Metal Components Research Articles

Convertible glenoid replacement in the anatomical total shoulder arthroplasty: medium-term results.

The older generation of high thickness metal-backed glenoid prostheses had a high failure rate. The goal of our study was to analyze the medium-term clinical and radiological results of a technically modified generation of metal backed glenoids with 35% decrease in thickness. Thirty-nine patients (43 shoulders) with a mean age of 66.5 years at surgery were examined from two to ten years (mean 71.2 months) using the Constant-Score, Subjective Shoulder Value and X-ray in a.p. and axial view. Indication for surgery included patients with glenoid types B1, B2, or B3 and/or posterior subluxation but intact rotator cuff, or patients who did not want a reverse prosthesis and had high functional demands. Inclusion criteria comprised participation in a clinical and radiological follow-up examination, along with a minimum follow-up duration of 24 months. Additionally, in all cases, the Constant Score and the Subjective Shoulder Value (PROM) had to be determined. Exclusion criteria were an incomplete dataset, implantation of a different prosthesis type, and failure to meet the minimum follow-up time. The absolute Constant Score (CS) improved significantly (p < 0.0001) from 43 ± 13 (range: 20-69) points before to 80 ± 13 (range: 46-98) points after surgery. The only preoperative negative influencing factor on the result was the glenoid protrusion according to Lévigne (p = 0.0150). No significant differences in functional outcomes were found between glenoid types A2,B1,B2 and B3. Radiolucent lines at the interface were observed in a total of four patients (13%). Radiological signs of glenoid osteolysis were seen in six patients (20%).Humeral upward migration was observed in four patients (13%) and posterior shoulder joint decentering occurred in one patient (3%). Implant-specific complications occurred in three cases (7%). Due to a massive rotator cuff tear, two cases (4.7%) had to be converted to a reversed implant, with the primary metal component remaining in place. If the implant-specific and rotator cuff-associated complications are summarized, the rate is 11.7%. All components that required conversion to an reverse implant have so far remained free of complications. Favorable clinical results can be achieved, especially in patients with an eccentric glenoid type. Severe preoperative glenoid erosion (Walch A2, B2, B3) does not appear to have any influence on postoperative functional results. The complication and revision rates are significantly better than in previous studies with conventional metal-backed glenoid components. Conversion of the anatomical glenoid component to a reverse system was always possible and good clinical results were achieved.

Extrusion 3D Printing of Intrinsically Fluorescent Thermoplastic Polyimide: Revealing an Undisclosed Potential.

Thermoplastic polyimides (TPIs) are promising lightweight materials for replacing metal components in aerospace, rocketry, and automotive industries. Key TPI attributes include low density, thermal stability, mechanical strength, inherent flame retardancy, and intrinsic fluorescence under UV light. The application of advanced manufacturing techniques, especially 3D printing, could significantly broaden the use of TPIs; however, challenges in melt-processing this class of polymer represent a barrier. This study explored the processability, 3D-printing and hence mechanical, and fluorescence properties of TPI coupons, demonstrating their suitability for advanced 3D-printing applications. Moreover, the study successfully 3D-printed a functional impeller for an overhead stirrer, effectively replacing its metallic counterpart. Defects were shown to be readily detectable under UV light. A thorough analysis of TPI processing examining its rheological, morphological, and thermal properties is presented. Extruded TPI filaments were 3D-printed into test coupons with different infill geometries to examine the effect of tool path on mechanical performance. The fluorescence properties of the 3D-printed TPI coupons were evaluated to highlight their potential to produce intricately shaped thermally stable, fluorescence-based sensors.

Heterostructure-induced anisotropy of tensile property in laser directed energy deposition TC11 titanium alloy

Grain structure is generally considered as an important factor to influence the anisotropy of mechanical properties of the additive manufactured metallic component. In this work, we revisit the mechanical anisotropy of a TC11 alloy with heterogeneous grain structure fabricated by laser directed energy deposition(L-DED) technology, and fully unravel the plastic deformation behavior with different types of heterogeneous grain morphology. It is found that the 0-BD specimens and 45-BD specimens exhibit desirable strength-ductility synergy with considerable YS, high UTS and prominent ductility. The synergistic increase in strength and plasticity is induced by the hetero-deformation of equiaxed grain and columnar grain induced. Specially, the optimum hetero-deformation induced (HDI) strengthening is obtained in 45-BD specimen due to the symmetric constraint morphology of heterostructure. The lower strength and elongation of the 90-BD specimens are associated with the fracture of α phases at grain boundaries perpendicular to the loading direction.

Heterogeneous precipitation behavior and mechanism during the adsorption of cationic heavy metals by biochar: Roles of inorganic components

Heavy metals are commonly adsorbed by biochar in contaminated water and soil. However, the behaviour and underlying mechanisms of heterogeneous precipitation between the inorganic components of biochar and cationic heavy metals remain poorly understood. In this study, we comprehensively investigated the nucleation, growth, and aggregation of precipitates, ion exchange-coupled precipitation behaviour, adsorption-precipitation correlation, and the influence of environmental factors (e.g., anion content, pH, initial concentration, type of heavy metals, and biochar size). The kinetic results indicated that the generation of precipitates was accompanied by an adsorption reaction with a gradual increase in crystal size and aggregation behaviour. Moreover, precipitation includes both surface and solution precipitation. The increasing local concentration of Pb(II) around the biochar at high initial concentrations increased the supersaturation of the nucleating substance, which decreased the potential for heterogeneous nucleation and facilitated heterogeneous precipitation. Correlation analysis revealed the presence of a coupling mechanism between precipitation and cation exchange. The enhanced electrostatic attraction at high pH could lower the heterogeneous nucleation potential barrier, thus promoting heterogeneous precipitation. The small biochar size extended the induction time, which was unfavourable for heterogeneous nucleation. This study provides a deeper understanding of the heterogeneous precipitation behaviour of the inorganic components of biochar and cationic heavy metals.

Encapsulation of Cu/Fe3O4 With RT‐COF‐1 for Improved Stability in Water–Gas Shift Reaction

AbstractStability is crucial for the practical application of heterogeneous catalysts, particularly in industrial processes, where catalyst deactivation often occurs due to factors such as sintering, poisoning, and active site degradation. This study investigates the effectiveness of utilizing covalent organic frameworks (COFs), specifically RT‐COF‐1, to enhance the stability of Cu/Fe3O4 catalysts in harsh water–gas shift (WGS) reaction environments. By encapsulating Cu/Fe3O4 with trace RT‐COF‐1, we aimed to preserve the structural integrity and active interfaces between the metal components during catalytic reactions. Characterization techniques, including X‐ray photoelectron spectroscopy, nitrogen sorption, and high‐angle annular dark‐field scanning transmission electron microscopy, confirmed the successful COF coating and its role in preventing particle aggregation and maintaining active site structures over extended catalytic tests. Notably, Cu/Fe3O4@COF demonstrated significantly enhanced stability during a continuous 24‐h WGS test compared to uncoated catalysts, which exhibited rapid deactivation. Mechanistic insights indicated that COF coating reduced the number of active sites while preserving the overall morphology of the catalyst, contributing to its robust performance. Ultimately, this work highlights the potential of COF encapsulation as an effective strategy for enhancing the durability and efficacy of multifunctional catalysts in challenging reaction conditions.

Mechanisms and degradation pathways of tetracycline by Co7Fe3 nanoparticles anchored porous carbon activated peroxymonosulfate

In recent years, catalysts based on transition metals have been extensively employed for the activation of peroxymonosulfate (PMS) in the removal of tetracycline (TC) from aquatic environments. However, the efficiency of single transition metals and heterogeneous transition metals as catalysts has been somewhat limited. In this study, different bimetallic Co-Fe catalysts embedded in a porous carbon (Co7Fe3-500/600/700/800) were synthesized using a straightforward single-step calcination process at varying temperatures, addressing the issues of poor activation performance of single transition metals and low dispersion of active components in heterogeneous transition metals. The Co7Fe3-500/600/700/800 enhanced the electronic configuration, establishing electron-rich and highly active zones that promoted electron transfer between the Co and Fe transition metals. The results showed that Co7Fe3-600, exhibited excellent PMS activation performance, removing 95.1 % of TC from the solution within 10 min. Additionally, Co7Fe3-600 showed strong adaptability and resistance to interference under various environmental conditions. DFT calculations, HPLC-MS analysis and T.E.S.T analysis were used to predict potential degradation intermediates during TC degradation and assess their biological toxicity. This research introduces an innovative strategy for formulating sophisticated bimetallic alloy catalysts and contributes fresh perspectives on the mechanisms involved in the PMS activation process by bimetallic catalysts.

Recent development in polymer coating to prevent corrosion in metals: A review

Corrosion in metals is a pervasive and costly issue across various industries, from infrastructure to manufacturing. Corrosion is a complex electrochemical process, and mitigating it is paramount to extend the lifespan and maintain the integrity of metal structures and components. This review study provides a thorough overview of the state-of-the-art use of polymer coatings to stop metal corrosion. It then delves into polymer coatings’ essential properties and advantages, highlighting their role in corrosion inhibition. The paper surveys recent advancements in polymer coating techniques and their compatibility with different metal substrates. The case studies and real-world applications where polymer coatings have been successfully employed to prevent corrosion in diverse settings, including marine environments, automotive components, and aerospace structures, are explored. Case studies illuminate the efficacy of these coatings, showcasing their role in safeguarding assets, reducing maintenance costs, and promoting sustainability. By analyzing these cases, the paper elucidates the practical effectiveness of polymer coatings in corrosion prevention. This review article addresses numerous ways of shielding metals from corrosion, focusing on nanomaterials, conducting polymers, nano-composites, and carbon-based materials for corrosion resistance. This literature review stands out for its thorough analysis of the most recent developments in this field and the ways in which various polymer coatings are being used to prevent corrosion.

Directed energy deposition of Ti6Al4V wire with continuous layer varied laser power

The laser-based directed energy deposition (DED) additive manufacturing enables the efficient fabrication of metallic parts. The layer-wise performance in DED-built metallic parts is challenging to remain consistent due to the intricate heat accumulation. As such, it is of significance to control the printing quality by adjusting the process settings with layers. In this work, we used DED to achieve Ti6Al4V wire deposition with continuously layer-varied laser power. Three laser power settings were selected to investigate the variation in defects, microstructure, and mechanical properties with layers. Our findings suggested that optimizing real-time laser power is critical for achieving desirable manufacturing efficiency and resultant performance in the DED of metallic materials. This research provides valuable guidelines for parameter optimization in DED processes, aiming to enhance the production quality and performance of high-strength metallic components, particularly in sectors demanding high-performance materials.

Synchronous conversion and targeted separation of valuable metals from spent hydroprocessing catalysts

Sustainable recovery of spent hydroprocessing catalysts (sHPC) is crucial to address environmental and resources issues. However, the existing recycling methods recover limited metal components due to uncontrollable phase transition and complicated separation procedures, leading to poor utilization efficiency of the sHPC. Herein, a synchronous conversion and targeted separation strategy was designed to achieve full-component recovery of the sHPC. The insoluble phases of Al/Ni/Mo/V could be completely transformed into soluble sulfate via sulfation roasting at 400 °C. The roasted sulfate products can be directly leached by water with efficiencies close to 100%. Targeted separation of the multi-ions could be achieved based on their species difference in the leachates. Anionic HV10O285− and HMoO4− species were co-extracted by basic trioctylamine extractant, while cationic Ni2+ and Al3+ were extracted by acidic HBL110 and P204, respectively. Benefiting from the sulfation roasting and selective extraction procedures, the recovery efficiencies of Al, Ni, Mo, and V elements achieved 97.2%, 95.8%, 94.1%, and 94.3%, respectively. The explored synchronous conversion and targeted separation strategy is an industrial-feasible candidate for sustainable utilization of the retired catalysts.

Vibration behaviour of additively manufactured AlSi10Mg specimens

Abstract Additive manufacturing is in continuous development, and the obtained components still have some shortcomings. The vast majority of mechanical characterizations are performed on polymer materials, using in particular the material extrusion process, while metallic components face not negligible deficiencies. This paper presents an experimental investigation of the vibration behaviour of selective laser melting (SLM) 3D printed specimens. The specimens were printed “on-edge” from AlSi10Mg aluminium alloys and subjected to fatigue tests. By using an electrodynamic shaker, controller, acceleration transducer, and laser vibrometer, the tests have been performed and the data analysed. After the tests, a correlation was obtained by using a finite element analysis (FEA). The damping coefficients (alpha and beta) are obtained from the experimental data. These coefficients are then used to check the accuracy of each FEA model. The results reveal the correlation between structural damping and anisotropy of additive manufacturing specimens, and their impact on high-cycle fatigue performance.

Real-time monitoring and control of the layer height in laser metal deposition with coaxial wire feeding using optical coherence tomography

Laser metal deposition (LMD) with coaxial wire feeding is an additive manufacturing technology in which a metal wire is fed into a laser-induced melt pool. The repeated deposition of weld beads allows three-dimensional geometries to be created that can be used for manufacturing, repair, and modification of metal components. However, the process is highly sensitive to disturbances because the fed wire must always be fully melted, and no self-regulating effects as in powder-based LMD exist. The layer height is particularly important for process stability, as even small deviations accumulate over many layers and, ultimately, lead to the termination of the process. Therefore, monitoring and closed-loop control of the layer height during the deposition process are crucial. Due to process emissions, an interruption of the process is usually necessary for the accurate optical measurement of the layer height, which negatively affects the overall productivity. In order to overcome this drawback, an in-axis optical coherence tomography (OCT) sensor was employed in this work, which enabled real-time measurements of the layer height. It was found that positioning the OCT measurement spot as close as possible to the center of the wire provided the highest signal quality. Based on the real-time height data, a closed-loop layer height control was implemented, applying the wire feed rate as the manipulated variable. The experimental results showed that the proposed system was able to compensate for significant disturbances, ensuring dimensional accuracy and process stability.

Revealing the influence of ring-shaped beam profiles in high-speed laser beam microwelding by synchrotron x-ray imaging

Laser beam microwelding is a precise technique for joining miniature metal components with high feed rates, which is crucial for productivity. However, high feed rates provoke humping formation—periodic beadlike protuberances along the weld seam—that compromise weld integrity. While humping has been associated with the keyhole transition from a narrow to an elongated shape using standard laser intensity distributions (e.g., Gaussian, top-hat), the impact of complex beam profiles, like ring-shaped intensity distributions, remains less understood. In this work, the influence of core-only, ring-only, and superimposed core-ring intensity distributions on humping formation during laser beam microwelding is investigated by means of synchrotron x-ray imaging. Single-track experiments on stainless steel (1.4404) at 1000 mm/s reveal that the keyhole geometry shifts from deep and narrow with core-only power input to shallow and elongated with ring-only power input. Using a superimposed core-ring intensity distribution (Pc = 300 W, Pr = 600 W) results in a U-shaped capillary and the reduction of the humping amplitude by nearly 80% (from 45.61 μm with core-only to 10.29 μm). The additional laser power comes with the tripling of the melt pool width (from 81 μm with core-only to 263 μm) likely decreasing the melt flow velocity. The reduced variability of the capillary length present for the superimposed intensity distribution further indicates a stabilized evaporation behavior. This work provides valuable insights into mitigating humping formation during laser beam microwelding of stainless steel at elevated feed rates using core-ring intensity distributions.

Hydrothermal Fluid Activity on Mars Recorded in Phosphates of the Gabbroic Shergottite Northwest Africa 13581

AbstractApatites record crucial information on the origin, composition, and chemical evolution of volatiles on terrestrial planets. As a martian intrusive rock, the gabbroic shergottite Northwest Africa (NWA) 13581 provides key information on the volatile evolution related to magmatic processes in the interior, shedding light on the intricate volatile circulation on Mars. The textural and chemical characteristics of the phosphates in NWA 13581 indicate a complex formation history involving fractional crystallization, degassing, and fluid interaction. Degassing of the NWA 13581 parent melt is capable of exsolving chlorine‐rich fluids, resulting in the formation of notably fluorine‐rich apatite with a high x‐site occupancy of fluorine up to 90%. The degassed/exsolved volatile‐rich fluids could subsequently continue to migrate and interact with surrounding magmatic suites, leading to highly heterogeneous compositions of active fluids. The crystallization of apatite is initiated by the interaction of fluids with merrillite at the late stage of the magmatic process, leading to the formation of phosphate intergrowths. Influenced by the composition and chemical evolution of volatiles in fluids and melts, apatite exhibits notable variability in chlorine compositions both within individual grains and among different grains. Moreover, the presence of magnetite associated with phosphate intergrowth highlights the transportation of metallic components in addition to volatiles from deep layers to shallower depths or to the surface of Mars. This process, which is observed in young shergottites, indicates the persistent presence of hydrothermal systems until recent geological periods, contributing to the generation and circulation of volatiles within the martian interior and on the surface.

Electrochemical Performance of Ti Gr. 2 as Electrodes in Contact with Saline Suspension of Clays during the Electroflotation Process

The presence of clays in copper minerals has a significant negative impact during their processing, leading to low recoveries during the flotation process. In saline environments, the presence of these clays promotes operational problems associated with salinity, leading to decreases in the copper concentrate grade, alterations in the rheology of the mineral pulp, reduction in the selectivity of copper during the flotation process, declines in the quality of clarified water, and excessive corrosion of metallic components. This study explores the electroflotation of kaolinite and montmorillonite clays in NaCl solutions using a modified Hallimond tube coupled with Ti Gr. 2 electrodes for bubble generation via water electrolysis and the corrosion analysis of these electrodes applying the superposition model. The electroflotation results show recovery of clays close to 72.68% for kaolinite, 88.44% for montmorillonite, and 67.36% for a mixture of both clays. The presence of clays helps reduce the corrosive effects of Ti Gr. 2 from 0.069 A/m2 in NaCl to 0.0073 A/m2 in NaCl with montmorillonite clay.

Application of metal additive testing and thermal conductivity technology in optimizing product appearance design in intelligent manufacturing industry

Metal additive manufacturing technology has the advantages of rapid manufacturing and personalized production, but due to the complexity of the manufacturing process and differences in material characteristics, products made with metal additives often have appearance defects and process performance issues. Therefore, the purpose of this study is to explore the application of metal additive detection technology in product appearance design and process performance optimization. This study proposes a comprehensive detection and optimization method that utilizes non-destructive testing techniques to comprehensively inspect metal components. By identifying and locating these issues, the quality status of the components can be accurately understood. Based on the test results, a series of appropriate optimization measures have been taken to improve the appearance and process performance of the product, adjust process parameters, improve the forming quality and surface smoothness of the components, thereby achieving better appearance effects. Metal additive testing technology can effectively detect and locate appearance defects in products, and by optimizing process parameters and material selection, it can significantly improve the appearance quality and process performance of products, providing support for improving the reliability and production efficiency of industrial manufacturing.

Особливості структуроутворення заевтектоїдних сталей, легованих міддю

The structural state of pre-eutectoid steels alloyed with copper in the range of up to 28% was studied. It was established that the alloying of steel with a carbon content of 1.3% with copper in the amount of 8, 12 and 28% leads to the formation of the primary and secondary copper -phase The main metallic component of the structure of the studied copper-alloyed steels is represented by thin-plate copper pearlite with inclusions on the boundaries of the primary austenite grains of secondary cementite and secondary inclusions of the copper -phase. The results of the X-ray spectral microanalysis showed that the primary copperite of the -phase consists of 92.5% of copper and 7.1% of iron. The transition zone between the primary copper precipitate and the matrix, the distribution of chemical elements in it, was studied. The total size of the interphase zone is 0.4 μm. It was established that alloying of steels with 8-28% copper contributes to the formation of a highly dispersed structure of copper thin-plate pearlite, as well as the formation of areas with deformed microvolumes near the primary copper e-phase, which constitute a significant barrier to the movement of dislocations. Thus, a state with increased resistance to dynamic loads has been formed at the micro level. The obtained results open up the possibility of using post-eutectoid steels alloyed with copper in the corresponding highly loaded products Keywords: structure, post-eutectoid steel, alloying, thin-plate pearlite, e-phase, iron, spectrum.

Mechanistic elucidation of the molecular weight dependence of corrosion inhibition afforded by polyetherimide coatings

Corrosion of critical metal components exacts a heavy toll in terms of maintenance and replacement costs and damage to ecosystems upon failure. Polymeric barrier coatings protect against corrosion; however, design principles for modulating polymer structure to improve corrosion inhibition remain contested and elusive. Here, we examine molecular-weight-dependent differences in the efficacy of corrosion inhibition on aluminum substrates afforded by polyetherimide (PEI) coatings. Analyses of coated substrates evidence a clear trend denoting improved corrosion inhibition for higher weighted-average molecular weight (MW) PEI. The more rigid and entangled macromolecular network of higher-MW variants exhibit stable impedance values, |Z|0.01 Hz ca. 1010 Ω/cm2, upon extended immersion in brine media, whereas lower-MW variants are readily hydrated and disentangled resulting in a significant reduction in impedance values. Results illuminate mechanistic understanding of molecular-weight-dependence in corrosion inhibition, advance a framework for considering the dynamical evolution of secondary structure, and exemplify generalizable design principles for corrosion inhibition.

Making large-size fail-safe steel by deformation-assisted tempering process

Synergistically improving the strength and toughness of metallic materials is a central focus in the field of physical metallurgy. Yet, there is a noticeable lack of research in strengthening and toughening large-size metal components, whereas those components are extensively used in the modern industry. In this work, a deformation-assisted tempering (DAT) process was proposed to create a novel microstructure in 1.4 tons low-alloyed plain steel. After DAT treatment, the steel contains low dislocation density but high density of low-angle subgrain boundaries and dispersed spherical nano carbides. Such microstructure enables a much better combination of tensile strength and fracture toughness compared to the small-size quench and temper steels. The significant improvement in low-temperature impact toughness is due to the occurrence of delamination and subsequent large plastic deformation at the notch tip. The DAT process can provides a new strategy for the development of large-size fail-safe steel with excellent strength and fracture resistance.

A review of multiaxial low-cycle fatigue criteria for life prediction of metals

Most of real-world structural components that undergo cyclic loading feature multiaxial fatigue. When the cyclic loading involves also significant plastic deformation, multiaxial low-cycle fatigue takes place. Applications where multiaxial low-cycle fatigue can be observed very often involve metal components. To predict their lives multiple criteria and models have been proposed, but their development has not followed a regular path. Multiple reviews are available in literature. However, many of them are outdated, they often employ different classification methods to categorize available criteria, many focus on specific families of criteria, and others do not include sufficient theoretical background. Moreover, none of the available reviews is based on a systematic literature search method. As a result, approaching the topic can result arduous and chaotic, especially for first timers. This work aims at providing a clear, comprehensive, and definitive review of available criteria for multiaxial low-cycle fatigue. First, the basic theoretical background is explained. Secondly, a systematic approach is described and employed to identify all major currently available criteria. Then, they are classified and commentary about different classification styles that can be found in literature is added. Eventually they are described, together with their latest proposed variations. In this way this review can be employed as a guiding reference, especially for engineers approaching the topic for the first time.

Evaluation of a non-metallic dual-port expander for intensity modulated proton therapy.

To provide a methodology for characterization of the technical properties of a newly developed non-metallic tissue expander for intensity modulated proton therapy. Three tissue expanders (AlloX2-Pro: plastic-dual port, AlloX2: metal-dual port, and Dermaspan: metal-single port) were deconstructed, CT-scanned, and modeled in RayStation12A. A 165MeV single spot was used to create RayStation dose planes, and the integrated depth dose profiles were calculated and the DR90 extracted to predict water equivalent thickness (WET). These predictions were compared to measurements taken with an IBA Giraffe MLIC. Native, water, and fully modelled overrides were compared for the AlloX2 Pro to quantify differences in override choices. Geometric considerations between expanders were compared using a ray-tracing technique to contour the "no-fly" zone around metallic components using a clinical, three beam arrangement. Lastly, a planning and evaluation framework was provided using a single plan as an illustration. The measured AlloX2-Pro WET values were within 0.22cm of RayStation predictions while metallic values ranged from 0.08 to 0.46cm. Using natively scanned density values for the AlloX2 Pro improved the discrepancy in WET between predicted and measured from -0.22 to -0.09cm (drain) and from -0.17 to -0.12cm (injection). The "no-fly" zone volume of all three beams reduced 95% between the AlloX2-Pro and Dermaspan, which geometrically allowed more uniform coverage behind the port and reduced need for beam modulation. The beam perturbation of the AlloX2-Pro is well modeled, but improved agreement with measured WET values was observed when utilizing native densities in calculations. The AlloX2 Pro can support beam arrangements that traverse the ports, which can enable simpler beam geometry and a reduction in dose modulation around the port to promote improved robustness and treatment delivery quality.