MCHE 3920 REVIEW QUESTIONS WITH VERIFIED ANSWERS LATEST UPDATE 2024
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Course
MCHE 3920
Institution
MCHE 3920
MCHE 3920 REVIEW QUESTIONS WITH VERIFIED ANSWERS LATEST UPDATE 2024
Material properties of casts - Answers high stiffness and strength even at elevated temperatures
The oldest metal castings date back to - Answers 5000 BCE
Three main benefits of casting - Answers form freedom, strength, and char...
MCHE 3920 REVIEW QUESTIONS WITH VERIFIED ANSWERS LATEST UPDATE 2024
Material properties of casts - Answers high stiffness and strength even at elevated temperatures
The oldest metal castings date back to - Answers 5000 BCE
Three main benefits of casting - Answers form freedom, strength, and character
Cavity that defines the negative shape of the product - Answers mold
Pouring "top down" leads to - Answers oxidation and loss of material properties, especially ductility
An advantage for pouring "bottom up" is - Answers air inside the mold or vapors released during casting
can evacuate more easily
Is it better to have a metal with high or low viscosity for complex molds? - Answers low
Adding carbon to steel has what benefits for casting? - Answers lower melting temperature, viscosity,
and shrinkage
The ratio of a mixture where viscosity and melting point reach the minimum - Answers Eutectic
Composition
Castings have a much _____ alloy content than the typical compositions of wrought alloys - Answers
higher
Higher alloy content reduces what mechanical properties? - Answers toughness., ductility, and fatigue
strength
Why are lower filling speeds (laminar flow) preferred for casting? - Answers Minimum free surface area
(oxidation)
Flow speeds for casting are laminar below ___ m/s and turbulent above __ m/s - Answers .5, 1
When metal solidifies before a mold is fully filled - Answers cold running
What are ways to prevent cold running? - Answers Filling from multiple gates, increasing thickness
What is a downside of filling from multiple gates? - Answers More finishing required
What is a downside of increasing thickness when casting? - Answers Adds weight and cost
Filling a cast quickly at high pressures has what tradeoff? - Answers Poorer material properties
A metal mold for casting - Answers Die
The inlet channels of casting die - Answers runners
, The outlet channels of a casting die - Answers risers
Pour weight of a cast should be ____% or more of the weight of the casting itself - Answers 40
Minimizing surplus in pouring in casting by mold design - Answers Methoding
ratio of volume to surface area (casting) - Answers Thermal modulus
Chvorinov's Rule applies well to relatively _____ castings because the volume of material involved
determines the speed of solidification - Answers large
For thin-walled castings (less then 4mm thick), Chvorinov's Rule strongly _____________ the
solidification time - Answers underestimates
Three main quality issues in casting of metals - Answers porosity formation, internal stresses, distortion
Porosity increases when percent shrinkage ________ - Answers increases
What causes internal stresses in casting? - Answers Temperature differences during cooling for thick and
thin sections
If the temperature stresses in casting exceed ________, we get deformation or internal stresses based
on the surrounding mold - Answers yield stress
What categories of alloying elements are found in casting metals? - Answers improve processability,
properties, impurities
For a given casting alloy, a ______ casting will have poorer properties than a _______ one - Answers big,
small
High melting point powders added before pouring a casting - Answers innoculants
What are the positives of sand casting? - Answers Can deal with all common casting metals, cheap, wide
range of sizes
What are the negatives of sand casting? - Answers fragile, low filling speeds and pressures, poor
conductors of heat, qualities, tolerances.
Lower mold half in a sand mold - Answers Drag
Higher mold half in a sand mold - Answers Cope
Hollow products can be casted using _________ - Answers sand cores
Downward channel in a sand mold - Answers sprue
The feeder is located where on a sand cast? - Answers highest point in thickest part
Atmospheric pressure steel die casting is called _______ - Answers Gravity die casting
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