Metal Deposition Research Articles

Combination effects of laser heating and water cooling on the repair performance of Hastelloy C-276 by underwater laser direct metal deposition

The Ni-based Hastelloy C-276 was repaired by in-air and underwater laser direct metal deposition (in-air DMD and UDMD) with four gradient cooling rates (in-air DMD, in-air DMD with interlayer cooling, UDMD and UDMD with each layer re-covered by water). The microstructure and mechanical properties of repaired samples were systematically characterized with respect to the cooling rates. All samples presented good metallurgical bonding and columnar dendrites with epitaxial growth. The underwater environment had a more pronounced acceleration effect on the cooling rate compared to interlayer cooling. The rapid cooling induced intense thermal cycling, resulting in increased dislocation density and grain refinement with primary dendrite arm spacing (PDAS) diminishing from 5.30 to 3.21 μm. Accelerated cooling rate contributed to precipitation of massive M6C carbides. Carbides coarsened (sizes from 257 to 354 nm) and exhibited a reduced content as cooling rate slowed down due to intrinsic heat treatment (IHT). The residual water film in UDMD repair promoted oxide formation. Samples with increased cooling rates exhibited superior mechanical performance. The improved microhardness, tensile and impact properties were primarily attributed to the enhanced fine grain strengthening and Orowan strengthening facilitated via reduced grain size, increased dislocation density and carbide content. Quantities of large-size carbides were detrimental to tensile and impact properties as displayed in the in-air DMD sample with interlayer cooling (carbide size of 341 μm). The study could serve as a reference for in-situ restoration in deep-water environments.

MALDI target functionalization with deposited thin films of lanthanum stearate – An efficient tool for in situ enrichment of human globin adducts of chlorinated organic compounds

“Lab-on-a-plate” methodology encapsulates a number of different approaches aimed to shorten extensive sample processing for matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis. Lately, we have proposed two approaches to the enrichment of chlorine-containing adducts of human globin (HHb) in a “lab-on-a-plate” format based on different techniques for the sorbent application to MALDI target spots: (i) droplet-free electrospraying of metal oxide nanoparticles and (ii) deposition of lanthanum stearate thin films (FLa). The latter approach has turned out to be more time- and cost-effective and, therefore, seems to be more promising. In this work, we assessed the quantitative characteristics (sensitivity, selectivity) of the “thin-film” procedure in order to estimate its analytical potential. The FLa-modified MALDI target was used for the on-spot enrichment of HHb adducts from the tryptic digests of the protein incubated with two model mono- and dichlorine-containing alkylating agents. The sensitivity of the technique is in the range of hundreds of fmol. Furthermore, the FLa-based procedure shows high selectivity (maximum molar ratio of modified/unmodified form of LLGNVLVC112VLAHHFGK is 1:500). As a case study, on-plate extraction of HHb adducts, formed due to the interaction of the protein with in vitro generated diclofenac metabolites, was performed on FLa-functionalized spots. This resulted in specific extraction of the HHb adducts with two diclofenac oxidation products from the tryptic digest of modified HHb. The developed approach appears to be effective for in situ enrichment of chlorine-containing adducts of HHb.

Source-resolved atmospheric metal emissions, concentrations, and deposition fluxes into the East Asian seas

Source-resolved atmospheric metal emissions, concentrations, and deposition fluxes into the East Asian seas

Synergistic Regulation of Sodium Metal Deposition Pattern Through Three-Dimensional Sodiophilic Gradient ZnO/Fe0.7Co0.3 Frameworks and Magnetic Fields for High-Performance Sodium Metal Batteries.

The application of sodium metal battery is hampered by the large volume change and uncontrollable top growth of Na metal. Herein, a dual strategy including constructing a three-dimensional gradient ZnO/Fe0.7Co0.3 (ZFC) framework of decreasing sodiophilic capability from bottom to top, and imposing magnetic fields based on magnetohydrodynamic (MHD) effect, is proposed to regulate the sodium deposition/stripping behavior and realize the bottom-up deposition of Na. Therefore, the ZFC framework under a magnetic field of 200 mT exhibits high electrochemical reversibility with a Coulombic efficiency of 99.77 % at 1 mA cm-2 and 1 mAh cm-2. Meanwhile, the ZFC composite anode (ZFC@Na) with the magnetic field of 200 mT delivers a small polarization voltage of approximately10 mV and long cycle life of more than 2500 h at 5 mA cm-2 and 5 mAh cm-2 in symmetric cells, along with good cycle stability in ZFC@Na||Na3V2(PO4)3 full cells (200 cycles at 1 C with a high capacity retention of 98 %). Accordingly, the novel strategy of combining magnetic fields and sodiophilic gradient frameworks provides a perspective to solve the issues of sodium dendrite growth.

Non-Planar Helical Path Generation Method for Laser Metal Deposition of Overhanging Thin-Walled Structures

Laser metal deposition is a branch of additive manufacturing that offers advantages over traditional manufacturing techniques for forming overhanging thin-walled metal parts. Previously, helical paths that were suitable for manufacturing such parts were not only limited to stacking material on a flat surface but were also fixed to the model boundaries. In order to solve these two problems to meet more complex process requirements, a non-planar helical path generation method is proposed for laser metal deposition. The method is based on the characteristics of the additive manufacturing process planning flow, which first slices the model using curved surfaces, then offsets the contours on the sliced layering, and finally generates continuous helical paths according to the contracted or expanded contours. In order to verify the feasibility of the method, hollow blades are formed on cylindrical surfaces following the planned paths. The results show that the proposed method is not only capable of assisting the laser metal deposition process to fabricate thin-walled structures on non-planar surfaces but also capable of freely adjusting the contour dimension.

Visualizing Plasmon Mediated Metal Deposition and Gold Nanorod Reshaping with Liquid Phase Transmission Electron Microscopy

Visualizing Plasmon Mediated Metal Deposition and Gold Nanorod Reshaping with Liquid Phase Transmission Electron Microscopy

Integrating data-driven system to predict temperature and distortion in multi-layer direct metal deposition processes

This study proposed a framework to train an artificial neural network (ANN) by a data-driven system to predict the temperature and distortion in multi-layer direct metal deposition (DMD) of SS 304. By integrating thermomechanical variables, the research ensures the fidelity of finite element (FE) simulations, which are validated against existing data. Notably, the study achieves enhanced precision over prior work by varying the heat input sources and heat transfer equations. A novel aspect of this research is the use verified FE simulation to add data to data-driven system to train an efficient ANN for predicting temperature and distortion based on key parameters such as laser power and scanning speed. The iterative process involved multiple FE simulations with varying laser parameters to refine the ANN’s predictive capabilities. This methodology enabled the identification of relationships between manufacturing parameters, temperature, and distortion. The iterative training continued until the ANN’s predictions and subsequent FE simulation results converged within an acceptable margin. The findings confirm that the trained ANN can predict temperature and distortion both accurately and expediently, marking a significant advancement in the control of the DMD process.Graphical

A Detailed Properties Comparison of an Automotive Sealant Nozzle Produced Using Three Metal Additive Manufacturing Technologies.

Choosing the right metal AM equipment and material is a highly intricate process that forms a crucial part of every manufacturing company's strategic plan. This study undertakes a comprehensive comparison of the performance and material properties of three Metal Additive Manufacturing (AM) technologies: Powder Bed Fusion (PBF), Metal Filament Deposition Modeling (MFDM), and Bound Metal Deposition (BMD). An automotive nozzle was selected and manufactured using all three technologies and three metallic materials to understand their respective advantages and disadvantages. The samples were then subjected to a series of tests and evaluations, including dimensional accuracy, mechanical properties, microstructure, defects, manufacturability, and cost efficiency. The nozzle combinations were PBF in aluminum, MFDM in stainless steel, and BMD in hard tool steel. The results underscore significant differences in functionality, material characteristics, product quality, lead time, and cost efficiency, all of which are crucial factors in making equipment investment decisions. The conclusions drawn in this paper aim to assist automotive industry equipment experts in making informed decisions about the technology and materials to use for parts with characteristics like these. Future studies will delve into other technologies, automotive components, and materials to further enhance our understanding of the application of metal AM in manufacturing.

Influence of CMT welding parameters on microstructural and properties investigation of dissimilar weld joint for aluminum bronze and carbon steel

Cold Metal Transfer (CMT) welding technology has improved the appearance of weld beads and revolutionized the welding of thicker materials and dissimilar metals with precise metal deposition and reduced heat input. Cold Metal Transfer welding is predominantly used in a variety of industry applications, including aerospace, shipbuilding, automotive and marine industries. In this study, aluminum bronzes and carbon steel were joined by using CMT welding, a variant of the Gas Metal Arc Welding process, with ERCuAl-A2 as the filler metal. Optical microscopy was used to examine the microstructure of the CMT weld joint between aluminum bronze and carbon steel. Results have indicated that dissimilar metals such as aluminum bronze, and carbon steel could be successfully joined by CMT under various processing parameters. The tensile and bending strengths of the dissimilar joint were 490 MPa and 822 MPa, respectively. A variety of intermetallic compounds and solid solutions were generated in the weld zone and fusion zone. The micro-hardness in the carbon steel side of the fusion zones increased sharply, which was 164 HV in the welded condition. The dissimilar joint was stronger than the carbon steel, as the ductile fracture occurred on the carbon steel during the transverse tensile test of the welded specimen. The microstructure interpretation of welded dissimilar joints was analyzed by scanning electron microscopy and transmission electron microscopy.

Lithium capacity of Kazakhstan mineral resource base

Relevance. Weak knowledge of the territory of the Republic of Kazakhstan on lithium raw materials previously mined in the East Kazakhstan region. Aim. To study lithium raw material base in the Republic of Kazakhstan and prospects for the extraction of lithium raw materials. Methods. Content analysis of all information on the subject of the mineral resource base of lithium in the Republic of Kazakhstan. Results. Within the Republic of Kazakhstan, ore deposits of scapolite pegmatites and lithium-bearing greisens-hydrothermal growths are known along alkaline granites. Residual lithium reserves from previously developed rare metal deposits that are equivalent to 36.3 thousand tons of Li2O, predicted resources of known lithium occurrences are estimated at 140 thousand tons of Li2O. It is possible to develop known rare metal deposits with the extraction of tantalum, niobium, beryllium and associated extraction of spodumene concentrate. GRK «Ognevsky Mining and Processing Plant» is already planning to put back to mining of tantalum and beryl (with the associated extraction of spodumene concentrate – up to 2.5 thousand tons/year) at the Bakennoe deposit and processing the resulting ore concentrates at the operating Ulba metallurgical plant of Kazatomprom. With regard to lithium-bearing hydro-mineral resources of the Republic of Kazakhstan, the situation is more complicated, due to the data limitations on the completeness of formation water testing and the reliability of data on surface waters of stagnant lakes. Such oil and gas fields as Karachaganak (up to 196 mg/l Li2O), Kolkuduk (up to 130 mg/l Li2O), Teplovskoe (up to 82.5 mg/l), Urikhtau (up to 52 mg/l) and Western Opak (up to 45 mg/l) are known for high concentration of lithium in formation waters. First two deposits are ready for oil and gas development and production with an annual extraction of up to 1 thousand tons of lithium carbonate. With regard to the lithium content of stagnant lakes of the Republic of Kazakhstan, it should be noted almost total lack of reliable information on sampling their surface waters. Given the fact of finding industrially significant lithium-bearing hydro-mineral lake deposits in adjacent regions of China and Mongolia, it is necessary to intensify the thematic works to assess the lithium content of endorheic lakes throughout the Republic of Kazakhstan, with sampling not only of surface waters, but also of natural brine, lake mud, saline clayey rocks of solonchaks and takyrs.

Research progress on formation mechanism of pearl

Pearls are deeply cherished for their rich color and gorgeous luster, and their quality directly affects their value. Currently, the evaluation of pearl quality is mainly based on four aspects: color, shape, size and smoothness. The quality of pearls is influenced by a variety of factors, categorized into internal factors, such as the structural composition of the nacreous layer and genetic factors of the mussels, and external factors, including the aquaculture environment. Existing research results indicates that genetic factors are the dominant factor controlling the pearl quality. However, the macromolecules such as metal ions, organic pigments and various physical and chemical factors in the aquaculture water environment will also significantly impact pearl quality. Among these, matrix proteins are organic macromolecules found in the nacreous layer that play an important role in pearl quality. They participate in the deposition of calcium carbonate and the construction of the organic framework, affecting the pearls’ size and shape. The color of pearls is influenced by the deposition of metal ions, the transport of organic pigments and the regulation of microstructure.

Enhancing Microstructural, Thermal, Mechanical, and Corrosion Response of a Bio/Eco‐Compatible Mg–2Zn–1Ca–0.3Mn Alloy Using Two Types of Cryogenic Treatments

Biocompatible Mg–2Zn–1Ca–0.3Mn is synthesized using the disintegrated metal deposition process and subjected to two types of cryogenic treatments (refrigeration [RF] at −20 and −196 °C using liquid nitrogen) with a target to improve microstructural, thermal, mechanical, and electrochemical responses. The material exhibits densification and grain refinement after these treatments, which improves the physical, thermal, compressive, and corrosion responses. While both RF and liquid nitrogen exposures improve the overall combination of properties, overall improvement in properties is best met with RF treatment at −20 °C. In the results of this work, the efficacy of low energy option (RF) is convincingly established rather than liquid nitrogen exposure (as conventionally practiced) to enhance microstructure and properties.

Impact of Effluent Treatment Plant Sludge on Growth, Physiology, and Biodegradation Potential of Cyanobacteria: Anabaena variabilis, Nostoc muscorum, and Nostoc sp.

Organic compounds and pollutants from industries like oil refineries, such as total petroleum hydrocarbon (TPH) and polycyclic aromatic hydrocarbons (PAHs) are known to pose toxic effects to the environment by degrading the soil and water quality along with the deposition of heavy metals thereby causing a threat to the life forms existing in them. This pose of imbalance in the ecosystem calls for an exigent notice and effort regarding controlling it. Hydrocarbon sludge from Effluent Treatment Plant (ETP) is one such toxic effluent eluted from oil refineries, and that is yet to be reported for a biodegradation study. Among a huge number of physical and chemical techniques, bioremediation has been a much talked about measure but is not in the required scale of practice yet. The reason could be a lack of efficient standardization for environmental applications. Cyanobacteria being well-known for their ability to survive difficult environmental conditions efficiently and to adapt to a mixotrophic nature, makes them ideal for performing bioremediation at a large scale in the open environment. The study aimed to quantify this ability of cyanobacteria by assessing the TPH content of the treatment sample, Effluent Treatment plant (ETP) hydrocarbon sludge pre- and post-treatment using GC-FID. The study was designed to treat the sludge by cyanobacterial strains in a pre-determined lethal dose concentration and monitor the activity of enzymes vital for a basic degradation metabolism, in addition to the growth rates of the cultures. The figures obtained from the enzyme assays and the growth rates appeared to be collateral in the direction of it being a highly promising bioremediation approach that could be efficiently performed by increasing the scale of application. The chromatograms obtained from the GC-FID depicted significant reductions in the TPH content of the treated samples that strongly indicated the potential of the cyanobacterial cultures to bioremediate an oil- contaminated site or treat toxic effluents from oil refineries.

Non-contact ultrasonic vibration-assisted laser metal deposition manufacturing Fe-based powder: Numerical simulation and experimental investigation

Fe-based powder was manufactured on 42CrMoA steel substrate using non-contact ultrasonic vibration-assisted(UVA) laser metal deposition(LMD) process with different exciting distances(d), and the temperature field and stress field distribution, microstructure and mechanical properties of the deposited layers were investigated. The results show that the distribution of temperature field was more uniform, especially at the bottom of the molten pool, and the gradient of temperature field decreased. Compared with the condition without UVA, the residual stress peak value of the tensile stress area decreased significantly after UVA applied. When d=80 mm, the peak tensile stress and compressive stress were 90.5 MPa and 72.6 MPa, respectively, which were reduced by 45.6 % and 25.2 % compared with the condition without UVA. The length of the columnar crystals and the region of the columnar crystals decreased at the interface after UVA applied. The application of UVA can significantly improved the microhardness of deposition layer. With the reduction of the residual stress at the interface and the improvement of uniformity, the tensile properties of the deposit were also significantly improved. The highest tensile strength was 1281.3 MPa when d=80 mm, which was 30.12 % higher than that without UVA.

Development and experimental validation of a thermo-metallurgical-mechanical model of the laser metal deposition (LMD) process

The current paper presents the development and experimental validation of a thermo-metallurgical-mechanical model for a multi-pass Laser Metal Deposition (LMD) process, with the objective of accurately predicting the resultant constituent phases and residual stresses. The thermal model is calibrated using temperature readings and is shown to accurately capture the transient temperature field and extent of the fusion zone associated with the multi-pass LMD process. The metallurgical model incorporates the kinetics of ongoing solid-state phase transformations (SSPTs) and tempering reactions. The predictions are validated via hardness measurements, demonstrating a very good agreement with the predictions. The developed mechanical model predicts the residual stress field, which is validated using X-ray diffraction measurements, and the comparison also shows a very good agreement between the predictions and measurements. The validated numerical model is then used to explore alternative LMD strategies showing that the choice of deposition strategy can significantly impact resultant constituent phases and residual stresses.

Dual‐Gradient Engineering of Conductive and Hierarchically Potassiophilic Network for Highly Stable Potassium Metal Anode

AbstractPotassium (K) metal anodes are the most competitive candidates for low‐cost and high‐energy density rechargeable batteries. However, uncontrolled K dendrite growth strictly impedes the practical application of K metal anodes. Herein, a potassiophilic and conductive dual‐gradient free‐standing host (named TS‐PKS) composed of the bottom layer with Ti3CN and F doped SnO2 (F‐SnO2) and the top layer with perfluorinated sulfonic acid K (PFSA‐K) and ordered mesoporous silica (SBA15) is constructed to achieve dendrite‐free K deposition. The potassiophilicity and conductivity of the TS‐PKS host increase along with the depth direction to generate a bottom‐up dual‐gradient of K+ affinity and electroconductivity. Such bottom‐up dual‐gradient of K+ affinity and electroconductivity can synergistically manipulate uniform K metal deposition following the bottom‐up manner, preventing the notorious K dendrite growth. As a result, the TS‐PKS@K symmetric cell can stably cycle over 2800 h at 0.5 mA cm−2/0.5 mAh cm−2. Meanwhile, the TS‐PKS@K//PTCDA full battery also exhibits an initial specific capacity of 118.3 mAh g−1 at a high current density of 500 mA g−1 and maintains up to 81.1 mAh g−1 after 1000 cycles. This novel dual‐gradient strategy design offers a straightforward approach to effectively manipulate K metal deposition manner for achieving dendrite‐free K metal anodes.

Critical and Strategic Metal Resources of Greece

Greece has a large number of critical and strategic metal resources. The proven and indicated reserves of aluminum amount to 2.5 mt and their gross value €5.075 b. Those of chromium amount to 1.2 mt with gross value €4.320 b, while of cobalt are 129 th. t with gross value €3.348 b. The proven and indicated reserves of copper from Chalkidiki and Kilkis areas are approximately 3.04 mt and their gross value €24.776 b, while those of manganese are 2.25 mt with gross value €5.400 b. Molybdenum has been located in Pigi Kilkis with indicated reserves of about 7.7 th. t and gross value €326 m. Under mining are the vein type magnesite deposits of Gerakini Chalkidiki and North Evia. The total reserves (proven + indicated) of magnesite are 280 mt and their gross value €9.800 b. The most important lateritic Fe-Ni-bearing ores are those of Evia Island, Agios Ioannis Viotia, Lokrida Fthiotida, Mesopotamia and Ieropigi Kastoria. The proven and indicated reserves of nickel are 1.39 mt and their gross value €22.240 b. The Rizana/Lachanas porphyry-epithermal antimony deposit is considered the most important stibnite ore. The proven and indicated reserves of stibnite are at least 100 th. t with an average Sb content of 0.3 wt%. Copper, chromium, and cobalt present good prospects for mining. Platinum group metals (PGMs), with economic interest, are contained in the porphyry Cu deposits of Skouries Chalkidiki. Strymonikos Gulf, together with the neighboring coastal and submarine sands, is the most probable area for locating exploitable rare earth metals (REMs). There are excellent investment opportunities in the exploration and mining of Bi, Te, Ga, Ge, and In metals. The deposits of other critical and strategic metals of Greece should be adequately assessed.

The Enhancement Discharge Performance by Zinc-Coated Aluminum Anode for Aluminum–Air Battery in Sodium Chloride Solution

The main drawback of seawater batteries that use the aluminum (Al)–air system is their susceptibility to anode self-corrosion during the oxygen evolution reaction, which, in turn, affects their discharge performance. This study consist of an electrochemical investigation of pure Al, 6061 Al alloy, and both types coated with zinc as an anode in a 3.5% sodium chloride (NaCl) electrolyte. The electrolyte solution used for the deposition of zinc metal contained citrate, with and without EDTA as a complexing agent. Subsequently, the performance of the anode was tested in a seawater battery, using a carbon@MnO2 cathode and a 3.5% NaCl electrolyte. The performance of Al–air batteries has been significantly enhanced by applying a process of electrodepositing zinc (Zn) with a citrate deposition electrolyte solution in both pure aluminum and alloy 6061. The performance of the battery was further enhanced by adding EDTA as a chelating agent to the citrate-based electrolyte solution. The Al–air battery with aluminum alloy 6061 with Zn electrodeposition with an additional EDTA as the anode, carbon@MnO2 as the cathode, and NaCl 3.5% solution as the electrolyte has the highest battery performance, with a specific discharge capacity reaching 414.561 mAh.g−1 and a specific energy density reaching 0.255 mWh.g−1, with stable voltage at 0.55 V for 207 h.

Participation of Surface Oxygen in the Stabilization of the Rh/HOPG System with Respect to NO₂

In this work, using the method of X-ray photoelectron spectroscopy (XPS), a comparative study of the nature of the interaction of NO₂ at room temperature and a pressure of 10⁻⁵ mbar with two samples of highly oriented pyrolytic graphite (HOPG), on the surface of which rhodium was preliminarily deposited by vacuum deposition, was carried out. Before metal deposition, one of the HOPG samples was annealed in vacuum at 600°C, and the other was subjected to bombardment with argon ions, followed by exposure to air at room temperature for an hour in order to introduce strongly bound oxygen atoms into the surface composition. After deposition of rhodium on two samples of HOPG prepared, two model catalysts were obtained, designated as Rh/C and Rh/C(A)-O. It was found that the interaction of NO₂ with Rh/C led to the oxidation of graphite with the destruction of the surface layer. The Rh particles remained in the metallic state, but at the same time they were introduced into the near-surface layer of the carbon support. On the contrary, when the Rh/C(A)-O sample was treated with NO₂, the deposited rhodium was partially converted into RH₂O₃, while the graphite was oxidized to an insignificant degree and retained its original structure. The role of surface oxygen in the stabilization of graphite with respect to oxidation to NO₂ was discussed.

3D-Printed Hierarchically Microgrid Frameworks of Sodiophilic Co3O4@C/rGO Nanosheets for Ultralong Cyclic Sodium Metal Batteries.

Herein, hierarchically structured microgrid frameworks of Co3O4 and carbon composite deposited on reduced graphene oxide (Co3O4@C/rGO) are demonstrated through the three-dimensioinal (3D)printing method, where the porous structure is controllable and the height and width are scalable, for dendrite-free Na metal deposition. The sodiophilicity, facile Na metal deposition kinetics, and NaF-rich solid electrolyte interphase (SEI) formation of cubic Co3O4 phase are confirmed by combined spectroscopic and computational analyses. Moreover, the uniform and reversible Na plating/stripping process on 3D-printed Co3O4@C/rGO host is monitored in real time using in situ transmission electron and optical microscopies. In symmetric cells, the 3D printed Co3O4@C/rGO electrode achieves a long-term stability over 3950 at 1mA cm-2 and 1 mAh cm-2 with a superior Coulombic efficiency (CE) of 99.87% as well as 120h even at 20mA cm-2 and 20 mAh cm-2, far exceeding the previously reported carbon-based hosts for Na metal anodes. Consequently, the full cells of 3D-printed Na@Co3O4@C/rGO anode with 3D-printed Na3V2(PO4)3@C-rGO cathode (≈15.7mg cm-2) deliver the high specific capacity of 97.97 mAh g-1 after 500 cycles with a high CE of 99.89% at 0.5 C, demonstrating the real operation of flexible Na metal batteries.