Adhesive bonding of Aluminium 4

[TMJ]

Can anyone suggest an adhesive for bonding aluminuim. Adhesive would probably need to be a low temperature cure (two par mix). Joint strength will be important, I am looking for a simple method of making structural joints without welding.

Any suggestions greatfully received!

TJ

 

[Bradbury]

Bonding of Aluminum.

The recomended two part adhesive is:

Resin: Araldite A.Y.103
Hardener H.Y.951

Supplier: C.I.B.A. (ARL) Ltd., Duxford, Cambridge.

However when bonding aluminium surface preperation is very important. Many aerospace speicifations detail this in full.

But as a simple guide, you need to abrade, degrease (wipe in one direction), swab with Alocrom 1200, then apply adhesive as per manufactures instructions.

Cure: 24 hours at room temperature. Accelerated cure times can be achieved at higher temperatures.

Hope this is of help.

Paul Bradbury.

 

[TMJ]

Thanks for the information and advice Paul.

Best regards

Trevor

 

[TVP]

The following aerospace adhesives may be useful to you:

Scotch-Weld (especially 2214) from 3M:

http://www.3m.com/us/mfg_industrial/adhesives/pdf/SWLPProdSummary.pdf

Redux from Hexcel:

http://www.hexcelcomposites.com/Markets/Products/Adhesives/Selector.htm

FM® adhesive and METLBOND® adhesive from Cytec:

Cytec

http://www.cytec.com/products4/aerospacefrm.html

 

[astroclone]

EA9309.3NA A/B also cures at room temp. Pretty strong, too.

 

[TVP]

HYSOL EA 9309.3NA is available from Loctite Aerospace. You can obtain more information using the following link:

http://www.loctiteaero.com/index.cfm?ID=137

 

[AJone]

I'm not sure it would be appropriate to your application, but 3M scotch makes a VHB foam tape with double sided adhesive in various thickness.

It's amazingly strong and reliable. When applid properly, the adhesive will not lift from the surface. The only reliable way we found to remove it from aluminum is by grinding.

In addition the slight give of the tape allows the joint to absorb alot more energy than just an adhesive normally would.

We've used this to replace spot welded parts and it is often used to replace rivet panels/beams.

 

[0532]

We have a bearing steel tracks with diameter in the range 500-550mm with thickness of around 6mm, accounting for total area of contact to be around 2*3.14*(550/2)*6 mm2. this has to be glued to Aluminium structure. the glued portion is expected take on large load and the temperature of about 423K during Application.
Please apprise me of any High Strength Adhesive which can be effectively used for the purpose.

 

[rktsciguy]

As a follow up to Bradbury's comments (which were very precise, I must add), I would suggest omitting the Alocrom 1200, as this can interfere with the adhesives ability to really cling to the aluminium.
I would recommend also trying Araldite AV138/HV998 or possible 3M's DP490 - it all depends what your shear requirements are.

I couldn't agree more about the importance of the surface preparation prior to bonding - you really need to clean the surfaces with Isopropyl alcohol, abrade using 400grade wet and dry (used dry), re clean using IPA until no more traces of dirt/colour are left, let dry min 15 mins, then bond within the next 3 hours (to avoid further contamination/oxidation)

Hope that helps some more!

 

[WKTaylor]

TMJ...

Many of the adhesives noted above are fully acceptable... but be aware of performance limitations.

Hot-bond epoxy-type adhesives tend to have not only high shear strength, but also higher toughness, peel-resistance and max service temperatures.

Cold bond [paste] type adhesives tend to have good shear properties... but tend to compromise on the other properties [IE: low peel-resistance, low toughness, lower service temps, etc].

As a general rule, adhesives for general-purpose structural bonding [IE: metal-metal-bonding, metal-honeycomb bonding, etc] should have at least a 225F (250F is better) [105C or 121C] minimum service temp with good moisture resistance, in order to avoid strength problems due to extreme climates such as low desert [very hot, dry] or equatorial tropics [hot and very "moist"]. Also these adhesives should have a low service temperatures of at least -65F [-54C] to insure adequate arctic climate survival.

… And I cannot over-emphasize that joint configuration and surface preparation for adhesive-bonding are equally-critical aspects for high quality [durability, strength] adhesive-bonded structure.

A few good references for You to check-out...

SAE documents...

AIR4844 Metal Bonding and Composites Glossary
AIR4938 Composite and Bonded Structure Technician/Specialist: Training Document.
AIR5278 Composite and Bonded Structure Engineers: Training Document.
AIR5279 Composite and Bonded Structure Inspector: Training Document.
ARP1524 Surface Preparation and Priming of Aluminum Alloy Parts for High Durability Structural
Adhesive Bonding.
ARP1524 Surface Preparation and Priming of Aluminum Alloy Parts for High Durability Structural
Adhesive Bonding ~ Hand Applied Phosphoric Acid Anodizing
ARP1842 Surface Preparation for Structural Adhesive Bonding ~ Aluminum Alloy and Low Alloy Steel
Parts
ARP5089 Composite Repair NDT/NDI Handbook
ARP5144 Heat Application for Thermosetting Resin Curing
ARP5256 Mixing Resins Adhesives and Potting Compounds

MIL documents.

MIL-A-83377B Adhesive Bonding (structural) for Aerospace and Other Systems, Requirements For [CX’d]
MIL-A-83376A Adhesive Bonded Metal Faced, Sandwich Structures, Acceptance Criteria
MIL-HDBK-337 Adhesive Bonded Aerospace Structure Repair
MIL-HDBK-691 Adhesive Bonding [CX’d]

For some good books on adhesive bonding go-to:

http://www.aircraftdesign.com/books.html#Tip5

and look under “structures” category.

Also search for adhesive bonding topics in AGARD publications.

AFWAL [Air Force Wright Aeronautical Labs] Sponsored the PABST* program that resulted in extensive data on metal-metal adhesive bonding. *PABST = Primary Adhesive Bonded Structures Technology

Gotta Go…

Regards, Wil Taylor

 

[Wittenborn]

Brilliant, Wil!

Good list of resources!

Regards,
Grant
Aerospace Engineer