Thick Thermal Barrier Coatings (TTBC) Introduction of TTBC - - PowerPoint PPT Presentation

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Thick Thermal Barrier Coatings (TTBC) Introduction of TTBC - - PowerPoint PPT Presentation

Jul 16, 2023 366 likes •569 views

Thick Thermal Barrier Coatings (TTBC) Introduction of TTBC Microstructure of TTBC Test apparatus Monotonic test Strain hold Future research Ceramic 80% Ceramic- 20% Bond Coat 50% Ceramic-50% Bond Coat 20% Ceramic-

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SLIDE 1

Thick Thermal Barrier Coatings (TTBC)

  • Introduction of TTBC
  • Microstructure of TTBC
  • Test apparatus
  • Monotonic test
  • Strain hold
  • Future research
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SLIDE 2

Figure 1. Functionally graded material (FGM). Substrate Bond Coat 20% Ceramic- 80% Bond Coat 50% Ceramic-50% Bond Coat 80% Ceramic- 20% Bond Coat Ceramic

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SLIDE 3

In-plane direction In-plane direction

Figure 2. Micrograph of TTBC coating (100% ceramic) parallel to substrate

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SLIDE 4

In-plane direction Through thickness direction

10µm

Figure 3. Micrograph of TTBC coating (100% ceramic) normal to substrate

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SLIDE 5

In-plane direction Through thickness direction

Figure 4. Micrograph of TTBC coating (50% ceramic and 50% bond coat) normal to substrate

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SLIDE 6

In-plane direction Through thickness direction

Figure 5. Micrograph of 100% bond coating normal to substrate.

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SLIDE 7

Step 1: Press-fit and machine steel substrate Step 2: Plasma spray mid- section Step 3: Perform final machining and etch away inner steel press-fit tube

Figure 6. Specimen fabrication processes.

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SLIDE 8

Figure 7. Test system.

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SLIDE 9

Figure 8. Extensometer.

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SLIDE 10

5 10 15 20 25 1000 2000 3000 4000 5000 6000 Shear Strain (x10-6) Shear Stress (MPa) 800 °C 25 °C

Figure 9. Ceria-stabilized TBC in-plane monotonic shear deformation to failure.

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SLIDE 11

20 40 60 80 100 120 140 2000 4000 6000 8000 10000 12000 Principle Strain (x10-6) Principle Stress (MPa)

Compression Torsion Tension

Figure 10. CSZ: comparison of principle stress-strain curves for monotonic test at room temperature.

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SLIDE 12

14.6 126 Compression 8 10.2 Tension (6-10) 11.9-17.9 Shear Elastic modulus (GPa) E (G) Strength (MPa) Loading type Table 1. Material properties of CSZ

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SLIDE 13
  • 60
  • 40
  • 20

20

Strain Stress (MPa)

  • 0.02
  • 0.04

800 °C 20 °C

Figure 11. 10-hour compression strain hold of CSZ at 3800 µε.

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SLIDE 14
  • 300
  • 250
  • 200
  • 150
  • 100
  • 50

50 100

  • 4000
  • 3000
  • 2000
  • 1000

Strain (10-6) Stress (MPa)

Figure 12. 10-hour compression strain hold of bond coating at 3650µε.

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SLIDE 15
  • 8
  • 4

4 8 12 16 500 1000 1500 2000 2500 Shear Strain (x10-6) Shear Stress (M Pa) 800 °C 25 °C

Figure 13. 10-hours shear strain hold test of 100% CSZ at 2000µε.

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SLIDE 16
  • 10

10 20 30 40 50 60 70 500 1000 1500 2000 2500 Shear Strain (x10-6) Shear Stress (MPa) 25 °C

Figure 14. 10 hours shear strain hold test of bond coating at 2000µε.

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SLIDE 17

Table 2. Stress relaxation during 10 hours holding 65.3MPa to 62.9MPa (3.7%) Bond coating 281MPa to 267MPa (5.0%) Bond coating 12.0MPa to 10.1MPa (15.8%) 100% CSZ Shear 48.1MPa to 36.8MPa (23.5%) 100% CSZ Compression Stress relaxation Materials Loading type

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SLIDE 18

Future research:

  • To study and explain the phenomena of non-linear

deformation in the monotonic test and stress relaxation and creep at room temperature.

  • To model the deformation process of TTBC.

Future research:

  • Loading: Combined loading.
  • Materials: with controlled crack density.
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SLIDE 19

shear tension compression combined loading

Figure 15. The Mohr circle.