Submitted by curator on Fri, 10/16/2015 - 13:52
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Inv. 33-3-90
Sickle fragment
A cut across one corner of the fragmented end: magnification, 100x
Etchant: Ammonium hydroxide + hydrogen peroxide
(Sn, <0.011%; As, 0.52%; Ni, 0.25%)
The microstructure comprises polyhedral grains that, in the twinning and significant distortion, are indicative of annealing of the casting prior to a certain amount of cold-working. It is possible that, in this instance, the metals deformation occurred during the tools use, rather than through some treatment during manufacture.
Microhardness VHN: 129 ± 7 (n=5)
Very uniform; what data scatter there is (VHN ranging 137 to 120) seems to be a genuine record of variation in grain size within the blades body.
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