ASTM D3762 – Standard Test Method for Adhesive-Bonded Surface Durability of Aluminum (Wedge Test)
Description:
Significance and Use
5.1 The test is primarily qualitative, but is very discriminating in determining variations in adherend surface preparation parameters and adhesive environmental durability. The test has found application in controlling surface preparation operations and in screening surface preparations, primer and adhesive systems for durability. In addition to determining crack growth rate and assigning a value to it, the adhesive–joint failure is evaluated and reported. For example, adhesion failure; cohesion failure; or adherend failure are noted after opening up the specimen at the conclusion of the test period.
Scope
1.1 This test method2,3 simulates in a qualitative manner the forces and effects on an adhesive bond joint at metal-adhesive/primer interface. It has proven to be highly reliable in determining and predicting the environmental durability of adherend surface preparations. The method has proven to be correlatable with service performance in a manner that is much more reliable than conventional lap shear or peel tests (Note 2).
Note 1: While this test method is intended for use in aluminum-to-aluminum applications it may be used for determining surface durability of other metals and plastics provided consideration is given to thickness and rigidity of the adherends.
Note 2: This test method is not a quantitative fracture strength test method. To measure fracture strength see Test Method D3433.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
ASTM D3761