Hardness tester and method for hardness test

Patent metadata

Field	Value
Publication number	US-9366609-B2
Application number	US-201314024235-A
Country	US
Kind code	B2
Filing date	Sep 11, 2013
Priority date	Sep 19, 2012
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

Provided is a hardness tester and method including an indentation former creating an indentation in a sample surface with an indenter; a first area calculator calculating an area of the indentation during application of pressure, the indentation being formed in the sample surface while the indenter is pressed against the sample; an image capture controller controlling a CCD camera to obtain image data of the sample surface; a second area calculator calculating the area of the indentation remaining in the sample surface based on the obtained image data; an elasticity index calculator calculating an elasticity index of the sample based on the area of the indentation during application of pressure and the area of the indentation calculated by the second area calculator; and a hardness value calculator calculating a hardness value of the sample based on the indentation remaining in the sample surface.

First claim

What is claimed is:

1. A hardness tester measuring hardness of a sample placed on a sample stage by loading a predetermined test force on the sample with an indenter to form an indentation in a surface of the sample, then measuring dimensions of the indentation, the hardness tester comprising:
an indentation former configured to create the indentation in the sample surface by pressing the indenter against the sample surface;
a first area calculator configured to calculate an area of the indentation during application of pressure, the indentation being formed in the sample surface while the indenter is pressed against the sample surface by the indentation former;
an image capture controller configured to control an image capturer to capture an image of the sample surface and obtain image data of the sample surface;
a second area calculator configured to calculate the area of the indentation that remains in the sample surface based on the image data obtained by the image capturer after the indenter has retreated from the sample surface;
an elasticity index calculator configured to calculate an elasticity index of the sample based on the area of the indentation during application of pressure, calculated by the first area calculator, and the area of the indentation calculated by the second area calculator; and
a hardness value calculator configured to calculate a hardness value of the sample based on the indentation remaining in the sample surface.

2. The hardness tester according to claim 1 further comprising:
a display controller configured to display, on a display, an image of the sample surface based on the image data obtained by the image capturer, wherein the display controller is further configured to display, on the display, the elasticity index of the sample calculated by the elasticity index calculator and the hardness value of the sample calculated by the hardness value calculator.

3. The hardness tester according to claim 2 , wherein the display controller is configured to display, based on the area of the indentation during application of pressure calculated by the first area calculator, a shape of the indentation during application of pressure while the indenter is pressed against the sample, the shape being displayed overlaid on an indentation in an image of the sample surface.

4. A hardness testing method for a hardness tester measuring hardness of a sample placed on a sample stage by loading a predetermined test force on the sample with an indenter to form an indentation in a surface of the sample, then measuring dimensions of the indentation, the hardness testing method comprising:
creating the indentation in the sample surface by pressing the indenter against the sample surface;
calculating an area of the indentation during application of pressure, the indentation being formed in the sample surface when the indenter is pressed against the sample surface during the creating the indentation;
controlling an image capturer to capture an image of the sample surface and obtain image data of the sample surface;
calculating the area of the indentation that remains in the sample surface based on the image data obtained by the image capturer after the indenter has retreated from the sample surface;
calculating an elasticity index of the sample based on the area of the indentation during application of pressure, calculated during the calculating the area of the indentation during application of pressure, and further based on the area of the indentation calculated during the calculating the area of the indentation that remains in the sample surface; and
calculating a hardness value of the sample based on the indentation that remains in the sample surface.

Assignees

• Mitutoyo Corp

Inventors

• Kataoka Masanobu

Classifications

• G01N3/40

  Investigating hardness or rebound hardness · CPC title

• G01N2203/0094

  Visco-elasticity · CPC title

• G01N3/42 Primary

  by performing impressions under a steady load by indentors, e.g. sphere, pyramid (G01N3/54 takes precedence) · CPC title

• G01N2203/0082

  Indentation characteristics measured during load · CPC title

• G01N2203/0647

  Image analysis · CPC title