Non-destructive pole-figure measurements on workshop-made silver reference model of archaic objects

Abstract

Based on the knowledge of crystallographic texture, the parameters of the metal-forming heat treatment of metallic objects can be reconstructed well when conventional technologies (e.g. rolling, deep drawing, etc.) are applied. The characterisation of texture has been possible only by using destructive techniques, apart from neutron diffraction. Recently, a non-destructive texture measurement method has been developed for centreless diffractometers, providing a new dimension to the examination of archaic objects. In the present study, two types of Stresstech G3R centreless diffractometer were used with this new method, which proved it to be applicable to both the tabletop and robotic arm-assisted versions of the diffractometer. Although the texture of archaic objects can be revealed using this method, the production of these objects cannot be directly deduced from the results, since their manufacturing steps are not identical to the metal-forming operations applied today. In this study, workshop-made silver reference samples were produced with the help of three silversmiths. Wrinkling, metal spinning and intermediate annealing were applied to the rolled silver sheet with the aim of making real-sized silver cups. The workshop-made reference cups were then subjected to non-destructive texture examinations. The results reveal the textures developed during the conventional manufacturing steps of silver cups. The obtained information greatly assists future research in understanding the pole figures of archaic objects and the reconstruction of their manufacturing technology.