Interface optimization for thermal residual stress reduction at laser-brazed ceramic-stainless steel joints for miniaturized energy sensors.

Publikation: Beitrag zu KonferenzenWissenschaftliche VortragsfolienBeigetragenBegutachtung


The development of reliable joining techniques for ceramics and metals is crucial for energy applications, such as fuel cells, nuclear reactors, and high-temperature sensors, most especially for the sealing of miniaturized sensors to study multiphase flows. However, during one-step active laser brazing it is a serious problem that a high thermal stress concentration can occur at the joint interfaces or on the ceramic side of the joint due to mismatches between the CTEs (coefficients of thermal expansion) and/or elastic constants. The uncontrolled thermal residual stress can lead to cracks and defects in the brazement. In the present work, an elastic-plastic finite element method/numerical model was formulated to study the thermal residual stresses developed in the brazement between ceramics and austenitic stainless steel during cooling in active laser brazing. Analyses were conducted for planar and cylindrical specimen geometries relevant for miniaturized energy sensors. Laser interface patterning was employed to create micro-scale features on the metal and ceramic surfaces that promote interlocking and reduce thermal stress concentrations. The optimisation of the interface designing parameters including hatch size, structure width, pattern depth and metal/ceramic thickness ratio was performed using the Taguchi method with orthogonal arrays. The magnitude of the simulated stress thresholds in non-patterned specimens was validated by a simplified quantitative estimate. Overall, this study demonstrates that laser interface patterning is an effective method for controlling thermal residual stresses in ceramic-metal brazements, thereby increasing the reliability of miniaturized energy sensors.


PublikationsstatusVeröffentlicht - 7 Sept. 2023


Titel17th European Congress and Exhibition on Advanced Materials and Processes
KurztitelFEMS EUROMAT 2023
Dauer3 - 7 September 2023
BekanntheitsgradInternationale Veranstaltung
OrtJohann Wolfgang Goethe-Universität Frankfurt am Main & online
StadtFrankfurt am Main