A specimen of high-carbon nitrogen-doped steel has been synthesized to supplement previous studies on wootz-like steels. A comparison of different states of material as well as one of distinct methods of hardness testing has been performed. Electron microscopy of the specimens’ microstructure revealed nano-structuring similar to that observed with ancient sabers. Part of them was annealed so that the nano-structures dissolved. Nano-hardness values derived under ambient conditions from indentation as well as from scratch tests were determined and related to the microstructure prior to and after annealing. The disappearance of nanostructuring led to a significant drop of hardness. The ratio of indentation to scratch hardness proved a suitable indicator of hardening. From hardness as function of penetration depth and from friction as function of time and normal load various quantitative features of the mechanical properties and of the deformation process have been evaluated. When modeling friction, sliding and plowing parts have been distinguished quantitatively. Enhanced adhesion forces were attributed to surface layers.

In the present investigation, samples of five qualities of ultra-high carbon crucible or wootz steel - two of them genuine Damascus blades from the 17th century have been compared with respect to their response to nanoindentation. Values of nanohardness and elastic modulus derived that way were discussed in the light of microstructure and phase content. Cementite particles of different shape and distribution embedded in a pearlitic or divorced eutectoid matrix govern the mechanical behaviour. Testing of the nanoscratch resistance supports the idea of a grater-like effect of those wootz steel blades. Specimens of synthetic wootz and of original Damascus sabres showed the maximum response of these composite materials to elastic and plastic indentation.

Using high-resolution electron microscopy, we have found in a sample of Damascus sabres from the 17(th) century both cementite nanowires and carbon nanotubes. These might be the missing link between the banding and ancient recipes to make that ultrahigh carbon steel. The sample considered belonged to the wootz-type of Damascus steel which is fundamentally different from welded Damast. The nanotubes have only been revealed after dissolution of the sample in hydrochloric acid. Some remnants showed not yet completely dissolved cementite nanowires, suggesting that these wires were encapsulated by carbon nanotubes. Only recently. considerable progress has been achieved in reproducing the process of making the characteristic pattern of wootz. We propose a connection between impurity segregation, nanotube formation, nanotube filling with cementite, cementite wire growth, and formation of large cementite particles. Needless to say that the presence of a nanostructure will have ail impact upon the mechanical properties.

Comparison of the structure of ancient Damascene steel blades at nanoscale with more recent ones - all made using crucible (wootz) technology and exhibiting ultra-high carbon content - showed for the first time a common feature. Despite different microstructures, colonies of wire- and tube-like particles with diameters of 40-50 nm have been observed with the aid of high-resolution transmission electron microscopy. Crystalline Fe3C is the main phase forming those particles covered in numerous cases by a tube-like layer. These tubes were also found in an empty or partly - covered filled variant. To assess the strengthening capacity of cementite various models were compared. Dispersion strengthening seems the most efficient. Cutting edge qualities may be related to surface corrugations due to nanoparticles.

MicrosymposiaXRS has long been discussed in an important but somewhat limited context, specifically, as a bulk-sensitive alternative to x-ray absorption spectroscopies.However, continuing developments in both experimental apparatus and theoretical methods are steadily opening up new opportunities which are special to the large momentum transfers q which can be accessed in XRS.In this presentation, we will survey a few such recent studies.These will include applications for basic spectroscopy (He gas), environmental and renewable energy (N2 gas and LiTiOx), exotic chemical bonding (C2B10H12), and f-electron physics (CeO2 and UO2).

Extended abstract of a paper presented at MC 2007, 33rd DGE Conference in Saarbrücken, Germany, September 2 – September 7, 2007

Abstract X-ray phase analysis combined with high-resolution electron microscopy of samples taken from a genuine Damascus sabre after annealing for 24h at 400°C and 800°C followed by slow cooling down to room temperature has led to a better insight into the nature of cementite nanowires, which have been discovered recently. According to the present study, nanowires remained after 400°C annealing, but disappeared after heat treatment at 800°C and subsequent cooling down. On the other hand, perlitic cementite has been retained qualitatively after the same treatment. Knowing that the exceptional mechanical properties of Damascene blades disappear after annealing, the present results suggest a significant influence of the nanowires upon these features.

During the last years several works explored the potentials of neutron diffraction in the non destructive metallurgical characterisation of bronze artefacts. Despite the very interesting results in quantifying elemental and phase contents in binary and ternary alloys, as well as preferred orientation and residual stress distributions, the novel approach is still far from the common archaeometallurgical practice. In order to overcome a rather stationary situation, further insight aimed at enriching the analytical valence of neutron techniques and devising suitable integrations with other non-invasive methods are needed. Here, some recent developments in the use of time of flight neutron diffraction for investigating Middle Italy Iron Age bronze artefacts will be reported. Furthermore, the integration with other techniques and the general application perspective will be discussed.

The steel of Damascus blades, which were first encountered by the Crusaders when fighting against Muslims, had features not found in European steels--a characteristic wavy banding pattern known as damask, extraordinary mechanical properties, and an exceptionally sharp cutting edge. Here we use high-resolution transmission electron microscopy to examine a sample of Damascus sabre steel from the seventeenth century and find that it contains carbon nanotubes as well as cementite nanowires. This microstructure may offer insight into the beautiful banding pattern of the ultrahigh-carbon steel created from an ancient recipe that was lost long ago.

The surface and cross‐section of a genuine Damascus sword was characterised by means of wide‐angle X‐ray scattering techniques complemented by optical and transmisssion electron microscopy. Position‐resolved X‐ray phase analysis revealed that, unlike ferrite and martensite, the distribution of cementite is inhomogeneous in different spatial zones parallel to the cutting edge of the blade. For the first time a quantitative X‐ray phase and texture analysis was made possible by averaging all spatial zones of the surface and the cross‐section of the sword and applying the Rietveld method with code TOPAS. Differences concerning texture and structure characteristics of ferrite, martensite and cementite are discussed. More evidence for the structure of cementite nanowires is supplied. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The long-lasting search for the recipes of making the legendary Damascus swords may become a new direction by our finding that a genuine Damascus sabre contains a high density of cementite nanowires, which interact with dislocations and which might have influenced the nucleation of perlite. The nanohardness as measured separately for cementite and perlite indicated striking differences in the inelastic behaviour of those phases.

This paper reports the first results of studies made to determine the antiviral activity of dioxo hexahydro triazine, a newly developed antiphytoviral compound. After treatment with dioxo hexahydro triazine, the concentration of helical potato virus X in leaves of Nicotiana tabacum "Samsun" was found to be considerably reduced in both the serological test and local lesion test conducted on Nicotiana glutinosa at temperatures of 14 degrees C +/- 3 degrees C. In secondarily infected leaves, the reduction of the concentration of potato virus X in the range of from 1 mol/l to 10(-3) mol/l was so that it was no longer possible for viruses to be detected serologically. In vitro, however, dioxo hexahydro triazine, which was added to the inoculum, did not produce a significant change in the activity of the virion of potato virus X. Therefore, it is reasonable to assume that dioxo hexahydro triazine tends to affect replication steps of viruses. The use of dioxo hexahydro triazine also had the effect of greatly and highly significantly reducing the concentration of the isodiametric cucumber mosaic virus.

In mehrjährigen Parzellenversuchen wurde durch Behandlung mit 2,4-Dioxohexahydrotriazin (DHT), einer neu entwickelten antiphytoviralen Substanz im Durchschnitt von 57 stärker virusinfizierten Herkünften (durchschnittlicher Virusbesatz 24.6%) der Ertrag hochsignifikant um 1.1 t/ha (=6.5%) erhöht. Bei 49 gesunden Herkünften (durchschnittlicher Virusbesatz 4.8%) wurden demgegenüber die Erträge nicht verändert. Demnach darf die angeführte Ertragserhöhung der antiviralen Wirkung des DHT zugeschrieben werden. In 44 Grossflächenversuchen in Konsumkartoffelbeständen (Virusbesatz etwa zwischen 10 und 30%), wurde der Ertrag hochsignifikant um 1.4 t/ha (=8.0%) erhöht. Werden die im trocken-heissen Jahr 1976 in ausgesprochenen Dürregebieten erhaltenen Ergebnisse eliminiert, ergeben sich in den Parzellenversuchen mit virusinfizierten Herkünften hochsignifikante Mehrerträge von 1.9 t/ha (=9.7%) und bei den Grossflächenversuchen von 2.3 t/ha (=12.6%).