Nondestructive Test Technique Development Based on the Quantitative Prediction of Bond Adhesive Strength

摘要

Results of a Surface Condition Study on 6061-T6 aluminum alloy butt tensile, core shear, and single lap shear specimens of various roughnesses, bonded with an Epon 828/DETA formulation, have supported the creation of a practical equation for predicting bond adhesive strength (Zurbrick). Major controlling variables, i.e. substrate surface free energy, contact angle, and bondline thickness, are all potentially measurable nondestructively. A strong correlation between white light specular reflection values and values of aluminum substrate surface free energy calculated from experimental data was obtained, encouraging extensive investigation of this NDT technique. Exo-electron emission, ultrasonic gas-phase transmission, and electric field reflectometry techniques were also evaluated in continuing feasibility studies. (Author)