8/8/2019 IR Thermography of NAL Test Mockups

1/14

Non-Destructive Testing

Of Test Mock-Ups UsingInfra-Red Thermography

Santosh Pandya, Shwetang Pandyaand Dr.J.Govindarajan

Infra-Red Thermography Division

Institute for Plasma Research

8/8/2019 IR Thermography of NAL Test Mockups

2/14

Why NDT?

Plasma Facing Components (PFCs) are the components inside thetokamak to come in contact with the hot plasma and hence are subjectedto high heat flux (HHF) of the order of few tens of M W/ m2 andbombardment of energetic particle flux (EPF) from the high temperaturefusion plasma.

The exposure to the HHF and EPF may damage the structural integrityof PFCs and shorten their service life significantly, if the bonding betweenplasma facing materials (PFMs) to heat sink is not satisfactory.

Suitable non-destructive testing (NDT) technique is thus essential toevaluate the brazing quality between the PFM and the heat sink.

8/8/2019 IR Thermography of NAL Test Mockups

3/14

NDT of Brazed Macro-Brush using Different IR-Thermography methods

Schematic Diagram PFC with Graphite Tiles1

PFC with Tungsten Tiles1

1. Sample developed by National Aerospace Laboratories (NAL, Bangalore, INDIA) under MOU with Institute for Plasma Research (IPR, Gandhinagar, INDIA)

2. IR-Thermography Division, Institute for Plasma Research (IPR, Gandhinagar, INDIA).3. NDE Department, Indian Institute Technology-Madras (IIT-M, Chennai, INDIA).4. Quality Assurance Division, Indira Gandhi Centre for Atomic Research(IGCAR, Kalpakkam, INDIA)

Following are the active IR-NDT techniques used to examine test mock-ups

1. Transient NDT by passing Hot & Cold water through the sample 22. Heat stimulation using Induction Heating 3

3. Pulse IR-NDT 4

4. Lock-in IR-NDT 4

8/8/2019 IR Thermography of NAL Test Mockups

4/14

8/8/2019 IR Thermography of NAL Test Mockups

5/14

Principle of Operation Lock in Thermography

N

measures surfacetemperature

s/2mconstantdiffusion

J/kgK capacityheatspecific

3kg/mdensity

W/mK tyconductivithermal

p

p

c

c

VP

!E

V

P

a periodic heat flux is incident onthe surface of interest

the surface temperature ismeasured and local variations in

the phase and/or amplitude arerequired

8/8/2019 IR Thermography of NAL Test Mockups

6/14

8/8/2019 IR Thermography of NAL Test Mockups

7/14

Pulse thermography

8/8/2019 IR Thermography of NAL Test Mockups

8/14

Results from different methods for a Graphite tiles sample

Heat stimulation using Induction Heating Transient NDT by passing Hot &Cold water through the sample

Lock-in IR-NDT Pulse IR-NDT

8/8/2019 IR Thermography of NAL Test Mockups

9/14

10400

10600

10800

11000

11200

11400

11600

0 500 1000 1500 2000

Time (Seconds)

I R C a m e r a

S i g n a

l - D

i g i t a

l L e v e

lSeries1

Series2

Series3

Series4

Series5

Series6

Series7

Series8

Series9

Series10

Series11

Series12

Series13

Series14

Series15 -40

-30

-20

-10

0

10

20

30

40

50

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Tile Number

D e

l t a - P

h a s e

( D e g r e e

)

0.004 Hz0.005 Hz0.006 Hz0.007 Hz0.008 Hz0.009 Hz0.01 Hz0.02 Hz0.03 Hz0.04 Hz0.05 Hz0.06 Hz0.07 Hz0.08 Hz0.09 Hz0.1 Hz0.2 Hz0.3 Hz0.4 Hz0.5 Hz

20

25

30

35

40

45

50

15 16 17 18 19 20

Time (Sec)

T e m p e r a

t u r e

( C )

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

De f ect identi f ication in di ff erent methods

Transient NDT by

passing Hot & Cold water through thesample

Pulse IR-NDT Lock-in IR-NDT

8/8/2019 IR Thermography of NAL Test Mockups

10/14

Results from different methods for Tungsten Macro-Brush Test Mock-Ups

Transient NDT by passing Hot &Cold water through the sample

Pulse IR-NDT

Lock-in IR-NDT

TEBT

8/8/2019 IR Thermography of NAL Test Mockups

11/14

9900

10000

10100

10200

10300

10400

10500

0 500 1000 1500 2000

T i e

Sec

s

I R C a

e r a

S i

a l

D i

i a

l e e

lSe

ie

1

Se

ie

2

Se

ie

3

Se

ie

4

Se

ie

5

Se

ie

6

Se

ie

7

Se

ie

8

Se

ie

9

Se

ie

10

Se

ie

11

Se

ie

12

Se

ie

13

Se

ie

14

Se

ie

15

40

41

42

43

44

45

46

47

48

49

50

16

00 16

50 17

00 17

50 18

00 18

50 19

00

T i e Sec

T e

e r a

!

"

r e#

$

C%

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

Pulse IR-NDT

Transient NDT by

passing Hot & Cold water through thesample

8/8/2019 IR Thermography of NAL Test Mockups

12/14

NDT Results of Graphite Test Mock-Up using TBET Induction Heating

A tubular coil was designed to pass

through the inner passage / hole of theDIVERTORsample.The sample was heated for 5 sec andcooled at constant temperature undernatural convection.The temperature data was analyzedunder infra-red camera and recorded

Frequency used 3000 HzCurrent : 2.5-3 AmpsVoltage :40 VHeating time 5 sec

Tile with good bond Cu Tube

Tile with weak bond

Tile with good bond

Tile with weak bond

8/8/2019 IR Thermography of NAL Test Mockups

13/14

Time History Chart

Good Tile

Defective tile

Time History Thermal Images

NDT Results of Tungsten Test Mock-Up using Induction Heating

8/8/2019 IR Thermography of NAL Test Mockups

14/14

Conclusions

1. NDT carried out using different IR-Thermography

techniques are compared on macro-brush test mock-ups with graphite and tungsten tiles as plasma facingmaterials;

2. Among four techniques studied, Transient IR-Thermography by Hot & Cold Stimulation is foundsuitable for both Graphite and Tungsten mock-ups;

3. Results of NDT using various techniques shows goodconsistency for Graphite mock-ups.

4. More work is needed for NDT of Tungsten mock-ups.