Substrate Deposition Research Articles

Efficient and highly amplified imaging of nucleic acid targets in cellular and histopathological samples with pSABER.

In situ hybridization (ISH) is a powerful tool for investigating the spatial arrangement of nucleic acid targets in fixed samples. ISH is typically visualized using fluorophores to allow high sensitivity and multiplexing or with colorimetric labels to facilitate covisualization with histopathological stains. Both approaches benefit from signal amplification, which makes target detection effective, rapid and compatible with a broad range of optical systems. Here, we introduce a unified technical platform, termed 'pSABER', for the amplification of ISH signals in cell and tissue systems. pSABER decorates the in situ target with concatemeric binding sites for a horseradish peroxidase-conjugated oligonucleotide, enabling the localized deposition of fluorescent or colorimetric substrates. We demonstrate that pSABER effectively labels DNA and RNA targets in cultured cells and FFPE specimens. Furthermore, pSABER can achieve fivefold signal amplification over conventional signal amplification by exchange reaction (SABER) and can be serially multiplexed using solution exchange. Therefore, by linking nucleic acid detection to robust signal amplification capable of diverse readouts, pSABER will have broad utility in research and clinical settings.

Fracture Behavior of Hardfacing Alloy Coated Over Stainless Steel under Quasi-Static and Dynamic Loads

AbstractThe fracture behavior of bi-material made of Ni-Cr-B-Si hardfacing alloy deposited over SS316LN substrate was evaluated under quasi-static and dynamic loads. The crack growth started from notch made on the deposit side and progress toward the substrate deposit interface under both loading conditions was monitored. The displacement rate in quasi-static loading and the loading rate for dynamic loading varied and crack propagation was studied. It was observed that the crack was deflected at the interface and not penetrated to the substrate, irrespective of loading conditions. The reason for crack deflection at the interface was analyzed using the energy-based method. It is shown that the ratio of fracture toughness of the interface to that of the substrate (0.044) is lower than the ratio of energy release rate for the deflecting crack to that of the penetrating crack (0.235). Thus, this material combination satisfies the condition for crack deflection rather than penetration. The fracture toughness of the interface was estimated as ~ 68 MPa m1/2 and it falls between that of hardfacing alloy and SS316LN base metal. Optical and SEM examinations were conducted to corroborate the crack path deviations during crack growth. Results suggest that isolated cracks might be present on hardfaced coatings on critical components for which such cracks are usually not permitted. It may be allowed in preference to repair of these cracks, which is difficult and significantly increases the risk of additional cracks forming on the deposits because of the high susceptibility of the hardfacing alloy to cracking.

Microstructure and friction properties of NiTi2-based composite layer prepared by ultrasonic assisted underwater wet laser deposition

An in situ TiC-enhanced NiTi2-based composite deposition layer was prepared by ultrasonic assisted underwater wet laser deposition. The evolution of the microstructure and interface state, and the friction properties in the air and brine solution environments of the deposition layer were analyzed and researched. The results demonstrated that the thermal and steady-state cavitation from ultrasound effects increase the total energy of the melt pool and promote mixing. The dilution rate of the ultrasonic assisted underwater laser deposition layer increases to 86.72 % compared with that of the underwater laser deposition layer (78.75 %). Ultrasonic reduced underwater laser deposition defects such as lack of fusion and weld slag, and enhanced the wettability between the deposition layer and substrate. The contact angle of the UWNT layer (24.40°, in average) is smaller than the WNT layer (29.80°, in average). Ultrasonic shortened the contact time between the deposition layer surface and the solution, which reduced the reaction of the Ni element with the brine solution. It also transformed the deposition layer from hypereutectoid microstructure to hypoeutectic microstructure and from planar interface to cellular interface. With the effect of the ultrasonic field, the elements in the deposition layer become more uniformly distributed and the secondary phases undergo spheroidization. In the ultrasonic assisted deposition layer, stress-induced FCC-Ti was discovered. Ultrasonic field also reduced the dispersion of the microhardness and increased the average microhardness to 863.3 ± 45.1 HV0.3. Tribology properties show that ultrasonic field effectively improved the wear resistance and friction stability of the ultrasonic assisted deposition layer. The COF of the ultrasonic assisted deposition layer was less affected by the environment, with values of 0.25 and 0.24 observed in air and brine solution, respectively. Overall, the research results in this paper can provide a new insight to improve the surface properties of NiTi2-based alloy underwater laser deposition.

The Erosion Pattern and Hidden Momentum in Debris‐Flow Surges Revealed by Simple Hydraulic Jump Equations

AbstractThe erosion‐deposition propagation of granular avalanches is prevalent and may increase their destructiveness. However, this process has rarely been reported for debris flows on gentle slopes, and the contribution of momentum hidden under the surge front to debris‐flow destructiveness is ambiguous. Therefore, the momentum carried by the apparent surge front is often used to indicate debris‐flow destructiveness. In this study, the erosion‐deposition propagation is confirmed by surge‐depth hydrographs measured at the Jiangjia Ravine (Yunnan Province, China). Based on simple hydraulic jump equations, the eroded deposition depth of surge flow is quantified, and the erosion pattern can be divided into two patterns (shallow and deep erosion). For surge flows with erosion‐deposition propagation, significant downward erosion potential is confirmed, and debris‐flow surge erosion is considered the deep erosion. The total momentum carried by surge flow is further quantified by two Froude numbers (surge‐front and rearward Froude numbers) and verified through the field observation of surge flows. The total momentum of surge flow not only originates from the apparent surge front, but also includes the momentum within the eroded deposition layer. This study provides a theoretical approach for quantifying the upper limit of erosion depth and revealing the destructiveness of debris‐flow surges. A perspective on the importance of substrate deposition for debris‐flow erosion on gentle slopes is emphasized, as this approach can improve the reliability of debris‐flow risk assessment.

Long-term enzyme replacement therapy in Fabry patients protects against oxidative and inflammatory process.

Fabry disease (FD) is an X-linked recessive lysosomal storage disorder, characterized by a deficiency of α-galactosidase, which causes the progressive accumulation of glycosphingolipids, especially globotriaosylsphingosine (Gb3), in lysosomes across multiple organs. Substrate deposition, associated with tissue damage in FD, also contributes to the emergence of a pro-inflammatory state presented by some patients. We investigated pro- and anti-inflammatory cytokines, and the expression of inflammation-associated genes in treated FD patients, as well as oxidative parameters. We found a decrease in the production of cytokines IL-1β, IL-6, IL-10, and TNF-α in male FD patients and a normalization of redox status in male and female FD patients, once the levels of protein, lipid oxidation, and nitrite and nitrate content were like healthy individuals. Our results suggest that long-term ERT in men with FD contributes to the reduction of a pro-inflammatory scenario and a decrease of oxidative damage in patients, reflecting greater control throughout the disease and in the multisystemic changes characteristic of this disorder. These findings lead us to believe that long-term ERT can improve the redox status and protect these individuals against oxidative and nitrative stress, as well as the inflammatory process.

Microstructure and stress evolution of W nanofilms prepared by arc ion plating under different deposition time and substrate bias

Microstructure and stress evolution of W nanofilms prepared by arc ion plating under different deposition time and substrate bias

Colossal Dielectric Constant of Nanocrystalline/Amorphous Homo-Composite BaTiO3 Films Deposited via Pulsed Laser Deposition Technique.

We report the pulsed laser deposition (PLD) of nanocrystalline/amorphous homo-composite BaTiO3 (BTO) films exhibiting an unprecedented combination of a colossal dielectric constant (εr) and extremely low dielectric loss (tan δ). By varying the substrate deposition temperature (Td) over a wide range (300-800 °C), we identified Td = 550 °C as the optimal temperature for growing BTO films with an εr as high as ~3060 and a tan δ as low as 0.04 (at 20 kHz). High-resolution transmission electron microscopy revealed that the PLD-BTO films consist of BTO nanocrystals (~20-30 nm size) embedded within an otherwise amorphous BTO matrix. The impressive dielectric behavior is attributed to the combination of highly crystallized small BTO nanograins, which amplify interfacial polarization, and the surrounding amorphous matrix, which effectively isolates the nanograins from charge carrier transport. Our findings could facilitate the development of next-generation integrated dielectric devices.

Advancements in biomedical coatings: A comprehensive review of DC magnetron sputtering on Ti–6Al–4V alloy

This study investigates the application of DC magnetron sputtering (MS) technology for producing TiN and ion-substituted Ca-P coatings on dental implant materials, demonstrating ultimate tensile strength (UTS) of 887 MPa, a modulus of elasticity of 11.3 × 106 MPa. The influence of various physical vapor deposition (PVD-MS) parameters—such as substrate temperature, post-heat treatment, deposition duration, discharge power, and bias voltage—on the characteristics of these coatings is examined. The research evaluates the advantages and limitations of PVD-MS in fabricating TiN and Ca-P coatings, with an emphasis on their impact on surface topography and chemical composition, which are critical factors influencing cellular behavior. The study reveals that while ion-substituted HA coatings can enhance cell adhesion, they may also exhibit cytotoxic effects, potentially limiting cell growth. It compares osteogenic cell proliferation rates between low-crystalline HA coatings and highly crystalline variants on Ti-based substrates, highlighting significant performance disparities. Additionally, PVD-MS demonstrates robust adhesion capabilities and facilitates the incorporation of therapeutic ions, effectively replicating bioapatite properties. The addition of coating on the substrate promotes additional strengthening mechanisms of the layers, leading to improved wear resistance compared to an alloyed substrate. Estimated values for hardness range between 7.2 and 8.4 GPa, and for Young's modulus, they range from 126 to 162 GPa. The study highlights the potential of PVD-MS in creating nanostructured Ca-P coatings on biodegradable metals, alloys, and polymeric biomaterials. This technology improves corrosion resistance, biocompatibility, chemical stability, wear resistance, and overall performance in various biomedical applications.

Substrate and potential-driven surface morphology of bifunctional Ni-Fe electrode for efficient alkaline water electrolysis

Nickel-iron (Ni-Fe) alloy electrodes are synthesized using chronoamperometry. The influence of substrate type (copper, stainless steel, and nickel) and deposition potential on the structural, morphological, and electrocatalytic characteristics are systematically investigated. X-ray diffraction (XRD) analysis revealed the formation of a face-centered cubic (FCC) Ni-Fe alloy. Electrodeposition at higher potential (−1.45 V) forms well-defined nanoflakes, whereas electrodeposition at lower potential (−1.00 V) results aggregated Ni-Fe particles. The Ni-Fe alloy electrodes having well-defined nanoflakes demonstrated superior electrocatalytic performance, exhibiting a overpotential of −168 mV vs. RHE for the hydrogen evolution reaction (HER) and 236 mV vs. RHE for the oxygen evolution reaction (OER), at current density of 10 mA/cm2. The enhanced electrocatalytic activity of the nanoflakes based Ni-Fe alloy is attributed due to their larger catalytic surface area, porous morphology and higher Fe concentration. The Ni-Fe alloy electrodes displayed bifunctional electrocatalytic behavior, making them highly suitable for both HER and OER processes.

Laser directed energy deposition remanufacturing of LPBF-processed TA15 parts: Hybrid process interface induced microstructure inheritance and mechanical performance

The laser additive hybrid manufacturing technology, which combines the precision of Laser Powder Bed Fusion (LPBF) and the flexibility of Laser Directed Energy Deposition (LDED), provides an effective solution for efficient forming and remanufacturing of large, complex components. The bonding zone (BZ) between LPBF and LDED forming regions is crucial for the final component performance. This study utilized LDED to remanufacture annealed LPBF substrates and investigated the microstructure and mechanical properties of TA15 alloy remanufactured parts. Results shows that a gradient microstructure forms at the bonding zone (BZ), where the bottom region exhibits a mixed structure including transitional β phase (βt), lamellar α and secondary α phase (αs). The top region shows a "ghost structure" of fine needle-like α phases. The mechanical property matched the microstructure well, as the hardness in the upper BZ reaches up to 463 MPa, whereas the LFZ exhibits the lowest hardness at 401 MPa. As the angle between the LDED region edge and tensile direction increases, the tensile strength first increases and then stabilizes, while elongation increases initially and then decreases. At a tilt angle of 60°, the strength peaks at 1098 MPa; at a 30° angle, the elongation reaches a maximum of 10.336%. All samples fracture at the LPBF zone, indicating that the formation of fine lamellar α phases in the BZ contributes to its higher strength compared to LPBF substrate and LDED deposition zones.

Evaluating the Hydrogen Evolution Reaction Activity of Colloidally Prepared PtSe2 and PtTe2 Catalysts in an Alkaline Medium.

The hydrogen evolution reaction (HER) in alkaline electrolytes using transition metal dichalcogenides is a research area that is not tapped into. Alkaline HER ( ) is harder to achieve relative to acidic HER ( ), this is attributed to the additional water dissociation step that occurs in basic HER to generate H+ ions. In fact, for most catalysts, their HER activity decreases tremendously when the electrolyte is changed from acidic to basic conditions. Platinum dichalcogenides, PtX2 (X=S, Se, Te), are an interesting member of transition metal dichalcogenides (TMDs) as these show an immense hybridization of the Pt d orbitals and chalcogen p orbitals because of closely correlated orbital energies. The trend in electronic properties of these materials changes drastically as the chalcogen is changed, with PtS2 reported to exhibit semi-conductor properties, PtSe2 is semi-metallic or semi-conductive, depending on the number of layers, while PtTe2 is metallic. The effect of varying the chalcogen atom on the HER activity of Pt dichalcogenides will be studied. Pt dichalcogenides have previously been prepared by direct high-temperature chalcogen deposition of Pt substrate and evaluated as electrocatalysts for HER in H2SO4. The previously employed synthesis procedures for PtX2 limit these compounds' mass production and post-synthesis treatment. In this study, we demonstrated, for the first time the preparation of PtSe2 and PtTe2 by colloidal synthesis. Colloidal synthesis offers the possibility of large-scale synthesis of materials and affords the employment of the colloids at various concentrations in ink formulation. The electrochemical HER results acquired in 1 M KOH indicate that PtTe2 has a superior HER catalytic activity to PtSe2. A potential of 108 mV for PtTe2 and 161 mV for PtSe2 is required to produce a current density of -10 mA cm-2 from these catalysts. PtTe2 has a low Tafel slope of 79 mVdec-1, indicating faster HER kinetics on PtTe2. Nonetheless, the stability of these catalysts in an alkaline medium needs to be improved to render them excellent HER electrocatalysts.

Plasma-chamber wall interaction and its impact on polymer deposition in inductively-coupled C4F8/Ar plasmas

Plasma processing chambers, key tools in semiconductor device fabrication, must be meticulously maintained to ensure tool-to-tool matching. Processing chamber walls are liable to contamination with fluorocarbon (CxFy) film, which acts as a source and/or sink for active species during plasma processes. This contamination potentially affects processing quality and alters the plasma properties, increasing deviations between processing chambers. However, quantitative studies on the impact of wall contamination on the substrate deposition outcomes have been limited. Additionally, spatially resolved investigations are crucial for understanding the plasma-wall interaction. Therefore, this study evaluated the influence of polymer (CxFy) film wall contamination on plasma deposition via various plasma diagnostics and surface analyses. When the chamber inner wall was coated with polymer film, the thickness, surface roughness, and chemical composition of the deposited film on the bottom substrate were more uniform. These results were linked to alterations in the uniformity of active species in the plasma, such as CF2 and F, resulting from interaction with the polymer film on the wall's surface. The C–Fx and C–CFx composition ratios in the wall-coated films dramatically reduced, indicating that this film supplied the depositing precursors to the plasma. These results suggest that controlling the chamber wall conditions is important to maintain tool-to-tool matching and modulate the processing performance.

Tuning interfacial molecular asymmetry to engineer protective coatings with superior surface anchoring, antifouling and antibacterial properties

Multifunctional robust protective coatings that combine biocompatibility, antifouling and antimicrobial properties play an essential role in reducing host reactions and infection on invasive medical devices. However, developing these protective coatings generally faces a paradox: coating materials capable of achieving robust adhesion to substrates via spontaneous deposition inevitably initiate continuous biofoulant adsorption, while those employing strong hydration capability to resist biofoulant attachment have limited substrate binding ability and durability under wear. Herein, we designed a multifunctional terpolymer of poly(dopamine methyacrylamide-co-2-methacryloyloxyethyl phoasphorylcholine-co-2-(dimethylamino)-ethyl methacrylate) (P(DMA-co-MPC-co-DMAEMA)), which integrates desired yet traditionally incompatible functions (i.e., robust adhesion, antifouling, lubrication, and antimicrobial properties). Direct normal and lateral force measurements, dynamic adsorption tests, surface ion conductance mapping were applied to comprehensively investigate the nanomechanics of coating-biofloulant interactions. Catechol groups of DMA act as basal anchors for robust substrate deposition, while the highly hydrated zwitterion of MPC provides apical protection to resist biofouling and wear. Moreover, the antimicrobial property is conferred through the protonation of tertiary amine groups on DMAEMA, inhibiting infection under physiological conditions. This work provides an effective strategy for harmonizing demanded yet incompatible properties in one coating material, with significant implications for the development of multifunctional surfaces towards the advancement of invasive biomedical devices. Statement of significanceMultifunctional robust protective coatings have been widely utilized in invasive medical devices to mitigate host responses and infection. However, modified surface coatings often encounter a trade-off between robust adhesion to substrates and strong hydration capability for antifouling and antimicrobial properties. We propose a universal strategy for surface modification by dopamine-assisted co-deposition with a multifunctional terpolymer of P(DMA-co-MPC-co-DMAEMA) that simultaneously achieves robust adhesion, antifouling, and antimicrobial properties. Through elucidating the nanomechanics with fundamentally understanding the interactions between the coating and biomacromolecules, we highlight the role of DMA for substrate adhesion, MPC for biofouling resistance, and DMAEMA for antimicrobial activity. This approach presents a promising strategy for constructing multifunctional coatings on minimally invasive medical devices by tuning interfacial molecular asymmetricity to reconcile incompatible properties within one coating.

Omitting the Application of Nitrogen or Potassium Reduced the Growth of Young Chestnut (Castanea sativa) Trees, While a Lack of Boron Decreased Fruit Yield

The chestnut tree (Castanea sativa Mill.) is gaining importance in the mountainous regions of southern Europe due to the high value of its fruits. It is essential to establish effective cultivation protocols, considering that this species is still relatively understudied. In this study, we present the outcomes of the initial establishment of a chestnut orchard conducted through a nutrient omission trial for four years. The treatments included a fertilization plan with nitrogen, phosphorus, potassium, and boron (NPKB), the control, and four other treatments corresponding to the omission of each nutrient (-NPKB, N-PKB, NP-KB, NPK-B). The -NPKB and NP-KB treatments showed significantly lower trunk circumferences and canopy volumes compared to the other treatments. The NPK-B treatment resulted in the lowest fruit production, with a total accumulated yield (2020–2022) of 0.56 kg tree–1, a value significantly lower than that of NPKB (1.12 kg tree–1) and N-PKB (1.19 kg tree–1). The assessment of nutrient concentrations in the leaves revealed plants with deficient levels of B and K in treatments that did not receive these nutrients. Conversely, N levels in the leaves in the -NPKB treatment fell within the sufficiency range (20 to 28 g kg–1). This suggests that the sufficiency range should be adjusted to higher values, given the treatment’s effect on tree growth. It was also observed that the -NPKB treatment led to lower soil organic matter compared to the other treatments, likely due to reduced herbaceous vegetation development under the canopy, leading to decreased organic substrate deposition in the soil. The main findings of this study are that N and K were crucial elements for the optimal growth of chestnut trees, while B played a significant role in fruit production.

Research on the Corrosion Resistance of Electrodeposited Ni-SiC Composites Constructed for Steel Storage Tank Application.

In this paper, the effects of the SiC phase incorporated in Ni substrate deposits on storage tank steel during electrodeposition at different current densities are explored. The microstructure, phase content, and corrosion resistance of the resulting Ni-SiC composites were investigated by scanning electron microscopy (SEM) matched with energy disperse spectroscopy (EDS), X-ray diffraction (XRD), and an electrochemical workstation, respectively. SEM micrographs and EDS results show that at 2.5 A/dm2, the composites presented a smooth and compact structure with high SiC content, while at 1.8 or 3.2 A/dm2, it became uneven and loose in structure with low SiC content. XRD patterns showed that the nickel grain size of composites firstly increased and then decreased with the growth of the current density. Notably, the Ni-SiC composite produced at 2.5 A/dm2 possessed a higher corrosion potential (-0.507 V) and lower corrosion current density (2.439 μA/cm2), illustrating that its excellent anti-corrosion ability was superior than that of other two composites. Hence, SiC co-deposited at 2.5 A/dm2 conducted as a protective barrier and inhibited the corrosion rate against a corrosion medium of Cl- and SO42- ions. In addition, the corrosion relationship illustrated that the SiC content of Ni-SiC composite firstly increased and then decreased with the growth of the current density, while the corrosion weight loss of Ni-SiC composites firstly decreased and then increased.

Innovative Tin and hard carbon architecture for enhanced stability in lithium-ion battery anodes

Tin (Sn), with a theoretical capacity of 994 mAh g-1, is a promising anode material for lithium-ion batteries (LIBs). However, fundamental limitations like large volume expansion during charge-discharge cycle and confined electronic conductivity limit its practical utility. Here, we report a new material design and manufacturing method of LIB anodes using Sn and Hard Carbon (HC) architecture, which is produced by Physical Vapor Deposition (PVD). A bilayer HC/Sn anode structure is deposited on a carbon/copper sheet as a function of deposition time, temperature, and substrate heat treatment. The developed anodes are used to make cells with a lithium-ion electrolyte using a specific fabrication process. The morphology, atomic structure, conductivity, and electrochemical performance of the developed HC/Sn anodes are studied with SEM, TEM, XPS, and electrochemical techniques. At a discharge rate of 0.1C, the Snheated + HC anode performs exceptionally well, offering a capacity of 763 mAh g-1. It is noteworthy that it achieves a capacity of 342 mAh g-1 when fast charging at 5C, demonstrating exceptional rate capability. The Snheated + HC anode maintains >97 % Coulombic efficiency of its capacity after 3000 cycles at a rate of 0.1C after 3000 cycles 730.5 mAh g-1 recorded, demonstrating an impressive cycle life. The novel material design approach of the Snheated + HC anode, which has a multi-layered structure and HC acting as a barrier against volumetric expansion and improving electronic conductivity during battery cycling, is perceived as influential in uplifting anode's performance.

Investigation on the effects of deposition strategy on the mechanical characteristics and microstructure of austenitic stainless steel 308LSi manufactured via wire arc additive manufacturing

This study examines the impact of deposition strategy on ASS 308LSi thin-walled structure manufactured via the Wire Arc Additive Manufacturing (WAAM) technique on the microstructural characteristics, tensile strength, microhardness, Charpy impact testing, and fracture morphology of the WAAM 308LSi. The analysis of the microstructure reveals that the deposition strategy promotes transitioning from columnar to equiaxed fine grain structure. The tensile strength results show that specimens with a 45° deposition strategy exhibit lower anisotropy and higher tensile properties compared to those with a 0° deposition strategy, with improvements of 33.1% in the transverse direction and 26.7% in the longitudinal deposition directions, respectively. The microhardness in WAAM SS308LSi demonstrates variations in the bottom, middle, and top regions, with the highest average value observed at a 45° deposition strategy (213.3 ± 6.5 HV, 201.1 ± 10.7 HV, and 191.5 ± 5.2 HV) as well. The impact testing results indicate that the highest absorbed energy occurs at a 45° deposition strategy, with 75 ± 4.2 J and 74 ± 4.0 J for the transverse and longitudinal directions, respectively. The fractures observed during testing exhibit ductile characteristics, with the presence of dimples and particles. This study demonstrates the significant potential of the 45° deposition strategy with the implementation of double-sided substrate deposition, resulting in a refined microstructure, nearly isotropic behavior, and excellent mechanical performance.

Electroplating of zinc onto polyelectrolyte complex membranes as anode for aqueous zinc-ion batteries

Conventionally, the anode of a primary Aqueous zinc-ion batteries (ZIBs) is metallic and rigid, which made it difficult to integrate into flexible designs. In this research, a composite polyelectrolyte complex (PEC) with cationic poly(diallyldimethylammonium chloride), anionic poly(sodium-4-styrenesulfonate) and carbon black (CB) as conductive filler (PEC-CB) was developed as an anode substrate for zinc deposition via electroplating technique. The Zinc-electroplated PEC-CB (Zn-PEC-CB) anode was characterized using electron microscopy and X-Ray diffraction analysis to verify the successful zinc coating. The Zn-PEC-CB was then assembled with PEC-CB-MnO cathodes in an ZIB setup. The results demonstrated the potential of PEC-based electrodes as a promising alternative to conventional materials in ZIBs, encouraging further exploration in energy storage applications.

Peak microhardness recovery via T6 heat treatment with extremely soft annealed Al7075 feedstock in additive friction stir deposition

With standard T6 heat treatments, precipitate-hardened alloys such as Al7075 and Al6061 fabricated using Additive Friction Stir Deposition (AFSD) method restore to noticeablely different peak mechanical properties. Previous research observed similar results but did not provide a viable solution. This study proposes a new processing strategy, namely enhanced plastic deformation by subjecting the Al7075 feedstock to annealed softening treatments. Specifically, by annealing the standard T651-Al7075 feedstock and deposition substrate (179 HV), their Microhardness were first degraded to its lowest state (80 HV), which is called a Soft-to-Soft system. For the Soft-to-Soft system subjected to AFSD, after undergoing appropriate T6 heat treatment, the microhardness of the AFSD 7075 alloy was restored to its peak value (183.1 ± 1.8 HV). The results indicate that this softening strategy can effectively reduce the non-strengthening phase in the AFSD matrix, thereby increasing the strengthening phase (η′ phase). This addresses the issue of traditional AFSD-prepared aluminum alloys being unable to achieve peak performance through T6 heat treatment.

Effects of growth rate and dynamic substrate tilt on properties of Au-Ta alloy films deposited by high-power impulse magnetron sputtering

Gold‑tantalum (AuTa) alloys are promising for next-generation hohlraums for magnetically-assisted indirect-drive inertial confinement fusion. Hohlraum fabrication involves sputter deposition of ultrathick coatings on sphero-cylindrical substrates. The control of physical properties of such coatings remains a challenge. Here, we systematically study effects of the growth rate and dynamic substrate tilt on properties of AuTa4 films deposited onto rotating planar substrates mounted at different tilt angles to mimic different regions of the sphero-cylindrical surface of a hohlraum. We use high-power impulse magnetron sputtering (HiPIMS) in the constant charge per pulse mode with a pulse duration of 100 μs, a charge per pulse of 190 μC, a peak target current of about 3 A, and the pulse frequency varied in the range of 400–1400 Hz. The Langmuir probe, mass-resolved ion energy spectrometry, and optical emission spectroscopy are used to monitor plasma discharge characteristics in order to isolate and study effects of the growth rate. The deposition rate and the ballistics and energetics of depositing species are estimated by Monte Carlo simulations. Results show that the film microstructure, crystallographic phase, residual stress, and electrical resistivity strongly depend on both the deposition rate and substrate tilt, highlighting their critical role in tailoring properties of AuTa films during hohlraum fabrication.