TY - JOUR T1 - Detection of the Material and Processing Technology of the Discovered Bowl in Chalade’em Shal Cemetrery of Khalkhal-Ardabil, NW Iran TT - شناسایی جنس و فن فراوری جام مکشوفه در گورستان چالادئم شال خلخال-اردبیل JF - JRA JO - JRA VL - 7 IS - 2 UR - http://jra-tabriziau.ir/article-1-262-en.html Y1 - 2021 SP - 1 EP - 16 KW - Silver Bowl KW - Chalade’em Shal Khalkhal Cemetery KW - Warm Hammering KW - Recrystallization KW - Twining KW - Galvanic Corrosion N2 - During an archeological excavation project from two discovered cemeteries in Shal village-Khalkhal of Ardabil province in Iran in March 2019 many metallic objects such as warfare were found. Owing to the similarities between these discovered and the Mannaeans’ objects, it seems that they could be suggested for this period. One of these discovered objects is a unique narrow-waist bowl whose material and processing technique detection is important for archeologists to understand the native knowledge, technology, art and culture of that region in ancient times. Regarding this, the microstructure and chemical composition of this object was evaluated using optical as well as scanning electron microscopes (SEM) equipped with an X-ray energy dispersion spectrometer (EDS). The results show that the mentioned bowl is a silver-base alloy containing about 2.5 weight percent copper with a double phase microstructure including silver matrix grains and dispersed fine copper particles. The metallographic cross-section of this bowl also shows two distinguishable microstructures of ambient temperature graving induced sever flow/plastic deformation in surfaces and low energy incomplete recrystallized matrix grains and twining lines in central regions which have been dynamically formed during production of the bowl via warm hammering. Also some evidence of galvanic sulfide/sulfate localized corrosion is observed in the under layer of the surfaces just at the interface of the low energetic central region and high energetic surface layer. In addition, observation of the silver chloride and silver sulfide or sulfate/oxide compounds respectively in central regions and surfaces of the metallographic section indicate internal chlorine corrosion and sulfide/sulfate corrosion/oxidation in surface layers of the beaker. However, affirming about the commencing of the studied beaker needs further precise techniques for quantitative chemical analysis which are postponed for future investigations. M3 10.52547/jra.7.2.1 ER -