METHOD FOR CHARACTERIZING A COATING

Abstract

The present invention relates to a method for characterizing a coating, in which method a mass and/or a volume of a basic body is/are measured prior to coating; a mass and a volume of the basic body with the applied coating are measured; for characterizing the coating, a density of the coating is determined from the volume and mass measurements; wherein the volume is optically measured.

Claims

1. A method for characterizing a coating, comprising the steps of: i) prior to coating, measuring a mass and/or a volume of a basic body; ii) measuring a mass and a volume of the basic body with an applied coating; iii) for characterizing the coating, determining a density of the coating from volume and mass measurements, wherein the volume is optically measured.

2. The method according to claim 1, wherein the optical measurement is produced in a structured-light projection method.

3. The method according to claim 1, wherein a density of the basic body is known and only the volume or the mass is measured prior to the coating.

4. The method according to claim 1, wherein, during the optical measurement of the volume, a surface roughness of the coating is optically measured at the same time.

5. The method according to claim 4, wherein the surface roughness of the coating is post-processed in a model created on the basis of the volume measurement for comparing with a mechanical measurement.

6. The method according to claim 1, wherein the coating has a layer thickness of at least 0.05 mm and a maximum of 5 mm.

7. The method according to claim 1, wherein, prior to step ii), a surface of coating, which surface is to be measured, is treated to reduce reflections.

8. The method according to claim 1, further comprising the step of: coating a component for a turbomachine.

9. The method according to claim 8, wherein the component is coated and, in parallel therewith, a basic body that is different from a component coated for characterizing the coating.

10. The method according to claim 8, wherein the coating is a thermally sprayed coating.

11. The method according to claim 8, wherein the coating is heat-treated after it is applied, whereby step iii) is carried out prior to the heat treatment.

12. The method according to claim 8, wherein the component is a housing part.

13. The method according claim 12, wherein the coating is a run-in lining of the housing part.

14. The method according to claim 1, further comprising the steps of: providing a holder for arranging the basic body; providing an optical measurement unit configured and arranged for measuring the volume of the basic body arranged in the holder; a weighing unit for measuring a mass of the basic body arranged in the holder; and a control unit, wherein, when the basic body is arranged in the holder before and after the coating, the control unit is configured and arranged to induce the optical measurement unit and the weighing unit to carry out the steps i) and ii), and to determine the density of the coating according to step iii).

15. The method according to claim 14, further comprising the step of: providing a computer program, which has commands that, during execution thereof by the control unit to induce the latter to initiate and carry out steps i) to iii).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The invention will be explained in more detail in the following on the basis of an example of embodiment, wherein the individual features in the scope of the independent claims can also be essential to the invention in another combination, and wherein also no distinction is made individually between the different claim categories.

[0026] Taken individually,

[0027] FIG. 1 shows a jet engine in an axial section;

[0028] FIG. 2 shows a device for characterizing a coating according to the invention in a schematic representation; and

[0029] FIG. 3 shows the surface roughness of the coating of FIG. 2 in a schematic representation.

DESCRIPTION OF THE INVENTION

[0030] FIG. 1 shows a turbomachine 1, concretely a turbofan engine, in an axial section. The turbomachine 1 is functionally divided into compressor 1a, combustion chamber 1b, turbine 1c, and fan 1d. Both the compressor 1a as well as the turbine 1c are each constructed of several stages; each stage is composed of a guide vane ring and a rotating blade ring. During operation, the rotating blade rings rotate around the longitudinal axis 3 of the turbomachine 1. Here, the aspirated air is compressed in the compressor 1a, and then burned in the downstream combustion chamber lb along with kerosene mixed in. The hot gas is expanded in the turbine lc and propels the rotating blade rings. The housing part 2 of the compressor la can be provided, for example, with a so-called run-in lining.

[0031] FIG. 2 shows a device 21 for characterizing a coating 14 according to the invention in a schematic representation, for example, a run-in lining. The device 21 comprises a holder 12 for the arrangement of a basic body 13, an optical measurement unit 16 for the volume measurement of the basic body 13 arranged in the holder 12, a weighing unit 11 for the measurement of the mass of the basic body 13 arranged in the holder 12, and a control unit 22. The optical measurement unit 16 comprises a projector and two cameras in a three-dimensional measurement system (not shown individually); the measurement takes place in a structured-light projection method.

[0032] Prior to the coating, the weighing unit 11 measures the mass of the basic body 13, and in this example. its volume is also measured by the optical measurement unit 16. After the coating, the volume and the mass of the basic body 13 with the applied coating 14 are measured; from this, its density is determined for characterizing the coating. The depicted integration of optical and weight measurement is given by way of example; in general, the weight measurement can also be produced independently from the volume measurement with a separate weighing unit.

[0033] FIG. 3 shows in a schematic representation in a digital model the optically measured roughness of the surface 15 of the coating 14. The roughness peaks of the surface 15 are referenced by the reference number 31. The reference character z.sub.1 references a smoothing of the surface roughness in order to eliminate the roughness peaks 31. In this way, the measurement can be compared with a mechanical measurement, for example with a measurement calipers.