Adhesion Measurement Methods: Theory and Practice

INTRODUCTION Overview What Is Adhesion and Can It Be Measured? Definition A: Criteria for a Truly Useful Definition of the Term Adhesion Definition B: Adhesion Comments on Nomenclature and Usage References OVERVIEW OF MOST COMMON ADHESION MEASUREMENT METHODS Preamble Peel Test Introduction Advantages of the Peel Test Disadvantages of the Peel Test Summary and Recommendations 2.3 Tape Peel Test Introduction Advantages of the Tape Peel Test Disadvantages of the Tape Peel Test Summary and Recommendations Pull Test Introduction Advantages of the Pull Test Disadvantages of the Pull Test Summary and Recommendations Indentation Debonding Test Introduction Advantages of the Indentation Debonding Test Disadvantages of the Indentation Debonding Test Summary and Recommendations Scratch Test Introduction Advantages of the Scratch Test Disadvantages of the Scratch Test Summary and Recommendations Blister Test Introduction Advantages of the Blister Test Disadvantages of the Blister Test Summary and Recommendations Beam-Bending Tests Introduction Three-Point Bend Test Four-Point Bend Test Standard Double Cantilevered Beam Test Tapered Double Cantilevered Beam Test Double-Cleavage Drilled Compression Test Brazil Nut Test Wedge Test Topple Beam Test Advantages of Beam-Bending Tests Disadvantages of Beam-Bending Tests Summary and Recommendations Self-Loading Tests Circle Cut Test Modified Edge Liftoff Test Microstrip Test Advantages of Self-Loading Tests Disadvantages of Self-Loading Tests Summary and Recommendations More Exotic Adhesion Measurement Methods Laser Spallation: Early Work Later Refined Experiments Laser-Induced Decohesion Spectroscopy Experiment Advantages of Laser Spallation Tests Disadvantages of Laser Spallation Test Summary and Recommendations Electromagnetic Test Advantages of the Electromagnetic Test Disadvantages of the Electromagnetic Test Summary and Recommendations Nondestructive Tests Dynamic Modulus Test Advantages of the Dynamic Modulus Test Disdvantages of the Dynamic Modulus Test Summary and Recommendations Surface Acoustic Waves Test Advantages of the Surface Acoustic Waves Test Disadvantages of the Surface Acoustic Waves Test Summary and Recommendations Notes THEORETICAL FOUNDATIONS OF QUANTITATIVE ADHESION MEASUREMENT METHODS Introduction to Continuum Theory Concept of Stress in Solids Special Stress States and Stress Conditions Equation of Motion in Solids Deformation and Strain Constitutive Relations or Connecting the Stress to the Strain Examples Simple Deformations Solving the Field Equations Uniaxial Tension Biaxial Tension Triaxial Stress Case Application to Simple Beams General Methods for Solving Field Equations of Elasticity Displacement Formulation Stress Formulation Mixed Formulation Numerical Methods Introduction Detailed Stress Behavior of a Flexible Coating on a Rigid Disk Strain Energy Principles The Marvelous Mysterious J Integral Summary Notes ELEMENTARY FRACTURE MECHANICS OF SOLIDS: APPLICATION TO PROBLEMS OF ADHESION Introduction Introductory Concepts Fracture Mechanics as Applied to Problems of Adhesion Elementary Computational Methods Decohesion Number Approach of Suo and Hutchinson Back-of-the-Envelope Calculations Summary Notes APPLIED ADHESION TESTING The Peel Test Sample Preparation Test Equipment Peel Testing in Action Advanced Peel Testing Thermodynamics of the Peel Test Deformation Calorimetry Fully Quantitative Peel Testing Earliest Work, Elastic Analysis Elastic-Plastic Analysis Full Elastic-Plastic Analysis The Scratch/Cut Test The Cut Test Simplified Analytical Model for Cut Test The Pull Test Summary Notes ADHESION ASPECTS OF COATING AND THIN FILM STRESSES Introduction General Measurement Methods for Thin Films and Coatings Cantilevered Beam Method Variations on Bending Beam Approach Optical Measurement of Deflection X-ray Measurements Ultrasonics Photoelasticity Strain Relief Methods Magnetics Raman Spectroscopy Miscellaneous Methods Summary References CASE STUDIES FROM THE FIELD A Study in Adhesion Sensitivity to Contamination Case of the Improperly Cured Film Case of the Stressed Pin Stability Maps Summary Notes Appendix A: Vectors and Vector Calculus Appendix B: Notes on Elementary Strength of Materials (SOM) Theory Appendix C: Material Property Data for Selected Substances Appendix D: Driving Force Formulae for a Variety of Laminate Structures Appendix E: Selected References and Commentary on Adhesion Measurement and Film Stress Literature Appendix F: General Adhesion Measurement References