Lecture 2B Flashcards
Once a system is at a state of equilibrium, a shift from equilibrium may result by alternation of which of the following? A. Pressure. B. Composition. C. Temperature. D. All of the above.
D. All of the above.
Define triple point as it relates to a single component phase diagram.
The point on a phase diagram at which the three states of matter: gas, liquid, and solid coexist.
A solidus line separates which phase fields?
Alpha and liquid + alpha
Define critical point as it relates to a single component phase diagram.
The point on a phase diagram at which the substance is indistinguishable between liquid and gaseous states.
State three variables that determine the microstructure of an alloy.
.
Define eutectic temperature as it relates to binary eutectic systems phase diagram.
The lowest possible temperature of solidification for any mixture of specified constituents.
What do you understand by lamellar eutectic structure? When are they formed?
Lamellar structures are fine, alternating layers of different materials. The are often formed when the phase transformation front moves quickly.
What is the primary difference between ferrous steels and cast irons?
Cast iron has a low melting point and is also brittle so it is easy to form cast.
Name two types of cast iron and state a distinguishing features of each of those materials.
White iron: extremely hard, but brittle.
Gray iron: weak and brittle under tension, strong under compression.
State two limitation in properties for the applications of ferrous alloys.
Relatively high density.
Poor corrosion resistance.
Differentiate between hot and cold working of metals.
Hot working: temperature is high enough for recrystallization and used for larger deformations.
Cold working: well room temperature, work hardening, smaller deformations.
Name and describe two metal forming methods.
Forging: (hammering)
Rolling: (hot or cold)
Describe the process of metal casting to form final metallic products.
Mold is filled with metal.
Metal melted in furnace (add alloy).
Case in a mold.
Describe briefly the powder metallurgy fabrication method.
Metal powder is compacted at high pressure to form metal particles.
Metal particles are heated in a sintering process to form final product.
When the concentration of solute in a solid solution exceeds the solubility limit, which of the following situations results?
A. The formation of a new solid solution or phase that has a composition similar to that of the original solid solution.
B. The formation of a new solid solution or phase that has a distinctly different composition that the original solid solution.
B. The formation of a new solid solution or phase that has a distinctly different composition that the original solid solution.
