摘要
设计了β-锂霞石/BS复合玻璃钎料(BSL),探究了β-锂霞石掺入量对复合玻璃钎料特征温度、热膨胀系数、润湿性及连接微观组织和力学性能的影响机制。随β-锂霞石掺入量增加,BSL复合玻璃钎料热膨胀系数逐渐降低且下降程度逐渐增大,其特征温度则逐渐升高且升高程度呈逐渐增大趋势,在相同温度下的表观接触角增大,同时其表观接触角随温度的变化变缓。当T=850℃、t=10 min时,复合玻璃钎料(BSL3)连接RB–Si C陶瓷的界面与相同工艺参数下的RB–SiC/BS界面组织相似,但在玻璃焊缝中,β-锂霞石转变为块状灰色KAlSiO4(钾霞石)晶体。块状KAlSiO4负膨胀相可降低热膨胀系数、阻止裂纹扩展,连接接头因此取得了较好的强化效果,接头的压剪强度从未强化前的5.2 MPa提高到10.9 MPa。
To solve thermal mismatch problem in the bonding process of RB–SiC ceramic using borosilicate glass braze(BS),β-eucryptite/BS composite braze(BSL)was designed.The effect ofβ-eucryptite addition on a)the characteristic temperature,thermal expansion coefficient and wettability of composite glass braze,as well as b)the microstructure and mechanical properties of joints was investigated.The thermal expansion coefficient of BSL decreases and its rate increases with the increase ofβ-eucryptite amount.Also,the characteristic temperature of BSL and its rate both increase with the increase ofβ-eucryptite amount.The apparent contact angle of BSL increases at the same temperature,and the variation of apparent contact angle along with temperature becomes slow.The RB–SiC/composite glass solder(BSL3)/RB–SiC joint has the similar interface to the RB–SiC/BS/RB–SiC joint bonded at 850℃for 10 min.However,in the glass seam,β-eucryptite turns into massive gray KAlSiO4 crystals(i.e.,kaliophilite).The massive KAlSiO4 crystals with a negative expansion characteristic can reduce the thermal expansion coefficient and prevent the crack propagation,thus strengthing the joint.The shear strength of the joint after reinforcement increases from 5.2 MPa to 10.9 MPa.
作者
林盼盼
于凯凯
林铁松
何鹏
刘守相
徐李刚
龙伟民
鲍丽
马佳
LIN Panpan;YU Kaikai;LIN Tiesong;HE Peng;LIU Shouxiang;XU Ligang;LONG Weimin;BAO Li;MA Jia(State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,China;Beijing Institute of Radio Measurement,Beijing 100845,China;State Key Laboratory of Advanced Brazing Filler Metals and Technology,Zhengzhou Research Institute of Mechanical Engineering,Zhengzhou 450001,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2020年第3期408-415,共8页
Journal of The Chinese Ceramic Society
基金
“战略性国际科技创新合作重点专项(2016YFE0201300)
国家自然科学基金青年科学基金项目(51805112)
哈尔滨工业大学科研创新基金项目(HIT.NSRIF.2020004)
装备预研领域基金项目(61409230512)”.
关键词
反应烧结碳化硅陶瓷
复合玻璃钎料
微观组织
剪切强度
reaction sintering silicon carbide ceramic
composite glass braze
microstructure
shear strength
