Fabrication of high temperature moiré grating and its application

Stress-Strain Measurement of Rubber with Optical Moiré Fringes

“…Hence, it is suitable for measuring physical properties of a deformable object due to its ability to detect the displacements of points. The moiré interferometry has been employed in many types of materials such as solids, films and composites in measurement of mechanical properties, such as stress and strain, as well as in the study of crack propagation and morphogenesis [2][3][4][5][6].…”

Evaluating deformation at high temperatures

“…To address the need for accurate characterization of the mechanical behavior of materials at high temperatures, numerous non-contact optical measurement techniques have been developed. These techniques include moiré interferometry (MI), 1,2 digital image correlation (DIC), 3 and electronic speckle pattern interferometry. 4 As a basic component for deformation measurement, the quality of the deformation carriers (i.e., gratings that arise due to the periodic structure of a medium, and random patterns called speckles) directly influence the moiré fringe contrast and the speckle pattern quality.…”

“…A micro-speckle particle fabrication method 3 has also been developed, based on adsorbing two types of heat-resistant particles with high color contrast (zirconium dioxide and cobaltous oxide, Zr0 2 and CoO) on the sample surface. 2,3 Using a thermal nanoimprint technique, the holographic grating (used as a mold) can be copied onto the glass substrate with the photoresist on its surface. The hightemperature chromium film is then coated on the surface of the glass substrate.…”

“…The resulting heat-resistant grating can be transferred onto the surface of a sample using high-temperature adhesive (see Figure 1). We have successfully implemented these gratings in the MI analysis of the mechanical properties of a high-performance alloy (GH3030) at high temperatures, in a tensile experiment carried out at 650 • C. 2 Our DIC method can be used to measure deformation in the near-interface regions and surfaces of thermal barrier coatings (TBCs) during thermal shock (at temperatures of up to 1100 • C) by using a high-temperature blackbody radiation suppression technique. 3 filter (532˙10nm), which is set between a CCD camera and the optical lens.…”

Fabrication of high-density moiré gratings

“…Our technique can be used to produce gratings with large areas and high frequencies on different specimens, and at fast rates (see Figure 1). [7][8][9] The preparation of the stamp that is used for imprinting is a key issue in our method. When imprinting is conducted at low pressure, a full-contact condition (between the specimen and stamp) is almost impossible to achieve and defects may be generated on the grating.…”