Metastable Pitting Research Articles

Metastable pitting corrosion behavior of laser powder bed fusion produced Ti6Al4V-Cu in 3.5% NaCl solution

Laser powder bed fusion (LPBF) technology realized the surgical personalized devices. However, LPBF-produced titanium alloys face several limitations, such as obvious metastable pits. This work presented a promising strategy to enhance the corrosion resistance of LPBF-produced Ti6Al4V alloy by the Cu alloying. Compared to the Ti6Al4V alloy, Ti6Al4V-Cu alloy possessed a more protective passive film with stable oxides due to its finer grains. Furthermore, Ti6Al4V-Cu alloy demonstrated superior metastable pitting corrosion resistance in a 3.5 wt% NaCl solution, because Cu substituents effectively consumed the cationic vacancies in the passive film, thus inhibited the nucleation of the metastable pits.

Porosity, roughness, and passive film morphology influence the corrosion behavior of 316L stainless steel manufactured by laser powder bed fusion

The development of additively-manufactured (AM) 316L stainless steel (SS) using laser powder bed fusion (LPBF) has enabled near net shape components from a corrosion-resistant structural material. In this article, we present a multiscale study on the effects of processing parameters on the corrosion behavior of as-printed surfaces of AM 316L SS formed via LPBF. Laser power and scan speed of the LPBF process were varied across the instrument range known to produce parts with >99 % density, and the macroscale corrosion trends were interpreted via microscale and nanoscale measurements of porosity, roughness, microstructure, and chemistry. Porosity and roughness data showed that porosity φ decreased as volumetric energy density Ev increased due to a shift in the pore formation mechanism and that roughness Sq was due to melt track morphology and partially fused powder features. Cross-sectional and plan-view maps of chemistry and work function ϕs revealed an amorphous Mn-silicate phase enriched with Cr and Al that varied in both thickness and density depending on Ev. Finally, the macroscale potentiodynamic polarization experiments under full immersion in quiescent 0.6 M NaCl showed significant differences in breakdown potential Eb and metastable pitting. In general, samples with smaller φ and Sq values and larger ϕs values and homogeneity in the Mn-silicate exhibited larger Eb. The porosity and roughness effects stemmed from an increase to the overall number of initiation sites for pitting, and the oxide phase contributed to passive film breakdown by acting as a crevice former or creating a galvanic couple with the SS.

Microbiologically influenced corrosion behavior of 70/30 Cu-Ni alloy exposed to carbon starvation environments with different aggressiveness: Pitting mechanism induced by Desulfovibrio vulgaris

The present work investigated the microbial-induced pitting behavior of the 70/30 copper-nickel (Cu-Ni) alloy. Unlike the MIC of Cu by Desulfovibrio vulgaris, the alloy exhibited considerable pitting sensitivity and pit nucleation frequency under the 10%, 50%, and 100% carbon source (CS) levels. The metastable pit was more likely to evolve into stable growth in the full-strength medium. Meanwhile, a model was established to explain the alloy pitting mechanism induced by D. vulgaris. New evidence further verified that Cu-Ni alloy MIC was not only ascribed to the biogenic H2S but the electroactive D. vulgaris biofilms via extracellular electron transfer (EET) for energy harvest.

High Potential Inhibition of the 17-4 PH Stainless Steel in the Presence of Nitrate and Evolution of Metastable Pitting

In the present investigation, the potential effect of nitrate ions’ inhibition on pitting corrosion of 17-4 precipitation hardening (PH) stainless steel in different chloride and nitrate concentrations was investigated using potentiostatic and potentiodynamic examinations. Furthermore, metastable pitting was examined in depth to clarify nitrate inhibition. The results demonstrate that adding nitrate as an inhibitor to the chloride-containing solution decreases the metastable pit peak current, stability products, and pit radius. In contrast, no significant difference between metastable pit lifetime was observed in the presence and absence of nitrate in the chloride solution. It was also shown that introducing 17-4 PH stainless steel to the high potential resulted in the repassivation of the surface, even if the nitrate/chloride concentration ratio was less than the critical value needed for nitrate inhibition. Overall, nitrate ions have an inhibition effect in the chloride solution. Especially at very high potential, whether the nitrate concentration was less than the critical value or not, nitrate forces the surface to get repassivated.

Microstructure evolution of lean duplex stainless steel produced by a short process

A short process of direct cold rolling of continuous casting billets following solution treatment is proposed, and the effect of cold-rolled reduction on the microstructure evolution and corrosion resistance of lean duplex stainless steel (LDSS) 2101 is investigated. The results show that when the cold-rolled reduction increased to 50%, the strain-induced martensite (SIM) engulfed the austenite along the annealing twin boundaries (TBs). Furthermore, the galvanic corrosion of the martensite and matrix combined with the decreasing fraction of the low-Σ CSL boundaries results in a significant reduction in corrosion resistance at 50% cold-rolled reduction. Additionally, the majority of metastable pits were generated within the ferrite grains and at the α/γ phase boundaries.

Pitting Corrosion of Mild Steel in Long-Term Contact with Particulate Media in Seawater

Steel infrastructure in contact with particulate media is at risk of failure due to pitting corrosion. For reliability analysis, it is important to understand the progression of pit depth with time and the associated extreme value statistics. An analysis was conducted on an extensive dataset of pit depth observations, made on mild steel coupons buried in different particulate media and immersed in natural Pacific Ocean seawater. It showed that the trends for the deepest pits with time were consistent with the bimodal model, and that pitting was deepest under seawater and increased with particle size when under particulate media. Gumbel plots of the data showed that the deepest pits plotted as a straight line, indicating a good fit. The plots also showed small, regular deviations from this straight line, and these permitted interpretations for pit depths developing in incremental steps. These step sizes were largest for surfaces under seawater and increased with increasing particle size under particulate media. These findings allowed for new conceptual models for the process of pit depth growth under rust and particulate media. They also allow for new insights into metastable pitting for steels. Opportunities for further research are also presented.

Localized corrosion and repassivation behaviors of additively manufactured titanium alloys in simulated biomedical solutions

The localized corrosion behavior of additively manufactured (AM) titanium alloys is studied based on the relation between pitting potentials, the flux of oxygen vacancies in a passive film, and the repassivation rate using potentiodynamic polarization, Mott–Schottky, and an abrading electrode techniques. The relationship between the localized corrosion resistance and the repassivation behaviors of AM titanium alloys was explained by the survival probability constant based upon the point defect model which describe the generated oxygen vacancies and accumulated cation vacancies affect the occurrence of the localized corrosion. Localized corrosion can be initiated by survival pits under sufficient conditions of the breakdown passive films. Survival probability is constant means a quantitative probability value of the transition from metastable pit to stable pit to occur localized corrosion. The higher the survival probability constant of AM titanium alloys, the more difficult repassivation and the easier occurrence of localized corrosion.

MATHEMATICAL MODELING OF THE CORROSION BEHAVIOR OF AUSTENITIC STEELS IN CHLORIDE-CONTAINING ENVIRONMENTS DURING THE OPERATION OF PLATE HEAT EXCHANGERS

Purpose. It consists in the development of mathematical models that describe the dependence of the critical pitting temperatures of AISI 304, 08X18N10, AISI 321, 12X18N10T steels in model circulating waters with pH 4...8 and chloride concentration from 350 to 600 mg/l.
 Research methods. The developed mathematical models are based on linear square regression and a neural network of direct signal propagation for a reduced set of features.
 Results. It was established that the critical pitting temperatures of the studied austenitic chrome-nickel steels increase with an increase in the pH of the circulating water, the number of oxides up to 3.95 μm in size, the average distance between titanium nitrides, the Cr content and a decrease in the concentration of chlorides in the circulating water, the average distance between oxides, and the austenite average grain diameter.
 Scientific novelty. Based on the established relationships between the critical pitting temperatures of corrosion-resistant steels AISI 304, 08Х18Н10, AISI 321, 12Х18Н10Т, their chemical composition within the standard and structural heterogeneity, the mechanisms of their influence on the pitting resistance of these structural materials in circulating chloride-containing waters have been developed. It was established that metastable pitting is formed in a solid solution of austenite of steels around oxides with a size of 1,98...3,95 microns and repassivates before reaching critical dimensions of about 5 microns, which contributes to the growth of their pitting resistance in reversible chloride-containing environments.
 Practical value. The developed mathematical models are proposed to be used for the selection of optimal melts of austenitic chrome-nickel steels for the production of heat exchangers and prediction of their pitting resistance during their operation in circulating waters. The processes contributing to the perforation of heat transfer elements of heat exchangers during their operation have been identified.

Comparison of Metastable Pitting Behavior of Austenitic and Duplex Stainless Steels under U‐Bending Deformation

The metastable pitting behavior of austenitic stainless steel (304 SS) and duplex stainless steel (2205 DSS) under U‐bending deformation is comparatively investigated. This study highlights the effects of differences in inclusions and matrix between 304 SS and 2205 DSS with regard to the metastable pitting behavior under tensile and compressive deformation. The results show that the pit initiation frequency of 304 SS increases in the order: tensile < as‐received < compressive; in contrast, the initiation frequency of 2205 DSS increases in the order: as‐received < tensile < compressive. In addition, tensile and compressive deformation change the preferential initiation sites of metastable pitting in 2205 DSS. It is proposed that the types of transient signals can be comprehensively and objectively distinguished by the two parameters (t g/t rep) and [(I p/Q g):(I p/Q rep)]. The correlation relationship between transient signals and pitting morphologies is clarified by cluster analysis. Both tensile and compressive deformations promote the growth of a few metastable pits, thus increasing the transition probability from metastability to stability. Overall, both tensile and compressive deformations are detrimental to the pitting corrosion resistance of the experimental steels.

Effect of HSO3 − and alternating current on corrosion behaviour and mechanism of CoCrFeNi HEA in a simulated marine environment

ABSTRACT The corrosion behavior and mechanism of CoCrFeNi HEA under AC application were systematically studied in 3.5 wt.% NaCl solution containing different concentrations of NaHSO3. The results showed that the existence of HSO3 − increased the defect density within the passivation film on the surface of the HEA. With the increase of HSO3 − concentration, the passivation zone became narrow, Ep shifted negatively, and ip increased, which indicated that the corrosion resistance of the HEA was weakened. When the HSO3 − concentration increased to 0.1 M, a clear transition zone appeared, indicating that the increase in concentration reduced the passivity of the HEA, and its corrosion behavior changed from the typical passivation characteristic to the activation state with increasing iAC. The imposed AC promoted the nucleation of metastable pitting, which was indicated by a remarkable increase in the average pitting number density (Navg) from 5 to 17 mm−2 with the enhancement of iAC.

Response of the Metastable Pitting Corrosion of Laser Powder Bed Fusion Produced Ti–6Al–4V to H+ Concentration Changes

There is limited research on metastable pitting corrosion in an acidic environment, and acid is a major challenge for material corrosion. Therefore, this work investigated the metastable pitting corrosion of laser powder bed fusion (LPBF)-produced Ti–6Al–4V, in Hank’s solution, at different pH values (pH = 3, 5, and 7). This work investigated the effect of acid on the characteristics of passive films, as well as the change in metastable pitting behavior. Based on the results of electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS), the passive film will be inhibited and dissolved under the influence of H+. The higher the concentration of H+, the thinner the passive film. Potentiodynamic polarization tests reveal that LPBFed Ti–6Al–4V in Hank’s solution, at pH 3, has more obvious metastable pitting corrosion. This is because the higher the H+ concentration, the more Cl- is adsorbed on the surface of the passive film, which is prone to generate soluble chlorides by competitive adsorption with oxygen atoms and thus develop into metastable pitting corrosion.

Unveiling the significant contribution of matrix elements to passivation behaviour and corrosion resistance of alloys by modelling approach

This work elaborated the significant effect of matrix elements (Fe and Ni) on passivation behaviour and corrosion resistance of alloys containing same Cr content by experimental and modelling studies. Results indicated that each species of passive film deposited earlier on Febase alloy than on Nibase alloy. Moreover, the nucleation and growth rates of Cr-oxide/hydroxide were similar on both alloys, but those of Fe-oxides were much higher on Febase alloy. These agreed well with the higher thickening rate and thickness but lower Cr2O3 proportion of passive film on Febase alloy, which induced its higher metastable pitting sensitivity and lower corrosion resistance.

Development of an In Situ Micro-Corrosion Cell for the Investigation of Pitting Corrosion on Austenitic and Ferritic Stainless Steels

In order to investigate the electrochemical pitting corrosion in more detail, a micro-corrosion cell was developed, allowing real-time in situ optical observations of steel surfaces in direct correlation with electrochemical measurement results. In this study, the austenitic 1.4301–X5CrNi18-10 and the ferritic 1.4016–X6Cr17 stainless steel grades were examined in electrolytes containing chloride ions. The micro-corrosion cell revealed a stable pitting corrosion of the ferritic 1.4016 and metastable pitting corrosion of the austenitic 1.4301. The pits were characterized by means of scanning electron microscopy (SEM) and atomic force microscopy (AFM) in detail. A clear correlation between current peaks in the current density-potential curve and the growth of many small pits on the test surface was established and was identified as metastable pit growth. In general, the pitting corrosion potential increased as the diameter of the test surface decreased for both stainless steels. In contrast to the complex precipitates of 1.4301, chromium precipitates with a significantly higher amount was detected on the entire surface of the 1.4016. The corrosion initiation was identified at the interface between the precipitates and the base material for both stainless steels. By comparing both materials, the ferritic 1.4016 had a lower pitting corrosion potential than the austenitic 1.4301 under all test conditions.

Revealing the Corrosion Resistance of 316 L Stainless Steel by an In Situ Grown Nano Oxide Film.

It is widely accepted that the corrosion resistance of stainless steel originates from a compact Cr2O3 layer in the native passive film that serves as a barrier to aggressive ions. However, this suggestion has been questioned by some researchers. They believe that protectiveness might be related to the film recovery. Herein, the pitting development of bare 316 L stainless steel was compared with a corrosion-resistance enhanced steel obtained by tuning the native passive film of the alloy. Statistical software was employed for tracing the size and number of pits on the alloy surface. The statistical results for 12 weeks in 1 M sodium chloride solution (80 °C) revealed that there was a crossover in the growing rates of stable pits (diameter > 9 µm) between the bare alloy and the film-enhanced one. Stable pits on bare 316 L occurred early but showed a comparatively slow increase in the following weeks, demonstrating that self-repairability of metastable pits rather than impermeability of the native passive film plays the key role in the early stage of pitting corrosion.

Effect of alloying element content on anaerobic microbiologically influenced corrosion sensitivity of stainless steels in enriched artificial seawater

Stainless steels (SS) are not immune to microbiologically influenced corrosion (MIC) especially in the presence of sulfate reducing bacteria (SRB). It is necessary to study the influence of alloying elements on the MIC. SRB MIC behaviors of four stainless steels (2205 SS, 316L SS, 304 SS, and 410 SS), with different alloying element compositions were compared after 14 days of incubation at 37°C in enriched artificial seawater inoculated with Desulfovibrio sp. The sessile cell sequence was 410 SS > 316L SS > 304 SS > 2205 SS, inversely proportional to Cr content. The uniform corrosion rate (based on weight loss) sequence was 410 SS > 304 SS > 316L SS > 2205 SS, which matches the pitting resistance equivalent number (PREN) sequence inversely. 410 SS with the lowest Cr and Mo contents suffered the most severe pitting, with pit depth of 35 μm and weight loss of 0.75 mg/cm2 (0.91 mm/a pitting rate and 25 μm/a uniform corrosion rate). The other three stainless steels with higher Cr and Mo contents suffered only metastable pits. The semiconductor characteristics and the re-passivation abilities of the passive films were found to be affected by Cr and Mo contents.

Microbe-induced pitting of Fe-based amorphous coating

It is well known that Fe-based amorphous coatings demonstrate excellent performance against marine corrosion, but the corrosion resistance is significantly reduced in the presence of ocean-microbes. However, the mechanism of microbe-induced corrosion, named as microbiologically influenced corrosion (MIC), has yet to be understood. In this paper, the MIC mechanism of an Fe-based amorphous coating (with the composition of Fe43.7Co7.3Cr14.7Mo12.6C15.5B4.3Y1.9) in the presence of Pseudomonas aeruginosa (one of the typical ocean-microbes) was elaborately investigated by electrochemical impedance spectroscopy (EIS), electrochemical noise analysis (EN), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The electrochemical results show that P. aeruginosa reduced the corrosion resistance of the amorphous coating, manifested by the lower impedance values and higher metastable pitting initiation rate compared to those in a sterile medium. XPS analysis indicates the enrichment of soluble high-valent metal oxides in the passive film formed in the P. aeruginosa medium. In addition, TEM observation reveals pitting initiated exactly beneath P. aeruginosa cells, rather than defect regions (i.e., intersplat) as expected. In the pitting region, a thick biofilm was formed, which resulted in thinning of the underlying passive film. Based on these results, an MIC mechanism based on the inward extracellular electron transfer (EET) effect was proposed, and a potential strategy to relieve MIC was examined.

Effect of heat treatments on metastable pitting of 316L stainless steel fabricated by selective laser melting

Effect of heat treatments on metastable pitting of 316L stainless steel fabricated by selective laser melting (SLM) was studied by scanning electron microscopy, potentiodynamic polarization, electrochemical noise (EN) and transient analysis techniques. The results show that the selective laser melted (SLMed) 316L stainless steel was composed of honeycomb cells with different orientations, and a small number of lack-of-fusion (LOF) pores were randomly distributed. After heat treatment, the honeycomb-like cellular structure transformed into austenite structure, and the non-metallic inclusions coarsened and grew. Non-metallic inclusions can be divided into two types according to the composition difference, one was manganese silicate enriched by Mn, Si and O and the other was MnS coexisted with the manganese silicate. The potentiodynamic polarization results show that the pitting potential of SLMed 316L stainless steel decreased after heat treatment. During the EN tests, three kinds of current transient were found, which corresponded to the metastable pitting initiated by the manganese silicate oxide inclusions, MnS coexisted with the manganese silicate and pore defects, respectively. Statistical analysis results of the transient signals show that the heat treatment reduced the nucleation rate of metastable pitting, and increased the transient amplitude, pit radius and pit stability product. The decreased pitting performance after heat treatment can be attributed to the low pit growth resistance.

Susceptibility to Pitting and Environmentally Assisted Cracking of 17-4PH Martensitic Stainless Steel Produced by Laser Beam Melting.

Materials produced by additive manufacturing (AM) often have different microstructures from those obtained using conventional metallurgy (CM), which can have significant impacts on the materials’ durability, and in particular, resistance to corrosion. In this study, we were concerned with the susceptibility to pitting and environmentally assisted cracking (EAC) of 17-4PH martensitic stainless steel (MSS). We focused on the evolution from pitting to EAC, and the behaviour of MSS produced by AM was compared with that of its CM counterpart. Potentiodynamic polarisation tests were combined with chronoamperometry measurements performed without and with mechanical loading to study both stable and metastable pitting and the influence of stress on these processes. EAC tests were carried out and combined with observations of fracture surfaces. MSS produced by AM was more resistant to pit initiation due to fewer and finer NbC particles. However, the propagation kinetics of stable pits were higher for this MSS due to a higher amount of reversed austenite. The stress was found to stabilise the metastable pits and to accelerate the propagation of stable pits, which resulted in an increased susceptibility to EAC of the MSS produced by AM. These results clearly highlighted the fact that the reversed austenite amount has to be perfectly controlled in AM processes.

Electrochemical Assessment of Galvanized Steel Corrosion in Alkaline Sulfate Solution

Corrosion of steel prestressing strand in bonded post-tensioned bridge tendons have been associated with elevated concentrations of sulfate ions in deficient grout that can develop due to grout segregation [1]. Previous research indicated that the early presence of elevated sulfate ion concentration in the deficient grout in contact with the embedded steel can impair steel passivity. Metastable pitting was observed for steel in saturated calcium hydroxide solutions with sulfate ion concentrations greater than 1,300 ppm and pitting was observed in solutions above 20,000 ppm [2-4]. In addition to steel strand corrosion, galvanized steel ducts in direct contact with the deficient grout with elevated sulfate ion concentrations were also observed to have severe localized corrosion [1]. Galvanized steel in alkaline solutions, such as in cement pore water, have been characterized to have greater resistance to chloride-induced corrosion with chloride threshold concentrations as much as 2.5 times greater than carbon steel [5]. Information relating to sulfate concentrations is less available. Electrochemical testing including the electrochemical noise (EN) technique was conducted to identify the role of early sulfate ion presence on corrosion of galvanized steel.EN provides a test method to assess the corrosion modality without the influence of an external excitation that can affect the electrode surface and electrolyte chemistry (such as metal oxidation and oxygen reduction) [6-7]. The testing aims to identify the corrosion mitigation characteristics of the galvanized steel such as zinc activity and protective barrier surface oxide layers in presence of sulfate ions as well as combined cases with chloride ion contamination below reported threshold concentrations for galvanized steel. In the testing here, steel specimen were exposed to alkaline solutions simulating pore solutions with pH 12.6 with varying sodium sulfate levels and sodium chloride. Supplemental electrochemical experiments included the steady-state condition (open circuit potential, linear polarization test, and electrochemical impedance spectroscopy). References K. Lau, and I. Lasa. "Corrosion of prestress and post-tension reinforced-concrete bridges." Corrosion of steel in concrete structures. Woodhead Publishing, 2016. 37-57. DOI: https://doi.org/10.1016/B978-1-78242-381-2.00003-1.S. Permeh, K. K . Krishna Vigneshwaran, K.Lau., and I.Lasa. “Corrosion of Post-Tensioned Tendons with Deficient Grout. Part 3: Segregated Grout with Elevated Sulfate and Vestigial Chloride Content.” Corrosion 75 (2019) pp.848-864.S. Permeh, K. Lau, M. Duncan, and R. Simmons. “Initiation of localized steel corrosion in alkaline sulfate solution.” Materials and Structures, 54 (2021), pp.1-17.S. Permeh, K. Lau, M. Duncan, and R. Simmons. “Identification of steel corrosion in alkaline sulfate solution by electrochemical noise.” Materials and Corrosion, 72(2021), pp.1456-1467.S. Yeomans. Galvanized steel reinforcement in concrete. Elsevier, 2004.S. Permeh, and K. Lau. "Electrochemical Behavior of Steel in Alkaline Sulfate Solutions with Low Level Chloride Concentrations." ECS Meeting s. No. 10. IOP Publishing, 2021.K. Lau, S. Permeh. “Assessment of durability and zinc activity of zinc-rich primer coatings by electrochemical noise technique.” Progress in Organic Coatings, 167(2022): 106840.

Exposure Aging of Passive Films on Multi-Principal Element Alloys and Ramifications Towards Local Corrosion Resistance

Both highly engineered legacy and emerging alloys lack information on the precise attributes of protective passive films especially after long-time exposures when it really matters. Relevant field exposure periods are nearly infinite in time but both accelerated testing and high-fidelity experiments are often very short term in duration. Recent studies have explored passivation and protection of a number of different MPEAs connecting oxide chemistry to corrosion electrochemistry but most reports are after reality brief exposure periods.The goals of this work are to (a) review the nature of passive films (i.e., solid solution oxides, phase separated single element oxides, and/or complex oxides) and (b) determine the effect of exposure aging on the evolution of oxide features such as composition, structure, phase separation and physical attributes such as thickness in MPEAs; and to correlate these features with both protectiveness in the passive range and local corrosion resistance. Furthermore, we aim to understand what factors limit beneficial alloying element enrichment in the oxide, and further insights on potential third element effects.The focus of the current work extends from the solid solution Ni-22Cr, Ni-22Cr-6Mo, and Ni-22Cr-6Mo-3W family to a variety of emerging MPEAs containing “d-block” elements. AC and DC electrochemistry during potential sweeps and potential step passivation studies were conducted in 0.1 M NaCl pH 4 (HCl) as well as other solutions in the passive range. Exposure and high-fidelity characterizations were investigated over 10 s to 10 days at select potentials.Improvements in passive films protectiveness were correlated with the enrichment of certain elements and depletion of others. Mn oxides were found to be detrimental when formed over the long term in the outer layer of oxides on MPEAs. The most corrosion-resistant alloys possess passivating films that are efficacious not only just after formation, but that self-heal as well as improve over long exposure times as evident from impedance spectroscopy and metastable pitting resistance. Such alloys were observed to be the most resistant when interrogated for local corrosion compared to inferior alloys whose impedance response degraded over time as the passive film evolved. The latter alloys eventually arrived at conditions susceptible to local corrosion. Time-potential-transformation diagrams based on long-term exposures in Cl- followed by high fidelity characterization is suggested to be an approach to improve scientific understanding of long-term passive-protection features relevant to chloride exposures.This work was supported as part of the Center of Performance and Design of Nuclear Waste Forms and Containers, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award # DE-SC0016584; the Office of Naval Research under MURI ONR N00014-16-1-2280 and N00014-19-1-2420.