Engraving device and method for creating and measuring stress corrosion cracking on a flat coated test specimen

Patent metadata

Field	Value
Publication number	US-2020371017-A1
Application number	US-201816766804-A
Country	US
Kind code	A1
Filing date	Oct 15, 2018
Priority date	Nov 23, 2017
Publication date	Nov 26, 2020
Grant date	—

Abstract

The invention relates to a method for carrying out a test and measuring method on a flat test specimen (1), wherein a mechanical load is introduced into a test specimen surface (2) by means of a rotating engraving head (3) of an engraving device (4), wherein the engraving head (3) penetrates with a defined contact pressure at least into a layer system (5) applied to the test specimen (1), wherein the rotating engraving head (3) is moved along the test specimen surface (2) and relative to the test specimen (1) in order to create at least one engraving (6) on the test specimen surface (2) by plastic deformations and/or brittle chipping of the layer system (5), and wherein the at least one engraving (6) introduced into the test specimen surface (2) is measured using a photo-optical method in order to evaluate layer adhesion of the layer system (5) to the main body (11). The invention also relates to an engraving device (4) for carrying out such a method.

First claim

1 . A method for creating and measuring stress corrosion cracking on a flat coated test specimen ( 1 ) which has a basic body ( 11 ) with a basic body surface ( 9 ) and, applied thereto, a layer system ( 5 ) with a boundary surface ( 14 ) adjoining the basic body surface ( 9 ), the method comprising the following steps:
introducing a mechanical load into a test specimen surface ( 2 ) of the layer system ( 5 ) using a rotatable engraving head ( 3 ) of an engraving device ( 4 ), wherein the engraving head ( 3 ) at least partially penetrates into the layer system ( 5 ) with a constant pressing force and at a constant rotational speed; moving the rotating engraving head ( 3 ) along the test specimen surface ( 2 ) and relative to the test specimen ( 1 ) at a constant movement speed in order to create at least one engraving ( 6 ) on the test specimen surface ( 2 ) by plastic deformations and/or brittle chipping of the layer system ( 5 ); and measuring the at least one engraving ( 6 ) introduced into the test specimen surface ( 2 ) by a light-optical method for evaluating the layer adhesion of the layer system ( 5 ) on the basic body ( 11 ).

2 . The method as claimed in claim 1 , characterized in that the pressing force and the rotational speed of the engraving head ( 3 ) are monitored and controlled by a control unit ( 7 ).

3 . The method as claimed in claim 1 , the method further comprising the following steps:
at least partially covering the test specimen surface ( 2 ) with a corrosive medium in order to accelerate a stress corrosion cracking of the test specimen ( 1 ) by local delaminations between the layer system ( 5 ) and the basic body ( 11 ) of the test specimen ( 1 ); and after acceleration of the stress corrosion cracking, measuring the at least one engraving ( 6 ) introduced into the test specimen surface ( 2 ) by a light-optical method for evaluating the layer adhesion of the layer system ( 5 ) on the basic body ( 11 ).

4 . An engraving device ( 4 ) for carrying out the method as claimed in claim 1 , the engraving device comprising a three dimensionally movable sample table ( 10 ) for receiving the test specimen ( 1 ) and also comprising a rotatable engraving head ( 3 ) configured to load the test specimen ( 1 ) with a defined pressing force and at a defined rotational speed and to create an engraving ( 6 ) in a test specimen surface ( 2 ).

5 . The engraving device ( 4 ) as claimed in claim 4 , characterized in that the engraving head ( 3 ) has a diamond coating.

6 . The engraving device ( 4 ) as claimed in claim 4 , characterized in that the engraving head ( 3 ) is spherical.

7 . The engraving device ( 4 ) as claimed in claim 4 , characterized in that the engraving head ( 3 ) is disk-shaped.

8 . The engraving device ( 4 ) as claimed in claim 4 , further comprising a light microscope ( 12 ) for the light-optical measurement and evaluation of the at least one engraving ( 6 ) introduced into the test specimen surface ( 2 ).

9 . (canceled)

10 . The method as claimed in claim 2 , the method further comprising the following steps:
at least partially covering the test specimen surface ( 2 ) with a corrosive medium in order to accelerate a stress corrosion cracking of the test specimen ( 1 ) by local delaminations between the layer system ( 5 ) and the basic body ( 11 ) of the test specimen ( 1 ); and after acceleration of the stress corrosion cracking, measuring the at least one engraving ( 6 ) introduced into the test specimen surface ( 2 ) by a light-optical method for evaluating the layer adhesion of the layer system ( 5 ) on the basic body ( 11 ).

Assignees

• Bosch Gmbh Robert

Inventors

• Braak Richard
• May Ulrich

Classifications

• G01N19/04 Primary

  Measuring adhesive force between materials, e.g. of sealing tape, of coating · CPC title

• B44B3/009

  using a computer control means · CPC title