1. Advanced Ceramics Corp
Advancement of microporous insulation
Presented by: Darnelle Jones, Jeff Kay, Alex Melvin and Steven Chortos
Mentors: Ritch Mathews and Dr. Zhitomirsky
April 2nd, 2013

2. Contents









Background
Procedure and error
Linear change results
SEM and XRD
Sustainability
Gantt chart
Future direction
Conclusion
2

3. AC80i vs AC80

 Investigation done in 2011-2012 on AC80
 Assumed by both parties that the properties
were the same
3

4. Background

4

5. AC80i assumptions

 Thermally resistant (1000 °C)
 Made of:
 Amorphous fumed silica
 Rutile titania (mixture)
 Silica fibres
 Process:
 Mixed together
 Pressed by 75 ton force
 Not fired (reduced cost)
5

6. What’s the problem?

 Degradation of thermal properties at 1000°C
 Onset of sintering
 Shrinkage (densification)
 Cracking
6

7. Problem statement

The overall goal of this project is to
increase the operating temperature of
AC80i by 100°C while keeping it
economically viable.
7

8. Testing methods

 Fibre coating
 Reduce fibre-fibre contact (conduction)
 SEM
 Addition of fumed alumina
 Inhibit sintering and phase change
 Linear shrinkage
 SEM
 XRD
8

9. Procedure and error

9

10. Testing overview

 Total days spent testing = 36
 Total hours of furnace operation = 966
 Total samples tested = 145
 Usable samples = 90
10

11. Preparation

 Fumed silica, TiO2 and silica fibres weighed and
mixed in shear mixer
 Alumina addition and final mixing
 The Al2O3 was weighed and added to the bucket
 Materials were mixed for approx 5 mins using a drill
with a paint mixer attached to the end
 Error in homogeneity of mix
11

12. Testing

 Samples tested using a modified version of the
ASTM C356-10 testing procedure
 Samples were placed in furnace and held at
temperature for 24 hours
 Measurements
 Initial samples were measured in each dimension
 Significant error due to inconsistent measuring practice
12

13. Radiation Shields

13

14. Ladle example

14

15. Shield #1

 Feb 12th-19th
3

16. Shield #2

 Feb 25th-March 3rd
16

17. Shield #3

 March 4th-12th
17

18. Shield #4

 March 12th-April 1st (Morgan Thermal Ceramics –
insulating fire bricks)
18

19. Linear change results

19

20. Design compositions

 Alumina added





0 wt% (AC80i)
6 wt%
9.5 wt%
12.5 wt%
19 wt%
 Final brick design
 Cost vs linear shrinkage
 12.5 wt%
20

21. Importance of testing
direction

21

22. Morgan radiation shield
6% Worst Case Scenario
9.5% Worst Case Scenario
1100
1075
1050
0%
6%
1025
5% linear change
Temperature (°C)
Temperature (°C)
1100
1000
0
1
2
3
4
5
6
1075
1050
0%
9.5%
1025
5% linear change
1000
7
0
1
Linear Change (%)
3
4
5
6
Linear Change (%)
12.5% Worst Case Scenario
19% Worst Case Scenario
1100
1075
1050
0%
12.5%
1025
5% linear change
1000
Temperature (°C)
1100
Temperature (°C)
2
1075
1050
0%
19%
1025
5% linear change
1000
0
1
2
3
4
Linear Change (%)
5
6
0
1
2
3
4
Linear Change (%)
5
6
22

23. Final brick

ASTM Worst Case
1150
Temperature (°C)
1125
1100
1075
0%
FB
5% linear change
1050
1025
1000
0
1
2
3
Linear Change (%)
4
5
6
23

24. SEM and XRD

24

25. Went in looking for:

 Distribution of titania particles
 Hard/soft fracture
 Open/closed pores
 Coating of silica fibres
25

26. Titania Particles

 Titania acts as an opacifier, reducing the effects of
radiation
 Even distribution ensures effective scattering
 Titania does appear to be distributed evenly
26

27. 
3% alumina @ 1025 °C
27

28. Sharp/soft fracture

 Looking for:
 Sharp structures in the 1100 °C heated sample
 Rounder edges in pre-densified samples
 Some differences noted, but results were not
definitive
28

29. 
3% alumina @ 1100 °C
3% alumina @ 1025 °C
29

30. Open/closed pores

 Unable to effectively image the pores using SEM
 If the samples were mounted and polished rather
than crushed, results may have been more
informative
30

31. Coating of silica fibres

 Compressive shear mixing was proposed to coat the
silica fibres in a layer of fumed silica
 Munson Machinery was investigated to mix, but
communication fell through
 Devised our own shear mixing method, but did not
achieve fibre coating
31

32.  Centrifugal
compressive-shear mill
 Tomato strainer
32

33. Coated fibres
33

34. XRD Analysis

 Went in looking for cristobalite in our samples
 Alumina was originally added as a phase change
and sintering suppressant
 No cristobalite was found, even in the 0% alumina
samples
 Due to the difference in titania content
34

35. 0-1000C.raw
0-1025C.raw
0-1075C.raw
0-1100C.raw
11,000
10,500
10,000
9,500
Results

9,000
8,500
8,000
7,500
Counts
7,000
6,500
6,000
5,500
5,000
4,500
4,000
3,500
3,000
2,500
2,000
1,500
1,000
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
46
48
50
52
54
56
58
60
62
64
66
68
70
72
74
2Th Degrees
16,500
16,000
15,500
15,000
14,500
10-1025C.raw
10-1050C.raw
10-1075C.raw
10-1100C.raw
14,000
13,500
13,000
12,500
12,000
Counts
11,500
11,000
10,500
10,000
9,500
9,000
8,500
8,000
7,500
7,000
6,500
6,000
5,500
5,000
4,500
4,000
3,500
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
2Th Degrees
60
62
64
66
68
70
72
74
35

36. Sustainability

36

37. Environmental

 No increase in health risks to workers or
users
 No change in the environmental impact
37

38. Economical

53%
 New markets
 No new processing machines needed
38

39. Gantt chart

39

40. Proposed Gantt Chart
9/20/12
11/9/12
12/29/12
2/17/13
4/8/13
Meeting with Ritch Mathews
Preliminary research
Indepth research of proposed
solutions
Meeting with Dr. Zhitomirsky
Problem statement presentation
Meeting with Dr. Malakhov
Proposal presentation preparation
Proposal presentation
Written proposal
Testing preperation and testing
Progress presentation #2
Progress presentation #3
Final presentation preparation
Final presentation
Final written report
40

41. Final Gantt Chart
9/20/12
11/9/12
12/29/12
2/17/13
4/8/13
Meeting with Ritch Mathews
Preliminary research
Indepth research of proposed solutions
Meeting with Dr. Zhitomirsky
Problem statement presentation
Meeting with Dr. Malakhov
Proposal presentation preparation
Proposal presentation
Written proposal
Initial contact with Munson
Contacting and ordering Al2O3
Contacting for TiO2
Correspondance with Munson
Industry pick-up
Industry visit (sample prep)
Progress presentation #2
Furnace testing (JHE
Correspondance with CANMet
Progress presentation #3
SEM analysis
XRD analysis
Final report
Final presentation preparation
Final presentation
41

42. Future direction

42

43. General Heat Equation

q” = kΔT + hΔT +
Conduction
4
ϵσΔT
Convection
Radiation
k: thermal conductivity
h: convective heat transfer coefficient
ϵ: emissivity
σ: Stefan-Boltzmann constant
43

44. Recommendations

 Optimize particle size / opacifier material
 Optimized opacifier = less radiant heat transfer
 Evidence through radiation shields
 Radiation shield in industry
44

45. AC80i radiation shield

Densification Results (AC80i Shield)
1100
Temperature (°C)
1075
6%
1050
9.5%
12.5%
19%
5% linear change
1025
1000
0
5
10
15
Linear Change (%)
20
25
30
45

46. Morgan radiation shield

Worst Case Densification Results
1100
Temperature (°C)
1075
6%
9.5%
1050
12.5%
19%
0%
5% linear change
1025
1000
0
1
2
3
4
Linear Change (%)
5
6
7
46

47. Suggestions

 Design a solid radiation shield
 Easy loading and unloading
 Consistent heating
 Accurate and reproducible results
 Homogenous mix
 Consistent mixing procedure
 Reduction in error
 Sample orientation
 Consistent orientation of samples
47

48. Conclusion

 AC 80i – Best option up to 1100 °C
 Less linear shrinkage
 Cheaper
48

49. Acknowledgements

Thank you
• Ritch Mathews
• Dr. Zhitomirsky
• All of the MSE faculty
49

50. Questions?
50