Microhardness indentation measurement method based on confocal principle

Abstract

The invention discloses a microhardness indentation measurement method based on a confocal principle and belongs to the field of hardness metering. The method comprises the steps of pressing a micro indentation on a measured sample through a microhardness pressing head, performing three-dimensional scanning measurement on the microhardness indentation through a three-dimensional measurement function of a confocal microscope, obtaining a three-dimensional image of the microhardness indentation formed by a data array, obtaining a two-dimensional feature section of the three-dimensional image bytaking a diagonal line of the indentation as a section line, obtaining depth h from a bulge on the edge of the indentation to a lowest point of the indentation by analyzing a feature point of the feature section, substituting the depth h of the indentation into an algorithm formula to calculate the area of the microhardness indentation, and achieving the measurement of the microhardness indentation. The method can achieve the measurement of the microhardness indentation with the indentation diagonal line of less than 20 micrometers. The method is not influenced by an illumination intensity variation, can effectively identify a bulge state of the edge of the indentation, is high in resolution in Z direction and ensures measurement precision.

Description

technical field [0001] The invention belongs to the field of hardness measurement, in particular to a method for measuring tiny microhardness indentations based on the confocal principle. Background technique [0002] For the measurement of microhardness indentation, the traditional optical microscope or CCD image acquisition and processing methods are generally used to obtain the length of the two diagonals of the microhardness indentation, and then the projected area of ​​the microhardness indentation is calculated by the formula. As for the tiny microhardness indentation, the indentation diagonals are all less than 20 μm, touching the limits of the two traditional indentation measurement methods. Using an optical microscope to directly measure the indentation diagonal, its measurement accuracy, degree of automation and measurement efficiency can no longer meet the requirements, and the introduction of personnel errors is also greater; the way of CCD image acquisition and ...

AI Technical Summary

Problems solved by technology

Using an optical microscope to directly measure the indentation diagonal, its measurement accuracy, degree of automation and measurement efficiency can no longer meet the requirements, and the introduction of personnel errors is also greater; the way of CCD image acquisition and processing is due to the impact of light source illumination intensity on The impact of image formation is large, which makes it impossible to measure under small indentations with diagonal lines less than 20μm

In addition, since the two traditional methods cannot analyze the protrusion changes at the edge of the micro-hardness indentation image, neither can achieve accurate measurement of the micro-hardness indentation

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