Metal Corrosion Products Research Articles

Role of reactive transport in the alteration of vitrified waste packages: the MOS model

The MOS model (acronym coming from the French MOdèle Simplifié) was born from the desire to have a simple tool that can quantify the contribution of the diffusive reactive environment to the alteration of a vitrified nuclear waste package in deep geological disposal conditions. In the model, this environmental contribution consists partly of the ability of iron, metallic casing corrosion products, and argillite to consume silicon, and partly of the brake on diffusive transport provided by silicon through the successive layers of environmental material. It is a modeling tool serving as an intermediary between operational modeling for the calculation of the source term from the glass, mathematically more simple and giving higher upper margins, and models that use geochemistry and transport, giving greater accuracy for the interactions between glass and its environment. The goal of the MOS model is to calculate the possible impact of silicon reactive diffusion on the alteration rate within the different layers of material surrounding nuclear glass. This article lists the simplifying hypotheses on which the MOS is based, presents the digital resolution method for an environment consisting of several successive layers with different reactivity and transport properties, and explains the model’s implementation.

Multi-Technique Assessment of Chelators-Loaded PVA-Borax Gel-like Systems Performance in Cleaning of Stone Contaminated with Copper Corrosion Products.

Currently, one of the most important challenges for the conservation of stone artworks is the removal of metal corrosion products on their surfaces. Traditional cleaning methods, which typically involve the application of aqueous solutions containing chelating agents capable of complexing these metal ions, have shown some weaknesses. These weaknesses become apparent when such methods are applied to statues and other vertical surfaces or when aiming to limit the cleaning process to a specific area with controlled application times. Furthermore, the porosity of the stone surface plays a role concerning the cleaning efficiency. To address these issues, chelating agents can be incorporated into gel-like materials. This study is a proof of concept to evaluate the cleaning efficacy of various gel formulations composed of polyvinyl alcohol (PVA), borax (B), and agarose (AG), loaded with two chelators: ethylenediaminetetraacetic acid (EDTA) and potassium sodium tartrate (PST or Rochelle salt). Three types of carbonate stones (travertine, Lecce stone, and Carrara marble) characterized by different porosities were artificially stained with copper sulphates and treated with the different PVA-B-AG formulations. The effectiveness of the treatment was directly monitored on the stones using a multi-technique approach that included scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and non-invasive portable nuclear magnetic resonance (NMR). Additionally, the rheological properties of the gels were investigated, and the Fourier transform infrared attenuated total reflection spectroscopy (FTIR ATR) was used to analyse the chemical structure of the gel before and after treatment, aiming to understand the changes induced by the cleaning process.

Industrial scale fouling of heat exchangers in isocyanate production

The fouling of a commercial stainless steel (AISI 316L) during the manufacture of polymeric methylene diphenyl diisocyanate (pMDI) has been studied using laboratory‐based fouling apparatus that simulates commercial production conditions. The goal of the work is to understand the mechanisms behind the corrosion and fouling during isocyanate production with a view to improving process efficiency, not only in this process, but also others using similar plant and processes. Steel coupons were exposed to a solution of pMDI and solid amine hydrochloride, with hydrogen chloride gas being bubbled through the reaction cell. A number of different conditions were investigated, the variables being pMDI concentration, HCl gas flow duration, immersion time and temperature. Following the fouling experiments the coupons were removed from the fouling rig, photographed, and examined by XPS and ToF‐SIMS; principal component analysis was used to extend the ToF‐SIMS analysis to identify organic fouling products. The extent of fouling is shown to be relatively insensitive to pMDI concentration, but significantly influenced by continual HCl flow and increased temperature, features which increase the extent of substrate corrosion thought to be a precursor to the fouling process itself. Both XPS and ToF‐SIMS confirm the formation of various nickel chlorides in the corrosion process. Urea and metal corrosion products are found to co‐exist on certain (random) areas of the coupon surface.

Pigments, minerals, and copper-corrosion products: Terahertz continuous wave (THz-CW) spectroscopic characterization of antlerite and atacamite

In this work, the optical properties of atacamite, antlerite and azurite are characterized for the first time by exploiting a high-resolution coherent THz-CW spectrometer in the spectral range 0.1–2.8 THz adopting transmission configuration; the spectral response of atacamite and antlerite is reported for the first time in literature in this frequency range. The absorption spectra of the two copper-based pigments showed the presence of distinct absorption peaks defining their fingerprints. In particular, atacamite presents a peak centered at 2.45 THz and antlerite presents two spectral fingerprints centered at 1.77 and 2.52 THz; the retrieved average refractive index is 1.19 and 1.29, respectively. The absorption spectrum of azurite is in good agreement with previous works in the far infrared region and presents two sharp peaks centered at 1.83 and 2.23 THz with an average value of the refractive index of 1.65. Furthermore, by means of the same technique, it is possible to discriminate and quantify pure components in binary mixtures. This result is of great interest for the identification of pigments and metallic corrosion products, and it demonstrates that THz-CW spectroscopy can open the way to an innovative approach for the Cultural Heritage field.

Plant remains preserved in products of metal corrosion: source of evidence on ancient plant materials and environment from burial contexts

By-products of metal corrosion, when coming into contact with organic matter, have the capacity to preserve it from decay. A pilot study was conducted aiming to explore the potential and limitations of plant remains preserved in by-products of metal corrosion for archaeobotanical research. The organic remains considered come from the surface/immediate proximity of the metal funerary artefacts of two ancient cemeteries—Varna and Messambria, Eastern Bulgaria. Metal corrosion by-products were observed and sampled, under a low magnification stereo microscope. Subsequently, the plant macrofossils recognised were analysed under reflected light and a scanning electron microscope (SEM). Additionally, pollen was extracted from the metal corrosion by-products, using standard acetolysis. The analyses from the graves of both cemeteries allowed identification of textiles and plant fibres, as well as wood (Cornus sp., Pinus sp., Viburnum sp.). At Varna cemetery epidermis fragments of Juncus sp. were recognized, while at Messambria necropolis fruits of almond were found. The pollen analysis from Varna points to use of flowers in the ritual (Daphne tetrads were recorded) and shows a notably open landscape with 77% non-arboreal pollen (NAP). The palynological analysis from the Messambria necropolis revealed the use of flowers in the burial ritual indicated by clusters of Vitis, Cistus and Rosaceae pollen. The surrounding vegetation was dominated by open oak woodland and open habitats (43% NAP) with a strong presence of anthropogenic indicators. The outcome of the study proved to be promising for reconstructing details of the burial rituals including associated plant materials, as well as the surrounding plant habitats during the functioning of the cemeteries.

Potential release of trace metal ions from metallic orthodontic appliances and dental metal implants: A Review of in vitro and in vivo experimental studies

Metallic wear nanoparticles, corrosion products and trace metal ions release from metallic materials, e.g. metallic alloys and pure metals, implanted into the human and animal's body in orthodontic surgery is becoming a major cause for concern. Additionally, metallic wear nanoparticles can themselves undergo a corrosion process contributing to the total level of dissolved metal ions. This review briefly provides an overview of both metallic alloys and pure metals used in implant materials in dental surgery. A short section is dedicated to important biomaterials and their corrosive behavior in both real solutions and various types of media that model human and animal's biological fluids and tissues. The present review gives an overview of analytical methods, techniques and different approaches applied to the measurement of in vivo and in vitro trace metals released into body fluids and tissues from patients and animals carrying metal dental implants and metallic orthodontic appliances. Reference levels of ion concentrations in body fluids and tissues that have been determined by a host of studies are compiled, reviewed and presented in this paper. This review summarizes data, describing the potential toxicity of metal wear debris, free metallic ions and corrosion products release from metallic orthodontic appliances (metal surgical implants) in vivo and in vitro. Finally, a collection of published clinical data on in vivo and in vitro released trace metals from metal dental implants is included.

The synergetic effect of micro-blasting and thermal oxidation on the corrosion performance of Ti6Al4V

Ti6Al4V alloy is widely used for orthopaedic applications due to its excellent osteointegration, good biocompatibility, great strength-to-weight ratio, and comparable elasticity with bone. However, when this alloy is exposed for long-term in the body fluid, it releases the corrosion products of metals and metal oxides. The released particles react with the surrounding tissue and cause an adverse local tissue reaction (ALTR) which leads to pseudotumor formation, and osteolysis (bone degradation). Thus, corrosion is a critical parameter for bio-implants and in this study to minimize corrosion, thermal oxidation was performed on micro-blasted Ti6Al4V surfaces for 24 and 48 h. Surface morphology, phase analysis, surface roughness, and wettability of all types of samples were evaluated using FESEM, EDS, XRD, AFM, and Goniometer. The electrochemical performance was studied in 0.9 wt% NaCl. The combined mechanical and thermal process increases surface roughness and improves the hydrophilic nature of the Ti6Al4V surface by 67 %. The formation of metastable Ti2O3 during micro-blasting and further transformation of anatase and rutile TiO2 during thermal oxidation increases the intensity of anatase and rutile TiO2 formed on the surface and enhances corrosion resistance. Overall, micro-blasting with 48 h thermal oxidation showed 2 times higher corrosion resistance and reduced corrosion rate by almost 50 % as compared with the untreated Ti6Al4V.

Textiles in a Viking Age hoard: Identifying ephemeral traces of textiles in metal corrosion products

This paper presents a novel method and terminology to identify and describe textiles from ephemeral traces in metal corrosion products. Since the 1980s, mineralised textiles (positive and negative casts in Janaway’s terminology) have been an important source of archaeological evidence. A major issue now is the identification of textiles in metal corrosion products when only faint traces remain. These traces no longer appear like textiles and are vulnerable to misinterpretation. Confused with metal dendritic structures or the form of corrosion products themselves, they are often lost through handling or cleaned off through conservation practices. This loss is cumulatively significant. To remedy this issue, this paper defines and characterises the form and structure of ephemeral traces of archaeological textiles through examination of metal corrosion products on a Viking Age hoard from Scotland. It defines a new terminology to supplement Janaway: petal shapes, remnant textile surface, ghost textile surface. The analysis follows an investigative inquiry from assessment to laboratory analysis using a Dinolite portable digital microscope, optical light microscopy with Z stacking and scanning electron microscopy (SEM). The results allow the secure identification of textiles from previously unidentified corrosion features. The method has wide applicability to corroded archaeological metal objects and has the potential to significantly increase the identification of textiles associated with metals and transform current understanding of hoards.

Применение вибрационной галтовки при подготовке поверхностей деталей из алюминиево-магниевых сплавов в условиях мелкосерийного и серийного производства

The tumbling process is considered from the point of view of its technology on the basis of the experimental data obtained in the production workshops of JSC "TsNIRTI im. Academician A.I. Berg". The types of finishing equipment are analyzed taking into account the efficiency of the technological operation of finishing, depending on the material used and processing modes. The optimal modes are determined depending on the processing of parts made of aluminum alloys of the Al–Mg system, taking into account the requirements of regulatory documents [2]. The surface roughness of the base metal should be no more than Ra 10 (Rz 40) – for protective coatings and Ra 1.25 (Rz 6.3) – for solid and electrically insulating anodic oxide coatings. The surface of the parts after machining should be free of a visible layer of lubricant or emulsion, metal chips, burrs, dust and corrosion products without the introduction of particles of foreign material [2].

Analysis of deposits in superheater tubes at coal-fired thermal power plants by Fourier IR spectroscopy

THE PURPOSE. Determination of the qualitative composition of deposits on the inner surface of the superheater tubes of the Aksuskaya GRES and CHPP stations of Aluminum Kazakhstan JSC located in the Republic of Kazakhstan. METHODS. The most modern method of analysis is IR spectrophotometry, which is based on the absorption of IR radiation. Sediment analysis was carried out on an infrared spectrophotometer with Fourier transform of Shimadzu IRAffinity-1S. The peculiarity and justification of using this device is based on the high throughput of optics. A complementary function is a combination with a dynamic digital adjustment system. The DLATGS detector is used as a powerful ceramic radiation source. This detector is highly sensitive and thermally stabilized. RESULTS. As a result of the analysis, it was found that the deposits on the inner surface are represented by metal corrosion products and heat-resistant humus substances. The latter easily pass into steam from boiler water (steam distillation) and settle on the surface of the tubes. Also, mineral substances and silicates are present as impurities, which also pass into steam in a small amount. CONCLUSION. As a result of the analysis of deposits in superheater tubes at the stations of Aksuskaya GRES and CHPP of Aluminum Kazakhstan JSC located in the Republic of Kazakhstan, it was found that corrosion processes are quite intense, therefore corrosion products predominate in the deposits. To reduce the internal wear of the tubes, it is necessary to adjust the VCR, analyze the reagents used, and perform a step-by-step analysis of the coolant at each stage of cleaning.

Taper Material Loss in Total Hip Replacements: Is It Affected by Joint Friction?

Metal debris and corrosion products generated from the taper junctions of modular joint replacements have been recognized as contributors to failure. Therefore, understanding the factors associated with increased taper wear and corrosion is fundamental to improving implant performance. A cohort of 85 large-diameter metal-on-metal heads and cups retrieved at revision surgery, after 10 to 96 months of service, was evaluated. First, metrology was conducted to quantify head taper material loss and implant articular surface wear. Then, joint frictional moments for each retrieved head-and-cup pair were measured during 10 cycles of simulated physiological gait in a biomechanical model. Taper material loss was evaluated for correlations with frictional moments, articular wear, head diameter, head-cup clearance, and time in vivo. Peak resultant frictional moments ranged from 9.1 to 26.3 Nm, averaging 17.3 ± 2.7 Nm. Fretting and corrosion damage during in vivo service resulted in material loss from the head tapers ranging between 0.04 and 25.57 mm3, compared with combined head and cup articular wear of 0.80 to 351.75 mm3 in this cohort. Taper material loss was not correlated with higher frictional moments (R = -0.20 to 0.11, p = 0.07 to 0.81). Higher frictional moments from axial rotation were correlated with higher head and cup wear (R = 0.33, p < 0.01). The correlation between taper material loss and head diameter was weak and did not reach statistical significance (R = 0.20, p = 0.07). Taper material loss was not correlated with nominal head-cup clearance (R = 0.06, p = 0.6). Finally, taper material loss increased significantly over time (R = 0.34, p < 0.01). Despite serious concerns regarding trunnionosis, volumes of head taper wear were generally lower than those of articular surface wear. There was no statistical correlation between taper wear and frictional moments. Therefore, the results suggest that high friction in metal-on-metal implants does not contribute to higher material loss at the head taper, despite high bending moments. The amount of metal debris and corrosion products from taper junctions of the joint arthroplasties, widely recognized as an insidious cause of failure, was not correlated with joint frictional moments. Multiple factors affect taper wear: implant design, material, size, surface finish, and patient weight and activity level. However, in the present cohort, high friction of metal-on-metal total hip replacements likely did not contribute to increased volume of material loss at taper interfaces, despite increased moments at the locations of taper material loss.

Non-Invasive Assessment of PVA-Borax Hydrogel Effectiveness in Removing Metal Corrosion Products on Stones by Portable NMR.

The cleaning of buildings, statues, and artworks composed of stone materials from metal corrosion is an important topic in the cultural heritage field. In this work the cleaning effectiveness of a PVA-PEO-borax hydrogel in removing metal corrosion products from different porosity stones has been assessed by using a multidisciplinary and non-destructive approach based on relaxation times measurement by single-sided portable Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy—Energy Dispersive Spectroscopy (SEM-EDS), and Raman Spectroscopy. To this end, samples of two lithotypes, Travertine and Carrara marble, have been soiled by triggering acidic corrosion of some copper coins in contact with the stone surface. Then, a PVA-PEO-borax hydrogel was used to clean the stone surface. NMR data were collected in untreated, soiled with corrosion products, and hydrogel-cleaned samples. Raman spectroscopy was performed on PVA-PEO-borax hydrogel before and after cleaning of metal corrosion. Furthermore, the characterization of the dirty gel was obtained by SEM-EDS. The combination of NMR, SEM-EDS and Raman results suggests that the mechanism behind the hydrogel cleaning action is to trap heavy metal corrosion products, such as Cu2+ between adjacent boron ions cross-linked with PVA. Moreover, the PVA-PEO-borax hydrogel cleaning effectiveness depends on the stone porosity, being better in Carrara marble compared to Travertine.

Non-Invasive Assessment of PVA-Borax Hydrogel Effectiveness in Removing Metal Corrosion Products on Stones by Portable NMR

Non-Invasive Assessment of PVA-Borax Hydrogel Effectiveness in Removing Metal Corrosion Products on Stones by Portable NMR

Systemic toxicity of metal ions release from specific types of implanted medical devices: Systemic review of clinical studies

There is public concern over the long term systemic health effects of metal released from implanted medical devices that use metal alloys. Systemic toxic side effects have been associated with excessive metal ion release from implants into human biological specimen's circulation, in which cobalt and chromium plays an important role. Cobalt intoxication has become more frequent due to the wide use of metallic medical implants. Despite the technological improvements in replacement metallic medical implants, wear and corrosion products associated with the metal compounds of these implants may result in systemic reactions and toxicities. The current review encompasses a literature of the systemic toxicity studies concerning the effect of metallic wear debris released from wear and corrosion of specific types of implanted medical devices, resulting in a postoperative increase in metal ion levels in bodily fluids and at different organ sites. Release of metallic debris is mainly in the form of particles and ions of different valences, and oxides composed of cobalt and chromium. Toxicological, clinically significant, data regarding "potential hazards" of circulating metals after systemic chronic exposure to the metal ions from metals have been included. This review further highlights some of the clinical features of cobalt toxicity.

Количественная оценка скорости коррозии металлических материалов с помощью конфокальной лазерной сканирующей микроскопии

This study represents an alternative method for quantitative estimation of the corrosion rate of various metallic materials, in particular magnesium and its alloys, using confocal laser scanning microscopy (CLSM). This method makes it possible to obtain not only optical images of the specimen surface, but also accurate 3D height maps which allow a quantitative assessment of many characteristics such as surface profile, damage locality, number and maximum depth of corrosion pits, volume of metal loss and corrosion products. Specific methodological aspects and possibilities of using the CLSM method for the analysis of corrosion damage have been described. The proposed method is based on obtaining 3D images of the surface of specimens after corrosion tests with their subsequent processing and analysis, with the use of original software computer procedures for digital image processing and topographic data arrays. A technique for recording and subsequent analysis of specimens after corrosion tests using CLSM has been developed and tested. The optimal magnification, lens type, scanning step and noise filtering have been determined. The procedure prescribes mounting the test metallic sample into a non-corrosive material to create a stable reference plane surface. The dissolution of the metal at the specimen-mount interface is found to be notably more intensive than in the specimen interior when the conventional metallographic resins are used as the mount. This fact deteriorates the objectivity of the results of corrosion rate measurements. Polyethylene is proposed as the mounting material to minimize this effect. The geometry and the minimum size of the metal sample, providing a reduction in labor contribution for scanning and data processing without loss of accuracy and reliability of the data are established. The values of the uniform corrosion rate of commercially pure magnesium in Ringer's solution using the gravimetric method and the CLSM method showed satisfactory repeatability of measurements.

Corrosion Behaviors of Iron, Chromium, Nickel, Low-Carbon Steel, and Four Types of Stainless Steels in Liquid Antimony-Tin Alloy

Corrosion resistance of metals and alloys toward liquid metals determines the service performances and lifetime of the devices using liquid metals. This paper studies the static corrosion behaviors of iron, chromium, nickel, low carbon steel, and four types of stainless steels (SS410, SS430, SS304, and SS316L) in liquid Sb-Sn at 500°C, aiming to screen corrosion-resistant stainless steel for Li||Sb-Sn liquid metal batteries (LMBs). The corrosion rates of Fe and Ni are 0.94 μm/h and 6.03 μm/h after 160 h measurement, respectively. Cr shows a low corrosion rate of &amp;lt; 0.05 μm/h, which is due to the formation of a relatively stable Cr-Sb layer that may be able to prevent the interdiffusion between the solid substrate and liquid Sb-Sn. Ni has a high corrosion rate because the formed Ni-Sb and Ni-Sn compounds are soluble in the liquid Sb-Sn. The corrosion products of both pure metals and SS can be predicted by thermodynamic and phase diagram analysis. Among the four types of stainless steel, SS430 shows the best corrosion resistance toward liquid Sb-Sn with a corrosion rate of 0.19 μm/h. Therefore, a liquid Sb-Sn resistant material should have a high Cr content and a low Ni content, and this principle is applicable to design metallic materials not only for LMBs but also for other devices using liquid Sb- and Sn-containing liquid metals.

Сооружение комплекса переработки жидких радиоактивных отходов на белоярской АЭС

The tasks of ensuring the safety of the population and the environment during the operation of nuclear facilities are formulated. The necessity of the final isolation of conditioned radioactive waste generated as a result of production activities of enterprises and decommissioning of nuclear facilities is substantiated. Modern technologies for the safe management of liquid radioactive waste are considered. The experience of operation of liquid radioactive waste processing facilities at nuclear power plants is summarized. The capabilities of ion-selective sorption for the reduction of final radioactive product volume and its advantages in comparison with other methods of radioactive waste treatment are given. A description is given of a complex for liquid radioactive waste reprocessing which is being built at the Beloyarsk NPP in order to increase the reliability of operation and environmental protection. The methods chosen for the implementation of the liquid radioactive waste reprocessing program are listed as well as the processing lines forming the facility. The description is presented of a block-module facility of ion-selective treatment designed for the reprocessing of the residuum from the tanks of the liquid radioactive waste storages. Described is the block-module facility for the conditioning of the ion-exchange resins which were utilized for the purification of the residuum and discharged water from cobalt and cesium radionuclides and corrosion products of other transition metals, in order to gain the concentrated non-radioactive saline product and to pack it in the primary containers. A cementation facility is described which is designed for reprocessing of the sludge of radioactive waste from the tanks and vessels of the storages and the sludge of the ion-selective treatment facility by inclusion of radioactive waste into the cement blocks. The measures to prevent emissions into the environment during the operation of the liquid radioactive waste reprocessing complex are described. The data are presented on the systems of static and dynamic barriers preventing the ingress of radionuclides into the environment during the operation of the liquid radioactive waste reprocessing complex. The technical and managerial means are presented intended to protect the barriers and to preserve its efficiency in accordance with the general regulations of nuclear power plants safety ensuring.

Comparison and appraisal of techniques for the determination of material loss from tapered orthopaedic surfaces

This review examines the challenges associated with quantifying material loss at modular junctions. Determination of material loss from retrieved orthopaedic surfaces is regarded as a prerequisite for the evaluation of long-term implant performance. Methods previously adopted to overcome the challenges associated with determining material loss from non-articular surfaces will be presented and discussed in this paper.Total Hip Replacement (THR) is regarded as one of the most successful and cost-effective surgical interventions for the treatment of advanced osteoarthritis. The use of modular components offers surgeons an array of possible implant combinations to intraoperatively optimise range of motion and soft tissue tension. However, the taper interface used to connect modular components has been suggested to contribute to premature implant failure through the release of metal debris and corrosion products. Geometrical and topographical measurement of explanted modular interfaces has been used to correlate multifarious variables with an absolute volumetric value for material loss. To improve modular implant performance, medical device manufacturers have adopted numerous design philosophies, each presenting a unique set of challenges for the measurement of material loss. This review summarises the approaches used in previous studies to overcome these challenges and identifies future work required in this area. This field of research is currently the subject of discussion within standards bodies to create recommended best practices for centres to follow.

The impact of metal pipe materials, corrosion products, and corrosion inhibitors on antibiotic resistance in drinking water distribution systems.

Drinking water distribution systems (DWDS) are unique engineering environments that are important routes for the acquisition and dissemination of antibiotic resistance. Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in drinking water pose risks to human and environmental health. Metals are known stressors that can select for antibiotic resistance. The objective of this review was to assess the state of knowledge regarding the impact of metal pipe materials, corrosion products, and corrosion inhibitors on the prevalence of antibiotic resistance in DWDS. ARGs and mobile genetic elements (MGEs) have been detected in full-scale DWDS in concentrations ranging from ~ 101 to 1010 copies/L. Metal pipe materials can select for bacteria harboring ARGs and metal resistance genes (MRGs) through co-selection processes. Corrosion products that develop in metal drinking water pipes (Cu, Fe, and Pb oxides) may also stimulate antibiotic resistance selection during distribution. Different corrosion inhibitor regimes (phosphates, sodium silicates) may also have impacts on microbial communities and the abundance of resistance genes in DWDS. Research is needed to quantify how engineering decisions related to drinking water infrastructure and corrosion inhibitor practices impact the abundance and distribution of ARG, MRGs, and MGEs in potable water systems. KEY POINTS: • Lack of quantitative measurements of antibiotic and metal resistance genes in drinking water distribution systems. • Pipe materials and corrosion products that develop in pipe scales may impact antibiotic resistance. • Corrosion inhibitors with zinc or phosphate could alter antibiotic resistance. • Management decisions should consider antibiotic resistance ramifications. Graphical abstract.

On the Corrosion Behaviour of Low Modulus Titanium Alloys for Medical Implant Applications: A Review

The corrosion behaviour of new generation titanium alloys (β-type with low modulus) for medical implant applications is of paramount importance due to their possible detrimental effects in the human body such as release of toxic metal ions and corrosion products. In spite of remarkable advances in improving the mechanical properties and reducing the elastic modulus, limited studies have been done on the electrochemical corrosion behaviour of various types of low modulus titanium alloys including the effect of different beta-stabilizer alloying elements. This development should aim for a good balance between mechanical properties, design features, metallurgical aspects and, importantly, corrosion resistance. In this article, we review several significant factors that can influence the corrosion resistance of new-generation titanium alloys such as fabrication process, body electrolyte properties, mechanical treatments, alloying composition, surface passive layer, and constituent phases. The essential factors and their critical features are discussed. The impact of various amounts of α and β phases in the microstructure, their interactions, and their dissolution rates on the surface passive layer and bulk corrosion behaviour are reviewed and discussed in detail. In addition, the importance of different corrosion types for various medical implant applications is addressed in order to specify the significance of every corrosion phenomenon in medical implants.