Metals and Alloys Flashcards
6 cards from real ME practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Metals and Alloys flashcards as text
Austenitic stainless steels (e.g., 304) are non-magnetic primarily because:
Answer: The FCC austenite phase is paramagnetic
Austenitic stainless steels retain the FCC austenite phase at room temperature due to high nickel content, and this phase is paramagnetic (non-magnetic).
The tempering of martensite in steel is performed to:
Answer: Improve toughness by relieving internal stresses and precipitating carbides
Tempering heats quenched martensite to an intermediate temperature, allowing carbon to precipitate as fine carbides and relieving residual stresses, improving toughness.
Which copper alloy is known for its excellent spring-back properties and electrical conductivity?
Answer: Beryllium copper (Cu-Be)
Beryllium copper has the highest strength and hardness of any copper alloy, combined with excellent spring properties, making it ideal for electrical connectors and springs.
The Jominy end-quench test is used to measure which property of steel?
Answer: Hardenability
The Jominy end-quench test measures hardenability by quenching one end of a bar and measuring hardness as a function of distance from the quenched end.
Grain refinement in metals typically results in:
Answer: Increased yield strength and toughness
According to the Hall-Petch relationship, smaller grain size increases yield strength, and fine-grained metals also generally show improved toughness.
Which heat treatment process produces a spheroidized microstructure in steel to improve machinability?
Answer: Spheroidize annealing
Spheroidize annealing involves extended heating near the eutectoid temperature, causing cementite to assume a spheroidal morphology, which maximizes machinability and ductility.