Enhancement mechanism of shear properties for SiO2 ceramics by laser welding with Al2O3/SiO2 powder

Abstract

The laser direct fusion welding of SiO2 ceramics was a global challenge in the manufacture of radome. The paper explored the laser direct fusion welding of SiO2 ceramics, investigated the influence of filling powder addition and welding material composition on the formation of weld. The findings revealed that the addition of welding material effectively addressed the issue of weld formation in laser direct fusion welding SiO2 ceramic. However, the abundance of internal bubbles within the weld emerged as a significant impediment to further enhancing weld strength. The addition of SiO2/Al2O3 mixed powder not only significantly reduced the quantity and size of internal bubbles within the weld but also generated the strengthening phase Al2SiO5, leading to a substantial increase in weld shear strength, reaching a maximum of 106% of the base material. The research results provided a new solution for direct melting welding of ceramics.