Chapter 24 GRINDING AND OTHER ABRASIVE PROCESSES
24.10 Which of the following will improve surface finish in grinding (three best answers): (a) denser wheel structure, (b) higher wheel speed, (c) higher work speeds, (d) larger infeed, (e) lower infeed, (f) lower wheel speed, (g) lower work speed, and (h) more open wheel structure?
Answer. (a), (b), and (g).
24.15 Which of the following will help to reduce the incidence of heat damage to the work surface in grinding (four correct answers): (a) frequent dressing or truing of the wheel, (b) higher infeeds, (c) higher wheel speeds, (d) higher work speeds, (e) lower infeeds, (f) lower wheel speeds, and (g) lower work speeds?
Answer. (a), (d), (e), and (g).
24.1 The abrasive machining processes are generally used as finishing operations: (a) true or (b) false?
Answer. (a).
24.11 Which one of the following abrasive materials is most appropriate for grinding steel and cast iron: (a) aluminum oxide, (b) cubic boron nitride, (c) diamond, or (d) silicon carbide?
Answer. (a).
24.16 Which one of the following is the best description of the grinding ratio: (a) rate at which the grinding wheel wears per unit time, (b) ratio of volume of grinding wheel worn relative to the volume of the work material removed, (c) ratio of volume of work material removed relative to the volume of the grinding wheel worn, or (d) ratio of wheel surface speed relative to work surface speed?
Answer. (c).
24.4 Which one of the following is not one of the five basic parameters of a grinding wheel: (a) abrasive material, (b) bonding material, (c) grain hardness, (d) grain size, (e) wheel grade, or (f) wheel structure?
Answer. (c).
24.8 Smaller grain size in a grinding wheel tends to (a) degrade surface finish, (b) have no effect on surface finish, or (c) improve surface finish?
Answer. (c).
24.13 Which one of the following abrasive materials is most appropriate for grinding nonferrous metals: (a) aluminum oxide, (b) cubic boron nitride, (c) diamond, or (d) silicon carbide?
Answer. (d).
24.14 The specific energy in a grinding operation is much greater than the specific energy in a conventional machining operation such as milling: (a) true or (b) false?
a
24.18 Which one of the following abrasive processes is capable of achieving the highest production rates: (a) external centerless grinding, (b) internal centerless grinding, (c) external cylindrical grinding, or (d) internal cylindrical grinding?
a
24.20 Which one of the following abrasive processes is commonly used to finish the bores of internal combustion engines: (a) honing, (b) lapping, or (c) superfinishing?
a
24.17 Which of the following terms applies to the procedure of sharpening the grinding wheel and restoring the shape of its outside perimeter: (a) dressing or (b) truing?
b
24.19 The term deep grinding refers to which one of the following: (a) alternative name for any creep feed grinding operation, (b) external cylindrical creep feed grinding, (c) grinding operation performed at the bottom of a hole, (d) surface grinding that uses a large crossfeed, or (e) surface grinding that uses a large infeed?
b
24.21 Which one of the following abrasive processes is commonly used in the production of glass optical lenses: (a) honing, (b) lapping, or (c) superfinishing?
b
24.22 Which one of the following abrasive processes is capable of achieving the best surface finish: (a) centerless grinding, (b) honing, (c) lapping, or (d) superfinishing?
d
24.9 Which of the following would tend to give higher material removal rates: (a) larger grain size, or (b) smaller grain size?
Answer. (a).
24.12 Which one of the following abrasive materials is most appropriate for grinding hardened tool steel: (a) aluminum oxide, (b) cubic boron nitride, (c) diamond, or (d) silicon carbide?
Answer. (b).
24.2 Which one of the following conventional machining processes is closest to grinding: (a) drilling, (b) milling, (c) shaping, or (d) turning?
Answer. (b).
24.6 Of the following abrasive materials, which one has the highest hardness: (a) aluminum oxide, (b) cubic boron nitride, or (c) silicon carbide?
Answer. (b).
24.7 Depth of cut in a peripheral grinding operation is called which one of the following: (a) crossfeed, (b) infeed, or (c) penetration?
Answer. (b).
24.5 Friability refers to the capacity of the abrasive material to retain its sharpness during the grinding operation: (a) true or (b) false?
Answer. (b). Friability refers to the capacity of the abrasive material to fracture when the cutting edge of the grain becomes dull, thereby exposing a new sharp edge.
24.3 Either the face or the periphery of the grinding wheel can be used for cutting, with face grinding being the more common operation: (a) true or (b) false?
Answer. (b). Peripheral grinding is more common than face grinding.