Investigation of glass sintering to improve strength and interfacial interactions in glass-to-AISI 316L metal joints

The relationship between sintering and glass-to-metal bonding, which are almost the initial and the last stages of glass-to-metal seal production, has been demonstrated in this study. In this context, a type of barium alkali silicate glass was prepared, and thermal properties were determined by differential thermal analysis, dilatometer, hot-stage microscope, and high-temperature viscosity analysis. Detailed porosity investigations were examined with an optical microscope and ImageJ quantitative analyses, after binder removal and sintering processes carried out at different temperatures and times. An increase in porosity was observed when the sintering and binder removal temperatures and times were increased. The bending strength of the sintered glass sample was decreased with the increment in porosity. A typical housing material AISI 316L stainless steel was used for preparing glass-to-metal joints. The high porosity after sintering caused larger bubbles to form after bonding and reduced the shear strength. The effect of sintering conditions on the interfacial interaction for glass-to-metal joints are revealed by cross-sectional scanning electron microscopy–energy-dispersive spectrometer analyses. Atomic force microscopy analyses and contact angle measurements were conducted to supplement investigation. This study addressed that the mechanical strength and chemistry of glass-to-metal joints showed strong dependency on glass sintering conditions.