1. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 CHAPTER 9 Material- Removal Processes: Abrasive, Chemical, Electrical, and High-energy Beams

2. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Knoop Hardness for Various Materials TABLE 9.1 Knoop hardness range for various materials and abrasives.

3. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Physical Model of a Grinding Wheel FIGURE 9.1 Schematic illustration of a physical model of a grinding wheel, showing its structure and wear and fracture patterns.

4. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Common Types of Grinding Wheels FIGURE 9.2 Some common types of grinding wheels made with conventional abrasives. Note that each wheel has a specific grinding face. Grinding on other surfaces is improper and unsafe.

5. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Superabrasive-Wheel Configurations FIGURE 9.3 Examples of superabrasive-wheel configurations. The annular regions (rim) are superabrasive grinding surfaces, and the wheel itself (core) is generally made of metal or composites. Note that the basic numbering of wheel type is the same as shown in Fig. 9.2. The bonding materials for the superabrasives are (a), (d) and (e) resinoid, metal,or vitrified; (b) metal; (c) vitrified; and (f) resinoid.

6. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Standard Marking System For Aluminum- Oxide Abrasives FIGURE 9.4a Standard marking system for aluminum-oxide and silicon-carbide bonded abrasives.

7. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Standard Marking System for Diamond Abrasives FIGURE 9.4b Standard marking system for diamond and cubic-boron-nitride bonded abrasives.

8. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Grinding and Chip Production FIGURE 9.5 The grinding surface of an abrasive wheel (A46-J8V), showing grains, porosity, wear flats on grains (see also Fig. 9.8), and metal chips from the workpiece adhering to the grains. Note the random distribution and shape of the abrasive grains. Magnification: 50X FIGURE 9.6 Grinding chip being produced by a single abrasive grain: (A) chip, (B) workpiece, (C) abrasive grain. Note the large negative rake angle of the grain. The inscribed circle is 0.065 mm (0.0025 in.) in diameter. Source: M. E. Merchant.

9. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 TABLE 9.2 Typical ranges of speeds and feeds for abrasive processes. Variables in Surface Grinding FIGURE 9.7 Variables in surface grinding. In actual grinding, the wheel depth of cut d, and contact length, l, are much smaller than the wheel diameter, D. The dimension t is called the grain depth of cut.

10. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Chip Formation FIGURE 9.8 Chip formation and plowing of the workpiece surface by an abrasive grain. FIGURE 9.9 Schematic illustration of chip formation by an abrasive grain. Note the negative rake angle, the small shear angle, and the wear flat on the grain.

11. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Energy in Abrasive Machining TABLE 9.3 Approximate specific energy requirements for surface grinding.

12. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Residual Stresses on Workpiece Surface FIGURE 9.10 Residual stresses developed on the workpiece surface in grinding of tungsten: (a) effect of wheel speed and (b) effect of grinding fluid. Tensile residual stresses on a surface controlled to minimize residual stresses. This process is known as low-stress grinding. Source: After N. Zlatin et al., 1963.

13. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Wheel Dressing FIGURE 9.11 Shaping the grinding face of a wheel by dressing it with computer controlled shaping features. Note that the diamond dressing tool is normal to the surface at point of contact. Source: Okuma Machinery Works Ltd.

14. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Surface-Grinding Operations FIGURE 9.12 Schematic illustration of surface-grinding operations. (a) Traverse grinding with a horizontal-spindle surface grinder. (b) Plunge grinding with a horizontal-spindle surface grinder, producing a groove in the workpiece. (c) Vertical-spindle rotary-table grinder (also known as the Blanchard-type grinder).

15. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Horizontal-Spindle Surface Grinder FIGURE 9.13 Schematic illustration of a horizontal-spindle surface grinder. The majority of grinding operations are done on such machines.

16. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Traverse and Plunge Grinding of Threads FIGURE 9.14 Thread grinding by (a) traverse and (b) plunge grinding.

17. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Internal-Grinding Operations FIGURE 9.15 Schematic illustrations of internal-grinding operations.

18. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Centerless-Grinding Operations FIGURE 9.16 Schematic illustration of centerless-grinding operations.

19. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Computer-Numerical-Control Centerless Grinding Machine FIGURE 9.17 A computer-numerical- control centerless grinding machine. The movement of the workpiece is perpendicular to the page. Source: Coutesy of Cincinnati Milacron, Inc.

20. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Creep-Feed Grinding Process FIGURE 9.18 (a) Schematic illustration of the creep-feed grinding process. Note the large wheel depth of cut. (b) A shaped groove produced on a flat surface in one pass by creep-feed grinding. Groove depth can be on the order of a few mm. (c) An example of creep-feed grinding with a shaped wheel. Source: Courtesy of Blohm, Inc., and Manufacturing Engineering, Society of Manufacturing Engineers. See also Fig. 9.30.

21. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Ultrasonic-Machining Process FIGURE 9.19 (a) Schematic illustration of the ultrasonic-machining process by which material is process by which material is removed through microchipping and erosion. (b) and (c) typical examples of holes produced by ultrasonic machining. Note the dimensions of cut and the types of workpiece materials.

22. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Structure of a Coated Abrasive FIGURE 9.20 Schematic illustration of the structure of a coated abrasive. Sandpaper, developed in the 16 th century, and emery cloth are common examples of coated abrasives.

23. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Honing Tool FIGURE 9.21 Schematic illustration of a honing tool to improve the surface finish of bored or ground holes.

24. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Superfinishing of a Cylindrical Part FIGURE 9.22 Schematic illustration of the superfinishing process for a cylindrical part: (a) cylindrical microhoning; (b) centerless microhoning.

25. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Lapping Process FIGURE 9.23 (a) Schematic illustration of the lapping process. (b) Production lapping on flat surfaces. (c) Production lapping on cylindrical surfaces.

26. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Magnetic Fields Used to Polish Balls and Rollers FIGURE 9.24 Schematic illustration of the use of magnetic fields to polish balls and rollers: (a) magnetic float polishing of ceramic balls; (b)magnetic-field-assisted polishing of rollers. Source: R. Komanduri, M. Doc, and M. Fox.

27. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Characteristics of Abrasive Machining TABLE 9.4 General characteristics of abrasive machining operations.

28. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Characteristics of Abrasive Machining (cont.)

29. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Chemical Milling FIGURE 9.25 (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 chemical milling of aluminum-alloy plates. These panels are milled after the plates have first been formed into shape, such as by roll forming or stretch forming. The design of the chemically machined rib patterns can be modified readily at minimal cost. Source: Advanced Materials and Processes, ASM International, December 1990, p.43.

30. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Chemical-Machining Process FIGURE 9.26 (a) Schematic illustration of the chemical-machining process. Note that no forces or machine tools are involved in this process. (b) Stages in producing a profiled cavity by chemical machining.

31. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 FIGURE 9.27 Surface roughness and tolerances obtained in various machining processes. Note the wide range within each process. (See also Fig. 8.33.) Source: Reprinted from Machining Data Handbook, 3d. ed. Copyright © 1980, by permission of the institute of Advanced Manufacturing Sciences. Surface Roughness and Tolerances

32. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Chemical Blanking FIGURE 9.28 Various parts made by chemical blanking. Note the fine detail. Source: Courtesy of Buckabee-Mears St. Paul.

33. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Electrochemical-Machining FIGURE 9.29 Schematic illustration of the electrochemical-machining process. This process is the reverse of electroplating, described in Section 4.5.1. FIGURE 9.30 Typical parts made by electrochemical machining. (a) Turbine blade made of a nickel alloy, 360 HB. Source: Metal Handbook, 9 th ed., Vol. 3, Materials Park, OH: ASM International, 1980, p. 849. (b) Thin slots on a 4340- steel roller-bearing cage. (c) Integral airfoils on a compressor disk.

34. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Electrochemical-Grinding Process FIGURE 9.31 (a) Schematic illustration of the electrochemical-grinding process. (b) Thin slot produced on a round nickel-alloy tube by this process.

35. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Electrical-Discharge-Machining Process FIGURE 9.32 Schematic illustration of the electrical-discharge-machining process.

36. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Cavities made with electrical-discharge- machining process FIGURE 9.33 (a) Examples of cavities produced by the electrical-discharge-machining process, using shaped electrodes. The two round parts (rear) are the set of dies for extruding the aluminum piece shown in front. Source: Courtesy of AGIE USA Ltd. (b) A spiral cavity produced by a rotating electrode. Source: American Machinist. (c) Holes in a fuel-injection nozzle made by electrical-discharge machining. Material: Heat-treated steel.

37. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Stepped Cavities FIGURE 9.34 Stepped cavities produced with a square electrode by EDM. The workpiece moves in the two principal horizontal directions, and its motion is synchronized with the downward movement of the electrode to produce various cavities. Also shown is a round electrode capable of producing round or eliptical cavities. Source: Courtesy of AGIE USA Ltd.

38. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Wire EDM Process FIGURE 9.35 Schematic illustration of the wire EDM process. As much as 50 hours of machining can be performed with one reel of wire, which is then discarded.

39. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Laser-Beam-Machining Process FIGURE 9.36 (a) Schematic illustration of the laser-beam-machining process. (b) and (c) Examples of holes produced in nonmetallic parts by LBM.

40. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Laser Applications TABLE 9.5 General applications of lasers in manufacturing.

41. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Electron-Beam-Machining Process FIGURE 9.37 Schematic illustration of the electron-beam-machining process. Unlike LBM, this process requires a vacuum, and hence workpiece size is limited.

42. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Water-Jet-Machining FIGURE 9.38 (a) Schematic illustration of water-jet machining. (b) Examples of various nonmetallic parts cut by a water-jet machine. Source: Courtesy of Possis Corporation.

43. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Abrasive-Jet-Machining Process FIGURE 9.39 Schematic illustration of the abrasive-jet-machining process.

44. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Cost of Machining/Surface Finish Required FIGURE 9.40 Increase in the cost of machining and finishing a part as a function of the surface finish required.

45. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Guidant MULTI-LINK TETRA TM System FIGURE 9.41 The Guidant MULTI-LINK TETRA TM coronary stent system.

46. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 The MULTI-LINK TETRA TM Pattern FIGURE 9.42 Detail of the 3-3-3 MULTI-LINK TETRA TM pattern.

47. Manufacturing Processes for Engineering Materials, 4th ed. Kalpakjian Schmid Prentice Hall, 2003 Evolution of the Stent Surface FIGURE 9.43 Evolution of the stent surface. (a) MULTI-LINK TETRA TM after lasing. Note that a metal slug is still attached. (b) After removal of slag. (c) after electropolishing.