Connector component with temperature-resistant sensor element

1. A connector component with an integrated ultrasonic sensor for determining a prestressing force or a stressing force of the connector component, wherein the ultrasonic sensor comprises a layer construction having an electrode layer, at least one mechanical protection layer and at least one layer composed of a material having piezoelectric properties, and the at least one electrode layer, the at least one mechanical protection layer and the at least one layer composed of a material having piezoelectric properties are arranged in a manner applied by sputtering at a freely accessible end of the connector component, wherein the layer construction is embodied compactly and in a manner free of pores, and the ultrasonic sensor is adapted to withstand multiple thermo cycles, wherein the at least one mechanical protection layer separates the layer composed of a material having piezoelectric properties from the electrode layer, and wherein the layer thickness of the mechanical protection layer is at most half the layer thickness of the layer composed of the material having piezoelectric properties.

2. The connector component as claimed in claim 1 , wherein the connector component is constructed as a high-temperature sensor to withstand a temperature range of between 200° C. and 1000° C.

3. The connector component as claimed in claim 1 , wherein the connector component is produced from a member of the group consisting of: high-alloy steels, special steels, titanium and alloys thereof, TiAl6V4, aluminum and alloys thereof, nickel alloys, Inconel, nonmagnetic steels, or brass.

4. The connector component as claimed in claim 1 , wherein the layers of the layer construction are applied an adhesion force between 20 N/mm 2 and 80 N/mm 2 in relation to one another.

5. The connector component as claimed in claim 1 , wherein the layer composed of a material having piezoelectric properties is applied with an adhesion force of more than 40 newtons per mm 2 to a first end or a second end of the connector component.

6. The connector component as claimed in claim 1 , wherein the ultrasonic sensor is adapted to withstand temperatures above the Curie temperature of the material having piezoelectric properties and is adapted to supply meaningful ultrasonic pulse echoes for temperatures below the Curie temperature of the material having piezoelectric properties in a layer.

7. The connector component as claimed in claim 1 , wherein the layer thickness of the electrode layer is <30 μm.

8. The connector component as claimed in claim 1 , wherein the layer thickness of the mechanical protection layer is <20 μm.

9. The connector component as claimed in claim 1 , wherein the layer thickness of the layer composed of a material having piezoelectric properties is <50 μm.

10. The connector component as claimed in claim 1 , wherein the first end is the end side of a screw head.

11. The connector component as claimed in claim 1 , wherein the second end is the end side at the end of a threaded part.

12. The connector component as claimed in claim 1 , embodied as an element of the group consisting of a screw, a hollow screw, a stay bolt, a bolt, a rivet a pin or a special component for aeronautics applications.

13. The connector component as claimed in claim 1 , wherein the integrated ultrasonic sensor, at the freely accessible first end of the connector component, is incorporated into a cutout or depression formed there.

14. The connector component as claimed in claim 13 , wherein the layer construction of the ultrasonic sensor is embedded into the first end or the second end of the connector component.

15. The connector component as claimed in claim 4 , wherein the layers are applied an adhesion force of 50 N/mm 2 .

16. The connector component as claimed in claim 4 , wherein the layers are applied an adhesion force of 40 N/mm 2 .

17. The connector component as claimed in claim 1 , wherein the ultrasonic sensor, after multiply undergoing a thermal cycle with a short heating period in which an increased temperature level prevails, and after undergoing a cooling period, supplies an ultrasonic pulse echo capable of providing an accurate ultrasonic measurement at the cooled connector component.

18. The connector component as claimed in claim 1 , wherein the at least one mechanical protection layer is sandwiched between the layer composed of a material having piezoelectric properties and the electrode layer.