Abstract
Residual stress in coating layer cause scracks and peelings.Value of residual stress is determined by the gap of thermal expansion ratio of coating polymer and that of base material,and also by polymer's material constants such like elastic modulus.That means residual stress value can be calculated by obtaining material constants of polymer.In general,pure polymer has considerably higher value of thermal expansion ratio than that of base material. Therefore residual stress in coating layer of pure polymer tends to have higher value. Addition of inorganic filler into pure polymer is effective to obtain smaller gap between thermal expansion ratio of coating composite polymer and that of base material.But in most of the cases,composite polymer added inorganic filler came to have higher value of elastic modulus.Therefore residual stress in coating layer of composite material was not as low as expected.In this study,hollow glass microspheres were added as inorganic filler,into epoxy polymer.Composite polymer with hollow glass microspheres showed low thermal expansion with small increase of elastic modulus. As are sult,residual stress in coating layer of composite material was decreased by compounding hollow glass microspheres. Improvement on avoiding cracks and peelings were expected by this result.
