Improved multi-scale high-temperature speckle preparation method

Abstract

The invention discloses an improved multi-scale high-temperature speckle preparation method, which comprises the following steps of: 1, determining and optimizing characteristic parameters of a digital speckle field, generating an optimized multi-scale simulation speckle pattern, and converting the optimized multi-scale simulation speckle pattern into a computer-aided design (CAD) file; 2, coating a double-layer film on the surface of the test piece; 3, performing a speckle manufacturing process test on a glass sheet or a silicon sheet which is subjected to double-layer film coating with the test piece by using a femtosecond laser system, and designing the depth of a micro-scale speckle micropore and the depth of a macro-scale speckle hole according to the coating thickness of an outer layer, obtaining laser pulse parameters of the femtosecond laser system under the speckle diameter and the speckle depth of each scale; and 4, etching the double-layer film on the surface of the test piece to obtain a multi-scale speckle pattern. The coating does not damage the surface of the test piece, is not easy to fall off in a high-temperature environment, and can enhance the high-temperature resistance, corrosion resistance and the like of the test piece.

Description

technical field [0001] The invention belongs to the technical field of optical measurement mechanics and the technical field of macro and micro deformation measurement, and in particular relates to an improved multi-scale high temperature speckle preparation method. Background technique [0002] With the development of modern science and technology, the service environment of advanced materials and structures has become increasingly extreme. For example, the working temperature of turbine blades, the hot-end components of aero-engines, can be as high as 1000°C or more. Deformation measurement in extreme environments such as high temperature is an important technical support to ensure the structural integrity of core components. Digital Image Correlation (DIC) is a modern photomechanical method based on the surface images of objects before and after deformation. It has the characteristics of full-field, non-contact, online real-time measurement, etc. There are great advantag...

AI Technical Summary

Problems solved by technology

One of the most commonly used methods in artificial speckle is the artificial painting method. The quality of the speckle obtained by this method is heavily dependent on the experience of the speckle maker, and there are problems such as high technical requirements for personnel, inability to parameterize design, and difficulty in quality control; in addition , S A Collette et al (S ACollette, M A

[0004] Sutton, P Miney et al., Nanotechnology 15 (2004) 1812-1817) developed a speckle fabrication method for nanoscale strain measurement, by pressing a porous alumina plate coated with a gold film into a polymer specimen, and the oxide The gold film speckle pattern is obtained by dissolving the aluminum plate, but the scope of application of this method is small, it is only suitable for polymer materials that can be softened, and it is difficult to control the size of the speckle; Xie Huimin et al. developed a method for making micro-nano scale speckle (Chinese Patent Publication No. CN101832759A), which is a method of etching microscopic speckles on the surface of a specimen based on a femtosecond laser. This method uses a focused ion beam system to directly etch micro-nano-scale speckles on the surface of a specimen. This method is mainly aimed at making speckles in the small area of ​​the small sample, and there are problems such as damage to the surface of the sample itself; Chen Zhenning and others have developed a multi-scale digital image correlation measurement method (Chinese Patent Publication No. CN112857243A), using oil, Ink and paint print digital speckle fields one by one on the surface of the sample, and different bandpass filters need to be installed on the camera surface to correspond to the selection of oil, ink, and paint. This method has certain requirements for the DIC imaging system , and the speckle pattern is easy to volatilize or fall off in a high temperature environment

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