Thermal and Mechanical Properties of Borosilicate Glass to Kovar Alloys Joint

The aim of the current study was to find a reliable joint between Borosilicate glass and Kovar alloys. For this purpose, the Dilatometer test was applied to calculate the thermal expansion coefficient of glass and Kovar alloys, and the materials with lower differences in the thermal expansion coefficient were used to join the Kovar to glass. Due to the nonmetallic properties of glass, it is theoretically impossible to join glass to metal as it shows no wettability. Therefore, a material was applied as a sealer between Kovar and glass to solve this problem. The Kovar samples were oxidized in the N2-H2-H2O atmosphere to control the chemical composition and also form an oxide layer that does not contain Fe2O3. The tensile strength of the produced joints was investigated at different times and temperatures. The results showed that the highest tensile strength was 16.63 MPa which was achieved at 10 min and 1000°C.