TY - GEN

T1 - Press hardening tool integrated thin film temperature sensor

AU - Dencker, Folke

AU - Schlenkrich, A.

AU - Wurz, Marc Christopher

N1 - Copyright: Copyright 2018 Elsevier B.V., All rights reserved.

PY - 2017

Y1 - 2017

N2 - Controlling of process parameters like temperature is crucial in technical applications of all kinds. But there is only a certain amount of processes where detecting of temperatures is even a matter of safety. One is the press hardening of chassis parts in the automotive industry. The simultaneous forming and microstructural transformation requires a temperature rise of at least 27 K per second to fabricate martensitic phase with a tensile strength of more than 1, 500 MPa. In terms of quality assurance a 100 % accurate monitoring of this gradient is necessary to guarantee the desired material properties. So far several concepts like optical measurements or tool integrated standard thermocouples have been evaluated. These either influence the thermal transport or don't have the required sensitivity. A possible solution is the use of a thin film sensor on the surface of the forming tool. Its heat capacity is very low, which increases the sensitivity and minimizes the influence on thermal transport. However micro technical approaches of depositing and structuring are usually performed on flat substrates. To fabricate microsystems on top of tools made of steel, different challenges like surface flatness, electrical contacting and abrasion resistance need to be overcome. This work focuses on the manufacturing of temperature sensors on the surface of a press hardening tool's steel by means of thin film deposition and structuring. A combination of photoresist spray coating and laser direct imaging in comparison to direct coating using shadow masks for the thermo resistive and thermocouple sensor were analysed. Both concepts were realized and briefly characterized in terms of reliability and response behaviour.

AB - Controlling of process parameters like temperature is crucial in technical applications of all kinds. But there is only a certain amount of processes where detecting of temperatures is even a matter of safety. One is the press hardening of chassis parts in the automotive industry. The simultaneous forming and microstructural transformation requires a temperature rise of at least 27 K per second to fabricate martensitic phase with a tensile strength of more than 1, 500 MPa. In terms of quality assurance a 100 % accurate monitoring of this gradient is necessary to guarantee the desired material properties. So far several concepts like optical measurements or tool integrated standard thermocouples have been evaluated. These either influence the thermal transport or don't have the required sensitivity. A possible solution is the use of a thin film sensor on the surface of the forming tool. Its heat capacity is very low, which increases the sensitivity and minimizes the influence on thermal transport. However micro technical approaches of depositing and structuring are usually performed on flat substrates. To fabricate microsystems on top of tools made of steel, different challenges like surface flatness, electrical contacting and abrasion resistance need to be overcome. This work focuses on the manufacturing of temperature sensors on the surface of a press hardening tool's steel by means of thin film deposition and structuring. A combination of photoresist spray coating and laser direct imaging in comparison to direct coating using shadow masks for the thermo resistive and thermocouple sensor were analysed. Both concepts were realized and briefly characterized in terms of reliability and response behaviour.

KW - Hot forming

KW - Laser direct imaging and spray coating

KW - Press hardening

KW - PVD

KW - Temperature sensor

KW - Thermocouple

KW - Thin film

UR - http://www.scopus.com/inward/record.url?scp=85041340867&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:85041340867

T3 - Proceedings of the 17th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2017

SP - 349

EP - 350

BT - Proceedings of the 17th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2017

T2 - 17th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2017

Y2 - 29 May 2017 through 2 June 2017

ER -