Cleavage resembles peel but with rigid adherends: a wedge or offset force opens the joint at one edge. Adhesives resist it poorly, so designers avoid it like peel. The wedge test, which drives a wedge into a bonded aluminum specimen and tracks crack growth in hot humid air, is the standard check on aerospace surface treatments.
Wedge test crack ran right along the interface in the humidity cabinet, that anodize won't hold up in cleavage.
Also heard as
- cleavage strength
- cleavage loading
Related terms
Peel stress
Tension pulling one adherend away from the other at the edge of a bond, concentrated along a thin line.
Butt joint
A joint where two parts are bonded end to end, with only the small end area carrying the load.
Toughened
Describing an adhesive modified with rubber or soft particles so the bond resists cracking, peel and impact.
Adhesive failure
A break at the interface between adhesive and part, leaving one surface clean or nearly clean.