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‘Thermal runaway’ was the most popular mechanism in flash sintering, but this theory was inappropriate under high electric field. In this paper, we described electric discharge and breakdown phenomena in experiment to verify this point. And water moisture was found an important role in conducting electric discharge, that increasing moisture content of samples decreased the onset electric field of flash sintering and as low as 1628 V/cm of onset electric field was realized in this paper. With high electric field that can induce electric discharge in the sample, the flash sintering can be induced at room temperature and atmosphere.

Si3N4 ceramics with 10 mol% (MgSiN2+Y2O3) additives were prepared by sintering at 1900 °C for 8 h in 1 MPa N2 atmosphere. Both the bending strength and thermal conductivity of the ceramics increase with increasing content of MgSiN2, and reached 689 MPa and 97 Wm−1K−1 with the addition of (7 mol% MgSiN2 + 3 mol% Y2O3). The bending strength and thermal conductivity were enhanced to 698 MPa and 105 Wm−1K−1 by post annealing at 1400 °C for 20 h. By annealing at 1600 °C, the thermal conductivity could be further improved to 117 Wm−1K−1, but the strength decreased to be 517 MPa. From the experimental results, adding more MgSiN2 and increasing the annealing temperature are helpful to improve the thermal conductivity, by reducing the grain boundary phase and increasing the grain size.

The preparation of solar grade silicon (Si) is popularly carried out in silica (SiO2) crucible containing porous α-Si3N4 coating, in which poorly wetting SiO2 film around α-Si3N4 particles act as barrier for Si infiltration. The present investigation studies the influence of oxygen (O) content in coating on wettability and infiltration for Si/α-Si3N4/SiO2 ternary system. The amorphous SiO2 film surrounding Si3N4 particles is firstly synthesized by pre-oxidizing coating in air, and the O content is controlled by adjusting pre-oxidizing temperature and holding time. In this work, dynamic wetting behavior of Si drop on coating containing various content of O is investigated using the sessile drop method. Meanwhile, via microstructural analysis, infiltration under the drop and infiltration beyond the drop (including infiltration on coating surface and under coating surface) are distinguished on coatings with different O content. Finally, wettability transformation (from wetting to non-wetting) is analyzed; mechanism of infiltration resistance for O in coating is interpreted by analytical model.

Isolated growth hormone deficiency (IGHD) is the most common pituitary hormone deficiency and can result from congenital or acquired causes. Among the known factors, genetic mutations in human growth hormone (hGH) remain the most frequent cause of IGHD, which influence the binding of hGH to its cognate receptor (hGHbp). Although previous studies have systematically investigated the residue importance at hGH–hGHbp complex interface, the molecular role of IGHD-associated residue mutations in the complex function still remains largely unexplored. Here, a total of 21 known hGH naturally-occurring missence mutations that have been clinically observed to be involved in IGHD disorder are collected and confirmed by original literature; they effects on the conformation, energetics and dynamics of hGH–hGHbp recognition and interaction are dissected at molecular level by using atomistic dynamics simulations, binding energy calculations and fluorescence spectroscopy assays. A systematic profile of hGH–hGHbp binding response to these clinical missence mutations is created, based on which it is revealed that (i) most mutations have appreciably unfavorable effect on the binding, which potentially destabilize the complex interaction, while only very few are predicted as moderate stabilizers for the complex system, and (ii) these disease-related mutations can locate either at complex interface or in hGH protein interior far away from the interface; both can influence the complex binding through either direct interaction or indirect allostericity. Two mutations, E100K (non-interface) and G146R (interface), are identified to address potent destabilization effect on hGH–hGHbp complex system; they can reduce the complex binding affinity by 8-fold ( K d changes from 0.76 to 5.9 nM) and 46-fold ( K d changes from 0.76 to 34.7 nM), respectively.

ZnSe powders have been prepared by vapor reaction during combustion synthesis. The powders contain both cubic and hexagonal ZnSe, where the fraction of the hexagonal phase increases with increasing distance from the evaporation source. The powders consist of spherical particles and rod-like crystals with sizes from submicron to a few microns. In UV–Vis region, the ZnSe powders have two absorption edges at 450–500 nm and 650–700 nm, likely connected with intrinsic band-gap transition and defect energy levels. From the optical absorption data, the band-gap of the ZnSe powders is estimated to be 2.4–2.5 eV. Under an UV or blue excitation, the ZnSe powders show very weak near-band-edge emission but strong defect-induced red emission. It appears that the ZnSe powders synthesized by vapor reaction clearly differ from the bulk ZnSe sample by melt solidification in both phase composition and optical properties.

A novel freeze drying assisted combustion synthesis route was developed to fabricated Eu2+-activated Ca-Sialon phosphors with high nitrogen content. Highly pure Ca-Sialon powders with 100% uniform elongated grains were obtained at a relatively low nitrogen pressure without using any NH4Cl or NH4F additive. The phosphors exhibited an orangish yellow light peaking at 592 nm under the 450 nm excitation, with optical properties of high quantum efficiencies and very low thermal quenching.

Heat dissipation is important in high-power LEDs and depends on the thermal conductivity of the substrate. This work investigates the heat dissipation performance of AlN ceramic substrate in high-power LEDs. AlN substrate with a thermal conductivity of 193 W m −1 K −1 and flexural strength of 380 MPa has been prepared by pressureless sintering, and then bonded with a Cu film by direct plating copper (DPC). By using the AlN substrate for heat dissipation, the junction temperature (78 °C) is lowered by 42 °C compared with the case using Al 2 O 3 substrate and well below the upper limit of the operation temperature of the LEDs. From the experimental results, AlN ceramic substrate with a high thermal conductivity is a promising candidate for heat dissipation in high-power LEDs.

To investigate the clinical value of the alpha-fetoprotein (AFP) response following transcatheter arterial chemoembolization (TACE) in intermediate-stage hepatocellular carcinoma (HCC).Data on patients with Barcelona Clinic Liver Cancer B staging system were analyzed. An AFP response was defined as a decrease in AFP of more than 20% after a TACE session. The association between AFP response and treatment outcome regarding imaging response and overall survival (OS) was explored. Cox proportional hazards models were applied to identify independent risk factors for OS after TACE.Of the enrolled 376 patients with elevated serum AFP20 ng/mL, 214 (57%) with AFP responses were identified. AFP responders had improved median survival than non-responders (20 vs. 12 months, P = 0.002). AFP response was significantly correlated with imaging response (P 0.001). The Cox proportional hazards model revealed that AFP response was an independent factor for OS (hazard ratio, 0.59; 95% confidence interval, 0.45-0.78; P 0.001). In stratified analyses, an AFP response achieved improved survival in patients with tumor diameters ≤5 cm, diameters5 cm, tumor number ≤3 and without underlying cirrhosis.The AFP response indicates enhanced survival after TACE in patients with intermediate-stage BCLC.

Combustion synthesis is a fast and energy-efficient process to prepare inorganic materials from self-sustained combustion reactions. It is widely used for preparing ceramics, metals, and their composites. The unique condition in combustion synthesis with high temperatures and large heating rates offers good opportunities to explore new materials and novel microstructures. This paper gives a viewpoint on recent progress in combustion synthesis, from fundamentals to applications. New results on theories, processings, and materials are reviewed, and perspectives on the development of combustion synthesis are provided.

This paper investigates the reaction mechanism in mechanochemical synthesis of Cu 2-x Se by vibrational milling of (Cu+Se) powder mixture. The effects of milling time, milling mode, ball-to-powder weight ratio (BPWR), and Cu/Se molar ratio in the starting composition on the phase assemblage of the products are investigated. It is found that, the synthesis of Cu 2-x Se is improved by increasing milling time, BPWR, and Cu/Se ratio. For a fixed total milling time, continuous milling is better than intermittent milling to facilitate the formation of Cu 2-x Se. By continuous milling for 20 min with BPWR = 6 and Cu/Se = 2, almost single-phase β-Cu 2-x Se is produced except for minor un-reacted Cu. A diffusion-controlled reaction mechanism is proposed for the mechanochemical synthesis of Cu 2-x Se, where intermediate phases such as CuSe and Cu 3 Se 2 with lower Cu/Se ratios are produced at first and then gradually converted into Cu 2-x Se with the diffusion of Cu atoms.

ReS2 is emerging as a promising saturable absorber for solid-state lasers from visible to mid-infrared. In this paper, we report on a new approach of integrating a ReS2 saturable absorber into Yb:Lu 0.74 Y 0.23 La 0.01 VO4 crystal based Q-switched laser. Under maximum pump power, the highest pulse energy at 1.03 μ m wavelength was measured as 5.3 μ J, which is one order of magnitude higher compared with the previously reported 1 μ m solid-state passively Q-switched lasers based on ReS2 saturable absorber.

This paper reports combustion synthesis of α-Si 3 N 4 with the addition of NH 4 Cl. The effect of NH 4 Cl on the phase composition of the products is investigated, and the reaction mechanism in the nitridation of Si with the participation of NH 4 Cl is discussed. The content of α-Si 3 N 4 in the products increases with increasing content of NH 4 Cl in the starting compositions, and reaches 93% when 10 wt% NH 4 Cl is added. It is proposed that the addition of NH 4 Cl promotes the nitridation of Si by gaseous reaction and improves the formation of α-Si 3 N 4 . In the reaction, NH 4 Cl decomposes into HCl and NH 3 , and HCl reacts with Si to form SiCl 4 , which is later nitridized into Si 3 N 4 . In the nitridation of Si, HCl acts as a catalyst and a carrier to transfer Si atoms from solid and liquid Si particles into gas phase. The contribution of NH 3 to the nitridation of Si is limited, and most N atoms required for the synthesis of Si 3 N 4 are provided by N 2 .

AlN ceramic substrates are prepared by tape casting and presureless sintering at 1850 °C for 10 h, with 8 wt% Y2O3 and yttrium aluminates of Y3Al5O12 (YAG), YAlO3 (YAP), and Y4Al2O9 (YAM) as sintering additives. The effects of the sintering additives on the phase assemblage, microstructure, thermal conductivity, and bending strength of the sintered AlN ceramics are discussed. With Y2O3, YAG, YAP, and YAM as sintering additives, the secondary phases in the sintered AlN ceramics are YAM, YAG, YAP + YAG, and YAM + YAP, and the average sizes of AlN grains are 5.5, 3.6, 4.4, and 4.9 µm, respectively. In the order of sintering additives with decreasing Y2O3/Al2O3 ratio, viz. Y2O3 > YAM > YAP > YAG, both the thermal conductivity and bending strength of the sintered AlN ceramics decrease. With Y2O3 as the sintering additive, the sintered AlN sample shows the maximum thermal conductivity of 205 W/(m K) and bending strength of 295 MPa.

ZrN and AlN nitride ceramic powders have been synthesized by combustion synthesis using Si 3 N 4 and BN as solid nitrogen sources. The experimental results show that the metallic particles of Zr and Al are fully nitridized by the solid nitrogen sources and are converted into ZrN and AlN. Zr reacts with both Si 3 N 4 and BN in a self-sustained way, while Al reacts only with Si 3 N 4 and does not react with BN. By using Si 3 N 4 and BN as solid nitridizing agents, this work provides an alternative way to synthesize the nitrides of ZrN and AlN, which differs from the conventional nitridation method using N 2 gas as a nitridizing agent.

Titaniothermic reduction of nitrides in a self-propagating way is reported here to produce TiN-based ceramic powders. In the titaniothermic reaction, where solid nitrides instead of N2 gas are used as the nitrogen source, N atoms required for the nitridation of Ti do not rely on the infiltration of N2 gas, but are in-situ supplied by the decomposition of solid nitrides, thus resulting in a higher conversion degree, more homogeneous microstructure, and smaller grain size. In contrast to the well-known aluminothermic and magnesiothermic processes with the reduction of oxides, the titaniothermic reaction involves the reduction of nitrides, which applies to more other metals besides Ti and offers a new way to synthesize nitrides other than direct nitridation of metal powders in a N2 atmosphere.

Ti1−xWxC solid solution powders have been prepared by combustion synthesis in two reaction modes of self-propagating high-temperature synthesis (SHS) and thermal explosion (TE). The reaction mechanism in combustion synthesis is investigated and the effects of processing parameters are discussed. Two reaction paths are proposed for the formation of the Ti1−xWxC solid solution. In path 1, Ti1−xWxC crystals are directly precipitated from Ti-W-C melt, and in path 2 the Ti1−xWxC phase is formed by solid-state reaction between TiC and WC. The availability of the two reaction paths depends on the x value and reaction temperature. For smaller x values and higher temperatures, the reaction path 1 dominates and almost full conversion is achieved. For larger x values and lower temperatures, however, path 2 becomes dominant. In path 2, the rate-limiting step is the formation of WC by slow diffusion-controlled solid-state reaction between W and C, which is unable to be completed during the short reaction period and results in the presence of W2C and unreacted W in the products. The reaction between W and C cannot be improved by the addition of excessive C, but can be promoted by using carbon black instead of graphite powder as C source or carrying out the synthesis in a high-pressure N2 atmosphere instead of vacuum. In the fast combustion reaction with high heating/cooling rates, a non-equilibrium state is likely to be created because the mass transfer and energy exchange are limited. The non-equilibrium condition has a strong influence on the reaction kinetics, where the decomposition of W2C is avoided, a localized compositional heterogeneity is caused, and ultrafine grains on a submicron scale are obtained in the products.

Graphene with tuned surface area has been prepared by combustion synthesis (CS) from the reaction between Mg powders and CO2 gas. The content of the MgO diluent has an important influence on the morphology, crystallinity, surface properties, and thus adsorption performance of the prepared graphene. Graphene exhibits a macroporous microstructure with a broad pore size distribution and is abundant in wrinkles and ripples. From adsorption experiments, methyl orange (MO) molecules can be effectively removed by the graphene. The adsorption data fit the Langmuir isotherm well and the adsorption kinetics follows the pseudo-second-order rate reaction.

This paper reports the combustion synthesis of α-Si3N4 using green additives of water and alcohol. The addition of water and alcohol is demonstrated to be effective in controlling the reaction kinetics and improving the formation of α-Si3N4 by vapor reactions. With increasing proportion of additives in the starting composition, the content of α-Si3N4 in the product is clearly enhanced. In contrast to the ammonium halides usually employed as additives in the combustion synthesis of α-Si3N4, the green additives used here are nontoxic, noncorrosive, and thus more attractive for industrial applications.

An orange-red emitting Mn2+/Si4+ co-doped AlN phosphor was prepared by an efficient combustion synthesis method. Phase identification and structure characterization were performed using powder X-ray diffraction (XRD) and refined by the Rietveld method. Luminescence and afterglow properties of the AlN-based phosphors such as photoluminescence spectra (PL), CIE values, afterglow decay curves, thermoluminescence glow curves (TL) were systematically studied. Using the Tanabe-Sugano diagram, the Racah parameters B, C, and crystal field splitting parameter Dq of as-prepared phosphor were calculated to be 812 cm−1, 2168 cm−1, and 780 cm−1, respectively. The luminescence intensity and afterglow time were increased, respectively, by about 1.1 and 2.2 times after 3% Si4+ co-doping. Particular attention was paid to study the mechanism of Si4+ co-doping on improving luminescence properties using a combination of the above-mentioned method and X-ray photoelectron spectroscope (XPS). Two hypothetical stress cancellation and charge rebalance effects due to Si4+ co-doping were discussed. Besides, it was found a shallower trap level (0.56 eV, compared to 0.84 eV for those without Si4+ co-doping) was formed after the co-doping of Si4+, which results in enhanced afterglow performance.

TiB 2 -TiC-WB composite ceramic powders have been prepared by fast combustion synthesis from Ti, W and B 4 C, by coupling the weak exothermic reaction of W + B = WB with strong ones of Ti + 2B = TiB 2 and Ti + C = TiC. With increasing W/(Ti + W) ratio, the reaction temperature and heating rate decrease while the content of WB increases, and unreacted W appears for W/(Ti + W) = 0.24. The addition of excessive B 4 C leads to lower reaction temperature, smaller grain size, and formation of WB 2 . The products show a homogeneous microstructure without element segregation on the scale of agglomerates, and in most products the average grain size is smaller than 1 µm.

A new model for a plasma-facing component with built-in tungsten wires and a W-Cu functionally graded layer is proposed and investigated. Using ABAQUS software on the basis of finite element method, the distributions of temperature and thermal stress in different first wall models under normal ITER operation condition are simulated. The result shows that W-Cu functionally graded layer instead of Cu layer can significantly reduce the high thermal stress at the interface of tungsten and copper. Inclusion of W wires further decreases the thermal stress in W-Cu functionally graded layer. A variety of comparative simulations are performed to achieve the optimal design of this model, especially the diameter and spacing of tungsten wires.

Cu 2 SnSe 3 samples with different secondary phases are prepared from compositions of Cu x SnSe 3 (x=1.8–2.2) and Cu 2 Sn y Se 3 (y=0.8–1.2), and their thermoelectric properties are investigated. For Cu x SnSe 3 samples, the secondary phase is SnSe 2 for x=1.8 and 1.9 and SnSe for x=2.2, and nearly single-phase Cu 2 SnSe 3 is obtained for x=2.0 and 2.1. For Cu 2 Sn y Se 3 samples, the secondary phase is CuSe for y=0.8 and SnSe for x=1.1 and 1.2, and single-phase Cu 2 SnSe 3 is produced for y=0.9 and 1.0. The lattice structure of synthesized Cu 2 SnSe 3 depends on the x and y values, which is cubic for x≤2.0 or y≤1.0 and monoclinic for x>2.0 or y>1.0. Compared with the single-phase Cu 2 SnSe 3 sample (ZT=0.4 2 at 77 3 K), the samples with SnSe 2 secondary phase show a greatly-enhanced ZT of 0.84 at 773 K, which is likely the best result for un-doped Cu 2 SnSe 3 up to now. The samples with SnSe secondary phase exhibit poor thermoelectric properties.

ZTA-TiC-FeCrNi cermets are prepared by a fast and furnace-free way called high-gravity combustion synthesis. The synthesized cermet samples show the maximum relative density of 97.6% and a hierarchical microstructure with grain sizes from submicron to >50 µm. The content of TiC has a strong influence on the microstructure and mechanical properties of the cermet samples. A higher TiC content results in refined microstructure, improved hardness, and reduced coefficient of friction. With increasing TiC content, the strength and toughness of the samples first increase and then drops, and reach the maximum of 469±26 MPa and 11.3±0.2 MPa m 1/2 at 20% TiC. Compared with commercial polycrystalline Al 2 O 3 ceramics, the ZTA-TiC-FeCrNi cermets exhibit better wear resistance, and the volume loss is lower by one magnitude than Al 2 O 3 under the same condition.

Iron-based superconductor of FeSe0.5Te0.5 has been prepared by chemical-furnace-assisted combustion synthesis. The chemical furnace preheats the reactant and enhances the reaction temperature, thus increasing the volume fraction of liquid and the solubility of Fe and improving the mass transfer. Accordingly, the chemical reaction and crystal growth are greatly promoted, resulting in higher compositional homogeneity, better crystallinity, and larger crystal size. The synthesized FeSe0.5Te0.5 sample consists of two-dimensional thin slice crystals. It is proposed that, the slice crystal shape is derived from the intrinsic tetragonal lattice of FeSe0.5Te0.5, and forms by anisotropic crystal growth with fast growth in (001) face. The crystal growth of FeSe0.5Te0.5 is also affected by cooling condition, and by control of the cooling condition lamellar crystals are produced with a thickness of about 1 mm and (001) preferred orientation. The transport properties of the synthesized FeSe0.5Te0.5 sample have been investigated, showing an onset Tc of about 13 K in the resistivity vs. temperature curve and a sharp drop of magnetic susceptibility at about 15 K. Compared with the conventional solid state reaction approach, chemical-furnace-assisted combustion synthesis may provide a more efficient way to prepare iron-based superconductors with much-reduced processing time and not requiring furnaces.

The reaction mechanism in fast combustion synthesis of FeSe and FeSe0.7Te0.3 is investigated by a special quenching experiment and thermal analysis. The reaction temperature exceeds the melting point of Se but is below that of Fe, and the reaction takes place at the interface between solid Fe and liquid Se. By thermal analysis, the reaction almost immediately starts after Se melts and persists in a broad temperature range. By linear fitting from DSC data, the activation energies are calculated to be 102 ± 8 kJ/mol for the reaction of Fe + Se = FeSe and 138 ± 22 kJ/mol for Fe+0.7Se + 0.3Te = FeSe0.7Te0.3. The reaction zone consists of continuous liquid Se and separately distributed Fe solid particles, where each Fe particle together with the surrounding Se liquid layer can be regarded as a reaction cell. In a planar reaction front, the mass transfer and heat exchange between two reaction cells can be ignored, and the reaction happens individually but simultaneously in every cell. From microstructure characterization, it is suggested that the infiltration of Se liquid also plays an important role in mass transfer besides the conventional diffusion process. An evident element segregation is observed in the Fe(Se,Te) product, and the distributions of Se and Te are complementary. To explain the segregation phenomenon, an oscillatory reaction mechanism is proposed, where Se and Te alternatively reacts with Fe accompanying the oscillation of concentrations of Se and Te in the liquid. The reaction mechanism discussed here is likely to also operate in other solid-state synthesis approaches, and may help to optimize the processing parameters to improve the quality of synthesized Fe(Se,Te) samples.

Si3N4 coating is widely used in the production of photovoltaic silicon ingots. This work investigates the influence of pre-oxidation of Si3N4 powders on the interaction between Si3N4 coating and molten Si based on sessile drop experiments. It is found that the surface tension and surface roughness affect the contact angle and accordingly wetting behavior. A new mechanism for the permeation of molten Si in Si3N4 coating is proposed, where the driving force for the permeation is provided by chemical reaction between SiO2 and Si instead of usual capillary force.

W-Cr alloys have been prepared by high-gravity combustion synthesis from aluminothermic reactions. The alloy with the composition of W0.5Cr0.5 shows a hierarchical microstructure composed of both micro- and nano-sized grains, which is proposed to be produced by spinodal decomposition. The hierarchical microstructure contributes to an improved hardness of 11.2 GPa, which almost doubles that of the W0.5Cr0.5 alloy prepared by sintering. Compared with the conventional powder metallurgy approach, high-gravity combustion synthesis may offer a more efficient way to produce W-Cr alloys with much reduced time and energy consumption.

Thermoelectric materials are attractive for solar thermal energy conversion and waste heat recovery. The existing methods for fabricating thermoelectric materials involve multi-step processes with considerable time and energy consumption. Here we report a fast and one-step way to prepare thermoelectric materials by gas-pressure or high-gravity assisted combustion synthesis. Dense Cu2SnSe3 samples with a porosity below 2% were prepared from self-sustained combustion reaction of element powders. The electrical conductivity of the Cu2SnSe3 samples was greatly enhanced and the thermal conductivity was reduced by partial substitution of Sn with In. The ZT values of the un-doped and In-doped Cu2SnSe3 samples reached 0.51 and 0.62 at 773 K, respectively, which are comparable to the best results reported for Cu2SnSe3 produced by other methods. Combustion synthesis offers an efficient way to prepare thermoelectric materials with reduced time and energy consumption, which may open up new possibilities for synthesis of thermoelectric materials.

Thermoelectric materials are attractive for solar thermal energy conversion and waste heat recovery. The preparation of bulk thermoelectric materials usually involves multi-step processes with considerable time and energy consumption. Here we report an alternative way called combustion synthesis to realize one-step and fast fabrication of bulk Cu2ZnSnSe4 thermoelectric materials. The combustion synthesis was carried out in 2 MPa Ar gas atmosphere or in a high-gravity field in order to reduce the porosity in samples and complete simultaneous densification during synthesis. Nearly full-dense Cu2ZnSnSe4 samples with a porosity of

Tungsten fiber reinforced copper-based composites were successfully fabricated by a new method called combustion synthesis melt infiltration under ultra-high gravity. Between the tungsten fibers and the copper matrix, an interlayer consisting of W18O49 needles was observed at the surface of the pickled tungsten fibers. The interfacial strength was measured by the push-out test. For the tungsten fibers with a WO3 surface layer, the failure happened at the interface between the WO3 layer and the copper matrix by the debonding failure mechanism. For the case with the formation of a W18O49 interlayer, the failure happened at the interface between the W18O49 interlayer and tungsten fibers by the brittle failure model, which improved the interfacial strength. Keywords: W/Cu composites, Fiber reinforced composites, Combustion synthesis, Ultra-high gravity, Fusion

TiC1 − xNx-based cermets are attractive for high-speed cutting operations, and are usually produced by powder sintering at high temperatures and for a long time. In this paper, dense TiC1 − xNx–Ni3Ti cermet is directly prepared in one step by combustion synthesis in 2 MPa N2 atmosphere, from the reactant of (Ti + C + Ni) with a molar ratio of Ti:C:Ni = 1:0.7:0.4. The as-prepared TiC1 − xNx–Ni3Ti cermet shows a homogeneous microstructure, in which equiaxed TiC1 − xNx grains of a few microns are bounded by Ni3Ti grain-boundary phase, and a Vickers hardness of 12.1 ± 0.3 GPa. It is proposed that the deficiency of C in the starting reactant plays a key role in simultaneous densification during combustion synthesis. Compared with the conventional powder sintering approach, combustion synthesis may provide a one-step, ultrafast, and furnace-free way to prepare TiC1 − xNx-based cermets with reduced time and energy consumption. Keywords: Cermet, Carbonitride, Combustion synthesis

Porous magnesium aluminate spinel (MgAl 2 O 4 ) ceramic supports were fabricated by reactive sintering from low-cost bauxite and magnesite at different temperatures ranging from 1100 to 1400 °C and their sintering behavior and phase evolution were evaluated. The effects of sintering temperature on the pore structure, size and distribution as well as on the main properties of spinel ceramic supports such as flexural strength, nitrogen permeation flux and chemical resistance were investigated. The supports prepared at 1300 °C showed a homogeneous pore structure with the average pore size of 4.42 μm, and exhibited high flexural strength (35.6 MPa), high gas permeability (with nitrogen gas flux of 3057 m 3 m −2 h −1 under a trans-membrane pressure of 0.1 MPa) and excellent chemical resistance.

Ce-doped (Y,Gd) 3 Al 5 O 12 nanoceramics were fabricated by the method of hot-pressing sintering of glass microspheres followed by heat treatment. Glass microspheres prepared by the flame spraying-water quenching technique possess a high tendency toward crystallization. Crystallization below the onset crystallization temperature is observed when the glass microspheres were hot pressed. Nanostructured Ce-doped (Y,Gd) 3 Al 5 O 12 ceramics can be obtained when the sintered bulk samples were annealed at temperatures below 1200 °C. The relative density of prepared nanoceramics increases with increasing annealing temperatures and Gd contents and it can reaches about 95%. The effects of annealing temperature and Gd substitution on the luminescence properties of prepared samples were investigated.

Using a pure AlON powder synthesized by carbothermal reduction and nitridation, a bimodal particle size distribution (PSD) powder was prepared by planetary ball mill, and pressurelessly sintered at 1880 °C to fabricate transparent AlON ceramics. Relative density of ≥99.72% was achieved for all the obtained AlON ceramics samples held for 90–150 min. The maximum infrared transmittance for 3 mm thickness sample was up to 81.8% (93.8% of theoretical in-line transmittance). Therefore, the holding time to fabricate transparent AlON ceramics can be shortened to 90 min or 150 min, compared to 480 min holding reported in the literature. The fast sintering of transparent AlON ceramics is a combination of fast heating (40 °C/min) and shorter holding time, and should be mainly attributed to fast surface diffusion during heating due to the bimodal PSD of fine powder and fast grain boundary diffusion during both heating and holding due to the transient bimodal grain size distribution.

Amorphous Y 2 O 3 –Al 2 O 3 –SiO 2 beads were directly melted by a Nd:YAG laser. The structural features in multi-scale of the samples after solidification were investigated. The results showed that the cooling speed in the applied processing conditions was not high enough to retain the amorphous nature of ceramic beads into the consolidated bulks. In addition to an amorphous phase two crystalline phases, YAG and α-Al 2 O 3 , were formed yielding the formation of complex structural hierarchies.