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What is the expression for strain rate during diffusional creep? c) dꜪ/dt = (B1Db+σΩ/d2)B2Dv d) dꜪ/dt = (4ρΩd2/απkT)

What is the expression for strain rate during diffusional creep? c) dꜪ/dt = (B1Db+σΩ/d2)B2Dv d) dꜪ/dt = (4ρΩd2/απkT) Correct Answer ρkT/4π [ dꜪ/dt = (σΩ/d2KT)[B1Dv+(B2ΔDb/d)

The expression for strain rate during diffusional creep is given by dꜪ/dt = (σΩ/d2KT) where dꜪ/dt is strain rate, σ is the applied stress, d is the grain size, k is Boltzmann constant, T is the temperature, Ω is the atomic volume, B1 and B2 are some constants, Dv is the volume diffusion coefficient, Db is the grain boundary coefficient and Δ is the grain boundary width.

Related Questions

From an alloy, two specimens are machined and tested separately under tension and compression. The engineering stress-strain curves as well as the true stress-true strain curves for tension and compression are plotted in the same diagram. Identify the correct statements:
P. The engineering stress-strain curves in tension and compression are identical.
Q. The true stress-true strain curve in compression is lower than the true stresstrue strain curve in tension due to Bauschinger effect.
R. The true stress-true strain curve in tension is above the corresponding engineering stress-strain, curve.
S. The true stress-true strain curve in tension and compression are identical.
The true strain rate is given as ϒ, and conventional strain rate is given as ε. The engineering strain is equal to e. The relationship between conventional strain rate and true strain rate is _______
Study the following statements regarding creep.
i) Creep is greater on curves than on tangent railway track
ii) Creep in new rails is more than that in old rails
iii) Creep is more on steep gradients than on level track
The correct answer is
Which of the following statements are true/false?
1. A minimum rate of wages for the time spent by employees for the production of output is minimum time rate.
2. Minimum piece rate is the rate based on the quantity of the output employees have produced.
3. The guaranteed time rate is a minimum rate of remuneration to apply in the case of employees employed on piece work for the purpose of securing to such employees a minimum rate of wages on a time work basis.
4. A minimum rate of remuneration to apply in the case of employees employed on piece work for the purpose of securing to such employees a minimum rate of wages on a time work basis is overtime rate.
To maintain the constant true strain rate of a sample, the crosshead velocity should increase with the increase in the length of the specimen. What will be the optimum velocity with the change in length to keep the true strain rate constant? (True strain rate=ϒ, L=length of sample, t=time).
The relationship between the stress and strain rate is given as σ=Cϒm, where m is strain rate sensitivity. The strain rate sensitivity _____________ with increase in temperature.
The diffusional creep is the chief mechanism activated in the stress range of ___________
The primary state of the creep curve represents the ___________ creep rate in the strain vs. time curve.
If the strain rate on the material increases, the Coble creep region of the creep map will _________
Consider the following statements about Bligh’s Creep Theory. i. Creep length is the length of path traversed by percolating water ii. To increase the path of percolation vertical cut-off or sheet piles can be provided iii. Loss of head per unit creep length is hydraulic gradient iv. Bligh gave no criteria for the safety of weir against undermining Which of the following statements are correct?