Ceramizable phenolic adhesive modified by different inorganic particles: A comparative study of thermal stability, bonding strength and bonding mechanism.

In this work, two ceramizable phenolic adhesives were prepared using ZrSi 2 particles or ZrSi 2 /B 4 C mix particles as the inorganic fillers. The thermal stability, bonding strength, microstructure and phase composition of the adhesives were investigated by TGA, shear strength of Al 2 O 3 joints, SEM, EDS, XRD and XPS. The results show that these two adhesives have different bonding performances and ceramicization evolutions above 600 °C in air due to the addition of the second phase particles B 4 C. The bonding strength of ZrSi 2 /B 4 C modified phenolic adhesive after treatment at 1200 ℃ can be as high as 36.6 MPa, while the bonding strength of ZrSi 2 modified phenolic adhesive under the same conditions is only 17.5 MPa. B 4 C undergoes oxidation reaction before ZrSi 2 , and the oxidation product B 2 O 3 liquid phase not only reacts with ZrSi 2 to form oxidation-resistant ZrB 2 , but also can dissolve the high temperatures defects of the adhesive and chemically bond with the Al 2 O 3 substrates at the interface. [ABSTRACT FROM AUTHOR]