Mechanical Strength Characterization Research Articles

Machine learning-enabled characterization of concrete mechanical strength through correlation of flexural and torsional resonance frequencies

In this study, an assessment of concrete compressive strength was conducted using an impulse excitation data-driven machine learning (ML) framework. The model was constructed upon a deep neural network and aided by the backpropagation method, ensuring a precise training process. In contrast to prior research, which mainly focused on mixture components, a meaningful relationship between physical parameters—resonant frequencies and elastic moduli—and compressive strength was established by our ML model. Remarkable performance was demonstrated, with a root mean square error value of 2.8MPa and a determination factor of 0.97. Through Pearson analysis, correlations between input features and output targets, ranging from −0.29 to 0.90, were revealed. Notably, the strongest correlations with compressive strength were found in Young's and shear moduli, derived from flexural and torsional frequencies, highlighting the pivotal role of dynamic elastic response in concrete's mechanical behavior. Furthermore, the findings indicated slight prediction deviations in cases involving samples with a high Poisson's ratio. This work illuminates the potential for accurate compressive strength prediction by leveraging concrete's dynamic response, particularly flexural and torsional modes, thereby opening avenues for research into concrete compressive strength without direct consideration of sample ingredients.

Characterization of Mechanical Strength of Shingle Joints Using Die Shear Tests

For shingle interconnection there is no standard method to characterize the mechanical strength of the shingled joints. Therefore, we studied a die shear test for this purpose. In the first part, a single epoxy-based electrically conductive adhesive (ECA) was used in an industrial shingle stringer to produce shingle strings with different ECA printing widths and curing temperatures. It was observed that the printed ECA area increases at higher curing temperatures due to the increased formation of voids. Shear strength increased with elevating the curing temperature. In the second part of the study, three ECAs with varying glass transition temperature (Tg) were analysed with dynamic mechanical analysis (DMA). The shear strength of the ECAs correlates with the flexibility of the materials. ECA A, with the highest Tg, had the highest shear strength with an average of (25 ± 3) MPa, and ECA B with an average of (24 ± 9) MPa while ECA C had the lowest shear strength with an average of (15 ± 9) MPa. After characterising the shingled full-format PV modules produced using the three ECAs with electroluminescence and I–V measurements, it was found that the flexibility of the ECAs and the shear strength of the shingled joints had a very small effect on the module performance after thermal cycling 200 and mechanical load 5400 Pa. The ECAs with higher Tg showed more cell fracture but with negligible power loss. The ECA with the lowest Tg led to subtle joint degradation during the tests.

Mechanical strength characterization and seismic performance of rammed earthen walls built on eco-friendly lateritic soil and sustainable stabilizing materials

Mechanical strength characterization and seismic performance of rammed earthen walls built on eco-friendly lateritic soil and sustainable stabilizing materials

Influence of graphene oxide in the hydration mechanism by reinforcing mechanical strength and microstructural Characterization of ultra-high-performance concrete (UHPC)

In the past few years, one of the most promising graphite-based nanomaterials in the construction industry has been Graphene Oxide (GO) due to its outstanding performance combined with cementitious composites. Introducing extensive Engineering Cementitious Materials (ECMs) improves Ultra-High-Performance Concrete (UHPC) mechanical, durability, and microstructural characteristics. Very few studies have been concentrated on cement pastes, mortars, and regular concrete, high strength concrete. Limited studies on UHPC with large volumes of ECMs done. The present investigation mainly focuses on improving the UHPC in fresh, mechanical, and microstructural behavior. Four mixes were prepared with GO (0.00%, 0.03%, 0.06%, and 0.1% by weight of cement) and a water-cement ratio of 0.20. Results indicated that the mix with 0.06% GO had a better outcome and improved the compressive, split tensile, and flexural strength compared with other test mixes. Microstructural analysis carries out using x-ray fluorescence (XRF), x-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-dispersive x-ray Spectroscopy (EDS), Thermogravimetric Analysis (TGA), Fourier-Transform Infrared Spectroscopy (FTIR), Fourier-Transform Raman Spectroscopy (FT-RAMAN) on 28 days UHPC mixes and quality of the concrete mixes analyzed with Ultrasonic Pulse Velocity (UVP) test. They developed and established the fundamental step toward the cost-effective, eco-friendly, sustainable UHPC.

Facile preparation, characterization, and investigation of mechanical strength of Starchy NaCl-binder as a lightweight construction material

Sodium chloride (NaCl), commonly known as salt, is a substance that is utilized in a variety of businesses, including the tourism and construction industries. Therefore, the main purpose of this article is to accommodate a salt-based building material called NaCl-binder for tourist and industrial applications. By utilizing salt mortar with varying grain sizes, food-grade corn starch as an exclusive binder agent (without using any non-starch binder), and water under microwave-cured conditions, environmentally friendly hydrophobic hybrid NaCl-binder samples with low bulk density were successfully produced. The fabrication of these samples involved an inventive utilization of small quantities of starch. This study evaluated the impact of microwave exposure time on the strength of salt samples, particle interconnectivity and chemical composition using SEM, XRD, and XRF analyses. The compressive strength of the samples showed a remarkable increase, with a 600% improvement when using 0 to 1% corn starch, and a 137% increment when using 1 to 10% corn starch, indicating a lower rate of increment with higher starch consumption. A key aspect of this research is the significant reduction in starch consumption compared to other corn starch-based materials during the manufacturing process of the incorporated materials, highlighting its novelty and importance.

A high-throughput phenotyping method for sugarcane rind penetrometer resistance and breaking force characterization by near-infrared spectroscopy

BackgroundSugarcane (Saccharum spp.) is the core crop for sugar and bioethanol production over the world. A major problem in sugarcane production is stalk lodging due to weak mechanical strength. Rind penetrometer resistance (RPR) and breaking force are two kinds of regular parameters for mechanical strength characterization. However, due to the lack of efficient methods for determining RPR and breaking force in sugarcane, genetic approaches for improving these traits are generally limited. This study was designed to use near-infrared spectroscopy (NIRS) calibration assay to accurately assess mechanical strength on a high-throughput basis for the first time.ResultsBased on well-established laboratory measurements of sugarcane stalk internodes collected in the years 2019 and 2020, considerable variations in RPR and breaking force were observed in the stalk internodes. Following a standard NIRS calibration process, two online models were obtained with a high coefficient of determination (R2) and the ratio of prediction to deviation (RPD) values during calibration, internal cross-validation, and external validation. Remarkably, the equation for RPR exhibited R2 and RPD values as high as 0.997 and 17.70, as well as showing relatively low root mean square error values at 0.44 N mm−2 during global modeling, demonstrating excellent predictive performance.ConclusionsThis study delivered a successful attempt for rapid and precise prediction of rind penetrometer resistance and breaking force in sugarcane stalk by NIRS assay. These established models can be used to improve phenotyping jobs for sugarcane germplasm on a large scale.

Studies on Multi-step Addition of NMP in (LiNi0.80Co0.15Al0.05) (NCA) Cathode Slurry Preparation and its Rheological, Mechanical Strength and Electrochemical Properties for Li-ion Cells

For electrode stability and the electrochemical performance of the Li-ion cell, it is essential that the active ingredients and unique additives in the polymer binder be well dispersed with the solvent-based slurry. The efficient procedure used to create the slurry affects the rheological characteristics of the electrode slurry. When successively adding different steps of N-methyl-2-pyrrolidone (NMP) solvent to the cathode composition, it is evenly disseminated. The electrochemical performance of the Li-ion cells and the electrodes made with slurry formed by single step and multiple steps of addition of NMP solvent are examined. To preform rheological properties of cathode electrode slurry on Ni-rich Lithium Nickel-Cobalt-Aluminum Oxide (LiNi0.80Co0.15Al0.05) (NCA). Also, we investigate different step addition of electrode formation and mechanical strength characterization like peel strength. According to the EIS study, a multi-step electrode slurry has lower internal resistance than a single-step electrode slurry, which results in better electrical characteristics and efficiency. Further, microstructure of electrodes is obtained electrochemical performance in the 18650 cylindrical cells with targeted capacity of 1.5 Ah. The slurry of electrodes prepared by single step and multiple steps of addition of NMP solvent and its effect on the fabrication of 1.5 Ah cells. A three-step solvent addition on slurry has been found to be a lower internal resistance than a single-step electrode slurry as confirmed by the EIS analysis, yielding improved electrical properties and efficiency.

Effects of Carbonization Temperature on Mechanical and Thermal Insulation Properties of Carbon Aerogel Composites using Phenolic Fibers as Reinforcement

A series of carbon fiber-reinforced carbon aerogel composites (C/CAs) were prepared via carbonizing phenolic fibers impregnated organic aerogel at temperatures ranging from 1,000 to 1,600°C. Phenolic fiber as soft reinforcement shrinks synchronously with the aerogel matrix during the preparation process, which effectively avoided microcracks and achieved an excellent reinforcement effect. The effects of carbonization temperatures on the mechanical and thermal insulation properties of the C/CAs were investigated via pore structural and morphological analysis, as well as the characterization of mechanical strength and thermal conductivity. The results show that the compressive strength of C/CA is 1.26–2.14 MPa in xy-direction and 0.55–1.20 MPa in z-direction. The obtained bending strength range from 1.92 to 3.62 MPa with the carbonization temperature increase from 1,000 to 1,600°C. The thermal conductivity of C/CA-1000 at 1,800°C is 0.1637 W·m−1·K−1 while that of reached 0.2713 W·m−1·K−1 of C/CA-1600. Further study found that the change of porosity and pore size caused by the closure of micropores at high temperatures should be responsible for performance evolution.

Effects of Sterilization and Hydrolytic Degradation on the Structure, Morphology and Compressive Strength of Polylactide-Hydroxyapatite Composites.

Composites based on polylactide (PLA) and hydroxyapatite (HA) were prepared using a thermally induced phase separation method. In the experimental design, the PLA with low weight-average molar mass (Mw) and high Mw were tested with the inclusion of HA synthesized as whiskers or hexagonal rods. In addition, the structure of HA whiskers was doped with Zn, whereas hexagonal rods were mixed with Sr salt. The composites were sterilized and then incubated in phosphate-buffered saline for 12 weeks at 37 °C, followed by characterization of pore size distribution, molecular properties, density and mechanical strength. Results showed a substantial reduction of PLA Mw for both polymers due to the preparation of composites, their sterilization and incubation. The distribution of pore size effectively increased after the degradation process, whereas the sterilization, furthermore, had an impact on pore size distribution depending on HA added. The inclusion of HA reduced to some extent the degradation of PLA quantitatively in the weight loss in vitro compared to the control without HA. All produced materials showed no cytotoxicity when validated against L929 mouse skin fibroblasts and hFOB 1.19 human osteoblasts. The lack of cytotoxicity was accompanied by the immunocompatibility with human monocytic cells that were able to detect pyrogenic contaminants.

Preparation and Characterization of High Mechanical Strength Chitosan/Oxidized Tannic Acid Composite Film with Schiff Base and Hydrogen Bond Crosslinking.

Chitosan-based composite films with good biodegradability, biocompatibility, and sustainability are extensively employed in the field of food packaging. In this study, novel chitosan/tannic acid (CTA) and chitosan/oxidized tannic acid (COTA) composite films with excellent mechanical and antibacterial properties were prepared using a tape casting method. The results showed that, when 20% tannic acid (TA) was added, the tensile strength of the CTA composite film was 80.7 MPa, which was 89.4% higher than that of the pure chitosan (CS) film. TA was oxidized to oxidized tannic acid (OTA) with laccase, and the phenolic hydroxyl groups were oxidized to an o-quinone structure. With the addition of OTA, a Schiff base reaction between the OTA and CS occurred, and a dual network structure consisting of a chemical bond and hydrogen bond was constructed, which further improved the mechanical properties. The tensile strength of 3% COTA composite film was increased by 97.2% compared to that of pure CS film. Furthermore, these CTA films with significant antibacterial effects against Escherichia coli (E. coli) are likely to find uses in food packaging applications.

Assessment of mechanical and micro-structural characterization of novel ambient cured cement-free composite concrete

To minimize the utilization of natural resources & consuming of huge energy and in order to control the global warming, industrial waste based geopolymer has attracted by the researchers. The manufacturing of GGBS-FA based Geopolymer Concrete (GFGPC) are essential due to its cost-effective reuse by recycling the industrial wastes. The impact of various quantities of Ground Granulated Blast-furnace Slag (GGBS), activator concentration, alkaline solution to solid ratios and liquid ratios of silicate to hydroxide of sodium on experimented mechanical strength and microstructural characterization are investigated. The novelty and research significance lie in adoption of ambient curing techniques, reduced time interval between Alkali Activator Solution (AAS) preparation and concrete casting from 24 h to 3–6. It was observed that with decrease of GGBS content from 70% to 30%, compressive strength at 28 days was reduced from 53 MPa to 36 MPa. A mix containing 40–50% GGBS, AAS to binder ratio of 0.45–0.55, 7 M(Molar) solution of Sodium Hydroxide (SH), ratio of sodium silicate (SS) to sodium hydroxide (SH) of 1.5–2.0 along with 3–6 h of time interval between AAS preparation and concrete casting were proposed as an optimum design mix with respect to compressive strength, workability and setting time. The empirical predictions of splitting-tensile strength and flexural strength of developed GFGPC were made based on the experimental laboratory results and made comparisons with respect to the equations of ACI 318, Eurocode 2, AS 3600 and IS 456 for OPC based conventional concrete (CCOPC) and others existing literature for GPC. Additionally, XRF, XRD, FESEM and EDS were conducted to investigate the microstructural properties and the reaction mechanism of GFGPC.

Pressure-Assisted Development and Characterization of Al-Fe Interface for Bimetallic Composite Castings: An Experimental and Statistical Investigation for a Low-Pressure Regime

A review of the available literature indicates that the development of metal-reinforced castings present intriguing prospects but carry inherent challenges owing to differences in thermal coefficients, chemical affinities, diffusion issues and the varying nature of intermetallic compounds. It is supported that pressure application during solidification may favorably influence the dynamics of the aforementioned issues; nevertheless, not only certain limitations have been cited, but also some pressure and process regimes have not yet been investigated and optimized. This work employs the pressure-assisted approach for bimetallic steel-reinforced aluminum composite castings at a low-pressure regime and thoroughly investigates the role of three process parameters, namely pouring temperature (800–900 °C), pressure (10–20 bars) and holding time (10–20 s), for producing sound interfaces. The Taguchi L9 orthogonal array has been employed as the Design of the Experiment, while dominant factors have been determined via analysis of variance and the grey relational analysis multi-objective optimization technique. Supplementary analysis through optical micrographs, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) has been utilized to quantify interfacial layer thicknesses and to study microstructural and compositional aspects of the interface. Nano-indentation tests under static and dynamic loading have also been performed for mechanical strength characterization. It has been found that uniform interfaces with verifiable diffusion are obtainable, with the pouring temperature being the most influential parameter (percentage contribution 92.84%) in this pressure regime. The experiments performed at optimum conditions of pouring temperature, applied pressure and holding time produced a ~328% thicker interface layer, 19.42% better nano-hardness and a 19.10% improved cooling rate as compared to the minimum input values of the said parameters.

Review of Nanocomposite Dielectric Materials With High Thermal Conductivity

Dielectric materials with high thermal conductivity (TC) can enable disruptive performance enhancement in the areas of electronics packaging, thermal management, energy storage, cabling, and heat sinks. There have been widespread global efforts over the past decade on developing novel nanocomposite dielectric materials. As a baseline, legacy polymers and epoxies used in the abovementioned applications have very low thermal conductivities ranging from 0.1-0.5 W·m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> ·K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . Recent advances have led to the commercial availability of polymeric materials with thermal conductivities approaching 10 W·m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> ·K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . Importantly, several fundamental studies report novel nanocomposites with thermal conductivities > 50 W·m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> ·K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . This article summarizes progress in the development of such materials with a focus on developments that show promise for improved practical dielectrics. This review highlights that high TC alone is inadequate to characterize the suitability of any material for the above applications. Other thermal properties, such as thermal diffusivity, glass transition temperature, and the ratio of the in-plane to out-of-plane TC, are important to quantify the thermal performance of novel nanocomposites. In addition, characterization and understanding of mechanical properties (coefficient of thermal expansion (CTE), tensile strength and elastic modulus) and electrical properties (dielectric strength and dielectric permittivity) are critical for holistic multifunctional assessments of these materials. There are other parameters and properties that influence performance, life, and manufacturability, such as viscosity and moisture absorption. This study reviews all the above aspects of nanocomposite dielectric materials reported in the literature. More specifically, we analyze various filler-polymer combinations, and the influence of approaches to incorporate fillers in the polymer on the thermal, mechanical, and electrical properties. While the addition of fillers leads to huge enhancements in TC, the TC is highly anisotropic, with out-of-plane TC lower than in-plane TC by an order of magnitude. It is seen that most present-day materials are still inadequate for future applications due to their low glass transition temperatures; specific promising materials are highlighted. While the addition of fillers reduces the CTE, further reduction is needed to favorably improve the mechanical performance of these materials. While the electrical insulating properties of these composite materials are adequate, there is very little data reported on other electrical properties. In summary, while there is an understandable focus on enhancing the TC, other properties are underreported, and there is insufficient information to support the assessment of most novel materials for practical applications. Overall, this study summarizes the state-of-the-art dielectric nanocomposites and outlines directions for future research to bridge the gap between basic materials science and applications.

Mechanical strength characterization and modeling of hydroxyapatite/tricalcium phosphate biocomposite using the diametral-compression test

This study reports the enhanced mechanical resistance of the composite bioceramics of hydroxyapatite (HAP) and tricalcium phosphate (β-TCP) used as bone substitute. HAP/β-TCP mixture was prepared by wet mixing of powders and characterized. Effects of powder manufacturing and sintering temperature on the densification, microstructure and mechanical properties of the composite were studied. The rupture strength (σr) was calculated using the Brazilian test. At 1250 °C, the relative density and mechanical strength of the HAP/β-TCP ceramics reached the maximum value of 89% and 43 MPa, respectively. Experimental results were modeled by the finite element method to determine the stress distribution in the compacted disc.

Mechanical Strength Characterization of Plastic Fiber Reinforced Cement Concrete Composites

The reinforcing efficiency of plastic fibers obtained from shredded plastic waste was tested in plain concrete mixes and experimentally verified in this study. Plastic fibers up to 0.15% Vf were added to the design concrete mix to assess the fiber effectiveness in terms of improved load carrying capability of various plastic fiber incorporated concrete composites. The effects of plastic fibers distributed homogenously in the entire depth of concrete and confined in the tension zone were evaluated in flexural bending properties. Mechanical strength properties were evaluated for two different types of concrete containing (i) plastic fibers added homogenously throughout the entire depth of concrete and (ii) the plastic fibers confined in the tension zone only. Flexural bending parameters such as toughness, residual strength, crack width, post-peak drop load resistance, and fiber performance index of various plastic fiber substituted concrete mixes were tested in compressive and flexural bending to assess the fiber reinforcing efficiency. Test results indicated that the plastic fibers added in tension zone confinement exhibited higher flexural strength (5.26 N/mm2) improvements compared to homogeneously distributed concrete systems. Flexural bending characteristics in terms of absolute toughness and post peak strain softening were found to be appreciably higher (132%) in tension zone confined plastic fiber concretes compared to homogeneous fiber concrete systems.

Prosopis juliflora fibre reinforced green building plaster materials — An eco-friendly weed control technique by effective utilization

Abstract The use of eco-friendly materials are now becoming the field of interest in construction industry to ensure sustainability and healthy living. Gypsum plasters are eco-friendly building materials but are brittle in nature and hence reinforcement of these plasters using fibres has been found to be beneficial at its post tensioning stage. In this present work the control of harmful ecological impact of Prosopis juliflora invasive species by their effective utilization in building plaster is proposed. To assess the performance of this environmental friendly building plaster using Prosopis juliflora fibres the physical properties such as setting time, temperature rise and density were measured. Furthermore the Prosopis juliflora fibres were subjected to various chemical treatments (NaOH, KmnO4 and distilled water) and the effect of these treatments on the interaction of fibre with gypsum plaster was evaluated in terms of mechanical strength characterization. Based on the observed results the enhancement in flexural strength of the plaster was observed coupled with the transformation of brittle failure to ductile failure. The toughness of the composites were also much enhanced with the addition of the fibres.

Controlling Porosity of Anode Support in Tubular Solid Oxide Fuel Cells by Freeze Casting

Abstract Precise porosity control is highly desirable for improving the electrochemical performance of solid oxide fuel cells (SOFCs). Freeze casting is an established method for enabling high bulk porosity in structures and controlling pore orientation. In this study, freeze casting was used to fabricate tubular, anode-supported SOFCs with aligned and varying amounts of porosity by controlling the solids/water ratio in different casting slurries. SOFCs were prepared with a Ni/yttria and scandia stabilized zirconia (ScYSZ) anode support (AS), an anode functional layer (AFL), a ScYSZ electrolyte, a lanthanum strontium manganite (LSM)/ScYSZ cathode interlayer (CIL), and an LSM cathode. The permeability of the anode support was found to increase from 1.4 × 10−2 to 1.8 × 10−2 m2 as porosity was increased from 57 to 64 vol%, while the total cell resistance decreased by 35% from 0.93 to 0.60 Ohm cm2. When evaluated with 30 vol% H2 as the fuel at 800 °C, the decrease of concentration polarization enabled an increase in electrochemical performance by 42% from 0.35 to 0.50 W/cm2 as the porosity in the anode support was increased. Mechanical strength characterization using a three-point method showed there is a practical upper limit of the amount of porosity that can be designed into the anode support. This work paves a way for controlling porosity by freeze casting and understanding the correlation between porosity and concentration polarization losses in SOFCs.

Effect of fabrication parameters on strength of natural fiber polypropylene composites: Statistical assessment

This paper presents a statistically assessed processing and experimental characterization of mechanical strength of two types of natural fiber polymer composites reinforced with date palm fronds and pine needles. Fifteen bio-composites samples were fabricated per the Design of Experiment (DoE) using a simple hand lay-up method. The experimental design of bio-composite specimens includes three fabrication parameters with three levels for each parameter. These include fiber volume fraction (10, 30, and 50 vt.%), fiber length (10, 30, and 50 mm), and Alkali treatment (1, 2, and 3 wt%). The tensile and flexural strengths were evaluated in accordance with ASTM standards for all samples. Also, Response Surface Methodology approach was utilized to analyze the combined effect of interacting processing parameters on response. SEM analysis of untreated and treated fibers and tested bio-composites revealed that proper alkali treatment of fibers has a high impact on bonding between fiber and surrounding matrix.

Freeze-thaw durability of red mud slurry-class F fly ash-based geopolymer: Effect of curing conditions

Abstract Freeze-thaw (F-T) durability of geopolymers synthesized from the mixture of red mud slurry-Class F fly ash (RMSFFA) was investigated in this study, with an emphasis on the influence of curing conditions (i.e., curing time and curing temperature). F-T durability was evaluated on the basis of the sustained mechanical strength of RMSFFA geopolymer specimens after subjected to 50F-T conditioning cycles. The change in their chemical bonding, mineralogy, and pore characteristics at various F-T conditioning cycles was examined with Fourier transform infrared spectroscopy, X-ray diffractometer, and Brunauer–Emmett–Teller testing, respectively, to reveal the underlying processes during F-T conditioning. The results of both mechanical strength and microstructural characterization indicate that curing conditions influence F-T resistance of RMSFFA geopolymer samples through affecting their strength development. For 14-day cured RMSFFA samples at 50 °C, they experienced further geopolymerization at the early stage of F-T conditioning but the partial dissolution of geopolymer gel at the later stage of F-T conditioning. For 28-day cured samples at 50 °C, only the partial dissolution of geopolymer gel was likely to occur during the F-T conditioning because the strength development was likely to complete prior to the conditioning.

Characterization of mechanical strength and hydrogen permeability of a PdCu alloy film prepared by one-step electroplating for hydrogen separation and membrane reactors

A single phase, dense PdCu alloy film was prepared by one-step electroplating. The electroplated film was easily delaminated from the SUS electrode by cutting around the edge, and the single alloy film was thus collectable. The phase structure, surface morphologies, and alloy compositions were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). The plated film before and after hydrogen permeation tests consisted of a single face-centered cubic α phase and an ordered body-centered cubic β phase, respectively. The atomic ratios of Pd and Cu were 49 and 51 at%, respectively; the Pd and Cu contents were slightly higher and lower than Pd47Cu53, which shows the highest hydrogen permeability among Pd-Cu systems. The as-plated film exhibited high mechanical strength, and its load force at break point and displacement were 3 and 1.7 times those of the as-rolled Pd47Cu53 films. The hydrogen permeability of the plated film with the β phase was almost the same as that of the rolled film and the values reported in literature.