MECH 2060 Exam 3 ACTUAL UPDATED
QUESTIONS AND CORRECT ANSWERS
Extrusion - CORRECT ANSWERS✅✅Compression forming process in which work metal
is forced to flow through a die opening
In general, Extrusion is used - CORRECT ANSWERS✅✅Long parts of uniform cross
sections
Extrusion Types - CORRECT ANSWERS✅✅Direct (froward) and (Indirect) Reverse
Extrusion force - CORRECT ANSWERS✅✅the force F that must be exerted on the
workpiece during an extrusion process; Ao*k*ln(Ao/Af)
Metal flow in Extrusions - CORRECT ANSWERS✅✅Metal flow pattern influences the
quality and mechanical properties of the extruded product
Advantages of Extrusion - CORRECT ANSWERS✅✅Variety of shapes possible, especially
in hot extrusion
Limitation: part cross section must be uniform throughout length
Grain structure and strength enhanced in cold and warm extrusion
Close tolerances possible, especially in cold extrusion
In some operations, little or no waste of material
Hot Extrusion - CORRECT ANSWERS✅✅--prior heating of billet to above its
recrystallization temperature
--Reduces strength and increases ductility of the metal, permitting more size reductions and
more complex shapes
Cold Extrusion - CORRECT ANSWERS✅✅Extrusion performed at a room temperature,
improves strength due to work hardening, better surface finish and dimensional accuracy
, Cold extrusion advantages over hot extrusion - CORRECT ANSWERS✅✅Improved
Mechanical properties, Good dimensional Tolerances, Improved surface finish, Competitive
Costs
Cold Extrusion: Impact Extrusion - CORRECT ANSWERS✅✅Impact extrusion of a
collapsible tube (
Cold Extrusion: Hydrostatic Extrusion - CORRECT ANSWERS✅✅Pressure required in the
chamber is supplied through an incompressible fluid medium Brittle materials can be
extruded successfully as the hydrostatic pressure increases the ductility of the material
What is the effect of a low die angle in extrusion die design? - CORRECT ANSWERS✅✅It
increases friction, resulting in more ram force.
What happens with a large die angle in extrusion die design? - CORRECT ANSWERS✅✅It
causes more turbulence in metal flow, which increases ram force.
guidelines Die design - CORRECT ANSWERS✅✅Symmetry of cross section
Avoidance of sharp corners
Avoidance of changes in die dimensions
Extrusion Defects - CORRECT ANSWERS✅✅-surface cracking
-pipe
-internal cracking
Internal Cracking - CORRECT ANSWERS✅✅Center of the extruded product can develop
cracks, called centercracking, center-burst, arrowhead fracture, or chevron cracking
Drawing Processs - CORRECT ANSWERS✅✅Cross section of a long rod or wire is
reduced by pulling it through a draw die
What is Bundle Drawing? - CORRECT ANSWERS✅✅A process that increases
productivity by drawing many wires as a bundle.
QUESTIONS AND CORRECT ANSWERS
Extrusion - CORRECT ANSWERS✅✅Compression forming process in which work metal
is forced to flow through a die opening
In general, Extrusion is used - CORRECT ANSWERS✅✅Long parts of uniform cross
sections
Extrusion Types - CORRECT ANSWERS✅✅Direct (froward) and (Indirect) Reverse
Extrusion force - CORRECT ANSWERS✅✅the force F that must be exerted on the
workpiece during an extrusion process; Ao*k*ln(Ao/Af)
Metal flow in Extrusions - CORRECT ANSWERS✅✅Metal flow pattern influences the
quality and mechanical properties of the extruded product
Advantages of Extrusion - CORRECT ANSWERS✅✅Variety of shapes possible, especially
in hot extrusion
Limitation: part cross section must be uniform throughout length
Grain structure and strength enhanced in cold and warm extrusion
Close tolerances possible, especially in cold extrusion
In some operations, little or no waste of material
Hot Extrusion - CORRECT ANSWERS✅✅--prior heating of billet to above its
recrystallization temperature
--Reduces strength and increases ductility of the metal, permitting more size reductions and
more complex shapes
Cold Extrusion - CORRECT ANSWERS✅✅Extrusion performed at a room temperature,
improves strength due to work hardening, better surface finish and dimensional accuracy
, Cold extrusion advantages over hot extrusion - CORRECT ANSWERS✅✅Improved
Mechanical properties, Good dimensional Tolerances, Improved surface finish, Competitive
Costs
Cold Extrusion: Impact Extrusion - CORRECT ANSWERS✅✅Impact extrusion of a
collapsible tube (
Cold Extrusion: Hydrostatic Extrusion - CORRECT ANSWERS✅✅Pressure required in the
chamber is supplied through an incompressible fluid medium Brittle materials can be
extruded successfully as the hydrostatic pressure increases the ductility of the material
What is the effect of a low die angle in extrusion die design? - CORRECT ANSWERS✅✅It
increases friction, resulting in more ram force.
What happens with a large die angle in extrusion die design? - CORRECT ANSWERS✅✅It
causes more turbulence in metal flow, which increases ram force.
guidelines Die design - CORRECT ANSWERS✅✅Symmetry of cross section
Avoidance of sharp corners
Avoidance of changes in die dimensions
Extrusion Defects - CORRECT ANSWERS✅✅-surface cracking
-pipe
-internal cracking
Internal Cracking - CORRECT ANSWERS✅✅Center of the extruded product can develop
cracks, called centercracking, center-burst, arrowhead fracture, or chevron cracking
Drawing Processs - CORRECT ANSWERS✅✅Cross section of a long rod or wire is
reduced by pulling it through a draw die
What is Bundle Drawing? - CORRECT ANSWERS✅✅A process that increases
productivity by drawing many wires as a bundle.
