Salvatore Grasso

Queen Mary, University of London | QMUL

This work examines the impact of sintering thermal history on kinetics of grain growth for 1264 ppm (0.1 wt.%) MgO‐doped alumina. Results suggest that sintering with a high heating rate in the order of 10 ³ °C⋅min ⁻¹ retards grain growth rate. By contrast, a slow heating rate of 5°C⋅min ⁻¹ resulted in an increase in grain growth constant by a facto...

In this work, two new 312 MAX phases of Zr 3 PbC 2 and Hf 3 PbC 2 were successfully synthesized by spark plasma sintering. It is the first discovery of lead‐containing 312 MAX phases, which together with M 2 PbC (M = Ti, Zr, Hf) form the lead‐containing MAX phase family. Considering the extremely low electrical conductivity of Hf 2 PbC, these two n...

In this paper, the i‐MAX phase (Mo 2/3 Y 1/3 ) 2 AlC ceramic with high purity of 98.29 wt% (1.13 wt% Y 2 O 3 and 0.58 wt% Mo 2 C) and high relative density of 98.59% was successfully synthesized by spark plasma sintering (SPS) at 1500°C with the molar ratio of n (Mo): n (Y): n (Al): n (C) = 4:2:3.3:2.7. The positions of C atoms in the crystal of (M...

Perovskites have shown tremendous promise as functional materials for several energy conversion and storage technologies, including rechargeable batteries, (electro)catalysts, fuel cells, and solar cells. Due to their excellent operational stability and performance, high-entropy perovskites (HEPs) have emerged as a new type of perovskite framework....

Ultrafast high-temperature sintering (UHS) is a novel sintering technique with ultrashort firing cycles (e.g., a few tens of seconds). The feasibility of UHS has been validated on several ceramics and metals, however, its potential in consolidating glass-ceramics has not yet been demonstrated. In this work, an optimized carbon-free UHS was utilized...

Fully amorphous 45S5 bioactive glass pellets were successfully consolidated at room temperature using cold hydrostatic sintering (CHS) and their acellular bioactivity was determined by immersion test in simulated body fluid (SBF). Crystalline 45S5 BG samples prepared using conventional sintering (TS) at 1050 °C were also tested. Preliminary results...

Lithium aluminum germanium phosphate (LAGP) solid electrolyte is a promising candidate for all-solid-state batteries. The currently available processing techniques based on melting-quenching require a rather lengthy crystallization step lasting up to 10 h. In this work, the newly emerged Ultra-fast High-temperature Sintering (UHS) was proposed to a...

Graphite is a fascinating material with unique properties, thus making it irreplaceable for a wide range of applications. However, its current processing route is highly energy demanding as it requires dwelling for several hours at high temperatures (2500-3000°C). We report on the near full consolidation (relative density greater than 95%) at room...

Despite the well-recognized advantages of Ultrafast High-temperature Sintering (UHS) based on the application of a graphite felt/paper heater, the technology, however, remains mostly suitable to consolidate thin-shaped samples. This work proposes a novel UHS configuration based on the graphite powder medium (P-UHS) to obtain much larger and complex...

The ternary or quaternary layered compounds called MAB phases are frequently mentioned recently together with the well-known MAX phases. However, MAB phases are generally referred to layered transition metal borides, while MAX phases are layered transition metal carbides and nitrides with different types of crystal structure although they share the...

Extreme heating and cooling rates, approaching 10⁴ ºC min⁻¹ represent a paradigm shift in materials manufacturing. In the past two decades, new techniques like Ultrafast High-temperature Sintering (UHS), and Flash sintering (FS) have emerged. Compared to conventional sintering, consolidation times are shortened by at least a thousand folds. Densifi...

In this paper, we combine rare earth element Sc and lead-containing MAX to predict a new ternary layered MAX phase Sc2PbC. Sc2PbC with a purity of 87.40 wt% was successfully synthesized by spark plasma sintering, and its crystal structure and atomic positions were obtained by X-ray diffraction (XRD). The Rietveld refinement results show that Sc2PbC...

In this work, the rapid thermal shock behavior of Ti2AlC ceramics was studied using induction heating. The present evaluation method possesses the merits of very rapid heating within tens of seconds and fast quenching in water of less than 0.1 s, removing the shortcomings of traditional thermal shock. For comparison, the samples were also quenched...

Van der Waals (vdW) layered materials have a wide range of applications and their bulks are commonly prepared using energy intensive pressure assisted sintering. For example, in the case of graphite or boron nitride temperatures in excess of 2000 °C are required. In this work, for the first time, we demonstrated that most of the vdW layered materia...

With the new discovery of layered boride compounds M2AB (M = Zr, Hf, Nb; A = S, Se) with the typical Cr2AlC-type structure, MAX phases have been successfully expanded from carbides and nitrides to borides. However, only five MAX phase borides have been synthesized at present, which means that the research on MAX phase borides is still in its infanc...

The ternary or quaternary layered compounds called MAB phases are frequently mentioned recently together with the well-known MAX phases. However, MAB phases are generally referred to layered transition metal borides, while MAX phases are layered transition metal carbides and nitrides with different type of crystal structures although they share the...

In this paper, we solve the long-unsolved problem of whether β-Ta4AlC3 can be transformed from α-Ta4AlC3. By utilizing Ta, Al, and C as initial materials with molar ratios ranging from 4.0/1.2/2.6–4.0/2.0/2.6, it is shown that the synthesis of β-Ta4AlC3 is largely affected by the content of Al, and it is confirmed that α-Ta4AlC3 is stable at 1600 °...

In this work, hot forging texture of pre-sintered MoAlB ceramics (relative density, 97.9%) were achieved by spark plasma sintering (SPS). The radial compression and lateral expansion rates reached − 54.8% and 25.8%, respectively. The X-ray diffraction results exhibited a preferred orientation of tailored samples. The b-axis of grains were prone to...

The recent observations of unusual superconductive effects in highly oriented pyrolytic graphite (HOPG) and twisted bi-layer, tri-layer and multilayer graphene materials have attracted an important attention. In this work we present a novel investigation on the relationship between structural ordering and magnetism in HOPG. Orientation dependent X-...

The entropy stabilization effect has expanded the compositional diversity of inorganic compounds. Nevertheless, the correlation between processing conditions, properties, and microstructure remains poorly understood. So far, little attention has been dedicated to identifying processing strategies to facilitate (i.e., reduce processing temperature)...

MXene, an advanced family of 2D ceramic material resembling graphene, has had a considerable impact on the field of research because of its unique physiochemical properties. MXene has been synthesized by the selective etching of MAX via different techniques. However, with the passage of time, due to the need for further progress and improvement in...

In this paper, Zr 2 SB ceramic with purity of 82.95 wt% (containing 8.96 wt% ZrB 2 and 8.09 wt% zirconium) and high relative density (99.03%) was successfully synthesized from ZrH 2 , sublimated sulfur, and boron powders by spark plasma sintering (SPS) at 1300 °C. The reaction process, microstructure, and physical and mechanical properties of Zr 2...

Single-phase high entropy fluorite (Ce0.2Zr0.2Y0.2Gd0.2La0.2O2−δ) samples were synthesized by co-precipitation and consolidated by ultrafast high-temperature sintering (UHS) in less than 2 minutes. The chemical homogeneity of the sintered materials was confirmed by X-Ray Diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDXS), high-resolutio...

Transition metal sulfides and their corresponding derivatives, such as MAX phases, have been widely studied because of their unique physical properties. However, due to the low melting/boiling point and volatile characteristics of sulfur, it is difficult to control the element ratio in their in-situ synthesis, and some impurities are introduced. Ba...

Present work showed that Ti3SiC2 ceramic has good ablation resistance at 1600 °C. The mass ablation rate and linear ablation rate after exposure to plasma flame for 120 s are −0.23 mg/s and 5.58 μm/s, respectively. After ablation for 120 s, the micro-morphologies of cross section of the ablation fringe show that the ablation layer was divided into...

Free access 50 days https://authors.elsevier.com/a/1eM4s4r9TE1Vgv Ultra-fast High temperature Sintering (UHS) relies on a carbon felt to heat the specimen. As in the case of a graphite furnace, carbon contamination leads to undesired blackening when the UHS temperature exceeds 1800 °C. In this work, we developed a novel UHS configuration based on...

Single-phase Hf2Al4C5 ternary carbide was fabricated from Hf/Al/C powder mixtures by pressure assisted sintering techniques such as hot pressing and spark plasma sintering at 1900 °C for 3h and 10min, respectively. XRD confirmed that the ternary carbide started to form at temperatures as low as 1500°C and with total formation of Hf2Al4C5 after reac...

https://www.mdpi.com/1996-1944/14/24/7655/htm We report on an ultrarapid (6 s) consolidation of binder-less WC using a novel Ultrahigh temperature Flash Sintering (UFS) approach. The UFS technique bridges the gap between electric resistance sintering (≪1s) and flash spark plasma sintering (20-60 s). Compared to the well-established spark plasma si...

In this work the double perovskites Sr2SmNbO6, Sr2CoNbO6 and Ba2CoNbO6 are investigated with first principles computations based on the density functional theory and plus U treatment. Firstly, different calculation methods are examined in order to quantitatively approach the exact band gap. It was found that neither the Strongly constrained and app...

Pressure-less consolidation of transparent alumina requires several hours dwelling at high temperature (1600 ℃) under a strongly reducing atmosphere (hydrogen). Here, we report on the ultrafast consolidation of translucent alumina ceramics at 1360 ℃. Transparency was promoted by the synergistic of high initial green density (62.7 %) and rapid sinte...

In this paper, in situ V2C-reinforced Cu composites were successfully fabricated by hot pressing at 750 °C under 25 MPa using Cu and V2SnC powders. Due to decomposition of V2SnC to V2C and Sn during sintering, Sn atoms entered the crystal structure of Cu. Therefore, final compositions of composites consisted of Cu(Sn) and V2C phases. Here, copper c...

Your personalized Share Link: https://authors.elsevier.com/a/1e8ug%7E2-F3qNJ The renewed interest on Fast Firing has been motivated by the suppressed Li, Na volatilization during the short sintering cycle (a few seconds). Ultra-fast high temperature sintering represents the latest development in Fast Firing with heating rates approaching 10⁴ °C/mi...

Flash spark plasma sintering (FSPS) of SiC was carried out using additives (10 vol%) with different electrical conductivities: alumina (insulator), boron carbide (semiconductor), and titanium carbide metallic (conductor). The electrical conductivity of the additives plays a determinant role on the FSPS process, it controls the electrical SPS power...

In this paper, Zr 2 SB ceramics with high relative density (99.03%) and high purity of 82.95 wt% (containing 8.96 wt% ZrB 2 and 8.09 wt% zirconium) were successfully synthesized from ZrH 2 , sublimated sulfur and boron powder by spark plasma sintering at 1300 ℃. The reaction mechanism, microstructures, physical properties and mechanical properties...

Water-Assisted cold isostatic Pressing (WAP) enabled pressure-less sintering of fine grained (0.6 µm) and nearly full dense (99.3%) weak translucent alumina ceramics. As a term of comparison, dry pressed samples, prepared under identical processing conditions, maintained an opaque appearance and their relative density did not exceed 97.7%. The enha...

In this study, a new type of highly porous ceramic was successfully fabricated from α-Al2O3 whiskers and nano-sized Al2O3 particle slurry by vacuum infiltration with the subsequent annealing in air. It was found that with an increase in the alumina slurry amount or sintering temperature, the porosity of the foam ceramic decreased while its compress...

A thermally-insulated Ultra-fast High temperature Sintering (UHS) has been developed to maximize the densification of 3 mol% yttria-stabilized zirconia and improve the energy efficiency of the process. Thermally-Insulated UHS (TI-UHS) employed a fibreboard insulator, which reduced the energy consumption by ≈40% compared to the reference setup. An u...

In this work, ultrafast thermal shock of Ti3AlC2 ceramic was evaluated in water and air by utilizing the induction heating method. First, the annealed samples were heated to the set temperature in tens of seconds and dropped into the cooling water within 0.1 s which is rather short not to degrade the sample temperature. Compared to the traditional...

Due to unique osteogenic properties, tricalcium phosphate (TCP) has gained relevance in the field of bone repair. The development of novel and rapid sintering routes is of particular interest since TCP undergoes to high-temperature phase transformation and is widely employed in osteoconductive coatings on thermally-sensitive metal substrates. In th...

Ultrafast High-temperature Sintering (UHS) has been successfully applied to fabricate the silicon nitride (Si3N4) bulks, as the first attempt of ultra-rapid consolidation of a non-oxide ceramics. At a heating rate of 875 °C/min, the bulk Si3N4 ceramic with a relative density greater than 96 % and an α-β phase transformation degree above 80 % could...

Boron carbide composites with 10 vol.% TiB2 were prepared by reactive sintering of B4C, TiO2, and carbon black powder mixture at the temperature of 1800 °C, under a pressure of 70 MPa in a vacuum. The combined effects of electric current and in-situ reactions led to a significant overheating of the central part of the sample, while no overheating w...

In this work, θ-Al2O3 whiskers with twins were successfully fabricated by a hydrothermal method followed by annealing at 1000 °C in argon atmosphere using Al2(SO4)3·18H2O, CO(NH2)2 and PEG2000 as initial materials. It is confirmed that precursor of AlO(OH) whiskers is suitable to be used for preparing alumina whiskers when the molar ratio of Al3+:...

Ultrafast High-temperature Sintering (UHS) allows consolidation of ceramics in just a few minutes. The green body is placed within a carbon felt heated by the Joule effect at temperatures up to 2000 ˚C. Here, we propose a combined experimental and numerical analysis to enable the fabrication of fully dense and fine-grain α-Al 2 O 3 samples using a...

Our work proposes a comparison between Spark Plasma Sintering of LiFePO4 carried out using an Alternating Current (AC) and Direct Current (DC). It quantifies the Li-ion migration using DC, and it validates such hypothesis using impedance spectroscopy, X-ray photoelectron spectroscopy and inductively coupled plasma optical emission spectroscopy. The...

We report on a novel consolidation technique based on the combination of a liquid (cold sintering) and electricity (flash sintering). The evolution of hydrogen from electrolysis of the solvent triggered the Flash Cold Sintering (FCS) event without need for external heating. Electrochemical effects became pronounced in presence of acetic acid soluti...

In this paper, B-containing MAX phase of Nb2SB ceramics with high purity of 96 wt% (4 wt% NbB impurity) was successfully synthesized using the molar ratio of Nb: S: B = 2: 1.3: 1 by spark plasma sintering at 1350 oC under 30 MPa. The reaction path, microstructure, physical and mechanical properties were systematically studied. It is found that the...

Li1.3Al0.3Ti1.7(PO4)3 (LATP) is one of the most promising inorganic solid electrolytes, it combines together good electrochemical stability with high ionic conductivity. Its properties are strongly dependent on the consolidation route and the relevant literature confirms the beneficial role of rapid heating. Therefore, the recently emerged Ultrafas...

We propose an innovative methodology to quantify the dependence of grain growth with respect to current density during flash sintering of zirconia (3YSZ) (under a nominal and current limit of 150 mA mm−2). This was achieved by using a notch (0.5 mm deep and 1.5 mm wide) located in the middle of a dog-bone specimen, allowing an uneven current distri...

Research on High Entropy Ceramics (HEC) is rapidly expanding, the myriad of unexplored compositions creates unique opportunities. Compared to the state of the art, HEC have shown favourable improvement on the long‐term stability and durability of secondary batteries (i.e., Li, Na, K and S). This short review summarizes the recent (2015‐2020) progre...

Flash Spark Plasma Sintering (FSPS) was used to rapidly sinter pure titanium diboride (TiB2). A pre-sintered green body (Ø= 20 mm with relative density 60%) was discharged under a current of 2-2.5 kA flowing entirely across the sample. The samples were locally densified up to 98% of relative density in a very short time of 20 seconds. The rapid hea...

A rapid throughput thermal shock resistance evaluation method was developed and tested on Ti3SiC2 ceramic traditionally known for its excellent thermal shock resistance. The sample was rapidly heated by the induction heating and dropped into the cooling water within 0.35 s. The three-point bending test of Ti3SiC2 after quenching at 1300 °C dropped...

Zircon (ZrSiO4) is a refractory structural ceramic material difficult to consolidate because of its thermal dissociation into ZrO2 and SiO2. Addition of sintering aids can improve its densification, but with detrimental effects on high temperature mechanical properties and corrosion resistance. In this work, zircon was consolidated by employing the...

The recent observations of superconductive-signals in grafoil and highly-oriented-pyrolytic-graphite (HOPG) have evidenced existence of unknown-defects responsible of electron-correlation-phenomena. Existence of anomalous-super-periodicities and doubled-diffraction-patterns has been also reported. Here we present an in-depth investigation of the st...

We report on novel cold sintering techniques (e.g. Cold Sintering Process (CSP and Cold Isostatic Sintering (CIS)) to enable fabrication of dense LiFePO4 (LFP) cathodes. This approach might be ideal to assembly a solid state Li-Ion batteries as the room processing temperature can effectively prevent undesired thermal degradation between the layers...

https://www.mdpi.com/2075-4701/10/12/1653 Abstract: In the past decade, a renewed interest on electromagnetic processing of materials has motivated several investigations on the interaction between matter, electric and magnetic fields. These effects are primarily reconducted to the Joule heating and very little attention has been dedicated to the m...

The synthesis, microstructure, and properties of high purity dense bulk Mo 2 TiAlC 2 ceramics were studied. High purity Mo 2 TiAlC 2 powder was synthesized at 1873 K starting from Mo, Ti, Al, and graphite powders with a molar ratio of 2:1:1.25:2. The synthesis mechanism of Mo 2 TiAlC 2 was explored by analyzing the compositions of samples sintered...

sostatic pressure of 300 MPa promoted the formation of strong bonds between fused silica pieces. The joining was performed using a 5 mol/l NaOH solution at room temperature for 20 min with and without an isostatic pressure. The as-received materials (with a roughness of 13.4 nm) joined with pressure resulted in a ~40% increase of the shear strength...

Free access https://authors.elsevier.com/c/1bsIq4r0U29n5y Despite sintering has a history even longer than human civilization (its discovery dates back at least to 25,000 years ago), in the past decade, new exciting challenges have emerged in the field: reduction of environmental impact, densification of metastable phases, complete consolidation o...

Observation of granular superconductivity in water doped graphite materials has motivated recent research because of the unexplored scenarios in the field of magnetism and spintronics. Diffusion of hydrogen and/or oxygen species has been reported to promote doping within graphitic grains; however, the origin and dynamics of the magnetic phenomena (...

Free access until Dec 4th 2020. https://authors.elsevier.com/a/1bvkr3aX7LHHgY Electricity is an efficient form of energy, and the growing interest in electricity-assisted manufacturing is motivated by its inherent energy saving and reduced environmental impact. Beyond this, Electromagnetic Processing of Materials (EPM) allows the fabrication of ma...

Guided by the theoretical prediction, a new MAX phase V2SnC was synthesized experimentally for the first time by reaction of V, Sn, and C mixtures at 1000 °C. The chemical composition and crystal structure of this new compound were identified by the cross-check combination of first-principles calculations, X-ray diffraction (XRD), energy dispersive...

In this report, the effect of the cold sintering process (CSP) on the electro-chemo-mechanical properties of 10 mol% Gd-doped ceria (GDC) is investigated. High purity nanoscale GDC powder is sintered via a cold sintering process (CSP) in pure water followed by post-annealing at 1000 {\deg}C. The resultant CSP ceramics exhibits high relative density...

In this report, the effect of the cold sintering process (CSP) on the electro-chemo-mechanical properties of 10 mol% Gd-doped ceria (GDC) is investigated. High purity nanoscale GDC powder is sintered via a cold sintering process (CSP) in pure water followed by post-annealing at 1000 °C. The resultant ceramics exhibits high relative density (∼90%) w...

An innovative sintering method that combines Flash (i.e. electricity) and Cold Sintering (i.e. water or other liquid) is presented. The electrolysis of water triggers Flash Cold Sintering (FCS) of ZnO at room temperature without external heating. In the best case, ZnO pellets were sintered up to 96.5% relative density in less than 60 s by applying...

We report a novel investigation on the relationship between magnetic-ordering and graphitic-structure in highly-oriented-pyrolytic-graphite (HOPG). By employing orientation-dependent-X-ray-diffraction, Raman-spectroscopy and temperature-dependent-superconductive-quantum-interference-device (T-SQUID) we examined the presence of ferromagnetic- and su...

A molecular design approach to fabricate nanofibrous membranes by self-assembly of aromatic cationic peptides with hyaluronic acid (HA) and nanofiber alignment under a magnetic field is reported. Peptides are designed to contain a block composed of four phenylalanine residues at the C-terminus, to drive their self-assembly by hydrophobic associatio...

In this work, TiC‐SiC‐Ti3SiC2 composites were synthesized by in situ reactive hot pressing using β‐SiC, graphite, and TiH2 powders as initial materials. Microstructure and mechanical properties of as‐prepared dense composites were systematically investigated. It was found that by increasing the initial SiC content the final SiC content in the compo...

The renewed research interest on MoAlB ceramic is motivated by its high temperature strength and high temperature oxidation resistance. Bulks were obtained by a reactive spark plasma sintering starting from elemental powders of Mo, Al, and B. Chemical reactions were characterized at intermediate temperatures to define reaction mechanism. The result...