X-ray study of corrosion products of some ancient Egyptian metals and alloys

1981 ◽  
Vol 37 (a1) ◽  
pp. C193-C193
Author(s):  
S. A. Saleh ◽  
F. M. Helmi
2021 ◽  
Vol 19 (1) ◽  
pp. 210-224
Author(s):  
Manal Maher ◽  
Yussri Salem

The article focused on the multi analytical characterization of unique copper model tools date back to the dynasty Xth, 1st intermediate period (c.2134-2050). The studied set consists of twenty-five objects that were excavated in the tomb of KHENNU AND APA-EM-SA-F (289) in the south of Memphis, Saqqara. Different microscopes were used to examine the morphology and stratigraphy of the corrosion product layers. Stereomicroscope was used to examine the corrosion phases on the surface objects. Metallographic microscopy was used to investigate the microstructure of the metal core as well as the morphology and stratigraphy of the corrosion product layers. Scanning electron microscope-energy dispersive X-ray analysis was used to identify the elemental composition of the objects. X-ray diffraction was used to analyze the corrosion phases formed on surface’s artifacts, while raman spectroscopy was carried out to identify the internal corrosion layers. The results revealed that that burial environment and long–term storage in an uncontrolled environment together caused a progressive stage of corrosion of the studied artifacts. The formed corrosion layers consists of the external layer, an under surface layer and internal corrosion products in the center of the cross-sectios. The surface and internal corrosion products were identified as Cuprite, Paratacamite, Nantokite, Atacamite, Malachite and Chalconatronite. Also, the results revealed that the metallic core consists of copper metal without any further alloying elements. Finally, the study presented suitable treatment and conservation strategies of these unique artifacts or such cases, and shows a safe fixing procedure using a sewing technique via transparent inert threads to display the set objects.  


2019 ◽  
Vol 207 ◽  
pp. 304-315 ◽  
Author(s):  
Guohao Fang ◽  
Weijian Ding ◽  
Yuqing Liu ◽  
Jianchao Zhang ◽  
Feng Xing ◽  
...  

CORROSION ◽  
10.5006/3912 ◽  
2021 ◽  
Author(s):  
Arthur Situm ◽  
Xiaoxuan Guo ◽  
Burke Barlow ◽  
Bao Guo ◽  
Ian Burgess ◽  
...  

Polymer coatings can be used to mitigate the corrosion of steel in high chloride environments. Obtaining speciation information from thin corrosion layers can be important for understanding corrosion mechanisms, including polymer coating failure. This study outlines the effectiveness of collecting glancing angle X-ray absorption near edge spectroscopy (GA-XANES) spectra at the Fe K-edge to obtain chemical speciation information at the polymer-steel interface without removal of the polymer film. The depth of penetration of the incident X-rays can be altered by changing the incidence angle, allowing for more fluorescence signal from corrosion products to be detected relative to the Fe metal fluorescence signal in GA-XANES spectra. This study demonstrates the use of GA-XANES to study thin layers of steel corrosion and obtain depth profile information of steel corrosion products beneath a polymethyl methacrylate polymer coating.


2012 ◽  
Vol 557-559 ◽  
pp. 139-142
Author(s):  
Jian Guo Liu ◽  
Yan Tao Li ◽  
Bao Rong Hou

The corrosion processes and mechanisms of Q235A steel under wet-dry cyclic condition were studied using polarization curve compared with immersion samples, while, the corrosion morphologies and corrosion products of the steel samples were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The cathodic process of wet-dry samples was likely to be controlled not by the oxygen reduction, but rather by the reduction of corrosion products. During the drying process of the wet-dry sample, the electrolyte thickness decreased and chloride concentration increased. Oxygen would be much easier to diffuse into the interface of electrolyte/metal, which improved the cathodic reduction processes. Except for this, the rust itself took part in the reduction processes and hence increased the corrosion rate of the steel samples.


1992 ◽  
Vol 28 (3) ◽  
pp. 326-328
Author(s):  
L. G. Zorina ◽  
Yu. M. Kaplin ◽  
Yu. V. Ponomarev ◽  
Yu. V. Zelenskii

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