As temperature decreases from 0 to l00°C, the ultimate tensile strength and yield strength of most metals will _________________?
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Answer: A. increase
Explanation
In the low-temperature range from zero to one hundred Celsius, metal strength properties increase. Reduced thermal energy at lower temperatures makes dislocation glide more difficult within the crystal lattice. This increased resistance to dislocation movement directly raises the ultimate tensile and yield strengths. Yield strength and ultimate tensile strength quantify a metal's resistance to plastic flow and fracture. Crystal structures of metals respond to thermal cooling by reducing atomic vibration amplitudes. Most structural engineering metals follow this trend of increasing strength as ambient temperatures drop.
Pressure vessels operating in cold environments must be selected carefully to account for elevated yield strengths. Cryogenic engineering studies metal behavior at extreme sub-zero temperatures where brittleness becomes critical. Automotive components experience slight variations in mechanical strength between winter and summer operating conditions. Option B suggests strength decreases, which only happens at elevated temperatures where thermal softening dominates. Option C ignores the measurable changes in dislocation mobility that occur across thermal intervals. Option D incorrectly implies complex non-monotonic trends for standard structural metals in this range.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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