Daftar Isi: Fracture Toughness on a Thin Film from Plastic Zone

Daftar Isi:

One of the advantages of thin films is its use as a coating that can be applied over a substrate as a protective layer. The application can either be mechanical or chemical, where these fine coatings are exposed to harsh environment. Therefore, quantification of such films are deemed necessary in order to understand the failure mechanisms of the material. Particularly for a thin viscoelastic film with appreciable recovery upon deformation, fracture toughness is difficult to evaluate due to the uncertainties associated with multilayers. Frequently, there exists influence of the substrate or immediate layer present, which shapes the physical properties of thin films. This in turn results in either reduced or compound values during the extraction of experimental data. In order to obtain the absolute value, true specimen must be prepared. However, certain thin films are either expensive or difficult to prepare in bulk condition. Hence, a simpler approach to determine the fracture toughness from plastic zone is proposed by combining in-situ tensile and nanoindentation tests. To the best of the author’s knowledge, such approach does not yet exist. The value of poly-phenylenediamine determined from the proposed method and classical extraction method are approximately equal at 2.45 MPa√m and 2.6 MPa√m respectively.