AUTOMATED SURFACE PREPARATION OF ORGANIC MATRIX COMPOSITES FOR STRUCTURAL ADHESIVE BONDING

摘要

Atmospheric plasma was examined as an alternative to abrasion for surface preparation ofrnbismaleimide composites for nutplate bonding. Torque-out and push-out tests yielded bondrnstrengths of 33 ± 2 Nm and 6280 ± 170 N, respectively, for oxygen plasma treatment for 7rnseconds. This may be compared to torque-out and push-out test results of 24 ± 1 Nm and 5380 ±rn446 N for a control case in which the substrate was abraded using a 3M Scotch-Brite™ pad.rnAfter plasma activation, the water contact angle was 4° as compared to 50° for the abradedrncontrol. In addition, the failure mode for a sample activated with 7 seconds of plasma averagedrn12 % adhesive failure on laminate, 34 % adhesive on nutplate, 2 % cohesive and 52 %rninterlaminar. The abraded control case yielded 70 % adhesive failure on laminate, 10 %rnadhesive on nutplate, 2 % cohesive and 23 % interlaminar. These results indicate that nutplaternadhesion to bismaleimide is improved by surface activation with plasma compared to currentrnabrasion methods.