Evaluation of Adhesive Bond Primers for Repair Bonding of Aluminum · 2012. 5. 24. · Evaluation...

Evaluation of Adhesive Bond Primers

2011 DoD Joint Committee on Tactical Shelters (JOCOTAS)for Repair Bonding of Aluminum

2 November 2011

Materials and Manufacturing DirectorateDan McCray and Jeff Smith (UDRI)

Jim Mazza and Kara Storage (AFRL/RXSAC)

JJM; AFRL/RXSAC 1

DISTRIBUTION STATEMENT A: Approved for Public Release; Distribution is Unlimited. (Case no. 88ABW-2010-5305, 1 Oct 2010).

Jim Mazza and Kara Storage (AFRL/RXSAC)

Report Documentation Page Form ApprovedOMB No. 0704-0188Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering andmaintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information,including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, ArlingtonVA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if itdoes not display a currently valid OMB control number.

1. REPORT DATE 02 NOV 2011 2. REPORT TYPE

3. DATES COVERED 00-00-2011 to 00-00-2011

4. TITLE AND SUBTITLE Evaluation of Adhesive Bond Primers for Repair Bonding of Aluminum

5a. CONTRACT NUMBER

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S) 5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Air Force Research Laboratory,AFRL/RXSAC,Wright Patterson AFB,OH,45433

8. PERFORMING ORGANIZATIONREPORT NUMBER

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S)

11. SPONSOR/MONITOR’S REPORT NUMBER(S)

12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution unlimited

13. SUPPLEMENTARY NOTES 7th Bi-Annual DOD JOCOTAS Meeting with Rigid & Soft Wall Shelter Industry & Indoor & OutdoorExhibition, 1-3 Nov 2011, Panama City Beach, FL

14. ABSTRACT

15. SUBJECT TERMS

16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Same as

Report (SAR)

18. NUMBEROF PAGES

48

19a. NAME OFRESPONSIBLE PERSON

a. REPORT unclassified

b. ABSTRACT unclassified

c. THIS PAGE unclassified

Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18

Overview

• Backgroundg

• Materials and Processes

T t d T t M th d• Tests and Test Methods

• Lap Shear and Peel Data

• Wedge Test Data

• Conclusions

• Future Work

JJM; AFRL/RXSAC 2DoD Distribution Statement A: Approved for Public Release; Distribution is Unlimited.

Background

• Large Screening Effort to Evaluate Low-VOC Bond Primers• Primary Focus is to Eliminate Chromated Bond PrimersPrimary Focus is to Eliminate Chromated Bond Primers• Working with Industry-Government Non-Cr Adhesive Bond

Primer TeamEffort is part of the larger picture but also has USAF focus– Effort is part of the larger picture but also has USAF focus

• Desire Performance Equivalent to that Currently Obtained with Chromated Primers− Cytec’s BR 127 and BR 6747-1, primarily

• Bond Strength and Moisture Durability are Both Important• Looking for Primer that Works Well with Multiple Adhesives

on Adherends Prepared Using Grit-Blast/Sol-Gel (GBSG)– Currently, GBSG is used exclusively with Cytec’s BR 6747-1 primer

C t ' FM 73 dh i i t d d f ith GBSG


– Cytec's FM 73 adhesive is not recommended for use with GBSG– 3M’s AF 163-2 adhesive tends to fail at its interface with BR 6747-1

Materials and Processes

• Five Waterborne Adhesive Bond Primers– Cytec’s BR 6747-1 (zero-VOC, chromated)– Cytec’s BR 6747-1NC (zero-VOC, nonchromated - no inhibitor)– Cytec’s BR 6700-1 (low-VOC, nonchromated corrosion inhibitor)y ( , )– 3M’s EW 5000 (low-VOC, chromated)– 3M’s EW 5000 AS (low-VOC, nonchromated corrosion inhibitor)

• Spray Applied Using Conventional Air Gun– Dry film thicknesses: 0.0025 mm - 0.0063 mm (0.0001 - 0.00025 in);

measured using Fischer Isoscope MP30E-S with ETA3 3H probemeasured using Fischer Isoscope MP30E-S with ETA3.3H probe(directly on PAA adherends and on travelers for GBSG adherends)

• Cured in an Air-circulating Oven at 121°C (250°F) for 60


g ( )Mins after Air Dry at Ambient Conditions for 30 Mins

Materials and Processes (cont.)

• Seven Adhesives Evaluated with Each PrimerSeven Adhesives Evaluated with Each Primer– Henkel’s Hysol EA 9696 and Hysol EA 9628– Cytec’s FM 73M, FM 209M, and FM 300-2M– 3M’s AF 163-2M and AF 500M

• Mat Carrier• 290g/m2 (0.06 psf) Areal Weight• Cured per Manufacturers’ Recommendations UnderCured per Manufacturers Recommendations Under

Positive Pressure– 121°C (250°F) for 60-90 Minutes


Materials and Processes (cont.)

• 2024-T3 (bare) Aluminum Adherends( )• Two Surface Preparations

– Phosphoric Acid Anodize (PAA) per ASTM D 3933• First choice for aluminum prebond surface preparation• Used in USAF for rework and preparation of repair doublers

– Grit Blast/Sol Gel (GBSG)– Grit-Blast/Sol-Gel (GBSG)• Al2O3 grit-blast followed by application of AC Tech AC-130

(Boegel-EPII) sol-gel solution; no rinse and ambient driedU d i USAF f ti f i ft dh d• Used in USAF for preparation of on-aircraft adherends


Tests and Test Methods

• Tensile Lap Shear (ASTM D 1002)– Ambient temperature at 22°C (72°F)– Ambient temperature at 22 C (72 F)– Hot/Wet at 82°C (180°F) after conditioning for 90 days at 60°C

(140°F) and 95-100% relative humidity (RH)

• Metal-to-Metal Climbing Drum Peel (ASTM D 1781)– Ambient temperature at 22°C (72°F)

• Wedge Test (ASTM D 3762)– Conditioned at 60°C (140°F) and 95-100% RH for 28 days

C diti d t 49°C (120°F) d 95 100% RH f 28 d *– Conditioned at 49°C (120°F) and 95-100% RH for 28 days*

• Five Specimens per Test for Each Adhesive/Primer/Surface Preparation Combination


Adhesive/Primer/Surface Preparation Combination

* These data are not reported in the paper and will not be presented; will be in a comprehensive report

The Wedge Test

• Used Extensively by AFRL for Screening to Assess Bonded Joint Moisture Durabilityy

• Considered by AFRL to be a Semiquantitative Test– Initial crack lengths provide important information (w.r.t. test severity)Initial crack lengths provide important information (w.r.t. test severity)– Crack extensions can be useful, but are not the bottom line– Most consideration is given to failure modes after conditioning

D i f il d 95% t h i ithi th dh i– Desire failure modes are 95% or greater cohesive within the adhesive

• CaveatsU f l f i f ti (i l di i )– Useful for comparing surface preparations (including primers)

– Many factors affect the test; must only vary the factor being evaluated– Several adhesive characteristics affect the test: modulus, bondline


thickness, carrier, degree of cure, hot/wet properties– Test cannot be quantitatively correlated with in-service performance

EA 9696 Adhesive22°C (72°F) Lap Shear

6000

700045

50

i)Pa) EA 9696 Tech Data Sheet

4000

5000

6000

25

30

35

40

Strength (psi

tren

gth (M

P

1000

2000

3000

5

10

15

20

Lap Shear S

Lap Shear S

00

5

R 67

47‐1

747‐1N

C

R 67

00‐1

EW 500

0

5000

AS

PAA

GBSG


BR

BR 67

BR E

EW GBSG

EA 9696 Adhesive82°C (180°F) Wet Lap Shear

3500

400025

30

si)

Pa)

2000

2500

3000

15

20

r Stren

gth (ps

Strength (M

P

e e e e e e

500

1000

1500

5

10

Lap Shear

Lap Shear

84% coh

esive

46% coh

esive

66% coh

esive

48% coh

esive

48% coh

esive

34% coh

esive

00

BR 674

7‐1

6747

‐1NC

BR 670

0‐1

EW 500

0

W 500

0 AS

PAA

GBSG

8 4 6 4 4 3


B

BR 6 B

EW

EA 9696 Adhesive22°C (72°F) Climbing Drum Peel

120500

600

EA 9696 Tech Data Sheet

80

100

300

400

500

ue (in*

lbs/in)

ue (N

*m/m

)

20

40

60

100

200

CDP To

rqu

CDP To

rqu

% coh

esive

% coh

esive

% coh

esive

% coh

.

% coh

esive

0

20

0

6747

‐1

47‐1NC

6700

‐1

W 500

0

000 AS

PAA

GBSG

64%

72%

22%

18%

65%


BR 6

BR 674

BR 6 EW

EW 50 GBSG

EA 9628 Adhesive22°C (72°F) Lap Shear

700045

50

)a) EA9628 Tech Data Sheet

4000

5000

6000

25

30

35

40

Strength (psi)

tren

gth (M

Pa EA 9628 Tech Data Sheet

1000

2000

3000

5

10

15

20

Lap Shear S

Lap Shear St

00

5

R 67

47‐1

747‐1N

C

R 67

00‐1

EW 500

0

5000

AS

PAA

GBSG


BR

BR 67

BR E

EW GBSG

EA 9628 Adhesive82°C (180°F) Wet Lap Shear

400030

)

2500

3000

3500

15

20

25

tren

gth (psi)

rength (M

Pa)

500

1000

1500

2000

5

10

15

Lap Sh

ear S

Lap Shear St

0% coh

esive

5% coh

esive

2% coh

esive

0% coh

esive

2% coh

esive

8% coh

esive

0% coh

esive

0

500

0

R 67

47‐1

747‐1N

C

R 67

00‐1

EW 500

0

5000

AS

PAA

G SG

80 8542 40 5 58 30


BR

BR 67

BR E

EW GBSG

EA 9628 Adhesive22°C (72°F) Climbing Drum Peel

70300

350EA 9628 Tech Data Sheet

40

50

60

200

250

ue (in*

lbs/in)

ue (N

*m/m

)

10

20

30

50

100

150

CDP To

rqu

CDP To

rq

00

R 67

47‐1

747‐1N

C

R 67

00‐1

EW 500

0

5000

AS

PAA

GBSG


BR

BR 67

BR E

EW GBSG

FM 73M Adhesive22°C (72°F) Lap Shear

700045

50

)a)

FM 73M Tech Data Sheet

4000

5000

6000

25

30

35

40

Strength (psi)

tren

gth (M

Pa

1000

2000

3000

5

10

15

20

Lap Shear S

Lap Shear St

00

5

R 67

47‐1

747‐1N

C

R 67

00‐1

W 500

0

5000

AS

PAA

GBSG


BR

BR 67

BR EW

EW 5 GBSG

FM 73M Adhesive82°C (180°F) Wet Lap Shear

400025

30

))

2000

2500

3000

3500

15

20

25

STreng

th (psi)

tren

gth (M

Pa

500

1000

1500

2000

5

10

Lap Sh

ear S

Lap Sh

ear St

84% coh

esive

7% coh

.

0% coh

.

70% coh

esive

60% coh

esive

38% coh

.

24% coh

.

4% coh

.

00

R 67

47‐1

747‐1N

C

R 67

00‐1

EW 500

0

5000

AS

PAA

GBSG

8 8 97 6 3 2 2


BR

BR 67

BR E

EW GBSG

FM 73M Adhesive22°C (72°F) Climbing Drum Peel

10000

450

500

)FM 73M Tech Data Sheet

60

80

250

300

350

400

ue (in

*lbs/in)

que

(N*m

/m)

20

40

50

100

150

200

CDP To

rq

CDP To

rq

00

BR 674

7‐1

6747

‐1NC

BR 670

0‐1

EW 500

0

W 500

0 AS

PAA

GBSG


B

BR 6 B

EW

FM 209M Adhesive22°C (72°F) Lap Shear

6000

700045

50

)a)

4000

5000

6000

25

30

35

40

Strength (psi

tren

gth (M

Pa

1000

2000

3000

5

10

15

20

Lap Shear S

Lap Shear St

00

5

R 67

47‐1

747‐1N

C

R 67

00‐1

W 500

0

5000

AS

PAA

GBSG


BR

BR 67

BR EW

EW 5 GBSG

FM 209M Adhesive82°C (180°F) Wet Lap Shear

400025

30

)a)

2000

2500

3000

3500

15

20

25

Tren

gth (psi

tren

gth (M

Pa

500

1000

1500

2000

5

10

Lap She

ar S

Lap She

ar St

8% coh

esive

3% coh

esive

5% coh

esive

8% coh

esive

6% coh

esive

0

500

0

6747

‐1

47‐1NC

6700

‐1

W 500

0

000 AS

PAA

88 93 85 68 76


BR 6

BR 674

BR 6 EW

EW 50

GBSG

FM 209M Adhesive22°C (72°F) Climbing Drum Peel

100

400

450

FM209M T h D t Sh t

60

80

250

300

350

e (in

*lbs/in)

ue (N

*m/m

) FM 209M Tech Data Sheet

20

40

50

100

150

200

CDP To

rqu

CDP To

rqu

84% coh

esive

86% coh

esive

00

R 67

47‐1

747‐1N

C

R 67

00‐1

EW 500

0

5000

AS

PAA

GBSG

8 8


BR

BR 67

BR E

EW GBSG

FM 300-2M Adhesive22°C (72°F) Lap Shear

500035

40

)a)

FM 300‐2M Tech Data Sheet

3000

4000

5000

20

25

30

35

Strength (psi)

tren

gth (M

Pa

1000

2000

5

10

15

Lap Shear S

Lap Shear St

00

BR 674

7‐1

6747

‐1NC

BR 670

0‐1

EW 500

0

W 500

0 AS

PAA

GBSG


B

BR 6 B

EW

FM 300-2M Adhesive82°C (180°F) Wet Lap Shear

400030

))

2000

2500

3000

3500

15

20

25

STreng

th (psi)

tren

gth (M

Pa

e e e

500

1000

1500

2000

5

10

Lap Sh

ear S

Lap Sh

ear St

82% coh

esive

91% coh

esive

84% coh

esive

40% coh

esive

71% coh

esive

00

BR 674

7‐1

6747

‐1NC

BR 670

0‐1

EW 500

0

W 500

0 AS

PAA

GBSG

8 9 8 4 7


B

BR 6 B

EW

GBSG

FM 300-2M Adhesive22°C (72°F) Climbing Drum Peel

50

250

30

40

50

150

200

e (in

*lbs/in)

ue (N

*m/m

)

FM 300‐2M Tech Data Sheet

10

20

50

100

CDP To

rqu

CDP To

rqu

00

BR 674

7‐1

6747

‐1NC

BR 670

0‐1

EW 500

0

W 500

0 AS

PAA

GBSG


B

BR 6 B

EW

AF 163-2M Adhesive22°C (72°F) Lap Shear

700045

50

)a) AF163 2M T h D t Sh t

4000

5000

6000

25

30

35

40

Strength (psi)

tren

gth (M

Pa AF 163‐2M Tech Data Sheet

1000

2000

3000

5

10

15

20

Lap Shear S

Lap Shear St

00

5

R 67

47‐1

747‐1N

C

R 67

00‐1

W 500

0

5000

AS

PAA

GBSG


BR

BR 67

BR EW

EW 5 GBSG

AF 163-2M Adhesive82°C (180°F) Wet Lap Shear

3000

350025

i)a)

2000

2500

3000

15

20

STreng

th (psi

tren

gth (M

Pa

500

1000

1500

5

10

Lap Sh

ear S

Lap Sh

ear S

4% coh

esive

00

R 67

47‐1

747‐1N

C

R 67

00‐1

EW 500

0

5000

AS

PAA

GBSG

74


BR

BR 67

BR E

EW 5 GBSG

AF 163-2M Adhesive22°C (72°F) Climbing Drum Peel

100450

500

60

80

100

250

300

350

400

e (in

*lbs/in)

e (N*m

/m) AF 163‐2M Tech Data Sheet

20

40

100

150

200

250

CDP To

rque

CDP To

rqu

00

50

6747

‐1

47‐1NC

6700

‐1

W 500

0

000 AS

PAA


BR 6

BR 674

BR 6 EW

EW 50

GBSG

AF 500M Adhesive22°C (72°F) Lap Shear

700045

50

)a)

AF 500M Tech Data Sheet

4000

5000

6000

25

30

35

40

Strength (psi)

tren

gth (M

Pa

1000

2000

3000

5

10

15

20

Lap Shear S

Lap Shear St

00

BR 674

7‐1

6747

‐1NC

BR 670

0‐1

EW 500

0

W 500

0 AS

PAA

GBSG


B

BR 6 B

EW

AF 500M Adhesive82°C (180°F) Wet Lap Shear

3000

350025

)a)

2000

2500

3000

15

20

STrength (psi

Strength (M

Pa

e e

500

1000

1500

5

10

Lap Sh

ear S

Lap Sh

ear S

70% coh

esive

88% coh

esive

00

BR 674

7‐1

6747

‐1NC

BR 670

0‐1

EW 500

0

W 500

0 AS

PAA

GBSG

7 8


B

BR 6 B

EW

AF 500M Adhesive22°C (72°F) Climbing Drum Peel

80

90

350

400AF 500M Tech Data Sheet

40

50

60

70

200

250

300

ue (in*

lbs/in)

ue (N

*m/m

)

10

20

30

40

50

100

150

CDP To

rqu

CDP To

rqu

00

R 67

47‐1

747‐1N

C

R 67

00‐1

EW 500

0

5000

AS

PAA

GBSG


BR

BR 67

BR E

EW GBSG

EA 9696 Adhesive with PAA60°C (140°F) Wedge Test

1 433.70

1.33

1.38

1.43

3 30

3.50

in)

cm)

BR 6747‐1

BR 6747 1NC

1.18

1.23

1.28

3.10

3.30

ack Length (i

ck Len

gth (c BR 6747‐1NC

BR 6700‐1

EW 5000

1.03

1.08

1.13

2.70

2.90

Cra

Crac EW 5000 AS

0.982.50

0 7 14 21 28

Conditioning Time (Days)



EA 9696 Adhesive with GBSG60°C (140°F) Wedge Test

1 481.533.90

1.331.381.431.48

3.50

3.70

h (in

)

(cm)

BR 6747‐1

BR 6747‐1NC

1.181.231.28

3.10

3.30

rack Len

gth

ack Length

BR 6700‐1 (22% coh)

EW 5000 (88% coh)

EW 5000 AS (86% h)

1.031.081.13

2.70

2.90 Cr

Cr EW 5000 AS (86% coh)

0.982.50

0 7 14 21 28



EA 9628 Adhesive with PAA60°C (140°F) Wedge Test

1 63

4.20

1.58

1.63

4.00

4.10

(in)

(cm)

BR 6747‐1

BR 6747‐1NC

1.48

1.53

3.80

3.90

ack Length

ack Length (

BR 6700‐1

EW 5000

1.433.60

3.70 Cra

Cra EW 5000 AS

1.383.50

0 7 14 21 28




EA 9628 Adhesive with GBSG60°C (140°F) Wedge Test

1 684.30

1.63

1.68

4.10

4.20

n)m)

BR 6747‐1

BR 6747 1NC

1.53

1.58

3 80

3.90

4.00

ck Len

gth (in

k Length (cm BR 6747‐1NC

BR 6700‐1

EW 5000 (88% coh)

1.43

1.48

3.60

3.70

3.80

Crac

Crack

EW 5000 AS

1.383.50

0 7 14 21 28



FM 73M Adhesive with PAA60°C (140°F) Wedge Test

3.70

1.40

1.42

1.44

3.55

3.60

3.65

(in)

cm)

BR 6747‐1

BR 6747‐1NC

1.34

1.36

1.38

3.40

3.45

3.50

ack Length (

ck Len

gth (c BR 6747 1NC

BR 6700‐1

EW 5000

1.28

1.30

1.32

3.25

3.30

3.35 Cra

Crac EW 5000 AS

1.263.20

0 7 14 21 28




FM 73M Adhesive with GBSG60°C (140°F) Wedge Test

1 754.50

1.65

1.70

1.75

4 10

4.30

n)m)

BR 6747‐1

BR 6747 1NC

1.50

1.55

1.60

3.90

4.10

ck Len

gth (i

ck Len


BR 6700‐1 (4% coh)

EW 5000 (84% coh)

1.35

1.40

1.45

3.50

3.70

Crac

Crac EW 5000 AS (64% coh)

1.303.30

0 7 14 21 28




FM 209M Adhesive with PAA60°C (140°F) Wedge Test

1.564.00

1 46

1.51

1.56

3 70

3.80

3.90

(in)

cm)

BR 6747‐1

BR 6747‐1NC

1.41

1.46

3.50

3.60

3.70

ack Length (

ck Len

gth (c BR 6747 1NC

BR 6700‐1

EW 5000

1.31

1.36

3.30

3.40

Cra

Crac EW 5000 AS

1.263.20

0 7 14 21 28




FM 209M Adhesive with GBSG60°C (140°F) Wedge Test

1.965.00

1.76

1.86

4.40

4.60

4.80

(in)

cm)

BR 6747‐1 (14% coh)

BR 6747‐1NC (50% coh)

1.56

1.66

3 80

4.00

4.20

ack Length (

ack Length ( ( % )

BR 6700‐1 (0% coh)

EW 5000 (0% coh)

1.36

1.46

3.40

3.60

3.80

Cra

Cra EW 5000 AS (0% coh)

1.263.20

0 7 14 21 28



g ( y )

FM 300-2M Adhesive with PAA60°C (140°F) Wedge Test

1 76

4.60

1.66

1.76

4.50

4.55

(in)

(cm)

BR 6747‐1

BR 6747‐1NC

1.46

1.56

4 40

4.45

ack Length

ck Len

gth (

BR 6700‐1

EW 5000

1.36

1.46

4.35

4.40

Cra

Crac EW 5000 AS

1.264.30

0 7 14 21 28

C di i i Ti (D )



FM 300-2M Adhesive with GBSG60°C (140°F) Wedge Test

5.00

1.89

1.94

4.80

4.90

in)

cm)

BR 6747‐1

BR 6747‐1NC

1 79

1.844.60

4.70

ack Length (

ck Len

gth ( c BR 6747‐1NC

BR 6700‐1 (74% coh)

EW 5000

1.74

1.79

4.40

4.50 Cra

Cra EW 5000 AS

1.694.30

0 7 14 21 28



AF 163-2M Adhesive with PAA60°C (140°F) Wedge Test

1 403.60

1 30

1.35

1.40

3.40

3.50

in)

cm)

BR 6747‐1*

BR 6747‐1NC

1.25

1.30

3.10

3.20

3.30

ck Len

gth (

ck Len


BR 6700‐1

EW 5000

1.15

1.20

2.90

3.00

3.10

Cra

Crac EW 5000 AS*

1.102.80

0 7 14 21 28




* Visually appeared to fail at the primer-adhesive interface, but a thin layer of AF 163-2M remains on the primer

AF 163-2M Adhesive with GBSG60°C (140°F) Wedge Test

1 594.10

1.49

1.54

1.59

3 70

3.90

in)

cm)

BR 6747‐1 (94% coh)*

BR 6747 1NC

1.34

1.39

1.44

3.50

3.70

ck Len

gth (i

ck Len


BR 6700‐1 (14% coh)

EW 5000 (42% coh)*

1.19

1.24

1.29

3.10

3.30

Cra

Cra c EW 5000 AS (32% coh)

1.142.90

0 7 14 21 28




* Visually appeared to fail at the primer-adhesive interface, but a thin layer of AF 163-2M remains on the primer

AF 500M Adhesive with PAA60°C (140°F) Wedge Test

4.20

1.54

1.59

3 90

4.00

4.10

(in)

(cm)

BR 6747‐1

BR 6747‐1NC

1 44

1.49

3.70

3.80

3.90

ack Length

ack Length (

BR 6700‐1

EW 5000

1.39

1.44

3.50

3.60

Cra

Cra EW 5000 AS

1.343.40

0 7 14 21 28




AF 500M Adhesive with GBSG60°C (140°F) Wedge Test

1 79

1.69

1.74

1.79

4.40

4.60

n)m)

BR 6747‐1 (94% coh)

BR 6747 1NC

1.54

1.59

1.64

4.00

4.20

ck Len

gth (i

ck Len

gth (cm BR 6747‐1NC

BR 6700‐1 (14% coh)

EW 5000 (42% coh)

1.39

1.44

1.49

3.60

3.80 Crac

Crac EW 5000 AS (32% coh)

1.343.40

0 7 14 21 28




Typical Failure Modes Observed in 60°C (140°F) Wedge Tests

Typical Primer-Aluminum Interfacial Failure ith FM 209M Adh iwith FM 209M Adhesive

Typical AF 163-2M “100 Percent Cohesive Failure” Near Primer-Adhesive Interface


Typical Good “100 Percent” Cohesive Failure

Summary of Failure Modes with GBSG in 60°C (140°F) Wedge Tests

100%

70%

80%

90%

hesi

ve)

BR 6700-1EW-5000ASEW-5000

40%

50%

60%

Mod

e (%

Coh BR 6747-1

BR 6747-1NC

BR 6747-1BR 6747-1NC

10%

20%

30%

Failu

re

BR 6700-1

EW-5000ASEW-50000%


Conclusions

• Large Amount of Data Generated to Guide Future Efforts

• No Clear Path Forward for Non Cr Primer Qualification• No Clear Path Forward for Non-Cr Primer Qualification– Based on initial screening with only 5 specimens per test

• PAA Test Results were Overall Superior to GBSG• PAA Test Results were Overall Superior to GBSG – PAA is the premier aluminum surface preparation– PAA can be used with more combinations of surface preps & primers

• Hot/Wet Lap Shear Results when Using GBSG Exhibit Poor Failure Modes– Routinely seen even with good wedge tests data for same combination– A bit concerning


• Wedge Test Results Must be Used with Caution– Screening w/ controlled variables; no quantitative correlation to service

Conclusions (cont.)

• BR 6747-1NC (No Corrosion Inhibitor) Yielded Amazingly Good Results

• BR 6700-1 Wedge Test Results with GBSG were Surprisingly Poor and Not Consistent with Previous AFRL (Good) Data

• FM 209M Wedge Test Data were Poor when with GBSG Prep

• FM 73M Generated Surprisingly Good Wedge Test Results p g y gwith GBSG/BR 6747-1; Contradicts Previous USAF Data

• FM 300-2M Adhesive Generated Larger Initial Cracks in the C GWedge Test and Tended to Produce Less Crack Growth

– Wedge test interrogates interface less stringently using FM 300-2M

AF 163 2M Adh i E hibit F il M d At N th


• AF 163-2M Adhesive Exhibits Failure Modes At or Near the Primer-Adhesive Interface with BR 6747-1 & Others

Future Efforts

• USAF Will Work with Industry-Government Non-Cr Adhesive Bond Primer Team to Further Evaluate Some of the Products Screened, as well as Promising New Candidates

• Another Industry-Government Team was Awarded a SERDP Project Aimed at Understanding the Requirements for Bond Primers and their Corrosion Inhibitors– Investigate failed bonds and relationship to primerg p p– Evaluate various types/levels of corrosion inhibitor in bond primers– Develop a risk assessment tool for bonded joints

I ti t lt ti l t d i t l– Investigate alternative accelerated aging protocols

• Much Work is Required to Implement any New PrimerLaboratory testing beyond screening


– Laboratory testing beyond screening– Generation of data based on field-level processing

Evaluation of Adhesive Bond Primers for Repair Bonding of Aluminum · 2012. 5. 24. · Evaluation...

Documents

Transcript of Evaluation of Adhesive Bond Primers for Repair Bonding of Aluminum · 2012. 5. 24. · Evaluation...