Abstract:
In view of the problems of poor machinability, difficult preparation of complex structure and large-size components of Al
2O
3 ceramics, 48.5SiO
2-48.5B
2O
3-3Na
2O(mol.%) borosilicate glass was used to obtain reliable bonding of Al
2O
3 ceramic which not only has excellent mechanical properties, but also can form a reinforced phase with Al
2O
3 ceramics in situ. The results show that during the brazing connection, Al
2O
3 ceramics diffuse and dissolve into the glass solder, and SiO
2-B
2O
3-Na
2O glass transformed to SiO
2-B
2O
3-Al
2O
3-Na
2O glass in the weld zone, and the integration of Al
2O
3 improves the mechanical strength of the glass matrix. Furthermore, a large number of dispersed aluminum borate whiskers were generated in situ inside the glass matrix and at the interface between glass solder and Al
2O
3 ceramics, forming an aluminum borate whisker reinforced borosilicate glass composite joint of Al
2O
3 ceramics, and the whiskers not only further strengthened the glass matrix through pull-out effect, crack deflection, crack bridging, absorption effect, etc., but also played the role of nailing and suturing at the connection interface, realizing the high-strength and high-reliability connection of Al
2O
3 ceramics. When temperature is
1250 ℃ and time is 60 min, the joint strength reached the highest value of 136 Mpa.