The use of vibratory welding is treated with some caution in the industry due to inconsistent beneficiary results. Here, a partial explanation is suggested by the differentiation between global vibrational effects (GVEs) and local vibrational effects (LVEs), and the latter is investigated experimentally. Two structural plates of steel are welded at three frequency/amplitude combinations using manual gas metal arc welding in an experimental setup that ensures only LVEs. After welding, tensile tests, microhardness tests, and metallurgical characterization are performed locally in the different welding zones and the results are compared to the non-vibrated welds. Novel use of digital image correlation (DIC) is implemented in tensile testing of welded samples, thus enabling the separate determination of local mechanical properties of the base metal, heat-affected zone and fusion zone of the same weld. LVE is found not to promote any distinct difference in weld properties, at least within the vibrational regimes studied. Nevertheless, depending on geometry and structural response, it is explained how vibratory welding may promote residual stress relief due to GVEs of the welded structure.
Selected iron arrowheads and bolts retrieved from the destruction layer of the Crusader castle of Arsur/Arsuf, which was taken down by the Mamluk army (headed by Baybars) in late April 1265, were studied. Being the only site within the boundaries of the Latin Kingdom of Jerusalem that has thus far yielded more than 1200 iron arrowheads, an archaeometallurgical characterization was performed. The aim of this research was to study the warfare methods and manufacturing technologies used by the Mamluk and Crusader armies. Examination included optical microscopy, SEM and SEM–EDS, XPS and microhardness tests. Analysis was performed on both the metallic iron and iron oxides. Ferrous wooden ‘fossils’, which were found on and within the bolts, were dendroarchaeologically tested. The microstructure analyses show that the weapons were made of wrought iron. These results are correlated with the function of the weapons. The different microstructures of the arrowheads and the bolts indicate dissimilar manufacturing processes. The graphitization of the ropes on the bolts and the oxide phases on their surfaces both provide evidence of high‐temperature fire. The ropes support the archaeological findings that these devices were used by the Mamluks to set the Crusader castle on fire.
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