ABSTRACT
The average joint strengths of Dynallox 96 (D-96) AG and Dynallox 100 (D-100) AG brazed joints made using 50-µm-thick TICUSIL® braze preforms were found to be 136 and 163-MPa, respectively. Fractography revealed two main failure modes in both D-96 AG and D-100 AG brazed joints made using 50-µm-thick TICUSIL® braze preforms: low-strength failures and high-strength failures. Several studies in the literature have reported that the strength of alumina-to-alumina and alumina-to-metal brazed joints can be improved by adding alumina particles or carbon fibres to create a composite-type Silver-copper-titanium braze alloy. In ceramic-to-ceramic and ceramic-to-metal brazed joints, high stresses can develop at the free edges of the joint interfaces due to either a change in temperature or mechanical loading. Nanoindentation testing techniques were used to evaluate changes in the nanohardness distribution as a result of the microstructural evolution in both D-96 AG and D-100 AG brazed joints, as the TICUSIL® braze preform thickness was increased from 50 to 150-µm.
