Dear all
I would like to update this older topic. Over the past 1.5 years, I have spent countless hours examining the sword, showing it to numerous experts and having it analysed. I would like to share the results with you here.
Metallographic examination:
A section of the surface was cut (polished and etched) and examined micrographically. It is bloomery steel with a medium carbon content. The number of slag inclusions is rather low -> high-quality steel was used. No evidence of hardening could be found at the examined site. This is the rule rather than the exception for medieval swords. The Widmannstättsche structures indicate overheating during forging
XRF analysis:
Two XRF analyses were performed, including on the surface exposed by the cut. The steel of the blade has a manganese content of ~0.8-1%. Similarly high manganese contents can be found in early medieval swords, among others (cf. publications by Lehmann, Williams, etc.). Modern trace elements such as Cu and Ni are absent. Manganese improves the properties of the steel, but was not added intentionally at the time; rather, it was present in manganese-rich ores. Interestingly, manganese was also detected in the crossguard, but not in the pommel.
Microscopic examination of the corrosion layers:
Optical microscopic examination of the corrosion surface reveals clearly defined, multi-phase iron mineralisation, which is characteristic of wrought iron artefacts that have been stored in the ground for a long time. The structures observed consist of a complex composite of different iron oxide and iron oxyhydroxide phases. These phases occur in a heterogeneous, clod-like and laminated texture, which was created by repeated oxidation and reduction cycles within the corrosion crust.
In some deeper areas, mineral deposits in the form of tiny grains of sand were found.
Occasionally, microscopic black, glass-like beads could be identified. They are located in rust craters and are not magnetic. These are most likely molten slag inclusions that have been exposed by the corrosion of the surrounding material.
The corrosion layer(s) and their structure differ significantly between the blade, tang, pommel and crossguard.
Attached are some pictures of the findings described above.
BR
Andreas
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