Hard Coating/Matrix Strength Evaluation Under Dynamic Load

Indium Tin Oxide(ITO)has good transparency and electrical conductivity as a hard coating material and is easy to manufacture.Flexible hard coating materials(Indium Tin Oxide/ polymer polyethylene terephthalate referred to as ITO/PET)formed by depositing ITO on polymer polyethylene terephthalate(PET)are widely used in flexible electronic devices such as rollable displays,solar cells,and touch screens.ITO is a kind of brittle material,so ITO/PET can be regarded as a hard coating material.ITO/PET will undergo dynamic loading such as impact,cyclic stretching and cyclic bending during use.The coating/substrate interface of the material and the ITO coating will be damaged,resulting in material failure.How to maintain the stability of coating material performance under dynamic load is the basis for the wide application and use of coating materials.Defining the coating/substrate bond strength is an important study to determine whether a hard coat material meets the requirements for use.In this paper,the ITO/PET film material is taken as an example to study the evaluation of the bond strength of the hard coat/substrate under dynamic load..First of all,this paper designed and built a quasi-static tensile real-time observation system and a cyclic fatigue experimental system.In the design stage,the 3D model of the cyclic fatigue test bench was established by using CATIA software,and the modal analysis was carried out by ANSYS finite element analysis software.The structural rationality and safety of the cycle fatigue test bench were verified.Tensile experiments were carried out on ITO/PET film materials by quasi-static tensile test real-time observation system.The effects of coating thickness and substrate thickness ITO/PET material on coating/matrix bonding strength under quasi-static conditions were investigated.Theoretical analysis and quantitative calculations were carried out to analyze and explain the experimental phenomena,and the ITO/PET film materials with different thickness structures were evaluated.Cyclic tensile test,ultimate bending test and cyclic bending test were carried out through the cyclic fatigue experiment system.The effects of coating thickness and substrate thickness on coating/matrix bonding strength of ITO/PET materials in different working environments were studied,and the experimental phenomena were analyzed and explained.