cap 9 Materiales

Question 1

1. Machining is a shape-producing process in which a power-driven device causes material to be removed in the form of:

a. strips.
b. blocks.
c. chips.
d. slices.

Answer 1

c. chips.

Question 2

2. When only a small number of pieces need to be
   manufactured,________is generally a cost-effective option.

a. casting
b. machining
c. forging
d. press working

Answer 2

b. machining

Question 3

3. Casting, welding, deformation, and machining all use different forms of energy to effect a shape change in a given material. Machining involves which of the following?

a. Primarily heat energy.
b. Heat and force energy.
c. Primarily pressure.
d. Localized force energy.

Answer 3

d. Localized force energy.

Question 4

4. Casting, welding, deformation, and machining all use different forms of energy to effect a shape change in a given material. Casting involves which of the following?

a. Primarily heat energy.
b. Heat and force energy.
c. Force energy over a large area.
d. Localized force over a small area.

Answer 4

a. Primarily heat energy.

Question 5

5. Casting, welding, deformation, and machining all use different forms of energy to effect a shape change in a given material. Welding involves which of the following?

a. Primarily heat energy.
b. Heat and force energy.
c. Force energy over a large area.
d. Localized force over a small area.

Answer 5

b. Heat and force energy.

Question 6

6. Casting, welding, deformation, and machining all use different forms of energy to effect a shape change in a given material. Deformation involves which of the following?

a. Primarily heat energy.
b. Heat and force energy.
c. Force energy over a large area.
d. Localized force over a small area.

Answer 6

c. Force energy over a large area

Question 7

7. When chips are formed during the machining process, the characteristics of the chip greatly depend on the tool orientation and the material being machined. Small chips are generally formed by which of the following?

a. Ductile material.
b. Brittle material.
c. Variations in the tool orientation.
d. Variations in the material travel speed.

Answer 7

b. Brittle material.

Question 8

8. When chips are formed during the machining process, the characteristics of the chip depend greatly on the tool orientation and the material being machined. Long continuous strips are generally formed by which of the following?

a. Ductile material.
b. Brittle material.
c. Variations in the tool orientation.
d. Variations in the material travel speed.

Answer 8

a. Ductile material.

Question 9

9. A satisfactory cutting tool material will be harder and stronger than the material it is to cut, abrasion resistant to reduce wear, and will be able to maintain these properties at:

a. low temperatures.
b. room temperature.
c. variable temperatures.
d. cutting temperatures.

Answer 9

d. cutting temperatures.

Question 10

10. High-speed steel (HSS) tool steel maintains cutting hardness and strength to approximately what
    temperature.?

a. 200 °C (392 °F).
b. 550 °C ( 1000 °F).
c. 750 °C ( 1382 °F).
d 1500 °C (2732 °F).

Answer 10

b. 550 °C ( 1000 °F).

Question 11

11. Cemented carbides, which are a powdered metallurgy product of tungsten, titanium, and/or tantalum carbides, are combined in various mixtures with cobalt or nickel to produce cutting tool tips that maintain hardness and strength to approximately what temperature?

a. 200 °C (392 °F).
b. 550 °C (1000 °F).
c. 750 °C (1382 °F).
d. 1100 °C (2000 °F).

Answer 11

d. 1100 °C (2000 °F).

Question 12

12. A surface condition with broad uniform variations that are spaced relatively widely apart would be described as:

a. roughness.
b. waviness.
c. smoothness.
d. phonographic.

Answer 12

b. waviness.

Question 13

13. A surface condition that has fine uniform variations described by the height, width, and direction of which establish the predominant surface pattern would be called:

a. roughness.
b. waviness.
c. smoothness.
d. phonographic.

Answer 13

a. roughness.

Question 14

14. Surface finishes on machined parts are often a compromise between tool life and machine time. If cutting speed is increased, then tool life will:

a. increase slightly
b. increase greatly.
c. decrease.
d. remain the same.

Answer 14

c. decrease.

Question 15

15. Machines that normally rotate the work-piece to produce a cutting motion and feed a single point tool parallel to the work axis or at some angle to it are referred to as:

a. drilling machines.
b. turning and boring machines.
c. milling machines.
d. straight line machines.

Answer 15

b. turning and boring machines.

Question 16

16. Machines that normally rotate a specially fluted tool with two or more cutting lips on its exposed end that is advanced axially into the work-piece are called:

a. drilling machines.
b. turning and boring machines.
c. grinding machines.
d. straight line machines.

Answer 16

a. drilling machines.

Question 17

17. Machines that normally rotate special, multi-edged cutters that perform their principle cutting on their peripheral edges and permit multidirectional feeding of the work-piece into the cutting edge are referred to as:

a. drilling machines.
b. turning and boring machines.
c. milling machines.
d. straight line machines.

Answer 17

c. milling machines.

Question 18

18. Manual or automatic torch cutting is mostly limited to what type of material?

a. Carbon and low alloy steel.
b. Cast and ductile iron.
c. most stainless steels.
d. Nonferrous alloys.

Answer 18

a. Carbon and low alloy steel.

Question 19

19. The slit or notch in a material that is removed by a saw or cutting torch is called:

a. skelp.
b. kerf.
c. sacrificial notch.
d. waste notch.

Answer 19

b. kerf.

Question 20

20. Aluminum oxide, silicon oxide, diamond, and boron cubic nitride are all examples of which of the following?

a. Surface coatings.
b. Abrasives.
c. Cutting tool alloys.
d. Cutting tool trade names.

Answer 20

b. Abrasives.

Question 21

21. When large numbers of small parts that do not need to have sharp detail or accurate dimensions require cleaning, this method is often very economical:

a. abrading.
b. buffing.
c. tumbling.
d. wire brushing.

Answer 21

c. tumbling.

Question 22

22. The biggest drawback when cleaning with a high-speed wire brush is that the surface material may be_____, which can disguise or cover over surface discontinuities.

a. annealed
b. smeared
c. discolored
d. hardened

Answer 22

b. smeared

Question 23

23. Electro-polishing increases the average smoothness of a given surface by:

a. adding material to the low spots on the material’s surface.
b. removing material from the high spots on the material’s surface.
c. plating the materials surface with chromium.
d. plating the surface with a cathode made from the same material.

Answer 23

b. removing material from the high spots on the material’s surface.

Question 24

24. A process that first masks off the area to be affected and then immerses the part in a suitable etchant, which is usually a strong acid or alkali, is referred to as:

a. chemical engraving.
b. chemical milling.
c. chemical etching.
d. chemical machining.

Answer 24

b. chemical milling.

Question 25

25. A machining process that charges and discharges a capacitor and utilizes the resulting arc or spark to remove a specific amount of material is called: a. resistance discharge milling. b. capacitor discharge milling. c. electrical discharge machining. d. conductive discharge machining.

Answer 25

c. electrical discharge machining.

Question 26

26. Electrical discharge machining techniques are often used to produce: a. complex shapes in plastics. b. complex shapes in ceramics. c. discontinuities in test standards. d. simple shapes in nonconductive materials.

Answer 26

c. discontinuities in test standards.

Question 27

27. Ultrasonic machining that is capable of producing and maintaining tolerances as close as 0.01 mm (0.0005 in.) is best suited for: a. low-carbon, softer stells. b. hard, brittle materials. c. only conductive materials. d. only nonconductive materials,

Answer 27

b. hard, brittle materials.

Question 28

28. The ease with which numerical control (N/C) equipment can be reprogrammed to produce a great number of different pieces makes it most suitable for producing: a. large quantities of the same part. b. small quantities of many different parts. c. many different parts simultaneously. d. large quantities of different parts.

Answer 28

b. small quantities of many different parts.

Question 29

29. A modern computer numerical control (CNC) machining center can have as many as _________ axes of movement. a. two b. three c. five d. seven

Answer 29

c. five