For ceramic-matrix composites, high interfacial strength is desirable. ( True , False )

An alloy is evaluated for potential creep deformation in a short-term laboratory experiment. The creep rate (ϵ˙) is found to be

cupoosta [38]

Answer:

Activation energy for creep in this temperature range is Q = 252.2 kJ/mol

Explanation:

To calculate the creep rate at a particular temperature

creep rate, $\zeta_{\theta} = C \exp(\frac{-Q}{R \theta} )$

Creep rate at 800⁰C, $\zeta_{800} = C \exp(\frac{-Q}{R (800+273)} )$

$\zeta_{800} = C \exp(\frac{-Q}{1073R} )\\\zeta_{800} = 1 \% per hour =0.01\\$

$0.01 = C \exp(\frac{-Q}{1073R} )$ .........................(1)

Creep rate at 700⁰C

$\zeta_{700} = C \exp(\frac{-Q}{R (700+273)} )$

$\zeta_{800} = C \exp(\frac{-Q}{973R} )\\\zeta_{800} = 5.5 * 10^{-2} \% per hour =5.5 * 10^{-4}$

$5.5 * 10^{-4} = C \exp(\frac{-Q}{1073R} )$ .................(2)

Divide equation (1) by equation (2)

$\frac{0.01}{5.5 * 10^{-4} } = \exp[\frac{-Q}{1073R} -\frac{-Q}{973R} ]\\18.182= \exp[\frac{-Q}{1073R} +\frac{Q}{973R} ]\\R = 8.314\\18.182= \exp[\frac{-Q}{1073*8.314} +\frac{Q}{973*8.314} ]\\18.182= \exp[0.0000115 Q]\\$

Take the natural log of both sides

$ln 18.182= 0.0000115Q\\2.9004 = 0.0000115Q\\Q = 2.9004/0.0000115\\Q = 252211.49 J/mol\\Q = 252.2 kJ/mol$

3 0

3 years ago

A steam power plant is represented as a heat engine operating between two thermal reservoirs at 800 K and 300 K. The temperature

Sergeeva-Olga [200]

Yeet is the answer .....

4 0

2 years ago

Tech A says that horsepower is a measurement simply of the amount of work being performed. Tech B says that horsepower can be ca

snow_tiger [21]

Answer:

Tech B

Explanation:

Horsepower (hp) refers to a unit of measurement of power in respect of the output of engines or motors.

Horsepower is the common unit of power. It indicates the rate at which work is done.

The formula $\frac{rpm*T}{5252}$ , where rpm is the engine speed, T is the torque, and 5,252 is radians per second.

So,

Tech B is correct

6 0

3 years ago

Q10: Technician A says that nearly all brands of scan tools will pull DTCs from the ABS

Llana [10]

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7 0

3 years ago

If they opened up the International Space Station to tourism, would you go? Why? answer in 2 sentences

Arlecino [84]

Personally, I would go to the space station. The space station has extreme different levels of technology and abilities, plus who doesn’t want to go to space.

6 0

3 years ago

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