Determination of compressive stress in glass-to-metal seals using photoluminescence spectroscopy technique

Abstract

The stress field and stress evolution of compression seals at micron-scale spatial resolution are experimentally quantified for the first time using photoluminescence spectroscopy (PS) technique. In analyzing the resulting dataset based on fluorescence line shift, it is found that the compressive stress is non-uniform from the center to the periphery of glass, and the highest compressive stress (>300 MPa) is located at the distance of 15∼20 μm to the interface. Further in-situ PS experiments performed at the high compressive stress region reveal that the compressive stress decayed near-linearly with increasing temperature, and instantaneous cracking generated by tensile stress was observed at 320 °C. Moreover, the compressive stress at the interface significantly decayed from 289 MPa to 90 MPa after aged for 800 h at 250 °C. The present work demonstrates an effective method to measure the stress field and sheds light on the future compressive stress tailorability for compression seals.