Research and analysis of methods for preventing silver alloys from tarnishing

Voprosy Materialovedeniya ◽

10.22349/1994-6716-2020-104-4-170-181 ◽

2021 ◽

pp. 170-181

Author(s):

S. A. Tyurina ◽

S. L. Chavushyan ◽

A. V. Makarova ◽

R. E. Khvostov ◽

G. A. Yudin

Keyword(s):

Silver Alloys

This paper examines factors causing the darkening of items made of silver alloys in showcases and storehouses of museums, the authors analyze methods to prevent this undesirable process. The results of studies of different methods for preventing tarnishing of silver alloys are also presented.

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Heterogeneous Precipitation at Dislocations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100062257 ◽

1969 ◽

Vol 27 ◽

pp. 70-71

Author(s):

A. K. Eikum

Keyword(s):

Electron Microscopy ◽

Room Temperature ◽

Dislocation Loops ◽

Silver Alloys ◽

Heterogeneous Precipitation ◽

Precipitation Phenomena ◽

Aluminum Base ◽

Silver Atoms

Precipitation phenomena in concentrated aluminum-base silver alloys have been studied with a variety of techniques including electron microscopy. The purpose of the present work was to investigate the dislocation reactions that occur as silver atoms precipitate (or segregate) under a relatively low supersaturation. Specimens (0.1 mm thick) of Al-1 at. % Ag were quenched from ~500°C into an oil bath at room temperature and aged 30 min. at 265°C. The initial configurations available as sites for heterogeneous precipitation will therefore include perfect prismatic dislocation loops, Frank sessile loops and random segments of grown-in dislocations.

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A non-cyanide method of electropolishing silver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100107873 ◽

1978 ◽

Vol 36 (1) ◽

pp. 146-147

Author(s):

R. L. Lyles ◽

S. J. Rothman ◽

W. Jäger

Keyword(s):

Electron Microscopy ◽

Sulphuric Acid ◽

Methyl Alcohol ◽

Health Hazards ◽

Silver Alloy ◽

High Quality ◽

Silver Alloys ◽

Free Sample ◽

Specimen Quality ◽

Standard Techniques

Standard techniques of electropolishing silver and silver alloys for electron microscopy in most instances have relied on various CN recipes. These methods have been characteristically unsatisfactory due to difficulties in obtaining large electron transparent areas, reproducible results, adequate solution lifetimes, and contamination free sample surfaces. In addition, there are the inherent health hazards associated with the use of CN solutions. Various attempts to develop noncyanic methods of electropolishing specimens for electron microscopy have not been successful in that the specimen quality problems encountered with the CN solutions have also existed in the previously proposed non-cyanic methods.The technique we describe allows us to jet polish high quality silver and silver alloy microscope specimens with consistant reproducibility and without the use of CN salts.The solution is similar to that suggested by Myschoyaev et al. It consists, in order of mixing, 115ml glacial actic acid (CH3CO2H, specific wt 1.04 g/ml), 43ml sulphuric acid (H2SO4, specific wt. g/ml), 350 ml anhydrous methyl alcohol, and 77 g thiourea (NH2CSNH2).

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