Optimizing Interfaces in Laser-Brazed Ceramic-Stainless Steel Joints for Hydrothermal Sensors through Finite-Element Modeling

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Abstract

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 hydrothermal 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 elastoplastic 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. Calculations and comparison experiments were conducted to validate the simulated stress distribution in un-patterned ceramics. Stress analyses were conducted for planar and cylindrical specimen geometries (lab joints) relevant for miniaturized energy sensors. Laser interface patterning was employed to create micro-scale features on ceramic interfaces that reduce thermal stress concentrations. The optimization 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 study suggests that laser interface structuring can modify thermal residual stresses in ceramic-to-metal brazements, thereby increasing the reliability of active brazing joints.

Details

OriginalspracheEnglisch
Seiten (von - bis)6372-6379
Seitenumfang8
FachzeitschriftJournal of materials engineering and performance
Jahrgang33 (2024)
Ausgabenummer13
PublikationsstatusVeröffentlicht - 27 Feb. 2024
Peer-Review-StatusJa

Externe IDs

ORCID /0009-0001-5269-5882/work/154742438
Scopus 85185936821
Mendeley 6e260414-f887-3138-9c18-41c33915fd17

Schlagworte

Schlagwörter

  • modeling and simulation, ceramics, brazing, structural, surface modification, energy