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Flashcards in 14. Creep Failure Deck (17):
1

List the three regimes of creep

1. Primary creep
2. Secondary (steady-state) creep
3. Tertiary creep (rupture)

2

Describe the effect of temperature and stress on creep

Increased stress = increased creep
increases temperature = increase creep

3

Describe material advancements that increase resistance to creep

- make a single crystal
- make channels for air cooling
- thermal coating which makes the material more heat resistant

4

Why does the creep rate continuously decrease during primary/instantaneous creep?

strain hardening

5

Why is the creep rate constant during secondary/steady-state creep?

due to balancing of strain hardening and recovery

6

Which creep regime is the longest?

secondary/steady-state creep

7

Which creep regime is the longest?

secondary/steady-state creep

8

As stress and/or temperature increase, the rupture time tr ______

decreases

9

As stress and/or temperature increase, the steady-state creep rate ______

increases

10

What is m in this equation?
𝑚 = 𝑇(𝐶 + log(𝑡𝑟))

the Larson-Miller parameter

11

Metals with a ____ melting temperature demonstrate greater resistance to creep

high

12

Metals with a ____ elastic modulus demonstrate greater resistance to creep

high

13

Metals with a ____ grain size demonstrate greater resistance to creep

large

14

Metals with a ____ grain size demonstrate greater resistance to creep

large

15

How does creep occur?

By the sliding of grain boundaries?

16

Is a material with more or less grain boundaries more resistant to creep?

Less
The most resistant material would be one made up of a single crystal

17

How do smaller grains result in more creep?

smaller grains = more grains = more grain boundaries = more grain sliding = more creep