Corrosion mechanism of tin-zinc alloys in neutral medium

The paper presents the results of a potentiodynamic study of the anodic behaviour of Zn0.5Al doped with molybdenum in the acidic (0.1 M, pH = 1; 0.01 M, pH = 2; 0.001 M, pH = 3), neutral (0.03, 0.3, 3%, pH = 7) and alkaline (0.001 M, pH = 10; 0.01 M, pH = 11; 0.1 M, pH = 12) media of HCl, NaCl and NaOH electrolytes. In the potentiodynamic mode with an electrode potential sweep rate of 2 mV/s, all Zn0.5Al-Mo samples containing from 0.01 to 1.0 wt% of molybdenum demonstrated a shift in the potentials of corrosion, pitting formation and repassivation. These potentials shift towards negative values in acidic and alkaline media, while shifting to positive values in a neutral medium. It was established that an increase in the concentration of electrolytes led to a shift of all the considered potentials towards negative values in all media - acidic, neutral and alkaline. This dependence is associated with the specific features of the process of anodic dissolution of alloys during the formation of an oxide film on their surface. The significance of the dependence of the stationary potential of free corrosion of alloys on time for establishing the passivity of surfaces in acidic, neutral and alkaline media was shown. It was determined that zinc alloys doped with molybdenum are resistant to pitting corrosion in all the investigated media. This resistivity is particularly high in acidic (0.001 M), neutral (0.03%) and alkaline (0.001 M) media of HCl, NaCl and NaOH electrolytes. The favourable effect of molybdenum on both the anodic behaviour of Zn0.5Al and the overall increase in the corrosion resistance of alloys was demonstrated. In comparison with undoped Zn0.5Al alloys, the corrosion rate of alloys doped with molybdenum (0.01-1.0 wt%) is 2-2.5 times lower. The proposed compositions of Zn0.5Al-Mo alloys can be used as noncorrosive coatings for steel products.

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216. Cadmium Overexposures in 3 Bronze Foundries Caused by Residual Trace Cadmium Levels in Zinc Alloys

10.3320/1.2765738 ◽

2001 ◽

Author(s):

T. Morris

Keyword(s):

Zinc Alloys ◽

Trace Cadmium

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Atomic absorption determination of Hg (II), Cd (II), and As (III) in natural and waste water after preliminary group preconcentration

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2019-85-2-12-16 ◽

2019 ◽

Vol 85 (2) ◽

pp. 12-16

Author(s):

I. V. Saunina ◽

E. N. Gribanov ◽

E. R. Oskotskaya

Keyword(s):

Waste Water ◽

Atomic Absorption ◽

High Sensitivity ◽

Distribution Coefficients ◽

Neutral Medium ◽

Atomic Absorption Determination ◽

Absorption Determination ◽

Relative Standard ◽

Preliminary Group

The sorption of Hg (II), Cd (II), and As (III) by natural aluminosilicate is studied. It is shown that the mineral absorbs those toxicants in a rather wide pH range, quantitative extraction of analytes being achieved in a neutral or close to neutral medium (pH values range within 7.0 - 8.0; 6.3 - 7.5; 7.4 - 8.5 for Hg (II), As (III), and Cd (II), respectively). The effect of the time of phase contact on the degree of extraction of elements is shown. The sorption capacity of the mineral in optimal conditions of the medium acidity (0.06 mmol/g for mercury, 0.31 mmol/g for cadmium, and 0.52 mmol/g for arsenic) is determined. The distribution coefficients attain values of aboutnX 103-nX 104. A new combined method for determination of Hg (II), Cd (II), and As (III) in natural and waste water is developed and tested. The method consists in a preliminary group sorption concentration of the analytes by aluminosilicate, desorption of the analytes from the surface of the mineral and their subsequent atomic absorption determination. The correctness of the method is verified in analysis of spiked samples. The method is easy to use and exhibits high sensitivity, reproducibility and accuracy of analyte determination. The relative standard deviation does not exceed 0.13. Economic availability and possibility of using domestic sorption materials are the important advantages of the proposed procedure which can be used in the practice of laboratories monitoring the quality and safety of environmental objects.

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Experimental Investigation of the Corrosion Mechanism of Cemented Soils in Magnesium Sulfate Solution

Materials Testing ◽

10.3139/120.110616 ◽

2014 ◽

Vol 56 (9) ◽

pp. 675-680 ◽

Cited By ~ 1

Author(s):

Pengju Han ◽

Y. Frank Chen ◽

Bozhu Shen ◽

David Y. Du

Keyword(s):

Experimental Investigation ◽

Magnesium Sulfate ◽

Sulfate Solution ◽

Corrosion Mechanism ◽

Cemented Soils ◽

Magnesium Sulfate Solution

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TITANALOY

Alloy Digest ◽

10.31399/asm.ad.zn0013 ◽

1972 ◽

Vol 21 (2) ◽

Keyword(s):

Corrosion Resistance ◽

Shear Strength ◽

Physical Properties ◽

Tensile Properties ◽

Base Alloy ◽

Heat Treating ◽

Zinc Alloys

Abstract TITANALOY is a zinc-base alloy containing copper and titanium. It can be readily formed, joined, and finished and is stronger and more dent resistant than the more common zinc alloys. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Zn-13. Producer or source: Matthiessen & Hegeler Zinc Company.

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An Overview of Cu Wire Intermetallic Compound Formation and a Corrosion Failure Mechanism

ISTFA 2012: Conference Proceedings from the 38th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2012p0310 ◽

2012 ◽

Author(s):

Dongmei Meng ◽

Laura Buck ◽

James Cargo

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Corrosion Mechanism ◽

Fundamental Study ◽

Corrosion Failure ◽

Transmission Electron ◽

Intermetallic Compound Formation ◽

Scanning Transmission ◽

Low K

Abstract Cu needs a higher level of ultrasound combined with bonding force to be bonded to the Al pad properly, not just because Cu is harder than Au, but it is also harder to initiate intermetallic compounds (IMC) formation during bonding. This increases the chances of damaging the metal/low k stack under the bondpad. This paper presents a fundamental study of IMC as well as one example of a failure mode of Cu/Al bonded devices, all based on detailed analysis using scanning electron microscopy, scanning transmission electron microscopy, energy dispersive spectrometers, and transmission electron microscopy. It presents a case study showing a corrosion mechanism of Cu/Al ballbond after 168hr UHAST stress. It is observed that all Cu9Al4 was consumed, while very little copper aluminide remained after 168 hours of UHAST stressing.

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Unique Autoclave Stress Induced Failure Mechanism

ISTFA 2005: Conference Proceedings from the 31st International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2005p0427 ◽

2005 ◽

Author(s):

John Butchko ◽

Bruce T. Gillette

Keyword(s):

Corrosion Rate ◽

Grain Boundary ◽

Failure Analysis ◽

Failure Mechanism ◽

Metal Corrosion ◽

Corrosion Mechanism ◽

Reliability Testing ◽

Process Change ◽

Transistor Reliability ◽

Pass Through

Abstract Autoclave Stress failures were encountered at the 96 hour read during transistor reliability testing. A unique metal corrosion mechanism was found during the failure analysis, which was creating a contamination path to the drain source junction, resulting in high Idss and Igss leakage. The Al(Si) top metal was oxidizing along the grain boundaries at a faster rate than at the surface. There was subsurface blistering of the Al(Si), along with the grain boundary corrosion. This blistering was creating a contamination path from the package to the Si surface. Several variations in the metal stack were evaluated to better understand the cause of the failures and to provide a process solution. The prevention of intergranular metal corrosion and subsurface blistering during autoclave testing required a materials change from Al(Si) to Al(Si)(Cu). This change resulted in a reduced corrosion rate and consequently prevented Si contamination due to blistering. The process change resulted in a successful pass through the autoclave testing.

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