CCT Surface Preparation & Bonding Flashcards

What NDT method is most commonly used to inspect adhesive bond quality after cure?

Answer: Ultrasonic testing (pulse-echo or through-transmission)

Ultrasonic testing detects voids, disbonds, and porosity within adhesive bondlines without damaging the structure.

What is the purpose of a 'kiss bond' test panel produced alongside a production bond?

Answer: A witness coupon used to verify adhesive cure and bond quality for the production run

Kiss bond panels (witness coupons) are cured with production parts to confirm adhesive cure under process conditions.

When bonding a honeycomb core sandwich panel, why must cell edges be filled or chamfered at the bond flange?

Answer: To provide a continuous bondline surface and prevent stress concentrations at cell edges

Unfilled cell edges create voids and stress risers at the bond that can initiate fatigue cracking under load.

What does a 'starved bond' condition mean?

Answer: Insufficient adhesive coverage, resulting in an incomplete or weak bond

Starved bonds occur when pressure squeezes out too much adhesive or too little was applied, leaving dry contact areas.

Which surface treatment is used on aluminum before bonding to create a durable oxide layer that improves adhesion?

Answer: Phosphoric acid anodize (PAA) or chromic acid anodize (CAA)

PAA and CAA create a stable porous oxide layer on aluminum that bonds well with epoxy adhesives and resists environmental degradation.

What is the correct sequence for preparing a composite repair area for bonding?

Answer: Dry, abrade, solvent wipe, prime (if required), apply adhesive

Removing moisture first, then abrading and wiping, ensures the cleanest possible surface in the correct order before adhesive application.