Chemical Corrosion of Lead-Iron Phosphate Glass

1987 ◽  
Vol 112 ◽  
Author(s):  
Werner Lutze ◽  
P. Schubert
Keyword(s):  
Corrosion Rate ◽  
Dissolution Kinetics ◽  
Iron Phosphate ◽  
Corrosion Mechanism ◽  
Chemical Corrosion ◽  
Total Mass Loss ◽  
Glass Corrosion ◽  
Activity Measurements ◽  
Doped Glasses ◽  
In The Beginning

AbstractThis study provides experimental data on the corrosion of lead-iron phosphate (LIP) glass (6.4 wt% LWR waste loading) and the first comparison with the dissolution kinetics of borosilicate (BS) nuclear waste glass (all experiments at 90°C). Based on previous experiments the hypothesis was made that the alteration phenomena and the corrosion mechanism are analogous to what is known for BS glasses. The corrosion rate was found to be constant, 0.06gm−2d−1, at high flow rates (MCC 5 type test), based on total mass loss and on ion conductivity measurements in the leachate. In an MCC 1 type experiment, doped glasses (32p, 210Pb and 137Cs, respectively) were corroded and the release of activity into solution monitored. The release rates were 0.05gm−2 d−1 in the beginning, but decreased drastically when the solution became saturated with respect to Pb(OH)2 and Pb3 (PO4)2. Glass corrosion continued at a low rate as indicated by Cs activity measurements. The higher chemical durability of the LIP glass vs. BS glasses in DI water is a result of a smaller initial corrosion rate (10 to 10O×) and the fact that the saturation concentration is lower for LIP glass, i. e. it takes less dissolved glass (10 to 50×) to reach saturation than in the case of BS glass.

Unique Autoclave Stress Induced Failure Mechanism

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.

Enhancement of Borosilicate Glass Dissolution by Silica Sorption and Diffusion in Compacted Bentonite: A Model Study.

1990 ◽  
Vol 212 ◽  
Author(s):  
Enzo Curti ◽  
P. A. Smith
Keyword(s):  
Corrosion Rate ◽  
Acid Concentration ◽  
Silicic Acid ◽  
Computer Code ◽  
Glass Block ◽  
Concentration Gradients ◽  
Compacted Bentonite ◽  
Glass Corrosion ◽  
Model Study ◽  
Average Corrosion Rate

ABSTRACTExperimental evidence indicates that glass corrosion rates decrease proportionally with the increase of silicic acid concentration in the solution contacting the glass surface. A minimum corrosion rate (Rsat) is reached when the solution becomes saturated with respect to an unidentified amorphous siliceous compound. In a repository where the vitrified waste form is surrounded by compacted bentonite, the silica dissolved from the glass will diffuse into the pore solution and concentration gradients will be established throughout the backfill material. The silicic acid concentration at the glass-bentonite interface, and thus the glass corrosion rate, will then be diffusion controlled. Moreover, experimental work suggests that significant sorption of silica by clay minerals in bentonite may accelerate glass corrosion.A model describing glass corrosion coupled with diffusive transport and sorption of silica in bentonite has been developed and incorporated in a FORTRAN computer code (GLADIS). The model assumes: (a) a linear isotherm for the sorption of silica (KD), (b) time and space invariant pH, temperature and ionic strength, (c) proportionality between the quantity of silica precipitated and the amount of glass dissolved and (d) cylindrical geometry. Preliminary calculations with a particular parameter set at 90°C, assuming no silica sorption on the bentonite, indicate for an unfractured glass block that a stationary state is rapidly reached in which the silica concentration at the glass-bentonite interface is lower than the saturation concentration. This implies that the glass corrodes at a more rapid rate than Rsat (RsS ∼ 8 Rsat) If moderate silica sorption is assumed (KD = 0.5 m3 kg−1), the attainment of stationary conditions is delayed by the removal of silicic acid from solution, and the average corrosion rate is further increased by a factor ∼ 2.

scholarly journals Wear and Corrosion of Wrought A6061 Aluminium Alloy in DOT3 Brake Fluid

2018 ◽  
Vol 7 (2.14) ◽  
pp. 512 ◽  
Author(s):  
Olawale Ajibola ◽  
Oladeji Ige ◽  
Peter Olubambi
Keyword(s):  
Corrosion Rate ◽  
Test Method ◽  
Alloy Sample ◽  
Corrosive Media ◽  
Chemical Corrosion ◽  
Brake Fluid ◽  
Wear And Corrosion ◽  
Cast Specimen ◽  
Fluid Environment ◽  
A6061 Alloy

The twofold impact of wear and corrosion on wrought A6061 alloy in hydraulic DOT3 brake fluid environment was studied. The wear studies were performed on the samples using a developed wear-jig. Weight loss corrosion test method was used to determine the corrosion rate of the wrought A6061 alloy samples immersed in the brake fluid for a total of 1680 hours. From the results of wear tests carried out on the A6061 alloy sample with brake oil, the highest wear value of 5.24x10-7 mg/mm2/cycle (approx.) was obtained from 6 N (approx) force after 130 minutes. The wrought A6061 alloy material demonstrated the highest corrosion rates nearly 3.0 x10-2 mg/mm2/yr within the early 168 hours of immersion in brake fluid. The result is practically lower than the corrosion rate of cast specimen in DOT3 brake oil or some other alloys immersed in other corrosive media that were previously reported in the literature. The results show that small amount of chemical corrosion is sufficient to cause and accelerate mechanical wear of the material in usage.

Effect of nickel content in the corrosion process of TiC/Cu-Ni composites immersed in synthetic seawater

MRS Advances ◽  
2019 ◽  
Vol 4 (63) ◽  
pp. 3475-3484
Author(s):  
Miguel A. Téllez-Villaseñor ◽  
Carlos A. León Patino ◽  
Ricardo Galván Martínez ◽  
Ena A. Aguilar Reyes
Keyword(s):  
Corrosion Rate ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Nickel Content ◽  
Corrosion Mechanism ◽  
Composite Surface ◽  
Synthetic Seawater ◽  
Ni Content ◽  
The Matrix ◽  
Static Conditions

ABSTRACTThe work presents an electrochemical study of the corrosion behaviour of two TiC/Cu-Ni metal matrix composites with a content of 10 and 20 wt.% Ni immersed in synthetic seawater. The composites were synthesized by a capillary infiltration technique, obtaining dense materials TiC/Cu-10Ni and TiC/Cu-20 Ni with a residual porosity of 1.8 and 1.7%, respectively. The corrosion rate (CR) was evaluated from the techniques of polarization curves (PC), linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS). Electrochemical measurements were carried out under static conditions, ambient temperature and atmospheric pressure at 24 hours exposure in the electrolytic medium. The corrosion rate is affected by the Ni content in the matrix, with less corrosion in the composite with a higher Ni content. The higher content of Ni in the Cu-Ni alloy provides higher passivation and stability to the corrosion products film that are absorbed on the composite surface. Microscopic examination (SEM) showed a characteristic morphology of a corrosion mechanism of the localized type (pits and crevices) generated by a differential aeration, where the TiC/Cu-10Ni composite showed greater degradation.

Effect of Vanadium Addition to Aluminum and Aluminum Grain Refined by Titanium on their Chemical Corrosion Rate in Acidic Solution, HCL, at Different Temperatures

2012 ◽  
Vol 510-511 ◽  
pp. 481-486
Author(s):  
A.I.O. Zaid ◽  
G.T.A. Allawi ◽  
A. Al-Haj-Ali
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Acidic Solution ◽  
Chemical Corrosion ◽  
Different Temperatures

The paper presents the effect of vanadium addition to aluminum and aluminum grain refined by titanium on the micron level, in the range from 0.005 wt % to 0.236 wt %, on their corrosion resistance in acidic solution, HCl, at three different temperatures namely: 25 °C, 40 °C and 60 °C. It was found that the corrosion rate was slightly increased by the addition of any percentage of vanadium at 25 °C. Furthermore, it was found that the corrosion rate increased with the increase of temperature at any percentage of vanadium addition in the case of both aluminum and aluminum grain refined by titanium. However it was found that addition of vanadium at any percentage to either aluminum or aluminum+ titanium, resulted in decrease of the corrosion rate i.e. improvement in their corrosion resistance in acidic solution at 40 °C and 60 °C. The maximum achieved reduction in corrosion rate was 77 % at 40 °C and 0.148 wt % vanadium addition.

On Comparison between Reinforcement Electricity Accelerated Corrosion and Natural Corrosion of Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 676-679 ◽  
Author(s):  
Sen Li ◽  
Jun Yin Yan ◽  
Xiao Gang Wang
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Rate ◽  
Experimental Research ◽  
Comparative Research ◽  
Corrosion Process ◽  
Common Method ◽  
Corrosion Mechanism ◽  
Accelerated Corrosion ◽  
Electric Flux ◽  
Natural Corrosion

Electricity accelerated corrosion is a common method to obtain corroded reinforced concrete specimens in current experimental research, and it has some relevance and differences with natural corrosion. The paper undertakes a detailed comparative research on the relevance and differences of the two corrosion conditions from the corrosion mechanism, the corrosion process, the corrosion rate, the electric flux and corrosion features, and this provide a better understanding of the research achievements based on accelerated corrosion.

Study on the FRP Tendons in Acid Erosion Test of the Durability

2013 ◽  
Vol 706-708 ◽  
pp. 571-574
Author(s):  
Yun Feng Zhang ◽  
Fei Fei Han ◽  
De Wang Zhao ◽  
Shuai Shao
Keyword(s):  
Resin Matrix ◽  
Corrosion Mechanism ◽  
Reinforcement Corrosion ◽  
Fiber Reinforced ◽  
Thermoplastic Resin ◽  
Durability Test ◽  
Chemical Corrosion ◽  
Corrosive Effect ◽  
Resin Matrix Composite ◽  
Frp Bars

Abstract：In this paper,HCI solution in the chemical corrosion tests carried out in room temperature,measured mass loss of CFRP tendons. After extraction and analysis, preliminary search the FRP reinforcement corrosion mechanism under acid erosion. The tensile test is done at 60d and 120d,respectively. Determination of the tensile strength of CFRP tendons. The experimental analysis of the data collected, identify the law of CFRP reinforcement corrosion. Fiber reinforced composite material (Fiber Reinforced Polymer, of FRP ) is a continuous non-metallic fibers and fabric reinforced thermosetting or thermoplastic resin matrix composite made of a new material . Fibers and resin matrix composed of FRP bars under normal circumstances is not easy to rust, but in recent years, the study found that acid salt , moisture , UV , temperature and other environmental conditions on the long-term performance of FRP bars have a certain impact[3-5]. By CFRP tendons under acidic corrosion durability test study reveals CFRP tendons under the corrosive effect of the variation of the quality and strength . Can provide a theoretical basis for CFRP tendons durability design , to provide theoretical guidance to improve the efficiency of the FRP bars in harsh conditions .

scholarly journals Laboratory Testing of Waste Glass Aqueous Corrosion; Effects of Experimental Parameters

1993 ◽  
Vol 333 ◽  
Author(s):  
W.L. Ebert ◽  
J.J. Mazer
Keyword(s):  
Ion Exchange ◽  
Corrosion Rate ◽  
Laboratory Tests ◽  
Water Diffusion ◽  
Waste Glass ◽  
Solution Chemistry ◽  
Exchange Reactions ◽  
Glass Corrosion ◽  
Hydrolysis Reactions

ABSTRACTA literature survey has been performed to assess the effects of the temperature, glass surface area/leachate volume ratio, leachant composition, leachant flow rate, and glass composition (actual radioactive vs. simulated glass) used in laboratory tests on the measured glass reaction rate. The effects of these parameters must be accounted for in mechanistic models used to project glass durability over long times. Test parameters can also be used to highlight particular processes in laboratory tests. Waste glass corrosion results as water diffusion, ion exchange, and hydrolysis reactions occur simultaneously to devitrify the glass and release soluble glass components into solution. The rates of these processes are interrelated by the effects of the solution chemistry and glass alteration phases on each process, and the dominant (fastest) process may change as the reaction progresses. Transport of components from the release sites into solution may also affect the observed corrosion rate. The reaction temperature will affect the rate of each process, while other parameters will affect the solution chemistry and the particular processes that are observed during the test. The early stages of corrosion will be observed under test conditions which maintain dilute leachates and the later stages will be observed under conditions that generate more concentrated leachate solutions. Typically, water diffusion and ion exchange reactions dominate the observed glass corrosion in dilute solutions, while hydrolysis reactions are dominant in more concentrated solutions. Which process controls the long-term glass corrosion is not fully understood, and the long-term corrosion rate may be either transport- or reaction-limited.

Effect of Temperature and H2S Concentration on Corrosion of X52 Pipeline Steel in Acidic Solutions

2013 ◽  
Vol 743-744 ◽  
pp. 589-596 ◽  
Author(s):  
Meng Liu ◽  
Jian Qiu Wang ◽  
Wei Ke
Keyword(s):  
Corrosion Rate ◽  
Pipeline Steel ◽  
Corrosion Products ◽  
Effect Of Temperature ◽  
Corrosion Mechanism ◽  
General Corrosion ◽  
Ferrous Sulfide ◽  
Immersion Corrosion ◽  
Different Temperatures ◽  
Diffraction Patterns

The corrosion behavior of X52 pipeline steel in H2S solutions was investigated through immersion corrosion test which was carried out in a high temperature and high pressure autoclave at different temperatures and H2S concentrations. General corrosion rates were calculated based on the weight loss of samples. The morphology and the chemical composition of the corrosion products were obtained by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The crystal structure of corrosion products was analyzed by X-Ray diffraction patterns (XRD). The corrosion products consisted mainly of the sulfide compounds (mackinawite, cubic ferrous sulfide, troilite and pyrrhotite). The corrosion products included two layers: the inner iron-rich layer and the outer sulfur-rich layer. Under H2S concentrations of 27g/L, the corrosion rate increased with the increase of temperature up to 90°C and then decreased at 120°C, finaly increased again. The corrosion rate first increased with H2S concentrations then decreased at 120°C. The structure and stability of the corrosion products due to different corrosion mechanism had a major impact on the corrosion rate. The corrosion resistance of the corrosion products increased as follows: mackinawite < cubic ferrous sulfide < troilite < pyrrhotite.

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