高级检索

Al2O3陶瓷玻璃钎焊接头原位强化及机理

In-situ strengthening of Al2O3 ceramic glass brazing joint and its mechanism

  • 摘要: 针对Al2O3陶瓷可加工性差、复杂结构及大尺寸构件制备困难等问题,本文提出采用具有优异机械性能、且能与Al2O3陶瓷原位形成增强相的48.5SiO2-48.5B2O3-3Na2O(mol.%)硼硅酸盐玻璃钎料钎焊连接Al2O3陶瓷. 研究结果表明,在钎焊连接过程中,Al2O3陶瓷向玻璃钎料内部扩散溶解,焊缝区域由SiO2-B2O3-Na2O玻璃转变为SiO2-B2O3-Al2O3-Na2O,其中Al2O3的融入提升了玻璃基体的机械强度.同时在玻璃基体内部以及玻璃钎料与Al2O3陶瓷界面结合处均原位生成了大量弥散分布的硼酸铝晶须,形成了Al2O3陶瓷的硼酸铝晶须增强硼硅酸盐玻璃复合接头,晶须通过拔出效应、裂纹偏转、裂纹桥联、吸收效应等不仅进一步强化玻璃基体,对连接界面处更是起到了钉扎、缝合的作用,实现了Al2O3陶瓷高强度、高可靠连接. 当连接温度为1250 ℃,保温时间为60 min时,接头剪切强度达到136 Mpa.

     

    Abstract: In view of the problems of poor machinability, difficult preparation of complex structure and large-size components of Al2O3 ceramics, 48.5SiO2-48.5B2O3-3Na2O(mol.%) borosilicate glass was used to obtain reliable bonding of Al2O3 ceramic which not only has excellent mechanical properties, but also can form a reinforced phase with Al2O3 ceramics in situ. The results show that during the brazing connection, Al2O3 ceramics diffuse and dissolve into the glass solder, and SiO2-B2O3-Na2O glass transformed to SiO2-B2O3-Al2O3-Na2O glass in the weld zone, and the integration of Al2O3 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 Al2O3 ceramics, forming an aluminum borate whisker reinforced borosilicate glass composite joint of Al2O3 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 Al2O3 ceramics. When temperature is 1250 ℃ and time is 60 min, the joint strength reached the highest value of 136 Mpa.

     

/

返回文章
返回