EMAE 160 EXAM QUESTIONS WITH
COMPLETE ANSWERS
Name 3 types of stress - ANSWER-tensile, compressive, shear
What is ultrasonic machining and can it be used for both metallic and non-metallic
materials? - ANSWER-it is a vibrating, oscillating tool used to remove material from a
workpiece with the help of an abrasive slurry flowing freely between the workpiece
and tool. Can be used for every material.
(Advantages: little grinding pressure, good for brittle materials especially glass,
ceramics, semiconductors.)
Are applications of electron beam machining limited to metallic materials? Why or
why not? - ANSWER-Can only be used on metal bc electron melts metal. The
energy and power density can be controlled and high velocity electrons can be
concentrated to a narrow beam.
What type of rockwell hardness scale indenter is used to measure the hardness of
heat treated high-carbon steel - ANSWER-120 degree diamond cone
What is impregnation in terms of the powdered metallurgy process? - ANSWER-
filling a porous substrate to make it airtight. In powder metallurgy, impregnate inner
void prior to plating to reduce corrosion. Fill sintered component with lubricants
Machining process used to produce square blind hole in steel is? - ANSWER-RAM
EDM
Machining process used to produce narrow slot in hardened tool steel is? -
ANSWER-Laser beam cutting and water jet cutting
Three steps in powder metallurgy include: - ANSWER-blending, compaction,
sintering
Ductility vs. malleability: - ANSWER-ductile = stretch without damage, stretched into
wires;
malleable = deformed under compression, rolled or hammered into sheets
What is work hardening for material that is ductile and malleable metal - ANSWER-is
strengthening of a metal by plastic deformation. Occurs most notably for ductile
metals.
What is metal injection molding? - ANSWER-finely-powdered metal is mixed with
binder material making 'feedstock', which is then handled by plastic processing
equipment in injection mold forming (powdered metallurgy)
What fluid is used in ECM metal removal? - ANSWER-conductive fluid/electrolyte
, What fluid is used for EDM metal removal? - ANSWER-dielectric fluid (deionized
water, oil- often kerosene based)
Resistance welding processes make use of the heat generated by electrical
resistance to achieve fusion of the parts to be joined; no pressure is used. T/F? -
ANSWER-False.
Welding failures always occur in the fusion zone of the weld joint, since this is the
part of the joint that has been melted. T/F? Why? - ANSWER-FALSE. Failures also
occur in the HAZ.
Roughening of mating surfaces prior to gluing tends to: - ANSWER-Increase the
strength of an adhesive joint
Which arc welding processes uses a non-consumable electrode? - ANSWER-GTAW
A fillet weld has a cross section that is approximately - ANSWER-triangular
The term weldability takes into account not only the ease with which a welding
operation can be pperformed, but also the quality of the resulting weld. T/F? -
ANSWER-True
Which of the following is NOT a function of flux in brazing and soldering? -
ANSWER-Chemical etching of surfaces to increase roughness for better filler metal
adhesion
What are the advantages and disadvantages of welding when compared to other
assembly operations? - ANSWER-Advantages:
faster than adhesives, cost-effective, parts don't need to fit, won't degrade in weather
over time, stronger than adhesives or brazing
Disadvantages:
contains more defects, less predictable, makes joint permanent, not all materials are
weldable, only similar metals can be welded together, welding thin sheets is very
difficult
Explain the mechanism that allows glues to work. - ANSWER-Adhesive forces
(attraction to part) overcome the cohesive forces (attractions amongst glue
molecules)
Describe the difference between a continuous weld and intermittent weld as applied
to a fillet weld in a lap joint. - ANSWER-Continuous = entire length Intermittent =
staggered with portions equally spaced
Difference between impact and deep draw in material yield. - ANSWER-deep draw =
<80 % material yield
impact = >90 % material yield
Difference between impact and deep draw in wall/bottom thickness ratio. -
ANSWER-deep draw = 1:1 max
COMPLETE ANSWERS
Name 3 types of stress - ANSWER-tensile, compressive, shear
What is ultrasonic machining and can it be used for both metallic and non-metallic
materials? - ANSWER-it is a vibrating, oscillating tool used to remove material from a
workpiece with the help of an abrasive slurry flowing freely between the workpiece
and tool. Can be used for every material.
(Advantages: little grinding pressure, good for brittle materials especially glass,
ceramics, semiconductors.)
Are applications of electron beam machining limited to metallic materials? Why or
why not? - ANSWER-Can only be used on metal bc electron melts metal. The
energy and power density can be controlled and high velocity electrons can be
concentrated to a narrow beam.
What type of rockwell hardness scale indenter is used to measure the hardness of
heat treated high-carbon steel - ANSWER-120 degree diamond cone
What is impregnation in terms of the powdered metallurgy process? - ANSWER-
filling a porous substrate to make it airtight. In powder metallurgy, impregnate inner
void prior to plating to reduce corrosion. Fill sintered component with lubricants
Machining process used to produce square blind hole in steel is? - ANSWER-RAM
EDM
Machining process used to produce narrow slot in hardened tool steel is? -
ANSWER-Laser beam cutting and water jet cutting
Three steps in powder metallurgy include: - ANSWER-blending, compaction,
sintering
Ductility vs. malleability: - ANSWER-ductile = stretch without damage, stretched into
wires;
malleable = deformed under compression, rolled or hammered into sheets
What is work hardening for material that is ductile and malleable metal - ANSWER-is
strengthening of a metal by plastic deformation. Occurs most notably for ductile
metals.
What is metal injection molding? - ANSWER-finely-powdered metal is mixed with
binder material making 'feedstock', which is then handled by plastic processing
equipment in injection mold forming (powdered metallurgy)
What fluid is used in ECM metal removal? - ANSWER-conductive fluid/electrolyte
, What fluid is used for EDM metal removal? - ANSWER-dielectric fluid (deionized
water, oil- often kerosene based)
Resistance welding processes make use of the heat generated by electrical
resistance to achieve fusion of the parts to be joined; no pressure is used. T/F? -
ANSWER-False.
Welding failures always occur in the fusion zone of the weld joint, since this is the
part of the joint that has been melted. T/F? Why? - ANSWER-FALSE. Failures also
occur in the HAZ.
Roughening of mating surfaces prior to gluing tends to: - ANSWER-Increase the
strength of an adhesive joint
Which arc welding processes uses a non-consumable electrode? - ANSWER-GTAW
A fillet weld has a cross section that is approximately - ANSWER-triangular
The term weldability takes into account not only the ease with which a welding
operation can be pperformed, but also the quality of the resulting weld. T/F? -
ANSWER-True
Which of the following is NOT a function of flux in brazing and soldering? -
ANSWER-Chemical etching of surfaces to increase roughness for better filler metal
adhesion
What are the advantages and disadvantages of welding when compared to other
assembly operations? - ANSWER-Advantages:
faster than adhesives, cost-effective, parts don't need to fit, won't degrade in weather
over time, stronger than adhesives or brazing
Disadvantages:
contains more defects, less predictable, makes joint permanent, not all materials are
weldable, only similar metals can be welded together, welding thin sheets is very
difficult
Explain the mechanism that allows glues to work. - ANSWER-Adhesive forces
(attraction to part) overcome the cohesive forces (attractions amongst glue
molecules)
Describe the difference between a continuous weld and intermittent weld as applied
to a fillet weld in a lap joint. - ANSWER-Continuous = entire length Intermittent =
staggered with portions equally spaced
Difference between impact and deep draw in material yield. - ANSWER-deep draw =
<80 % material yield
impact = >90 % material yield
Difference between impact and deep draw in wall/bottom thickness ratio. -
ANSWER-deep draw = 1:1 max
