High Melting Point Metals Research Articles

Pressure-constrained sonication activation of flexible printed metal circuit

Metal micro/nanoparticle ink-based printed circuits have shown promise for promoting the scalable application of flexible electronics due to enabling superhigh metallic conductivity with cost-effective mass production. However, it is challenging to activate printed metal-particle patterns to approach the intrinsic conductivity without damaging the flexible substrate, especially for high melting-point metals. Here, we report a pressure-constrained sonication activation (PCSA) method of the printed flexible circuits for more than dozens of metal (covering melting points from room temperature to 3422 °C) and even nonmetallic inks, which is integrated with the large-scale roll-to-roll process. The PCSA-induced synergistic heat-softening and vibration-bonding effect of particles can enable multilayer circuit interconnection and join electronic components onto printed circuits without solder within 1 s at room temperature. We demonstrate PCSA-based applications of 3D flexible origami electronics, erasable and foldable double-sided electroluminescent displays, and custom-designed and large-area electronic textiles, thus indicating its potential for universality in flexible electronics.

Solid-liquid phase boundary of oxide solid solutions using neural network potentials

We propose a cost-effective computational approach for predicting the phase boundary of oxide solid solutions, i.e., melting point, by identifying the point where the free energies of the solid and liquid phases are equivalent. To evaluate the melting point, we computed the temperature-dependent free energies of both phases using the thermodynamic integration (TI) method. This was combined with the reverse-scaling technique, employing the Einstein model for the solid and the scaled Uhlenbeck–Ford model for the liquid as the reference systems. The change in free energy between the real and reference states in the present TI method was calculated as the ensemble average of the configurations sampled from molecular dynamics (MD) simulations using neural network potentials (NNPs) trained on first-principles density functional theory (DFT) data. Initially, we benchmarked copper (Cu) as a typical metal. Tungsten (W) and magnesium oxide (MgO) were then tested as typical high melting-point metals and oxides, respectively, achieving good agreement with both ab initio MD (AIMD) results and experimental data. We then applied our established approach to a BaO–CaO oxide solid solution, observing that the computed phase boundary aligns well with Calphad predictions from previous studies. The integration of NNPs into phase boundary prediction is essential for reducing computational costs while ensuring accuracy, compared with AIMD-based approaches.

Active and Passive Filling Stir Repairing of AISI 304 Alloy

This study investigates active filling friction stir repair (AF-FSR) and passive filling friction stir repair (PF-FSR) for repairing AISI 304 stainless steel sheets, focusing on addressing the challenges posed by high melting point metals. The research involved repairing overlapping 2 mm thick sheets with pre-drilled holes of 2, 4, and 6 mm diameters, simulating broken components. Various process parameters, including rotational speed, dwell time, and the use of metal fillers, were tested to evaluate their impact on repair quality. The results demonstrated that PF-FSR provided superior mechanical strength to AF-FSR, particularly for larger pre-hole diameters. PF-FSR achieved higher shear tension strength due to better defect filling and reduced void formation, with shear tension strengths exceeding 25 kN for larger pre-holes and lower variability in strength measurements. AF-FSR was less effective for larger pre-holes, resulting in significant voids and reduced strength. Microstructural analysis revealed that PF-FSR facilitated more efficient material mixing and filling, minimizing unrepaired regions. However, excessive rotational speeds and dwell times in PF-FSR led to deformation and flash formation, highlighting the need for optimal parameter selection. Although further studies are needed, this study confirms the feasibility of FSR techniques for repairing small defects in AISI 304 steels, offering valuable insights for sustainable manufacturing practices in industries such as automotive and aerospace, where efficient and reliable repair methods are critical.

Ultrafine PtFeMo intermetallic compound nanowires for efficient oxygen reduction reaction in proton exchange membrane fuel cells

To advance the application of proton exchange membrane fuel cells (PEMFCs), it is crucial to develop high-performance oxygen reduction reaction (ORR) catalyst. Pt-based alloy nanowires exhibit excellent ORR activity due to their unique one-dimensional structure, but transition metals undergo spontaneous leaching under the harsh operating condition, often leading to decreased activity. Herein, ultrafine PtFeMo intermetallic compound nanowires were successfully synthesized as a high-performance ORR catalyst for PEMFC. The average diameter of the nanowires was 2.1 nm and the incorporation of inexpensive and high melting point metal Mo improved both catalytic performance and structural stability. The as-prepared ultrafine PtFeMo intermetallic compound nanowires exhibited mass activity of 2.56 A mgPt−1 for ORR, which is higher than that of disordered PtFeMo alloy nanowires (1.36 A mgPt−1) and commercial Pt/C (0.24 A mgPt−1) in rotating disk electrode test. And it exhibited peak power density of 2716 mW cm−2 under 250 kPa H2-O2 single-cell and mass activity of 0.62 A mgPt−1 under 100 kPa H2-O2 single-cell test in PEMFC. After long-time durability test, the intermetallic compound nanowires maintained their original structure, composition and electrocatalytic performance well, highlighting the importance of Mo incorporation and ordered phase structure generation.

Simulation of laser-plasma focusing using taper solenoid

A laser ion source can produce ion beams of various elements, including high melting point metals. Owing to its ability to switch beams rapidly by loading multiple solid targets, we are developing a laser ion source to implement it in a 400 kV ion implanter, which requires a wide range of ion species. Although a laser ion source offers above advantages, most of the plasma is lost in an ion source due to the generation of the beam from a part of the diffused plasma with a broad angular distribution. To suppress this loss and enhance beam intensity, we employ a linear solenoid to increase the amount of plasma reaching the extraction electrode by suppressing the three-dimensional plasma diffusion. However, the linear solenoid cannot suppress the loss of plasma near the target as the plasma spreads three-dimensionally from the plasma generation point. Therefore, by placing a taper solenoid near the target, it is possible to suppress the diffusion of plasma immediately after its generation and to transport most of the generated plasma to the extraction electrode. In this paper, we present the results of plasma trajectory calculations using the particle-in-cell method by the plasma simulations involving taper solenoids.

Elucidation of tool wear phenomenon in FSW using silicon nitride tool

Friction stir welding (FSW) has been widely used in welding of metal. However, it is difficult to weld high melting point metal by FSW because of short life or high price of FSW tools. Silicon nitride tool can have both long life and low cost. Although the silicon nitride tool, which has high temperature mechanical properties, could have a long tool life for FSW of steel, it is not clear how FSW conditions affected the tool life. In this study, changes in the shape of the FSW tool was focused. A comparative verification of the tool shape changes due to the FSW conditions was carried out, and specific shape changes in silicon nitride tools were verified. The silicon nitride tool was worn only at the shoulder and not at the probe. Furthermore, the wear shape was different depending on rotation speed and welding speed of the tool. The factors that cause them were analyzed using temperature and stress simulations for silicon nitride tools. Increasing the rotation speed broadened temperature distribution, increased the peak temperature and narrowed the stress distribution. When the welding speed was increased, the temperature distribution became narrower and peak temperature was lower, and the thermal asymmetry increased, while the stress distribution expanded and the stress asymmetry increased. When the welding speed was high, the agitation in the plastic flow zone was insufficient, and there were places where the stress and temperature were low around the shoulder. It is considered that these decrements of the stress and temperature lead to the concave part remaining on the outer circumference. Therefore, it is important to control both the welding speed and the rotation speed of the silicon nitride tool in order to suppress the protrusion which is main reason of the tool breakage.

Thermal sensing performance analysis, preparation and application of bimetallic layer MFBG

The FBG(fiber Bragg grating) can be embedded in metal to form smart structure, and to protect the FBG, the surface can be coated with high melting point metal such as Ni. MFBG(metalized FBG) will affect the temperature sensing performance of the FBG. In this paper, the thermal sensing performance of MFBG with single and double metal layers is investigated and the main factors affecting its temperature sensitivity and temperature response are analyzed. The thermal sensitivity of the MFBG gradually stabilizes as the thickness of the metal layer increases. The Ni-Ti MFBG (double-layer MFBG with Ni as the outer metal and Ti as the inner metal) was fabricated by magnetron sputtering and electroplating thickening, and a comparative thermal sensing performance experiment was conducted together with the bare FBG. Metallization of the FBG can improve the temperature sensitivity of the FBG. Samples with different metal layer thicknesses were subjected to thermal tests from 0 to 70 °C, the obtained data verified the soundness of the presented model. To verify the temperature sensing performance of the prepared Ni-Ti MFBG, it was embedded in a three-phase induction motor and the internal temperature of the motor was monitored. The experiments show that the prepared Ni-Ti MFBG has good temperature sensing performance and can accurately sense the motor temperature.

Microstructure evolution and mechanical properties of H13 steel produced by Selective Electron Beam Melting

As one of the additive manufacturing technologies, the Selective Electron Beam Melting (SEBM) process several advantages over Selective Laser Melting (SLM), including faster scanning velocity, higher energy utilization and higher preheating ability of up to 1100 °C. Thus, it is particularly advantageous for the production of high melting point and brittle metals, like the medium carbon high-alloy H13 steel. This study presents a systematic investigation of the microstructural evolution and mechanical properties of H13 steel fabricated using Selective Electron Beam Melting (SEBM) with varying deposition heights. The manufactured samples were examined using high-tech measuring instruments to evaluate different properties such as phase composition, microstructure, microhardness and grain morphology. The results reveal that the microstructure of the as-built SEBM-H13 sample consists of martensite, bainite, and residual austenite with a typical cellular/dendritic structure. As the deposition height decreases, the grain morphology degrades, and the grain boundary undergoes carbide precipitation ((Cr, Fe)7C3) and growth. Consequently, the sample exhibits a gradient hardness structure in the building direction with the highest hardness of 565.6 (±5.8) HV0.5 at the top surface, followed by a distinct decrease in hardness to approximately 506.7 (±3.3) HV0.5 at increased distances from the surface. This study provides a fundamental understanding of fabricating high-performance H13 steel using SEBM.

Effect of silicon nitride microstructure on characteristics of FSW tool for steel and tool life

Friction stir welding (FSW) has been widely used in the welding of low melting point metal, such as Al alloy or Cu alloy. However, high melting point metal, such as Fe alloy, it is difficult to be welded by FSW because of short life or the high price of FSW tools. Silicon nitride tool can have both long life and low cost. In order to obtain design guideline for silicon nitride FSW tool, the relationship between the mechanical properties and tool life was examined. Two silicon nitride materials which had different microstructure were prepared. One of them had lower high-temperature mechanical properties and the other had higher properties. Tools made by them could join the SUS 304 plate under the following conditions; welding speed was lower than 1000 mm/min, and revolutional pitch was lower than 1.8 mm/r. Even the tool which had excellent mechanical properties at high temperature worn faster when the joining temperature was 950 °C or higher. The tool with excellent high-temperature mechanical properties had a tool life 6 times longer than the other tool. It is considered the life of the tool was improved when the crystallization of the grain boundary phase promoted the rise in the melting point of the grain boundary phase and the precipitation of silicon oxide during FSW.

Sintering of metallic nano-aggregates in an atmospheric pressure non-thermal plasma

It has been recently demonstrated that non-thermal plasmas (NTP) can function as nanoparticle processing reactors by selectively heating particles, inducing chemical reactions and structural transformations. However, lacking in prior studies is direct comparison between NTP particle-processing and more traditional, equilibrium thermal processing. With tandem differential mobility analysis, we studied the sintering of metallic nano-aggregates as they traversed through an atmospheric pressure NTP. As a reference, sintering experiments with a tube furnace were also conducted. Silver and bismuth nano-aggregates were synthesized via gas phase reactors for experiments and were selected to represent high and low melting point metals, respectively. We found that the silver aggregate sintering behavior was similar in the plasma and the furnace systems. With increasing plasma power/furnace temperature, the sintering process can be divided into to an aggregate compaction stage, a constant mobility stage and a vaporization stage. The mobility size shift of the silver aggregates was used to estimate their equivalent temperatures in the plasma. With an aggregate sintering model, an equivalent particle sintering temperature was estimated to be 165–270 °C in the plasma as the silver aggregate mobility diameter decreased from 100 nm to 95-65 nm. In contrast to silver, due to the early onset of particle vaporization, the three stages of bismuth aggregate sintering were not as clearly discernible. The constant mobility stage was only observed in a narrow range of plasma powers for the 100 nm aggregates and was not evident for the 20 nm aggregates. Additionally, distinct patterns of bismuth particle mobility shifts were observed during plasma sintering and furnace sintering, with the plasma reactor being a more effective sintering unit. The reducing environment within the plasma and the partial oxidation of the bismuth aggregates could be the reason for the effectiveness of plasma sintering. Further measurements of the particle transmission efficiency through the plasma reactor shows that it is particle size and material dependent.

Electrolytic-dielectrics: A route to zero recast electrical discharge machining

Electrical discharge machining (EDM) is a widely used manufacturing process for machining hard or high melting point metals. A characteristic feature of this process is a brittle, porous and rough recast layer on machined surfaces, which undermines integrity and limits its applications. Previous attempts to remove the recast have increased process steps and complexity, and in the case of EDM ECM hybrid processes have failed to understand or explain process mechanisms and have not proposed methods to control removal mechanisms to produce tailored surfaces. Here, we introduce tailored electrolytic-dielectrics that eliminate the defective recast layer, while maintaining machining rate. By adding selected electrolytes to a conventional deionised water dielectric in a standard EDM machine, material removal mechanisms can be altered and controlled in a simultaneous electrical discharge and electrochemical process, producing discrete surface morphologies through passive oxidation, aggressive pitting, and electro-polishing. These bespoke dielectrics alter fundamental machining behaviour to alternate between conventional EDM discharging and electrochemical dissolution. For the first time, it is shown that machining rate can be maintained while reducing, and eliminating, the defective EDM recast layer, which would otherwise need removal, in a single step process that combines the accuracy of EDM with the surface finish of ECM with the potential to produce high integrity surfaces with high throughput. The mechanisms behind this unique machining process are described through fundamental waveform and discharge analysis, which revealed discrete pulse types and their significance to the process, the importance of pulse ratio balance, the time-varying nature of the process, and the significance of high-voltage regions to electrochemical removal. Key process parameters are determined, such as EDM: ECM pulse ratio balance, electrolytic-dielectric conductivity, salt type, machining/exposure time, and electrode/servo advance, which are crucial to producing tailored surfaces. A model is devised to describe the overall balance between discharge based and dissolution based removal. Through this model, the point during machining at which complete recast layer removal occurs is predicted and validated through experimental analysis. This adapted EDM process has significant potential to be used for producing recast-free features by using an easily modified dielectric.

Broadband Metamaterial Solar Absorbers Based on the Earth First-rate Temperature-Insensitivity Metals for High Temperature Energy Harvesting

Artificially engineered solar absorbers, known as metamaterial solar absorbers (MSA), are yielding new opportunities for designing new photons management systems. Furthermore, the noble metals are indispensable in creating MSA owing to their plasmonic resonance in a desired spectral region. Nevertheless, in high temperature applications, the noble metals suffer from low melting points that make their uses largely impractical. In this work, the solution of using four of the Earth first-rate temperature-insensitivity metals in a proposed MSA is investigated. The proposed MSA structure is composed of high melting point metals (HMPM), deposited on a magnesium fluoride (MgF\(_2\)) dielectric spacer and a tungsten continuous plate. Meanwhile, owing to the dependence of MSA properties on structural parameters rather than band structure or chemistry, a geometrical optimization of the proposed absorbers is reported. Furthermore, the proposed MSA performance is investigated by computing the absorption spectrums. Results show relatively long bandwidths in the visible and near-infrared regimes. Besides, an underlying mechanism of the absorption enhancement with the corresponding electromagnetic field distributions is elucidated in detail. The calculated results indicate that the proposed MSA present wide bandwidths owing to the excitation of resonance modes of surface plasmons, dipolar interactions and cavity modes. Equally important, absorption measurements under wide polarization angles show polarization-insensitive high absorption at higher wavelengths, which is among the most important factors for an ideal solar absorber. The conclusion of this investigation is undoubtedly important, specifically that the proposed HMPM-based MSA would be the best choice for energy harvesting in high temperature applications.

Peritectic Intermetallic Compound (IMC) Morphology of Transient Liquid Phase Solder - A Short Review

Transient Liquid Phase (TLP) has been a potential bonding technique for high temperature application solder alloy. TLP bonding for solder is a soldering method that using a low and high temperature metal layer for solid form solder, and a mixing of low and high temperature metal powder in flux medium, for paste form solder. Transient Liquid Phase bonding process involved thoroughly consumption of low melting point metal into high melting point metal and results in the formation of high temperature melting point peritectic intermetallic compound (IMC) which enables the solder to be soldered at typical low soldering temperature but, the solder connection can be applied in the high temperature application. The morphology of the peritectic IMCs mainly consist two solids, which is primary α as well as peritectic β together with liquid phase at peritectic temperature. The growth formation of those primary α and peritectic β phases has resulted with a variety of possible peritectic microstructure’s morphology as will be discussed further.

Two-dimensional oxide derived from high-temperature liquid metals via bubble templating

Two-dimensional (2D) oxide can be continuously produced by bubbling oxygen into liquid metals and the harvesting of these oxide relies on the proper choice of dispersion solvents. The mass-production of ligand-free 2D materials from high melting-point metals will not be possible if the limited stability of the traditional dispersion solvents is not circumvented. Herein, liquid tin was used for the first time in the bubbling protocol and 2D tin oxide was obtained in molten salts. The nanosheets were studied with combined microscopic and spectroscopic techniques, and high-density grain boundaries was identified between the sub-5-nm nano-crystallites in the nanosheets. It gives rise to the high performance in electrocatalytic CO2 reduction reaction. Density-functional-theory based calculation was applied to achieve a deeper understanding of the relationship between the activity, selectivity, and the grain-boundary features. The molten-salt based protocol could be explored for the synthesis of a library of functional 2D oxides.

Buoyancy-driven melting and solidification heat transfer analysis in encapsulated phase change materials

Controlled melting and solidification in encapsulated phase change materials (PCMs) is of practical interest, for example, in latent heat storage applications. The choice of PCMs and the dynamic heat transfer characteristics during phase change - affecting the transient charging/discharging rates - are decisive for the energy and power density of the heat storage option. For example, highly conductive, high melting point (above 700 K) metal alloys have a potential advantage as a high energy and power density latent heat storage, compared to the widely used low conducting molten salt and paraffin wax. This advantage depends on the relative dominance of heat transfer modes that vary depending on the thermal properties of the PCM, shape of the encapsulation, and the load conditions, and must be quantified to warrant a fair comparison. We developed a 2D transient phase change model of encapsulated PCMs, accounting for phase change over a temperature range, volumetric expansion and contraction, and multi-mode heat transfer within the encapsulated PCM. The enthalpy-porosity method was used to model the phase change in a fixed grid. Validation was performed with literature data of low and high-conductivity PCM experiments (RT27 and lead). Two types of PCMs were subsequently investigated in detail: a high-conducting binary-eutectic alloy Al-12.6Si and a low-conducting commercially available RT27 paraffin wax (Rubitherm GmbH). The model was used to compare the phase change process and the strength of the various modes of heat transfer in the PCM filled cylindrical stainless-steel encapsulations in horizontal and vertical orientation with constant temperature walls. A full parameter study and non-dimensional analysis are presented for different PCMs. The results quantified the influence of boundary conditions, thermophysical properties and geometrical parameters on the phase change process and the contribution of the natural convection within the encapsulation. The non-dimensional analysis linked the melt fraction and heat transfer rates to a combination of the Fourier, Stefan, Rayleigh and Nusselt numbers. Fitting of the exponents of non-dimensional number groups to the heat transfer calculations allowed to provide general correlations for melting time, melt fraction, heat transfer rates, and characteristics of melting. Such correlations provide general understanding of the transient heat transfer in phase change media and provide engineering tools for designing, for example, a latent heat storage unit.

A preliminary study on the Earth’s evolution and condensation

ABSTRACT Through many field geology observations, the authors find that sandstone and carbonate rocks, which were originally thought to be sedimentary, have magmatic characteristics and should classified as magmatic rather than sedimentary rocks. Combining this information with the principles of Bowen’s reaction series, the authors infer that the Earth has evolved gradually from high temperature to low temperature and, through crystallization differentiation, has experienced the following stages: high melting point metal to ultramafic rock to mafic rock to neutral rock to acidic rock to sandstone to carbonate rock to mudstone to ice. Since fossils that preserve the remains of creatures, such as fossil fish, occur in magmatic rocks rather than sedimentary rocks, the organisms were not aquatic but lived in high-temperature fluids with magmatic characteristics. Therefore, the authors conclude that during the evolution of rocks from high temperature to low temperature, biological evolution from high temperature to low temperature also occurred on the Earth and that carbon-based life did not originate in the ocean but in high-temperature carbon-containing fluids; this is a subversive statement. This understanding contradicts the original interpretation, that is, that fossils formed under normal temperature and pressure conditions. This point explains the Cambrian explosion and later mass extinctions.

Deposition and oxidation behavior of atmospheric laminar plasma sprayed Mo coatings from 200 mm to 400 mm under 20 kW: Numerical and experimental analyses

A stable laminar plasma jet with a jet length of above 600 mm was adopted to deposit molybdenum coatings to investigate the behavior of high-melting point metal, molybdenum, and particles during laminar plasma spraying process. The temperature, velocity, and species distribution of the plasma jet were calculated by numerical simulation. In the experiment, the temperature and velocity distribution of the in-flight particles were measured, and the microstructure and properties of the coatings were analyzed. Combining the results of the simulation and experimental results, the deposition behavior and oxidation mechanism of the coatings prepared at the spray distance from 200 mm to 400 mm were discussed. The results indicate that both the laminar plasma jet and injected particles exhibit high temperature and low velocity, and low temperature and velocity gradients. The microstructure of the coatings shows a high similarity and hardly changes when the spray distance exceeds 250 mm. When the spray distance is 200 mm, post-deposition oxidation occurs due to the heating effect of the long plasma jet on the substrate. In contrast, when the spray distance is longer, the particles undergo severe in-flight oxidation, and the oxide formed is uniformly distributed in the coating improving the hardness from 500 HV0.3 to 700 HV0.3.

An analytical and experimental investigation considering the effect of material flow velocity on tensile strength of a steel alloy joint produced by friction stir welding process

In this paper, the effects of linear speed, rotational speed, and tool radius of the pin and shoulder are investigated on the material flow velocity in friction stir welds. To obtain the maximum material flow velocity by an analytical method, a suggested relation is introduced for the rotational speed and tool optimum radius. The derived relation is based on the assumption of a velocity field in the stirring region. Besides, the effect of the linear speed on material flow velocity is investigated based on continuity and momentum equations. Finally, by using the experimental method and checking the mechanical properties of the welded parts obtained with different rotational speed, linear speed, and tool dimensions, the proposed analytical model is validated. The results indicate that in the friction stir welding process, the significant component effect on the stirring process is generated through the tool pin radius size. Besides, increasing the material flow velocity in the boundary layer increases the yield and ultimate strength of welds. To achieve the high-quality welds, rotational speed and other tool dimensions must be selected considering the equation extracted from the analytical method. Also, to make the maximum life for the pin and its components in friction stir welding of high melting point metals such as steel alloys, the operation is adjusted at a lower linear speed to prevent the destruction of the tool and improve the quality of the joint.

Synthesizing of Novel Bulk (Zr67Cu33)100−xWx(x; 5–30 at%) Glassy Alloys by Spark Plasma Sintering of Mechanically Alloyed Powders

Metallic glassy alloys with their short-range order have received considerable attention since their discovery in 1960’s. The worldwide interest in metallic glassy alloys is attributed to their unique mechanical, physical, and chemical properties, which cannot be found together in long-range order alloys of the same compositions. Traditional preparation methods of metallic glasses, such as rapid solidification of melts, always restrict the formation of glassy alloys with large atomic fraction (above 3–5 at%) of high melting point metals (Ta, Mo, W). In this study, (Zr67Cu33)100−xWx(x; 5–30 at%) metallic glassy alloys were fabricated through a mechanical alloying approach, which starts from the elemental powders. This system shows excellent glass forming ability in a wide range of W (0 ≤ x ≥ 30 at%). We have proposed a spark plasma sintering technique to prepare nearly full-dense large sized (20 × 20 mm) bulk metallic glassy alloys. The as-consolidated bulk metallic glassy alloys were seen to possess high thermal stability when compared with the other metallic glassy systems. This is implied by their high glass transition temperature (722–735 K), wide range of supercooled liquid region (39 K to over 100 K), and high values of crystallization temperature (761 K to 823 K). In addition, the fabricated ternary systems have revealed high microhardness values.

ALFRED: A revised concept to improve pool related thermal-hydraulics

ALFRED, namely the Advanced Lead-cooled Fast Reactor European Demonstrator, has been conceived to serve the industrial deployment of the Lead-cooled Fast Reactor (LFR) technology. ALFRED is a demonstrator reactor designed with the specific purpose to test and qualify innovative components and procedures to be used in commercial reactors. In its role of European Technology Demonstrator Reactor, it will offer a representative operational environment of interest for research organizations, industry and safety authorities. Initially developed as part of a collaborative effort funded through the European 7th Framework Programme, the project was taken over by an international consortium Fostering ALFRED Construction (abbreviated to FALCON). As one of the priorities of the consortium Expert Board, the ALFRED design underwent an in depth review, aimed at identifying and addressing vulnerabilities in terms of reliability and safety, investigating also scalability of the design, flexibility for maintenance and replacement, manufacturability of components, availability of codes and standards for nuclear components and materials. The reactor coolant system arrangement was found susceptible to two main thermal-hydraulic issues typical of Fast Reactor (FR) pool-type designs: (i) thermal stratification in the upper part of the pool and (ii) potential steam entrainment in case of Steam Generator Tube Rupture or leakage. Moreover, (iii) the risk of lead freezing, more specific to the use of high melting point metals as coolants, represented a third issue, of particular concern in conjunction with the passive residual heat removal function in accident conditions.Starting with a general description of the ALFRED Project framework, including the experimental facilities in support to the LFR Research, Development and Qualification plan, the paper will focus on the new system arrangement and Decay Heat Removal (DHR) system of the ALFRED concept design, aimed at improving the pool thermal-hydraulics against the above described issues and risks. Since the ALFRED revised configuration is considered to offer improved safety and robustness, the FALCON consortium is willing to share the outcome of private and national investments, with hope of stimulating new opportunities for further developments and investigations through advanced computational tools and experimental tests within the LFR research community.