Shamsheer Non-destructive Test

[Edster]

The following report was published in the EurekAlert. Thought it was worth sharing. The sword can be seen in the link below.

If this type of message is out of bounds, please scrap it.

Thanks,
Ed

http://www.eurekalert.org/multimedia/pub/86565.php

PUBLIC RELEASE: 10-FEB-2015
Historic Indian sword was masterfully crafted
Italian, UK researchers use non-destructive techniques and show the secrets of forging methods

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IMAGE: THIS IS A 75-CENTIMETER-LONG SHAMSHEER FROM THE LATE 18TH OR EARLY 19TH CENTURY MADE IN INDIA (WALLACE COLLECTION, LONDON). view more

CREDIT: DR. ALAN WILLIAMS/WALLACE COLLECTION

The master craftsmanship behind Indian swords was highlighted when scientists and conservationists from Italy and the UK joined forces to study a curved single-edged sword called a shamsheer. The study, led by Eliza Barzagli of the Institute for Complex Systems and the University of Florence in Italy, is published in Springer's journal Applied Physics A - Materials Science & Processing.

The 75-centimeter-long sword from the Wallace Collection in London was made in India in the late eighteenth or early nineteenth century. The design is of Persian origin, from where it spread across Asia and eventually gave rise to a family of similar weapons called scimitars being forged in various Southeast Asian countries.

Two different approaches were used to examine the shamsheer: the classical one (metallography) and a non-destructive technique (neutron diffraction). This allowed the researchers to test the differences and complementarities of the two techniques.

The sword in question first underwent metallographic tests at the laboratories of the Wallace Collection to ascertain its composition. Samples to be viewed under the microscope were collected from already damaged sections of the weapon. The sword was then sent to the ISIS pulsed spallation neutron source at the Rutherford Appleton Laboratory in the UK. Two non-invasive neutron diffraction techniques not damaging to artefacts were used to further shed light on the processes and materials behind its forging.

"Ancient objects are scarce, and the most interesting ones are usually in an excellent state of conservation. Because it is unthinkable to apply techniques with a destructive approach, neutron diffraction techniques provide an ideal solution to characterize archaeological specimens made from metal when we cannot or do not want to sample the object," said Barzagli, explaining why different methods were used.

It was established that the steel used is quite pure. Its high carbon content of at least one percent shows it is made of wootz steel. This type of crucible steel was historically used in India and Central Asia to make high-quality swords and other prestige objects. Its band-like pattern is caused when a mixture of iron and carbon crystalizes into cementite. This forms when craftsmen allow cast pieces of metal (called ingots) to cool down very slowly, before being forged carefully at low temperatures. Barzagli's team reckons that the craftsman of this particular sword allowed the blade to cool in the air, rather than plunging it into a liquid of some sort. Results explaining the item's composition also lead the researchers to presume that the particular sword was probably used in battle.

Craftsmen often enhanced the characteristic "watered silk" pattern of wootz steel by doing micro-etching on the surface. Barzagli explains that through overcleaning some of these original 'watered' surfaces have since been obscured, or removed entirely. "A non-destructive method able to identify which of the shiny surface blades are actually of wootz steel is very welcome from a conservative point of view," she added.

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Reference: Barzagli E. et al (2015). Characterization of an Indian sword: classic and noninvasive methods of investigation in comparison, Applied Physics A - Materials Science & Processing. DOI 10.1007/s00339-014-8968-0

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

[Battara]

Very nice. Thank you for this article.

[Oliver Pinchot]

Excellent article, thanks Edster

[Ian]

Thanks Edster.

That is a very informative article.

I note that there is an earlier article by the same authors (Barzagli et al, 2013) in which they examined the characteristics of six tsubas. Here is the Abstract of that article.

In this work we present a systematic study of Japanese sword hand-guards (tsuba) carried out by means of non-invasive techniques using neutrons. Several tsuba from different periods, belonging to the Japanese Section of the Stibbert Museum, were analysed using an innovative approach to characterise the bulk of the samples, coupling two neutron techniques, namely Time of Flight Neutron Diffraction (ToF-ND) and Nuclear Resonance Capture Analysis (NRCA). The measurements were carried out on the same instrument: the INES beam-line at the ISIS spallation pulsed neutron source (UK).

NRCA analysis allows identifying the elements present in the sample gauge volume, while neutron diffraction is exploited to quantify the phase distribution and other microstructural parameters of the metal specimen. The results show that all samples are made of high-quality metal, either steel or copper alloy, with noticeable changes in composition and working techniques, depending on the place and time of manufacturing.

These techniques look very promising non-invasive methods for examining the metallurgy of old swords. Unfortunately, they require state-of-the art technology and analysis that is not widely available at this time.

Ian.

Reference

Barzagli E, Grazzi F, CivitaF, Scherillo A, Pietropaolo A, Festa G, Zoppi M. Applied Physics A: Materials Science and Processing (2013) 113:1143–1150, DOI 10.1007/s00339-013-7832-y.

[Edster]

Ian,

Battara and Oliver thanks for your interest and support. Ian, thanks for the abstract. High tech non-destructive testing offers promise, but as you observe, it is not readily available. I wonder if we could recruit a university materials science lab to help with testing, maybe at Timonium one year.

My chief interest is the ID and dating of European vs native made kaskara. European makers marks are not always diagnostic since native smiths often replicate them. Forging skills would be more or less the same in both places since just a trip-wheel hammer wouldn't make a real qualitative difference. (Generally, machines require less technical skill than a master manual blade smith possess.) With the use of lorry spring steels for native made blades, I assume that native blades would be of more or less the same chemical composition since say 1920s. Also, I suspect that the forging and heat treating processes/techniques in Kassala, Sudan were the same in 1880s as they were in 1986 and probably today and in 1600 Sennar for that matter. I have some dated from the 20s and 80s and can't really tell the age difference by blade appearance and bending quality alone. Some older ones seem better quality than some newer ones, but this is probably based on individual smith skills rather than anything else.

But what is the composition of various European factory-made trade blades? Probably a range of steels available commercially at any time or place. What is diagnostic?

We need a bigger data base and hopefully non-destructive testing can help us create one.

Regards,
Ed