EMAE 160 FINAL REVIEW CWRU -
SURFACE FINISH AND CASTING EXAM
Q&A
In die casting, what is the ejection system and how does it operate? - ANSWER-The
ejection system pops the part away from the mold so that it doesn't stick to the mold.
What materials may be used in hot chamber die casting?
What about cold chamber? - ANSWER-Hot Chamber- Zinc, Lead, Tin.
Cold Chamber- Aluminium and Magnesium.
What is the function of a sprue and riser? - ANSWER-Sprue- The vertical passage
for molten metal to enter the mold.
Riser- Space for excess molten metal to flow into.
What is the function of a runner and gate? - ANSWER-Runner- For molten metal to
reach the mold cavity. Gate- To ensure that molten metal enters the cavity at the
same rate as solidification.
What are the differences between centrifugal casting and semi-Centrifugal casting? -
ANSWER-Centrifugal only wants metal to stick to the walls. Semi-Centrifugal wants
to evenly spread material through molds.
In sand casting, how does the volumetric size of the pattern compare to the finished
cast part? - ANSWER-The finished part is much smaller after being machined down
and having the risers removed.
Describe shell molding. - ANSWER-Resin and sand sticks to a heated surface then
is placed in a furnace to set.
Name another term for investment casting and explain the origin. - ANSWER-Lost
wax casting. People used beeswax 1000's of years ago.
List metals that are typically die cast. - ANSWER-Aluminum & Magnesium
In terms of die casting, what is flash? - ANSWER-Extra material from between the
two plates.
What is the symbol for surface finish? What parameters may be included? -
ANSWER-√. Can include roughness height, roughness width, roughness width
cutoff, waveness height, waveness width
What are ribs and gussets? - ANSWER-Ribs- Square supports.
Gussets- Triangular supports.
What is the significance of draft on a part? - ANSWER-So that it can easily come out
of the mold.
SURFACE FINISH AND CASTING EXAM
Q&A
In die casting, what is the ejection system and how does it operate? - ANSWER-The
ejection system pops the part away from the mold so that it doesn't stick to the mold.
What materials may be used in hot chamber die casting?
What about cold chamber? - ANSWER-Hot Chamber- Zinc, Lead, Tin.
Cold Chamber- Aluminium and Magnesium.
What is the function of a sprue and riser? - ANSWER-Sprue- The vertical passage
for molten metal to enter the mold.
Riser- Space for excess molten metal to flow into.
What is the function of a runner and gate? - ANSWER-Runner- For molten metal to
reach the mold cavity. Gate- To ensure that molten metal enters the cavity at the
same rate as solidification.
What are the differences between centrifugal casting and semi-Centrifugal casting? -
ANSWER-Centrifugal only wants metal to stick to the walls. Semi-Centrifugal wants
to evenly spread material through molds.
In sand casting, how does the volumetric size of the pattern compare to the finished
cast part? - ANSWER-The finished part is much smaller after being machined down
and having the risers removed.
Describe shell molding. - ANSWER-Resin and sand sticks to a heated surface then
is placed in a furnace to set.
Name another term for investment casting and explain the origin. - ANSWER-Lost
wax casting. People used beeswax 1000's of years ago.
List metals that are typically die cast. - ANSWER-Aluminum & Magnesium
In terms of die casting, what is flash? - ANSWER-Extra material from between the
two plates.
What is the symbol for surface finish? What parameters may be included? -
ANSWER-√. Can include roughness height, roughness width, roughness width
cutoff, waveness height, waveness width
What are ribs and gussets? - ANSWER-Ribs- Square supports.
Gussets- Triangular supports.
What is the significance of draft on a part? - ANSWER-So that it can easily come out
of the mold.
