Claims
- 1. A method of monitoring and controlling thermal spraying methods for coating a surface of a substrate by heated, inorganic particles as a coating material, including the steps of: coating the surface of the substrate by a spraying method with a stream of the heated, inorganic particles; measuring a substrate surface temperature as a characteristic variable for a transferred layer mass or layer thickness during the spraying method; comparing the measured substrate surface temperature with a nominal value; and if deviations from the nominal value occur, changing, for control purposes, at least one method parameter, which parameter affects the layer mass or layer thickness and which parameter is selected from the group consisting of a particle concentration in the stream of heated inorganic particles, a relative speed at which the stream of heated particles and the susbstrate to be coated move with respect to one another, and a number of coating passes leading to a desired transferred layer mass or desired layer thickness, to reduce the deviations.
- 2. A method as defined in claim 1, wherein the thermal spraying method is a plasma-spraying method.
- 3. A method as defined in claim 1, wherein the thermal spraying method is a flame-spraying method.
- 4. A method as defined in claim 1, wherein the thermal spraying method is an electric-arc spraying method.
- 5. A method as defined in claim 1, wherein the method parameter used for control purposes is the particle concentration in the stream of heated particles of the coating material.
- 6. A method as defined in claim 1, wherein the method parameter used for control purposes is the relative speed at which the stream of heated particles of coating material and the substrate to be coated move with respect to one another.
- 7. A method as defined in claim 1, wherein the method parameter used for control purposes is the number of coating passes leading to the desired transferred layer mass or desired layer thickness.
- 8. A method as defined in claim 1, wherein the temperature used for the comparison is a maximum substrate surface temperature measured during the coating step.
- 9. A method as defined in claim 1, wherein the temperature used for the comparison is an average substrate surface temperature measured during the coating step.
- 10. A method as defined in claim 1, comprising measuring, for control purposes, a difference between surface temperatures at a specific position on the substrate directly before and directly after a spraying process or spray pass.
- 11. A method as defined in claim 1, wherein the step of measuring includes periodically measuring the substrate surface temperature at a single specified position on the substrate surface during the spraying method.
- 12. A method of monitoring and controlling a thermal spraying method used to coat parts in mass production, with the method including the steps of: coating a surface of the part by a spraying method with a stream of the heated, inorganic particles; measuring a surface temperature of the part as a characteristic variable for a transferred layer mass or layer thickness during the spraying method; comparing the measured surface temperature with a nominal value; if deviations from the nominal value occur, changing, for control purposes, at least one method parameter that affects the layer mass or layer thickness to reduce the deviations; and implementing the step of changing at least one method parameter to control the transferred layer mass or layer thickness immediately after the part having the deviating surface temperature has been identified.
- 13. A method as defined in claim 12, wherein the parts to be coated are oxygen sensors for internal combustion engines.
- 14. A method as defined in claim 12, wherein the step of measuring includes periodically measuring the surface temperature at a single specified position on the surface of the part during the spraying method.
Priority Claims (1)
Number |
Date |
Country |
Kind |
195 35 078.2 |
Sep 1995 |
DEX |
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority of patent application Ser. No. 195 35 078.2, filed Sept. 21, 1995, in the Federal Republic of Germany.
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Mar 1985 |
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4588607 |
Matarese et al. |
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|
4897283 |
Kumar et al. |
Jan 1990 |
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