crack Crater cracks Weld Base metal (a) (b) Transverse crack Transverse crack Base metal WeldManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Weld Crack FIGURE 12.22 Crack in a weld bead, due to the fact that the two components were not allowed to contract after the weld was completed. Source: Courtesy of Packer Engineering. Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Distortion in Welds FIGURE 12.24 Residual stresses developed in a straight butt joint. Source: Courtesy of the American Welding Society. (a) (c) (d) (b) Transverse shrinkage Angular distortion Weld Longitudinal shrinkage Weld Neutral axis Weld Weld FIGURE 12.23 Distortion and warping of parts after welding, caused by differential thermal expansion and contraction of different regions of the welded assembly. Warping can be reduced or eliminated by proper weld design and ?xturing prior to welding. Weld Base metal (b) (a) Residual stress Compressive TensileManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Distortion of Welded Structures FIGURE 12.25 Distortion of a welded structure. (a) Before welding; (b) during welding, with weld bead placed in joint; (c) after welding, showing distortion in the structure. Source: After J.A. Schey. Rigid frame Hot zone (expanded) No shape change Melt (pushed out) Contraction Internal (residual) tensile stress Distortion (a) (b) (c)Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 T ension-Shear T esting FIGURE 12.26 (a) Types of specimens for tension-shear testing of welds. (b) Wraparound bend test method. (c) Three-point bending of welded specimens. (See also Fig. 2.21.) (a) (b) Longitudinal tension-shear Transverse tension-shear (c) Clamp Roller Weld Side bend Face bend Root bendManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 T ension-Shear T est of Spot Welds FIGURE 12.27 (a) T ension-shear test for spot welds; (b) cross-tension test; (c) twist test; (d) peel test. Hole left in part Button diameter indicates quality (c) (b) (a) (d) 1. 2. 3. Raised nuggetManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Roll Bonding & Ultrasonic Welding FIGURE 12.28 Schematic illustration of the roll-bonding, or cladding, process. Rolls Cladding metal Base metal FIGURE 12.29 (a) Components of an ultrasonic welding machine for lap welds. (b) Ultrasonic seam welding using a roller. Mass Anvil Transducer DC polarization supply AC power supply Direction of vibration (a) Force Coupling system Tip Workpiece (b) Transducer Toolholder Roller WorkpieceManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Friction Welding FIGURE 12.31 Shapes of the fusion zone in friction welding as a function of the force applied and the rotational speed. Force increased Beginning of flash Flash 1. 2. 3. 4. Force Speed Speed, Force, Upset length Time Force Total upset length Upset length FIGURE 12.30 Sequence of operations in the friction welding process. (1) The part on the left is rotated at high speed. (2) The part on the right is brought into contact under an axial force. (3) The axial force is increased, and the part on the left stops rotating; ?ash begins to form. (4) After a speci?ed upset length or distance is achieved, the weld is completed. The upset length is the distance the two pieces move inward during welding after their initial contact; thus, the total length after welding is less than the sum of the lengths of the two pieces. If necessary, the ?ash can be removed by secondary operations, such as machining or grinding. (a) High pressure or low speed (b) Low pressure or high speed (c) OptimumManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Friction Stir Welding FIGURE 12.32 The principle of the friction stir welding process. Aluminum-alloy plates up to 75 mm (3 in.) thick have been welded by this process. Source: TWI, Cambridge, United Kingdom. Shouldered non-consumable tool Weld Probe Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Resistance Spot Welding FIGURE 12.33 (a) Sequence in the resistance spot welding operation. (b) Cross-section of a spot weld, showing weld nugget and light indentation by the electrode on sheet surfaces. (b) Electrode Sheet separation Indentation Heat-affected zone Electrode tip Weld nugget Electrode (a) 1. Pressure applied 2. Current on 3. Current off, pressure on 4. Pressure released Lap joint Weld nugget Electrodes FIGURE 12.34 T wo types of electrode designs for easy access in spot welding operations for complex shapes. (a) (b) Workpiece Electrodes Workpiece Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Seam & Resistance Projection Welding FIGURE 12.35 (a) Illustration of the seam welding process, with rolls acting as electrodes. (b) Overlapping spots in a seam weld. (c) Cross- section of a roll spot weld. (d) Mash seam welding. Electrode wheels Electrode wheels Weld Sheet (b) (a) (c) (d) Weld Weld nuggets FIGURE 12.36 Schematic illustration of resistance projection welding: (a) before and (b) after. The projections on sheet metal are produced by embossing operations, as described in Section 7.5.2. Flat electrodes Sheet Workpiece Projections Weld nuggets Product Force Force (a) (b)Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Flash & Stud Welding FIGURE 12.37 Flash welding process for end-to- end welding of solid rods or tubular parts. (a) Before and (b) after. Arc (a) (b) FIGURE 12.38 Sequence of operations in stud arc welding, used for welding bars, threaded rods, and various fasteners on metal plates. Weld Push Push Pull Molten weld metal Arc Ceramic ferrule Stud Workpiece (base metal) 1. 2. 3. 4.Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Explosion Welding FIGURE 12.39 Schematic illustration of the explosion welding process: (a) constant interface clearance gap and (b) angular interface clearance gap. (a) (b) Detonator Explosive Clad metal (flyer) Constant- interface clearance gap Base plate Detonator Explosive Buffer Clad metal Angular-interface clearance gap Base plate FIGURE 12.40 Cross-sections of explosion welded joints: (a) titanium (top) on low-carbon steel (bottom) and (b) Incoloy 800 (iron-nickel- base alloy) on low-carbon steel. The wavy interfaces shown improve the shear strength of the joint. Some combinations of metals, such as tantalum and vanadium, produce a much less wavy interface. If the two metals have little metallurgical compatibility, an interlayer may be added that has compatibility with both metals. {\it Source:} Courtesy of DuPont Company. (a) (b)Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Diffusion Bonding FIGURE 12.41 Sequence of operations in diffusion bonding and superplastic forming of a structure with three ?at sheets. See also Fig. 7.46. Source: After D. Stephen and S.J. Swadling. Bonding pressure Die Stop off Die Gas pressure for forming 1. Core sheet 2. Diffusion bonding 3. Superplastic forming 4. Final structureManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Brazing & Braze Welding FIGURE 12.43 The effect of joint clearance on tensile and shear strength of brazed joints. Note that unlike tensile strength, shear strength continually decreases as clearance increases. (a) (b) Base metal Base metal Filler metal Torch Flux Brass filler metal FIGURE 12.42 (a) Brazing and (b) braze welding operations. Joint clearance Joint strength Tensile strength Shear strength Base Metal Filler Metal Brazing Temperature ( ? C) Aluminum and its alloys Aluminum-silicon 570-620 Magnesium alloys Magnesium-aluminum 580-625 Copper and its alloys Copper-phosphorus 700-925 Ferrous and nonferrous alloys (except Silver and copper alloys, 620-1150 aluminum and magnesium) copper-phosphorus Iron-, nickel-, and cobalt-base alloys Gold 900-1100 Stainless steels, nickel- and cobalt- Nickel-silver 925-1200 base alloys TABLE 12.4 Typical ?ller metals for brazing various metals and alloys.Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Furnace Brazing & Brazed Joints FIGURE 12.44 An application of furnace brazing: (a) before and (b) after. Note that the ?ller metal is a shaped wire. (b) Filler metal Filler-metal wire (a) FIGURE 12.45 Joint designs commonly used in brazing operations. Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Solder Joints FIGURE 12.46 Joint designs commonly used for soldering. (a) Flanged T (d) Line contact (b) Flush lap (c) Flanged corner Bolt or rivet (e) Flat lock seam (f) Flanged bottom (g) Gull wing Crimp (h) Through hole (i) Crimped (j) Twisted PC board Wire Solder Typical Application Tin-lead General purpose Tin-zinc Aluminum Lead-silver Strength at higher than room temperature Cadmium-silver Strength at high temperatures Zinc-aluminum Aluminum; corrosion resistance Tin-silver Electronics Tin-bismuth Electronics TABLE 12.5 Types of solders and their applications.Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Soldering for Circuit Boards FIGURE 12.47 Screening solder paste onto a printed circuit board in re?ow soldering. Source: After V. Solberg. Tensioned screen Screen material Squeegee Paste Paste deposited on contact area Emulsion Contact area FIGURE 12.48 (a) Schematic illustration of the wave soldering process. (b) SEM image of a wave soldered joint on a surface-mount device. See also Section 13.13. Oil mixed in Flux Copper land Copper land Oil or air Turbulent zone (oil prevents dross) Turbulent zone (dross formed in air) Plating or coating Residues (a) (b) Wetted solder coatManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Adhesive Bonding FIGURE 12.49 Various con?gurations for adhesively bonded joints: (a) single lap, (b) double lap, (c) scarf, and (d) strap. (a) Simple Beveled Radiused (b) Simple Beveled Radiused (c) Single taper Double taper Increased thickness (d) Single Double Beveled FIGURE 12.50 Characteristic behavior of (a) brittle and (b) tough and ductile adhesives in a peeling test. This test is similar to peeling adhesive tape from a solid surface. Peeling force (a) (b)Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Properties of Adhesives Epoxy Polyurethane Modi?ed Acrylic Cyanocrylate Anaerobic Impact resistance Poor Excellent Good Poor Fair Tension-shear 15-22 12-20 20-30 18.9 17.5 strength, MPa (2.2-3.2) (1.7-2.9) (2.9-4.3) (2.7) (2.5) (10 3 psi) Peel strength * , N/m < 523 (3) 14,000 (80) 5250 (30) < 525 (3) 1750 (10) (lb/in.) Substrates bonded Most Most smooth, Most smooth, Most non- Metals, glass, nonporous nonporous porous metals thermosets or plastics Service temperature -55 to 120 -40 to 90 -70 to 120 -55 to 80 -55 to 150 range, ? C ( ? F) (-70 to 250) (-250 to 175) (-100 to 250) (-70 to 175) (-70 to 300) Heat cure or mixing Yes Yes No No No required Solvent resistance Excellent Good Good Good Excellent Moisture resistance Good-Excellent Fair Good Poor Good Gap limitation, mm None None 0.5 (0.02) 0.25 (0.01) 0.60 (0.025) (in.) Odor Mild Mild Strong Moderate Mild Toxicity Moderate Moderate Moderate Low Low Flammability Low Low High Low Low Note: Peel strength varies widely depending on surface preparation and quality. TABLE 12.6 Typical properties and characteristics of chemically reactive structural adhesives.Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Rivets and Stapling FIGURE 12.51 Examples of rivets: (a) solid, (b) tubular, (c) split, or bifurcated, and (d) compression. (a) (b) (c) (d) FIGURE 12.52 Examples of various fastening methods. (a) Standard loop staple; (b) ?at clinch staple; (c) channel strap; (d) pin strap. (a) Standard loop (b) Flat clinch (c) (d) Nonmetal Metal channelManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Seams & Crimping FIGURE 12.53 Stages in forming a double- lock seam. See also Fig. 7.23. 1. 2. 3. 4. FIGURE 12.54 T wo examples of mechanical joining by crimping. (a) (b)Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Snap Fasteners FIGURE 12.55 Examples of spring and snap-in fasteners to facilitate assembly. Sheet-metal cover (d) (e) (f) (g) Integrated snap fasteners Sheet-metal cover Deflected Rigid Rod-end attachment to sheet-metal part (b) (a) (c) Spring clip Nut Push-on fastenerManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Design Guidelines for Welding FIGURE 12.56 Design guidelines for welding. Source: Bralla, J.G. (ed.) Handbook of Product Design for Manufacturing, 2d ed. McGraw-Hill, 1999. (a) (b) (c) (d) (e) (f) Poor Burr Good Poor Good Deburred edge Load Load Cut not square 90° Surface to be machinedManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Weld Designs FIGURE 12.58 Weld designs for Example 12.7. Poor Good FIGURE 12.57 Design guidelines for ?ash welding. Continuous weld (a) Intermittent welds (c) Double V groove Weld Base metal Single V groove (b) Moment, M 3M WeldsManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Brazing Designs FIGURE 12.59 Examples of good and poor designs for brazing. Good Poor Comments Too little joint area in shear Improved design when fatigue loading is a factor to be considered Insufficient bondingManufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Design for Adhesive Bonding FIGURE 12.60 Various joint designs in adhesive bonding. Note that good designs require large contact areas for better joint strength. (d) Combination joints Adhesive Adhesive Rivet Spot weld Good Very good Poor Adhesive (a) (b) (c) Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Design for Riveting FIGURE 12.61 Design guidelines for riveting. Source: Bralla, J.G. (ed.) Handbook of Product Design for Manufacturing, 2nd ed. McGraw-Hill, 1999. (c) (d) (b) Poor Good (a)Manufacturing Processes for Engineering Materials, 5th ed. Kalpakjian • Schmid © 2008, Pearson Education ISBN No. 0-13-227271-7 Case Study: Monosteel ® Pistons FIGURE 12.62 The Monosteel ® piston. (a) Cutaway view of the piston, showing the oil gallery and friction welded sections; (b) detail of the friction welds before the external ?ash is removed by machining; note that this photo is a reverse of the one on the left. Oil gallery Friction welds (a) (b)