Epoxy for CF to Titanium or Aluminum? 1

[Antrozous]

I'm building a lightweight shaft for a specialty tool handle, and need to bond a carbon fiber rod to Aluminum (7075) or CP5 grade Ti end cap.

The bond must be as rigid as possible, the "flex" epoxy isn't an option. I really need a high tensile and sheer strength.

Loctite® Hysol® 9430 has been recommended, and it looks like it will suffice for the CF to Al, but I have no idea how it will preform with Ti. Suggestions? My preference would be to have the same epoxy for both, but it's not an absolute requirement.

 

[CoryPad]

Henkel/Loctite's Hysol series and 3M's Scotch-Weld epoxies are good choices. Surface preparation is critical. Review standards on this subject for best practices: ASTM D 2651 Standard Guide for Preparation of Metal Surfaces for Adhesive Bonding and ISO 17212 Structural adhesives -- Guidelines for the surface preparation of metals and plastics prior to adhesive bonding.

http://www.astm.org/Standards/D2651.htm

http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=38283

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[RPstress]

It depends a bit on what properties you want from the bond. To get a really good bond to the Ti you'll need quite a bit of prep, but if you can put up with a minimum shear strength of maybe 15 MPa (2200 psi) then just cleaning and grit blasting would probably be adequate.

 

[MStiller]

We do a lot of bonding of CF to Aluminum parts (both 6061 and 7075), and we use 3M's DP-460, which has very good shear strength properties. I'm not sure what the strength characteristics are for bonding to Ti, but if 460 wouldn't work, I'm sure 3M has something else that would work better. CoryPad is correct, surface prep is essential, and for our critical aluminum parts that are bonded into the CF (these are structural pieces that are highly loaded), we followed a Boeing standard (which has been copied by a number of other companies) and had the pieces etched and coated with bond primer (Chromic Acid Etched, and BR-127 Primer), but if it's not a highly loaded piece, just doing a wipe with MEK (or similar)/sand/wipe type of thing will work. But (and I can't stress this enough), if it's an important piece that is highly loaded, you have to make sure your bond surface is as clean and well prepped as you can make it, or your glue joints wont have their full strength