Simplified models of several configurations of structural steel arc weldments were made as an aid to understanding the importance of penetration and weld size with respect to fatigue crack initiation tendencies. Surprising findings were that the presence of a gap (simulating less than ideal fit up) may increase or reduce the value of the highest stress depending on the configuration. The effect of residual stresses was not included in the model, however causes and effects of residual stresses in welds will be briefly described in a qualitative manner.

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This study investigated actively brazing Alumina-to-Alumina with Ag-Cu-Ti as the filler metal system and Alumina-to-Copper with Cu-Ti-Co as the filler-metal system. The research was conducted on four samples, two of which were alumina brazed to alumina (Samples 1 & 2), and the other two were alumina brazed to copper (Samples 3 & 4). The filler metal composition for each sample was as follows: Sample 1 consisted of Cu-96%, and Ti-4%; Sample 2 consisted of Ag-70%, Cu-26%, and Ti-4%; Sample 3 consisted of Cu-85%, Ti-10%, and Co-5%; and Sample 4 consisted of Cu-55%, Ti-40%, and Co-5%. The phase transformations between the filler and base metal of each brazed joint were studied using EDS, SEM, optical microscopy, and X-ray diffraction.

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