Since ceramic adhesives exhibit relatively poor tensile and shear strength, it is desirable to design a joint that will distribute the mechanical stress. A glue line with greater surface area, such as a tongue-and-groove joint, should be used to reduce joint stress and increase mechanical strength.
Flexible Ceramic adhesives offer excellent electrical, thermal and chemical resistance. Our adhesives, in contrast to organic-based materials, will not outgas under high vacuum. All operating conditions such as temperature, thermal cycling, humidity, corrosion and electrical requirements should be considered before selecting an adhesive.
Flexible Ceramic adhesives are somewhat brittle and may be affected by dynamic conditions such as vibration and mechanical shock. Expansion joints can be used to relieve stress. Adding ceramic cloth at the interface is also useful.
The clearance between mating parts at operating temperature should be 2-8 mils (50-200 microns). Less than 2 mils will prevent uniform adhesion, and greater than 8 mils will often result in cohesive shear failure within the adhesive.
General design criteria for bonding with adhesives are similar to those for epoxies and other organic adhesives. Main considerations include joint design, glue line thickness and operating environment.