Main deformation mechanisms found during Progressive Load Scratch Test and Constant Load Scratch Test were cohesive cracking, coating spallation and adhesive failure.
These tensile test results are consistent with coating cohesive strengths as measured by stud pull tests.
The material, opto-electrical properties, COS, the coating cohesive strength, as well as the influence of mechanical strain on the electrical properties of nc GZO thin films were investigated.
The presence of porosities may weaken the cohesive strength within coating, causing great deals of particles drop off from surface under the function of electrolyte.
This is considered a result of a competition between the strengthening of the ceramic reinforcing particles at the coating/substrate interface, and the weakening of coating cohesive strength due to an increase in the proportion of weaker Al Al2O3 bonds compared with stronger Al Al bonds.
The systems were, then, subjected to shear stress (without loading monitoring) for the removal of the dolly, and the cross-sections of the specimens were observed for failure mode analysis (cohesive failure in FBE coating, adhesive failure at the interface steel/FBE coating, and cohesive failure in metal substrate).
Cohesive failures in the coating also produced signatures on the load displacement (P h) indentation curves, which allowed the evaluation of coating fracture toughness with good agreement with the input toughness values in cases where the coating was thin.
The cohesive strength of the coating at critical length (ℓ c) can be expressed as (3).
It is the critical defects, such as microcracks that are the most detrimental to the coating effective cohesive properties.
This is clearly discerned from the fact that some damage mechanisms, such as cohesive spallation at the coating and adhesion failure at the interface, are exclusively observed under cyclic loading.
