Method for making micrometer scale speckle

Abstract

The invention relates to a method for making a micrometer scale speckle, belonging to the technical field of optical measurement mechanics. The method for making the micrometer scale speckle is technically characterized in that epoxy hardener and powder mixed solution are evenly coated on the surface of a test piece by using a photoresist spinner to complete the making of the micrometer scale speckle. The method is simple to operate. By changing the size of power particles, the volume mass ratio of the epoxy hardener and the power, centrifuge time and photoresist spinning speed parameter to control the density and the size of speckle particles, evaluating speckle grams obtained under different parameters through average grey scale gradient sum of squares and selecting a surface speckle gram with the largest average grey scale gradient sum of squares as the made micrometer scale speckle, the goal that the made speckle is suitable for the researches on micro deformation behaviors of different materials is realized.

Description

technical field [0001] The invention relates to a method for making micron-scale speckles, and belongs to the technical fields of photometric mechanics, engineering materials, component deformation and displacement testing. Background technique [0002] With the continuous advancement of science and technology, the research on micro-devices and some complex materials at the macro scale can no longer satisfy the analysis of their performance. The micro-deformation measurement technology has attracted more and more attention from researchers, but the micro-deformation measurement requires a deformation Therefore, the establishment of deformation tracking target points has become a primary problem to be solved in the deformation measurement of micro-devices and complex materials. The digital image correlation method was first proposed by Peter and Ranson of the University of South Carolina (University of South Carolina) in the early 1980s. measurement method. The digital spec...

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Problems solved by technology

[0003] At present, the commonly used speckle production methods are mostly speckle production methods at the macro scale, such as the artificial painting method. The speckle particles obtained by this method are relatively large, and the particle size is on the order of submillimeters, which is only suitable for macroscopic deformation of macroscopic specimens. Measurement, and the quality of speckle production is closely related to the experience of the producer, which cannot meet the requirements for the measurement of micro-area deformation of the sample

In terms of micro-nano-scale speckle fabrication, S A Collette et al. (S A Collette, M A Sutton, P Miney, etc., Nanotechnology 15 (2004) 1812-1817) developed a speckle fabrication method for nanoscale strain measurement, which is By first pressing the porous alumina plate coated with gold film into the polymer sample, the aluminum oxide plate is dissolved to obtain the speckle pattern of the gold film. This method has a small scope of application, and the size of the speckle is difficult to control.

T.A.Berfield et al. (T.A.Berfield, J.K.Patel, R.G.Shimmin et al. Experimental Mechanics (2007) 47: 51-62) used a spray gun to spray micron particles on the surface of the specimen to form micro-nano-scale speckles. Experience, and the speckle distribution is not easy to control

W.A.Scrivens et al. (W.A.Scrivens & Y.Luo & M.A.Sutton et al., Experimental Mechanics (2007) 47: 63-77) developed chemical vapor deposition and ultraviolet photolithography to produce micron-scale speckles. These two methods are complex in process, The same speckle size is difficult to control

Xie Huimin developed a method for making high-temperature micron-scale speckle (Chinese patent application 200810101918.X). This method uses software to simulate a speckle image and converts the speckle image into a binary image. A layer of photoresist is evenly coated on the surface of the test piece, and the surface of the test piece is exposed to electron beams according to the obtained binary image. Then coat a layer of high-temperature-resistant film to corrode the remaining photoresist, and finally obtain high-temperature speckles on the surface of the specimen. This method can adjust the size and density of the speckles, but the experimental process of this method is more complicated, and developing and fixing Time is difficult to control and not easy to promote

Recently, Xie Huimin developed a method for making micro-nano scale speckles (Chinese Patent Publication No. CN101832759A). This method controls the size and area of ​​the speckle by using the focused ion beam system and changing the magnification of the focused ion beam system. Beam intensity and etching time can change the speckle morphology, so that micro-nano scale speckle can be obtained on the surface of the specimen. This method is mainly aimed at making speckle in the small area of ​​the micro-sample, and the production cost is high, so it is not easy to be popularized.

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