Metal Beads Research Articles

Effect of Microgravity on the Metal Droplet Transfer and Bead Characteristics in the Directed Energy Deposition-Arc Process

Abstract Directed energy deposition-arc (DED-arc) is a viable method of metal 3D printing for manufacturing in-space under microgravity conditions. This study investigates the effect of reduced gravity on the droplet transfer in a gas metal arc welding (GMAW)-based DED-arc process. Single bead deposited using GMAW welding process under microgravity and standard terrestrial gravity (1 g) are compared. Microgravity was simulated in a drop tower where the experimental capsule was subjected to 2.5 s of free-fall. The experimental setup for GMAW welding process, including high-speed cameras and sensors, was present within the experimental capsule. Droplet frequency and diameter were measured and compared between microgravity and 1 g using the images obtained. Further, the impact of reduced gravity on weld bead geometry and the distribution of gas porosity was investigated. Microhardness analysis was also conducted on both 1 g and reduced gravity samples to assess variations in material hardness. A statistically significant difference in droplet diameter and frequency was found. This difference is attributed to the reduction in gravitational force. Upon analyzing the weld bead geometry, noticeable variations are detected in the contact angles and the reinforcement of beads formed under different gravity conditions. These differences are attributed to alterations in convection within the molten weld pool. The blowhole analysis revealed a noticeable trend, wherein reduced gravity facilitated the coalescence of gas porosity, resulting in larger diameters due to alterations in weld pool convection. There were no statistically significant changes observed in both microhardness and surface finish.

Impact of scanning strategies on the accuracy of virtual interocclusal records in partially edentulous arch using intraoral scanner: an in vitro study

PurposeTo evaluate the scanning strategies affecting the accuracy of virtual interocclusal records (VIR) in partially edentulous arches using an intraoral scanner in vitro.MethodsA reference model of a partially edentulous arch with implant analogs in positions 45,46 and 47 was constructed. Six pairs of 1-mm diameter metal beads were placed on the gingival tissue as markers for measurement. Four scanning strategies were tested: Quadrant-arch Scan (group 1), Quadrant-arch Scan with Auxiliary occlusal devices (AOD) (group 2), Full-arch Scan (group 3), Full-arch Scan with AOD (group 4). The model was digitalized with a lab scanner as a reference and 15 scans were obtained for each group. The accuracy of VIR was assessed by comparing the experiment data to the reference digital model.ResultsThe mean surface deviations of VIR for Groups 1–4 were 89.4 ± 105.2 μm,95.6 ± 132.8 μm,152.3 ± 159.7 μm and 107.6 ± 138.2 μm respectively. Quadrant-arch scans resulted in lower errors of VIR than full-arch scan (P < 0.001). There was a significant interaction between the AOD and scanning span (P = 0.017). The Quadrant-arch scan with AOD (group 2) produced the least error in the distally extended edentulous area.ConclusionsQuadrant-arch scans showed better accuracy of VIR than full-arch scans across all tooth positions. The combination of AOD and quadrant-arch scan further enhances VIR accuracy in distally extended edentulous areas.

Enhancing tribological performance of high‐density polyethylene polymer with diamond‐like carbon coating and mollusk shells filler

AbstractThis study explores the tribological properties of mollusk‐shell‐high‐density polyethylene (MS‐HDPE) biocomposites and diamond‐like carbon (DLC)‐coated metal beads as potential substitutes for hip joint prostheses. HDPE biocomposites with 0, 5, and 10 wt% of MS were developed using hot compression molding. Coatings included pure DLC, DLC‐Si, and DLC W:H. Wear tests on a ball‐on‐disk tribometer examined friction and wear rates against coated and uncoated balls, along with wear morphology. MS‐HDPE demonstrated superior tribological performance against DLC, achieving a 67% reduction in specific wear rate compared to pure HDPE. The study suggests that 5 wt% MS‐HDPE coupled with a DLC‐coated counterpart coating could be a promising combination for orthopedic applications, presenting a potential solution to metal corrosion and wear debris issues in orthopedic implants.Highlights Tested coatings: DLC, DLC‐Si, and DLC W:H. Biocomposite wear versus coated balls. DLC coating improves wear with shell fillers. Mollusk shell strengthens biocomposites. Reduced wear rate by 63% and friction by 77%.

First report of two Pantoea species causing bacterial leaf blight on wheat in the United States.

Wheat (Triticum aestivum) is an important crop worldwide, contributing to about one third of the global caloric intake. In June 2021, leaves with bacterial blight symptoms, including yellow and necrotic lesions running parallel to veins, were found in several fields across five counties in eastern Colorado (Weld, Morgan, Sedgwick, Baca, and Kit Carson). Plants exhibiting these symptoms were scattered throughout fields, but symptoms appeared consistent across counties. To determine the causal agent and complete Koch's postulates, a 1 cm2 symptomatic leaf area was excised and macerated in 0.5 mL of sterilized water from four field samples. The lysate was spread on yeast extract dextrose calcium carbonate medium (YDC agar, 1% yeast extract, 2% dextrose, 2% calcium carbonate, 1.5% agar) to isolate bacteria. Single colonies of yellow, mucoid morphology were selected and streaked on new YDC plates. Isolate genomic DNA was extracted (Zymo Research Quick-DNA Fungal/Bacterial Miniprep Kit, #D6005), and ~30 ng of gDNA was used to amplify the 16S rRNA, gyrB, and rpoB genes of all four isolates (Barret et al., 2015; Delétoile et al., 2009; Krawczyk et al., 2020; Ogier et al., 2019). Amplified PCR products were cleaned (Zymo DNA Clean & Concentrator kit, #D4033) and Sanger sequenced, and all sequences have been deposited in NCBI (16S rRNA: OR707336, OR707337, OR707338, OR707339), (gyrB: PP407951, PP407952, PP407953, PP407954), (rpoB: PP407955, PP407956, PP407957, PP407958). A BLAST search against whole genomes identified one isolate from Kit Carson county (CO314) and two isolates from Baca county (CO316 and CO317) as Pantoea agglomerans with 100% identity for the 16S rRNA, gyrB, and rpoB genes, and one isolate from Weld county (CO315) was 100% identical to Pantoea allii for all three genes. To complete Koch's postulates and confirm Pantoea sp. as the causal disease agents, isolates were grown as lawns on DifcoTM Nutrient Agar (NA) medium (48h, 28℃), suspended in 10 mM MgCl2 using a final optical density of 0.1 (~109 colony forming units per milliliter (CFU/mL)), and syringe-infiltrated into the entire leaf area of 10-day-old wheat seedling leaves (var. Hatcher). Treatments of 10mM MgCl2 and a field isolate that does not cause symptoms, identified as Pseudomonas synxantha by 16S rRNA and gyrB sequencing, were negative controls. Inoculated wheat plants were transferred to a growth chamber (22℃, 90% relative humidity). Symptoms developed 14 days post inoculation (dpi), with the most severe appearing 21 dpi. Each of the four Pantoea isolates were re-isolated from symptomatic leaves by grinding them in a Tissue Lyser II (Qiagen) with two metal beads and diluting with 0.4 mL of sterile water. A 20 µL sample of each isolate was plated on NA (24h, 28℃). The colonies appeared phenotypically identical to the original isolates, and Sanger sequencing confirmed the identities of the isolates. To our knowledge, this is the first report of P. agglomerans causing disease in wheat in the United States, and the first report of P. allii as a wheat disease-causing agent. This report is consistent with previous communications showing P. agglomerans causing wheat disease in China (Gao et al., 2023), and P. ananatis in Poland (Krawczyk et al., 2020). The growing numbers of reports of Pantoea spp. as pathogens in recent years suggests increasing novel disease emergence on cereals worldwide.

THE EFECT OF DIMENSIONALITY AND CURRENT STRENGHT ON CONDUCTIVITY OF GRANULAR METALS

&amp;lt;p&amp;gt;Metallic materials in granular packings show different electrical properties from their bulk counterparts.&amp;lt;br /&amp;gt;In this paper, we investigate the temporal evolution of the electrical conductivity of granular metals. We&amp;lt;br /&amp;gt;use metallic beads arranged in different one-, two- and three-dimensional ensembles through which&amp;lt;br /&amp;gt;different constant currents are injected. The conductivity behavior in all three types of systems is&amp;lt;br /&amp;gt;qualitatively similar. The results show the rise of conductivity which is more pronounced in the earlier&amp;lt;br /&amp;gt;stages of the time evolution. We investigate the influence of the dimensionality, number of the beads,&amp;lt;br /&amp;gt;and the values of the injected currents on the conductivity behavior.&amp;lt;/p&amp;gt;

STUDY OF THE EFFECT OF FLUXING MATERIALS ON THE DEPOSITION OF METAL BEADS FROM HIGH CARBON FERROCHROME SLAG

The study of the effect of the properties of high-carbon ferrochrome slags on the creation of favorable conditions for the deposition of metal beads with the introduction of the following fluxing additives in an amount of 3-10%: slag produced by refined ferrochrome (stale and stabilized), cryolite, fluorite, feldspar, colemanite, fused borate ore, aluminum slag of aluminum production. The influence of the type and quantity of fluxing materials on the viscosity and crystallization temperature of high-carbon ferrochrome slags has been studied. It is noted that the use of all types of fluxing materials under study leads to a decrease in the crystallization temperatures of the processed slag. It can be seen from the results of metallographic and phase analyses that the best values for the degree of coagulation and deposition of metal crowns were achieved with the introduction of aluminum slag, colemanite and borate ore.

Elemental and oxygen isotopic fractionation recorded in highly vaporized cosmic spherules from Widerøefjellet, Sør Rondane Mountains (East Antarctica)

AbstractUpon passage through Earth's atmosphere, micrometeorites undergo variable degrees of melting and evaporation. Among the various textural and chemical groups recognized among cosmic spherules, that is, melted micrometeorites, a subset of particles may indicate anomalously high degrees of vaporization based on their chemical and isotopic properties. Here, a selection of such refractory element‐enriched cosmic spherules from Widerøefjellet (Sør Rondane Mountains, East Antarctica) is characterized for their petrographic features, major and trace element concentrations (N = 35), and oxygen isotopic compositions (N = 23). Following chemical classification, the highly vaporized particles can be assigned to either the “CAT‐like” or the “High Ca‐Al” cosmic spherule groups. However, through the combination of major and trace element concentrations and oxygen isotopic data, a larger diversity of processes and precursor materials are identified that lead to the final compositions of refractory element‐enriched particles. These include fragmentation, disproportional sampling of specific mineral constituents, differential melting, metal bead extraction, redox shifts, and evaporation. Based on specific element concentrations (e.g., Sc, Zr, Eu, Tm) and ratios (e.g., Fe/Mg, CaO + Al2O3/Sc + Y + Zr + Hf), and variations of O isotope compositions, “CAT‐like” and “High Ca‐Al” cosmic spherules likely represent a continuum between mineral endmembers from both primitive and differentiated parent bodies that experienced variable degrees of evaporation.

Chicumbane Connections: Lower Limpopo Valley During the First Millennium AD

The discussion of the transition to farming in southern Africa and the formation of Early Iron Age society, referred to in Mozambican archaeology as the Early Farming Communities (EFC), is complicated by the lack of surveys in key areas of intensive contacts. This article presents the results of excavations at the EFC site Chicumbane in the eastern lower Limpopo Valley, dated 500–800 AD. The variation of ceramic styles in terms of decoration and shape suggests predominantly interior influences (Gokomere and Zhizo facies), but there are also decoration elements similar to what is found on the coast. A wide variety of ceramic technologies were used in terms of clay sources, temper, and ways of building the pot. Here, we reconstruct possible social interactions based on these differences. Together with the other artifact categories, such as slag, metal, and shell beads, the results show some aspects of regional interactions among Early Farming Communities. The combined ceramic analyses suggest a mix of traditions by female potters who, through marriage, moved between regions, bringing new ways of decorating, tempering, and building pots.

The effects of welding parameters on metal transfer and bead properties in the variable-polarity GMAW of mild steel

The effects of welding parameters on metal transfer and bead properties in the variable-polarity GMAW of mild steel

Iron Isotope Constraints on the Structure of the Early Solar System

The recent advent of nontraditional isotopic systems has revealed that meteorites display a fundamental isotopic dichotomy between noncarbonaceous (NC) and carbonaceous (C) groups, which represent material from the inner and outer solar system, respectively. On the basis of iron isotope anomalies, this view has recently been challenged in favor of a circumsolar disk structured into three distinct reservoirs (the so-called isotopic trichotomy). In this scenario, the CI chondrites—a rare type of carbonaceous chondrites with chemical composition similar to that of the Sun’s photosphere—would sample a distinct source region than other carbonaceous chondrites, located beyond Saturn’s orbit. Here, we report a model based on the available data for both mass-dependent fractionation of Te stable isotopes and mass-independent Fe nucleosynthetic anomalies. On the basis of the Te–Fe isotopic correlation defined by all carbonaceous chondrites including CIs, we show that the NC-CC dichotomy extends to Fe isotopes. Our finding thus supports (i) the existence of only two reservoirs in the early solar system and (ii) the ubiquitous presence of CI-like dust throughout the carbonaceous reservoir. Our approach also reveals that the carrier phase of 54Fe anomalies corresponds to Fe–Ni metal beads mostly located within chondrules. Finally, we propose that the CC chondrule component records a constant mix of refractory inclusions and NC-like dust.

Bioinspired dry-state polylactic acid adhesives-based wearable sensor with reversible adhesive performance in harsh environments via building hierarchical liquid metal bead structure

Dry-state self-adhesive wearable sensors show great application in various fields. However, the poor adhesive performance, unsatisfied reversible performance, and low sensitivity in a harsh environment still limit its broad applications. Mimicking the biological design for strong adhesive has given promise for realizing reversible adhesive and high-performance sensor capacity. Drawing inspiration from the biomimetic mechanism of mussels and the mechanical interlocking adhesion mechanism, we have devised a multi-level micro/nano adhesion strategy. This innovative approach aims to create polylactic acid (PLA)-Liquid metal (LM) 3D beaded structured adhesives, with the ultimate goal of achieving significantly enhanced adhesive strength, improved water resistance, and superior mold resistance. The bioinspired PLA-based adhesives exhibit bond shear adhesion strength of 2.7625 MPa and adhesion peel strength of 290 kPa, which is higher than that of reports. Importantly, the new concept of sunlight harvesting function was introduced into the system. The adhesives show enhanced shear strength (10.77% increment) under solar irradiation due to the photothermal capacity of EGaIn. For the concept of proof, a self-adhesive LM-based wearable sensor can be assembled to detect the electrical signals triggered by strain. This work paths the way for developing multifunctional bioinspired dry-state adhesives for wearable electronics.

Technological Features of Selection of Parameter Values of Arc Welding Mode in Shielding Gas Mixture Ar + CO&lt;sub&gt;2&lt;/sub&gt;

Gas-shielded arc welding today occupies a leading position among the methods for producing permanent joints in industrial conditions. The emergence of new materials with complex alloying and hardening systems makes carbon dioxide, traditionally used as a protective medium, inefficient for use. One of the effective ways to solve these problems is to change the composition of the protective gas atmosphere, which allows you to significantly change the physical and metallurgical processes of melting the electrode wire and the forming the weld. At the same time, the transition to the use of protective gas mixtures based on argon is usually carried out without understanding the essence of the technology and possible problems associated with the specifics of penetration of the base metal, which can cause a number of serious problems. The present paper describes important regularities between technological characteristics of arc welding in a shielding gas mixture Ar + CO2 and welding mode parameters under conditions of deviation of their values from the most effective ones in order to ensure the stability of the processes of electrode metal transfer and the formation of the deposited weld metal bead. On the basis of experimental data, the most probable causes of the appearance of a dangerous and difficult-to-detect defect in the formation of a welded seam in the form of non-fusion between individual beads of the deposited metal and along the fusion line with the base metal of the welded parts have been established. The defect is common and can cause unpredictable failure of the welded joint without visible plastic deformation. Empirical dependences for determining values of the main parameters of the welding mode are proposed as well. Important regularities have been established that make it possible to increase the efficiency of arc welding technology in the environment of protective gas mixtures in the conditions of domestic production.

Facet-Dependent Formation and Adhesion of Au Oxide and Nanoporous Au on Poly-Oriented Au Single Crystals.

Nanoporous Au (NPG) has different properties compared to bulk Au, making it an interesting material for numerous applications. To modify the structure of NPG films for specific applications e.g. the porosity, thickness, and homogeneity of the films, a fundamental understanding of the structure formation is essential. Here, we focus on NPG prepared via electrochemical reduction from Au oxide formed during high voltage (HV) electrolysis on poly-oriented Au single crystal (Au POSC) electrodes. These POSCs consist of a metal bead, with faces with different crystallographic orientations and allow screening of the influence of crystallographic orientation on the structure formation for different facets in one experiment. The HV electrolysis is performed between 100~ms and 30~s at 300 V and 540~V. The amount of Au oxide formed is determined by electrochemical measurements and the structural properties are investigated by scanning electron and optical microscopy. We show that the formation of Au oxide is mostly independent of the crystallographic orientation, except for thick layers, while the macroscopic structure of the NPG films depends on experimental parameters like the Au oxide precursor thickness and the crystallographic orientation of the substrate. Possible reasons for the frequently observed exfoliation of the NPG films are discussed.

Better late than never: Optimising the proteomic analysis of field-collected octopus.

Proteomics, the temporal study of proteins expressed by an organism, is a powerful technique that can reveal how organisms respond to biological perturbations, such as disease and environmental stress. Yet, the use of proteomics for addressing ecological questions has been limited, partly due to inadequate protocols for the sampling and preparation of animal tissues from the field. Although RNAlater is an ideal alternative to freezing for tissue preservation in transcriptomics studies, its suitability for the field could be more broadly examined. Moreover, existing protocols require samples to be preserved immediately to maintain protein integrity, yet the effects of delays in preservation on proteomic analyses have not been thoroughly tested. Hence, we optimised a proteomic workflow for wild-caught samples. First, we conducted a preliminary in-lab test using SDS-PAGE analysis on aquaria-reared Octopus berrima confirming that RNAlater can effectively preserve proteins up to 6 h after incubation, supporting its use in the field. Subsequently, we collected arm tips from wild-caught Octopus berrima and preserved them in homemade RNAlater immediately, 3 h, and 6 h after euthanasia. Processed tissue samples were analysed by liquid chromatography tandem mass spectrometry to ascertain protein differences between time delay in tissue preservation, as well as the influence of sex, tissue type, and tissue homogenisation methods. Over 3500 proteins were identified from all tissues, with bioinformatic analysis revealing protein abundances were largely consistent regardless of sample treatment. However, nearly 10% additional proteins were detected from tissues homogenised with metal beads compared to liquid nitrogen methods, indicating the beads were more efficient at extracting proteins. Our optimised workflow demonstrates that sampling non-model organisms from remote field sites is achievable and can facilitate extensive proteomic coverage without compromising protein integrity.

Reverse transcriptase recombinase polymerase amplification for detection of tomato spotted wilt orthotospovirus from crude plant extracts

Virus detection in early stages of infection could prove useful for identification and isolation of foci of inoculum before its spread to the rest of susceptible individuals via vectoring insects. However, the low number of viruses present at the beginning of infection renders their detection and identification difficult and requires the use of highly sensitive laboratory techniques that are often incompatible with a field application. To obviate this challenge, utilized Recombinase Polymerase Amplification, an isothermal amplification technique that makes millions of copies of a predefined region in the genome, to detect tomato spotted wilt orthotospovirus in real time and at the end point. The reaction occurs isothermically and can be used directly from crude plant extracts without nucleic acid extraction. Notably, a positive result can be seen with the naked eye as a flocculus made of newly synthesized DNA and metallic beads. The objective of the procedure is to create a portable and affordable system that can isolate and identify viruses in the field, from infected plants and suspected insect vectors, and can be used by scientists and extension managers for making informed decisions for viral management. Results can be obtained in situ without the need of sending the samples to a specialized lab.

Combined Aspiration and Ingestion of Multiple Metallic Beads Resulting in Tracheoesophageal Fistula

The introduction of magnetic toys has led to an increase in the incidence of pediatric magnet ingestion. A previously healthy 3-year-old girl was referred to our emergency room after ingesting multiple magnets more than a week ago. Although she did not show any subjective symptoms, imaging revealed three metallic foreign bodies in the trachea and upper esophagus, with multiple aggregated foreign bodies in the lower-middle abdomen. A total of 17 magnetic beads were successfully retrieved through operative exploration. A secondary tracheoesophageal fistula was identified during foreign body removal. Based on the size and granulation tissue coverage, the fistula was managed conservatively. The follow-up examination on postoperative day 7 showed spontaneous fistula resolution. Ingestion of multiple magnets may result in fatal consequences due to pressure necrosis of vital organs. Early identification and prompt management are crucial to minimize morbidity in these cases.

Peridynamic mesh-free simulation of glass and metal beads column collapses

The density of the metal beads is almost 3 times the density of glass beads, and the rheological response is consequently different from glass beads by using the μ(I) rheology. In this study, the μ(I) rheology is first applied to simulate metal beads column collapse, which is implemented in Peridynamics to capture the transition from the fluid-like state to the solid-like state in the granular flow. To achieve this, flow response by the rheological parameters in the μ(I) rheology is extensively investigated by simulating glass beads column collapse. The numerical results are compared to the experimental measurements in terms of the free surface, velocity distribution, and the interface in the collision of two adjacent granular columns. It is found that the mobility of the granular material is significantly affected by static friction μs. The friction μ2 with high inertia in the rheology can affect the movements of free surface points in the simulations. Another parameter of a constant I0 in the rheology can reduce the material's mobility if its value is very small and large values show insignificant effects on the flow characteristics. The parameters of (μs, μ2, I0) = (0.36, 0.42, 0.01) in the rheology model can capture the free surface profiles in good agreement with the experimental measurements for the metal beads column collapse with different aspect ratios by using the numerical method.

Generalised overlapping model for multi-material wire arc additive manufacturing (WAAM)

ABSTRACT The single-material overlapping models are incompatible with multi-material wire arc additive manufacturing (WAAM). A newly developed generalised model considers dissimilar adjoining beads in multi-material WAAM. The geometric model of dissimilar overlapping beads coupled with an algorithm identifies the process conditions for the two materials to maintain the same bead heights. The model, implemented for stainless-steel and creep-resistant-steel pair, yields significant scientific and practical findings. Compared to a fixed overlapping distance in single-material, e.g. 0.66 or 0.738 times the bead width, the multi-material overlapping distance is a complex function of individual bead widths. The bi-metallic interface fusion is affected by the molten metal flow, bead dimensions, and heat input. Contrary to the prevailing notion of a flat-top surface in the intermediate layer ideal for multi-layer deposition, a slight hill ensures a defect-free interface. The repeatable and defect-free bi-metallic walls and matrix is expected to have a breakthrough in multi-material WAAM.

Comparison of 3D Bone Position Estimation Using QR Code and Metal Bead Markers

To improve the accuracy of a 3D bone position estimation system that displays 3D images in response to changes in the position of fluoroscopic images, modified markers using quick response (QR) codes were developed. The aims of this study were to assess the accuracy of the estimated bone position on 3D images with reference to QR code markers on fluoroscopic images and to compare its accuracy with metal bead markers. Bone positions were estimated from reference points on a fluoroscopic image compared with those on a 3D image. The positional relationships of QR code and metal bead markers on the fluoroscopic image were compared with those on the 3D image in order to establish whether a 3D image may be drawn by tracking positional changes in radius models. Differences were investigated by comparing the distance between markers on the fluoroscopic image and that on the 3D image, which was projected on the monitor. The error ratio, which was defined as the difference in the measurement between the fluoroscopic and 3D images divided by the fluoroscopic measurement, was compared between QR code and metal bead markers. Error ratios for the QR code markers were 5.0 ± 2.0%, 6.4 ± 7.6%, and 1.0 ± 0.8% in the anterior-posterior view, ulnar side lateral view, and posterior-anterior view, respectively. Error ratios for the metal bead markers were 1.3 ± 1.7%, 13.8 ± 14.5%, and 4.7 ± 5.7% in the anterior-posterior view, ulnar side lateral view, and posterior-anterior view, respectively. The error ratio for the metal bead markers was smaller in the initial position (p < 0.01). However, the error ratios for the QR code markers were smaller in the lateral position and the posterior-anterior position (p < 0.05). In QR code marker tracking, tracking was successful even with discontinuous images. The accuracy of a 3D bone position estimation was increased by using the QR code marker system. QR code marker tracking facilitates real-time comparisons of dynamic changes in preoperative 3D and intraoperative fluoroscopic images.

X-ray Particle Tracking Velocimetry in an Overflowing Foam

In mineral processing, froth flotation is based on recovering valuable mineral particles by means of the overflowing froth. Industrial-scale froth flotation cells are typically equipped with optical measurement systems, which monitor the bubble sizes and flow velocities at the froth surface. However, the velocity profile of the overflowing froth underneath its free surface is not accessible by optical observation. The present study combines X-ray radiography and particle tracking velocimetry in a laboratory-scale experiment aiming to measure local flow velocities within an optically opaque foam at a weir, which here describes a one-sided horizontal overflow. For this purpose, we prepared custom-tailored tracer particles: small 3D-printed polymer tetrahedra with tiny metal beads glued to the tetrahedral tips. In parallel to the velocity measurements by means of X-ray particle tracking, we determined the liquid fraction of the overflowing foam by electric conductivity measurements using electrode pairs. The experiment was performed with aqueous foams of two different surfactant concentrations but similar bubble size range and superficial gas velocity, yielding around 10% liquid fraction near the weir. Employing the particles as tools for flow tracing in X-ray image sequences, we measured the velocity profile in vertical direction above the weir crest and found that the maximum velocity is reached underneath the free surface of the overflowing foam.