Deck 22: Nontraditional Machining and Thermal Cutting

Question 1

Which of the following processes use mechanical energy as the principal energy source (three correct answers):

A)electrochemical grinding
B)laser beam machining
C)conventional milling
D)ultrasonic machining
E)water jet cutting
F)wire EDM

Answer 1

conventional milling
ultrasonic machining
water jet cutting

Question 2

Ultrasonic machining can be used to machine both metallic and nonmetallic materials:

Answer 2

True

Question 3

In ultrasonic machining, material removal rate decreases with increasing frequency and amplitude of vibration:

Answer 3

False

Question 4

In water jet cutting and abrasive water jet cutting, the separation between the nozzle opening and the work surface is called which one of the following:

A)gap
B)gap size
C)orifice
D)overcut
E)standoff distance

Question 5

In abrasive water jet cutting, the abrasive particles are added to the water stream:

A)after it exits the nozzle
B)before it enters the pumping unit
C)just before it enters the nozzle
D)while it is in the nozzle

Question 6

Abrasive water jet cutting and abrasive jet machining are two different names for the same process:

Question 7

Disadvantages of electrochemical machining include which of the following (two best answers):

A)disposing of the electrolyte sludge created in the process
B)high cost of electrical power
C)high tool wear
D)low metal removal rates for hard metals
E)surface damage to work

Question 8

The metal removal rate in electric discharge machining depends on which of the following variables and properties (two correct answers):

A)discharge current
B)hardness of the work metal
C)melting temperature of the work metal
D)tensile strength of the work metal

Question 9

The liquid used to create the discharge path between the tool and the work in electric discharge machining is called which one of the following:

A)dielectric fluid
B)electrolyte

Question 10

Applications of electron beam machining are limited to metallic work materials because the work must be electrically conductive:

Question 11

Which one of the following is closest to the temperatures used in plasma arc cutting:

A)2750 $\degree$ C (5000 $\degree$ F)
B)5500 $\degree$ C (10000 $\degree$ F)
C)8300 $\degree$ C (15000 $\degree$ F)
D)11000 $\degree$ C (20000 $\degree$ F)
E)16500 $\degree$ C (30000 $\degree$ F)

Question 12

Which one of the following fuels used in flame cutting produces the highest flame temperatures:

A)acetylene
B)methylacetylene-propadiene
C)propane
D)propylene

Question 13

Chemical milling is used in which of the following applications (two best answers):

A)drilling holes with high depth-to-diameter ratio
B)making intricate patterns in thin sheet metal
C)removing material to make shallow pockets in metal
D)removing metal from aircraft wing panels
E)cutting of plastic sheets

Question 14

The etch factor in chemical machining is equal to which one of the following:

A)CIt
B)d/u
C)u/d; where C = specific removal rate d = depth of cut I = current t = time and u = undercut

Question 15

Of the following processes, which one is noted for the highest material removal rates:

A)electric discharge machining
B)electrochemical machining
C)laser beam machining
D)oxyfuel cutting
E)plasma arc cutting
F)ultrasonic machining
G)water jet cutting

Question 16

Which one of the following processes would be appropriate to drill a hole with a square cross section, 6 mm (0.25 in) on a side and 25 mm (1 in) deep in a steel workpiece:

A)abrasive jet machining
B)chemical milling
C)EDM
D)laser beam machining
E)oxyfuel cutting
F)water jet cutting
G)wire EDM

Question 17

Which of the following processes would be appropriate for cutting a narrow slot, less than 0.40 mm (0.016 in) wide, in a 3/8-in-thick sheet of fiber-reinforced plastic that is 9.5 mm (3/8 in) thick (two best answers):

A)abrasive jet machining
B)chemical milling
C)EDM
D)laser beam machining
E)oxyfuel cutting
F)water jet cutting
G)wire EDM

Question 18

Which one of the following processes would be appropriate for cutting a hole of 0.075 mm (0.003 in) diameter through a plate of aluminum that is 1.6 mm (1/16 in) thick:

A)abrasive jet machining
B)chemical milling
C)EDM
D)laser beam machining
E)oxyfuel cutting
F)water jet cutting
G)wire EDM

Question 19

Which of the following processes could be used to cut a large piece of 12.7-mm (0.50-in) plate steel into two sections (two best answers):

A)abrasive jet machining
B)chemical milling
C)EDM
D)laser beam machining
E)oxyfuel cutting
F)water jet cutting
G)wire EDM