scholarly journals Stress corrosion in gold alloys

Gold Bulletin ◽  
1979 ◽  
Vol 12 (4) ◽  
pp. 140-144 ◽  
Author(s):  
Jennifer M. M. Dugmore ◽  
Charles D. DesForges
Keyword(s):  
Stress Corrosion ◽  
Gold Alloys

Electron Metallography of Chemical Attack Upon Some Alloys Susceptible to Stress Corrosion Cracking

CORROSION ◽  
1963 ◽  
Vol 19 (11) ◽  
pp. 373t-389t ◽  
Author(s):  
H. W. PICKERING ◽  
P. R. SWANN
Keyword(s):  
Aluminum Alloys ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Surface Roughening ◽  
Gold Alloys ◽  
Atom Concentration ◽  
Chemical Attack ◽  
Copper Gold ◽  
Slip Planes

Abstract The microstructures of deformed copper-gold, copper-aluminum, copper-zinc and magnesium-aluminum alloys were examined by transmission electron microscopy. These specimens were further examined after exposure to solutions which do and do not cause stress corrosion cracking. Exposure to “cracking” solutions resulted in a localized pitting or tubular form of attack, whereas the solutions which did not produce cracking caused a uniform surface roughening. When thin-foil specimens were deformed within the corrosive environments, the tubular attack and the surface roughening were observed to be enhanced in the regions of heavy deformation. Observations also indicated that for all the alloys investigated, static dislocations did not initiate chemical attack. In general, the pitting or tubular type of attack may be initiated at grain boundaries, antiphase boundary junctions in ordered copper-gold alloys, at precipitates and the substructure of twins in magnesium-aluminum alloys and at other sites which could not be identified. It was concluded that compositional rather than physical disturbances initiate preferential chemical attack on the surface of the alloys studied. For copper-gold alloys the superficial chemical disturbance can be as small as a six-atom cluster. Rates of pitting greater than 0.4 cm/hr can be attained for copper-gold alloys, which compares well with stress corrosion crack velocities. In the discussion of these results a new mechanism for transgranular stress corrosion is presented. It is proposed that when susceptible alloys are exposed to stress corrosion cracking environments a mechanically weak, pitted structure is produced along active slip planes, and that ductile fracture occurs through this corroded material. The chemical activity of the slip planes, which are believed to initiate the pitting attack, is discussed in relation to (a) the type of surface slip structure found in alloys where cross slip is difficult, (b) increase in solute atom concentration at the crack tip through the mass transfer of solute atoms to the surface by planar groups of moving dislocations, and (c) segregation and precipitation on slip planes. It was found that very fine precipitates, which are either an intermediate magnesium-aluminum phase or Mg17Al12, formed on the basal planes of quenched magnesium-1 or 7 atomic percent aluminum (<0.001 percent Fe, Cu or Ni) alloys when aged at room temperature. The presence of these precipitates was associated with the transgranular stress corrosion susceptibility of these alloys.

scholarly journals A facile chemical screening method for the detection of stress corrosion cracking in 9 carat gold alloys

Gold Bulletin ◽  
2009 ◽  
Vol 42 (3) ◽  
pp. 209-214 ◽  
Author(s):  
B. Neumeyer ◽  
John Hensler ◽  
Anthony P. O’Mullane ◽  
Suresh K. Bhargava
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Screening Method ◽  
Corrosion Cracking ◽  
Gold Alloys ◽  
Carat Gold ◽  
Chemical Screening ◽  
Detection Of Stress

Surface Films on Zircaloy-2 Samples Cracked in Neutral Aqueous NaCl by Stress Corrosion

1973 ◽  
Vol 31 ◽  
pp. 46-47
Author(s):  
R.A. Ploc
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Film Thickness ◽  
Stress Corrosion ◽  
Zirconium Dioxide ◽  
Surface Film ◽  
Surface Films ◽  
Continuous Layer ◽  
Transmission Electron ◽  
Product Film

Samples of low-nickel Zircaloy-2 (material MLI-788-see(1)), when anodically polarized in neutral 5 wt% NaCl solutions, were found to be susceptible to pitting and stress corrosion cracking. The SEM revealed that pitting of stressed samples was occurring below a 2000Å thick surface film which behaved differently from normal zirconium dioxide in that it did not display interference colours. Since the initial film thickness was approximately 65Å, attempts were made to examine the product film by transmission electron microscopy to deduce composition and how the corrosion environment could penetrate the continuous layer.

CARLSON ALLOY C601

Alloy Digest ◽  
1994 ◽  
Vol 43 (7) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
High Temperatures ◽  
Stress Corrosion Cracking ◽  
Heat Treating ◽  
Resistance To Stress ◽  
Extended Exposure ◽  
Sulfur Containing

Abstract Carlson Alloy C601 is characterized by high tensile, yield and creep-rupture strengths for high temperature service. The alloy is not embrittled by extended exposure to high temperatures and has excellent resistance to stress-corrosion cracking, to carburizing, nitriding and sulfur containing environments. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on forming, heat treating, machining, and joining. Filing Code: Ni-458. Producer or source: G.O. Carlson Inc.

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