Study on improvement of reliability of the surface modification thin films based on fracture mechanics

In this study，a new method for evaluating the debonding strength of the interface between a surface modification film and a substrate has been developed for improvement of reliability of the surface modification thin films.An electroless nickel plating film on ABS resin plate and a paint film on a concrete surface are used as the surface modification films。Peel tests on the surface modification films are carried out.Then，a reinforcement plate is attached to the surface modification film so that it does not break during the peel test.The debonding load，the debonding length and the displacement of the loading point are measured during the peel test.We are particularly interested in the energy release rate(Gvalue)based on the fracture mechanics as a parameter to evaluate the debonding strength of the surface modification film.The critical energy release rage(G I D 2c Ii Value)is obtained from the debonding load and the displacement of the loading point measured during the peel test.As a result，provided that the interface conditions remain the same，the critical energy release rate in the propagation of debonding is constant and unaffected by the reinforcement plate。Therefore，the debonding strength of the surface modification film can be rationally evaluated by using the critical energy release rate。It is cleared that the debonding strength of a plating film increases with the etching time of ABS resin plate.Furthermore，the influence of the environment on psint films are elucidated by obtaining the critical energy release rate。

In this study, a new method for evaluating the debonding strength of the interface between a surface modification film and a substrate has been developed for improvement of reliability of the surface modification thin films. An electroless nickel plating film on ABS resin plate and a paint film on a concrete surface are used as the surface modification films. Peel tests on the surface modification films are carried out. Then, a reinforcement plate is attached to the surface modification film so that it does not break during the peel test. The debonding load, the debonding length and the displacement of the loading point are measured during the peel test. We are particularly interested in the energy release rate (G value) based on the fracture mechanics as a parameter to evaluate the debonding strength of the surface modification film. The critical energy release rage (GィイD2cィエD2 value) is obtained from the debonding load and the displacement of the loading point measured during the peel test. As a result, provided that the interface conditions remain the same, the critical energy release rate in the propagation of debonding is constant and unaffected by the reinforcement plate. Therefore, the debonding strength of the surface modification film can be rationally evaluated by using the critical energy release rate. It is cleared that the debonding strength of a plating film increases with the etching time of ABS resin plate. Furthermore, the influence of the environment on psint films are elucidated by obtaining the critical energy release rate.