Powder Sintering Process Research Articles

Transient Phase-Mediated Li+ Transportation in the Lithium Lanthanum Titanate Solid-State Electrolyte.

The lithium lanthanum titanium oxide (LLTO) perovskite is one type of superior lithium (Li)-ion conductor that is of great interest as a solid-state electrolyte for all-solid-state lithium batteries. Structural defects and impurity phases formed during the synthesis of LLTO largely affect its Li-ion conductivity, yet the underlying Li+ diffusion mechanism at the atomic scale is still under scrutiny. Herein, we use aberration-corrected transmission electron microscopy to perform a thorough structural characterization of the LLTO ceramic pellet. We reveal a prevalent transient phase transition of (La, Ti)2O3 existing at the antiphase boundaries between single-crystalline LLTO domains. This transient phase exhibits a specific crystal orientation with the LLTO phase and shows a gradual structural transition to a tetragonal LLTO structure, which enables detailed crystallographic analysis to correlate their formation to the sintering process of LLTO powders into ceramic pellets. We also find that Li diffusion is retarded by this phase and correlated with the excess amount of La, which is corroborated by the theoretical evaluation of the atomistic mechanisms of Li diffusion across this phase.

The role of calcium addition through powder sintering process in microstructure and mechanical behavior of a microalloyed magnesium

Calcium effectively strengthens magnesium through grain refinement when added in small quantities using the ingot metallurgy process. The extremely low solubility of calcium in magnesium restricts its addition using traditional powder metallurgy processes. However, the powder metallurgy process provides advantages like reduced material loss, properties control, and net-shape products. Hence, in this study, a diluted magnesium-calcium alloy was processed using the traditional blend-press-sinter (BPS) powder metallurgy process. Commercially pure magnesium was microalloyed with 0.4 wt% calcium. The sintered magnesium-calcium alloy was subjected to high-temperature extrusion. Microstructural characterization of the microalloyed Mg0.4Ca alloy revealed that the elemental calcium diffused into the magnesium particles during the sintering process and developed a gradient granular microstructure. The added initial calcium nanoparticles also acted as nucleation sites for magnesium during the sintering process. The gradient microstructure recrystallized and grew into equiaxed grains during the subsequent extrusion process. Mechanical properties characterization revealed that the addition of calcium as solute atoms increased the hardness, compressive strength, and ductility of magnesium, which was further enhanced by the extrusion process. The presence of calcium as solute atoms increased the tensile strength of extruded magnesium by a reasonable amount, while ductility remained almost unchanged.

Weight Factor as a Parameter for Optimal Part Orientation in the L-PBF Printing Process Using Numerical Simulation.

The L-PBF process belongs to the most modern methods of manufacturing complex-shaped parts. It is used especially in the automotive, aviation industries, and in the consumer products industry as well. Numerical simulation in the powder sintering process is a means of optimizing time efficiency, accuracy and predicting future errors. It is one of the means to optimize the L-PBF process, which makes it possible to investigate the influence of individual parameters on additive manufacturing. This research makes it possible to predict the correct orientation of a part based on selected criteria, which are assigned a weighting factor in the form of parameters with which the simulation software Simufact Additive can work. Based on these, three possible orientations of the part were analysed with respect to the area of the supporting material, the volume of the supporting material, the number of voxels, and the building risk. Finally, the results of a simulation and the results of the tensile test were compared. From the results of the static tensile test, as well as from the results of the numerical simulation, it was found that better characteristics were achieved for the orientation of part no. 1 compared to orientation of part No. 3.

Physical Characteristic and In-Vitro Bioactivity Property of Sintered Glasses made via Sol-Gel and Powder Sintering Process

In this work, ternary system (SiO2-CaO-P2O5) biocompatible glass with different compositions (CaO/P2O5 ratio) were prepared by sol-gel method and sintering process. The physical characteristic and bioactive properties of each different sample composition were analyzed using XRF, particle sizer, N2 adsorption-desorption, FTIR, XRD, and FESEM-EDX. The sintered glass pellets were subjected to immersion studies in a simulated body fluid (SBF) solution for 14 days. All compositions of gel-glass particulates showed mesoporous-type structures and consisted of very high porosities with nano-pores in size. Different Ca/P ratios in gel-glass composition are affected by different porous characteristics. All compositions of sintered glass showed very good bioactive behavior by significant deposition of the carbonate apatite layer. Sintered glass with the Ca/P ratio = 2.33 showed very significant bioactive properties as it also comprised the highest pore volume and size. However, sintered glass with the lowest Ca/P ratio (Ca:P=1.50) showed a quite significant reduction in the bioactive property as it also consisted of the lowest pore volume and pore sizes. Hence, the in-vitro bioactivity property of sintered glass is significantly influenced by the increase in its porous characteristics due to differences in the Ca/P ratio.

Microstructure and mechanical properties of high-pressure sintered B6O-SiC nanocomposites

Boron suboxide (B6O) is recognized as a superhard material with a low mass density, high resistance to chemical wear, and excellent wear resistance. Despite its desirable properties, the limited fracture toughness of B6O restricts its application in industrial contexts. This study presents the structural and mechanical characterization of B6O-SiC nanocomposites, which were synthesized via a high-pressure high-temperature sintering process of B6O powders and SiC whiskers. The sintering process induced fragmentation of SiC whiskers, resulting in the homogenous distribution of SiC fragments within the B6O matrix. An increase in SiC content was observed to decrease the composite's hardness, while initially reducing then enhancing its toughness. The nanocomposites containing 20 wt% and 30 wt% SiC whiskers exhibited significant improvements in fracture toughness, averaging 6.5 MPa m1/2 and 7.0 MPa m1/2, respectively—approximately threefold the toughness of polycrystalline B6O—while sustaining high hardness values of 36.3 GPa and 35.6 GPa on average. Microstructural analyses revealed that the composites’ superior mechanical performance is due to the presence of strong grain boundaries, as well as a high density of nanotwins and stacking faults. The findings demonstrate a viable method for producing B6O-based nanocomposites with enhanced hardness and toughness, potentially expanding their industrial applicability.

Effect of phase evolution and pyroplastic formation behavior on glass-ceramic foam derived from silicomanganese slag and feldspar tailings

Utilizing solid waste to produce foam material has become a significant direction in resource recycling. This study focuses solely on using silicomanganese slag and feldspar tailings as raw materials, utilizing a powder sintering process to produce autocatalytic foaming glass–ceramic foam. We formulated four mix ratios based on the compositional characteristics of the silicomanganese slag and feldspar tailings. The study then explored the evolution of phase formation and macroscopic pore morphology under varying preparation temperatures. Moreover, through multi-phase co-melting experiments, this work unveiled the high-temperature molten mass generation mechanism between silicomanganese slag and feldspar tailings. Our findings reveal that the glass melt generated from silicomanganese slag particles and the 'solid–liquid erosion behavior' of feldspar particles play pivotal roles in the formation of high-temperature co-melt substances. As the sintering temperature increases, the mixed powder exhibits three different states of high-temperature molten mass, which are the reasons for the evolution of the macroscopic pore structure. It is suggested that the addition of silicomanganese slag should be less than 50 %, and the heat treatment temperature should be below 1145 °C in preparing glass–ceramic foam with silicomanganese slag and feldspar tailings. The sample with 40 % silicomanganese slag and 60 % feldspar tailings, treated at 1140 °C, yielded glass–ceramic foam with a compressive strength of 1.68 MPa, apparent density of 0.279 g/cm3, porosity of 81.7 %, and thermal conductivity of 0.074 W·m−1·K−1. In summary, this study provides a novel approach for the high-value utilization of silicomanganese slag and offers an economical route for developing lightweight, eco-friendly structural materials.

Porous titanium alloys for medical application: Progress in preparation process and surface modification research

Excellent mechanical properties and biocompatibility are the most sought-after attributes in biomedical materials for the regeneration of damaged tissues. However, conventional dense titanium alloys possess a modulus significantly higher than that of human tissues, leading to potential stress-shielding effects. Medical porous titanium alloys can reduce the elastic modulus of the material, promote tissue fixation and vascular regeneration, and improve the suitability for human tissue properties. With the continuous development of technology, the preparation process of porous titanium alloys has undergone a series of multifaceted transformations and improvements in the aspects of powder sintering, fiber preparation, and additive manufacturing processes, and its structural characteristics and mechanical properties are constantly evolving in a controllable direction. Alongside the enhancement of the material’s mechanical properties through porous design, optimization of the properties at the implant-tissue interface also leads to improved antimicrobial and osteogenic properties of porous titanium. Due to the complex internal structure of porous titanium alloys, surface modification is mainly carried out in fluid media, which is realized by morphological modification and the introduction of functional substances. Over time, the surface modification of porous titanium alloys for medical applications has progressed from morphological modification and introduction of chemical composition to the loading of bioactive substances. This evolution aims to enhance safety and efficiency in the use of these materials. This paper reviews the preparation and surface modification processes of porous titanium alloys for medical use and summarizes the advantages, disadvantages, and influencing factors among different processes, with a view to providing new ideas for the development of porous implants for medical use.

Analysis of initial stage of liquid-phase sintering by combined multi-phase-field/discrete-element method

A combined multi-phase-field/discrete-element method in two dimensions is applied to the liquid phase sintering process of blended elemental powders. The boundary migration, diffusion of elements, and phase transformation between two dissimilar particles are calculated using a multi-phase-field method for sintering based on Gibbs energy functions. The sintering shrinkage is computed with the discrete-element method taking account of the neck size and sintering force, which are obtained from a multi-phase-field simulation. In this study, a pair or small cluster consisting of two elemental powders in a binary eutectic alloy is used as a model system. First, the formation of a liquid phase around the contact area between two dissimilar particles above the eutectic temperature of the system, and the motions of the particles due to grain boundary sliding along the liquid films are confirmed. Second, an Sn–Bi system is selected as the real eutectic system, and the sintering behavior of powder compacts with various mixing ratios of Sn and Bi particles is demonstrated. Finally, transient liquid-phase sintering of Sn–Bi system is simulated, that is, the generation and extinction of the liquid phase due to interdiffusion between Sn and Bi particles are calculated.

Multiphysics Simulation and Experimental Investigation of the Densification of Metals by Spark Plasma Sintering

Multivariant experimental investigations and multiphysics microstructural modeling of the spark plasma sintering process of metallic powders have been performed up to a relative density of approximately 80%. In comparison, the effect of sintering temperature, pressure, and particle size on the interparticle contact area growth and axial shrinkage of cylindrical specimens of copper and nickel particles is measured in laboratory scaled tests. Herein, for the first time all relevant for sintering phenomena are considered simultaneously: the fully coupled thermo‐electro‐mechanical modeling of the spark plasma sintering processes, additionally taking into account for lattice, grain boundary, surface diffusion, electromigration, and thermomigration, has been carried out. The computational analysis of various physical phenomena allows to identify dominant and insignificant mechanisms. The two‐level numerical simulation includes the modeling of the sintering setup at the macroscopic level and the neck formation process in particle chain systems at the microscopic level. The results of the numerical simulations show a very good agreement with the experimental data. Therefore, the impact of electrical and mechanical loads as well as of particle size on microscopic distribution of temperature, inelastic strain, and on densification has been studied by the finite element simulations.

Influence of Alumina Grade on Sintering Properties and Possible Application in Binder Jetting Additive Technology.

Alumina is one of the most popular ceramic materials widely used in both tooling and construction applications due to its low production cost, and high properties. However, the final properties of the product depend not only on the purity of the powder, but also, e.g., on its particle size, specific surface area, and the production technology used. These parameters are particularly important in the case of choosing additive techniques for the production of details. Therefore, the article presents the results of comparing five grades of Al2O3 ceramic powder. Their specific surface area (via Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods), particle size distribution, and phase composition by X-ray diffraction (XRD) were determined. Moreover, the surface morphology was characterized by the scanning electron microscopy (SEM) technique. The discrepancy between generally available data and the results obtained from measurements has been indicated. Moreover, the method of spark plasma sintering (SPS), equipped with the registration system of the position of the pressing punch during the process, was used to determine the sinterability curves of each of the tested grades of Al2O3 powder. Based on the obtained results, a significant influence of the specific surface area, particle size, and the width of their distribution at the beginning of the Al2O3 powder sintering process was confirmed. Furthermore, the possibility of using the analyzed variants of powders for binder jetting technology was assessed. The dependence of the particle size of the powder used on the quality of the printed parts was demonstrated. The procedure presented in this paper, which involves analyzing the properties of alumina varieties, was used to optimize the Al2O3 powder material for binder jetting printing. The selection of the best powder in terms of technological properties and good sinterability makes it possible to reduce the number of 3D printing processes, which makes it more economical and less time-consuming.

Microstructure and Wear Performance of CeO2-Modified Micro-Nano Structured WC-CoCr Coatings Sprayed with HVOF

Rare earth elements have been widely utilized in material manufacturing to enhance properties in various ways. In order to obtain the WC-10Co4Cr coating with uniform distribution of rare earths, CeO2-modified powder was prepared by mixing 1 wt.% nano-sized CeO2 during the initial ball-milling of the powder fabrication process. Bare and CeO2-modified WC-10Co4Cr coatings were deposited via high velocity oxygen fuel spraying to investigate the impact of CeO2 modification on the coating’s microstructure, mechanical properties and abrasive wear performance. The results show that the addition of CeO2 increased the interface energy, inhibiting the formation of the Co3W3C phase during the powder sintering process, as well as the W2C phase and CoCr alloy during the high-velocity oxy-fuel (HVOF) process. This led to a significantly decreased porosity and higher concentration of undissolved Cr-rich areas. The microhardness and fracture toughness of the CeO2-modified coating were 1230 HV0.3 and 5.77 MPam1/2, respectively. The abrasive wear resistance of the CeO2-modified coating was only 70.9% of that of the unmodified coating. Due to the weak cohesive strength between WC and Cr, Cr-rich areas were preferentially removed, resulting in an increased wear rate in the CeO2-modified coating.

Pulsed thermo-induction-dynamic welding and pressing of dissimilar materials

To obtain permanent joints from diversified parts and powder compositions, it is proposed to use discharge-pulse processes with the accumulation of stored energy in a capacitor bank. Technological difficulties in the manufacture of structures from non-ferrous metal and alloy parts of different thicknesses are listed. The thermal effect is carried out by passing the discharge current from the batteries of pulse capacitors, and the power effect is realized through the use of an inductive-dynamic drive. A scheme for the series connection of a compacted powder with an induction-dynamic drive, consisting of a flat inductor with a pusher, is proposed. The physical essence of the formation of compounds is described. The processes responsible for the formation of permanent connections by a pulsed current discharge have been identified. A picture of the relationship between the main parameters of the pressing process – sintering in time, as well as the results of measuring the temperature of the sintering process of powders by the photoemission method is presented. The results of energy consumption for the consolidation of powder compositions with simultaneous welding to a steel base are given.

Numerical simulation of selective laser melting by the SPH method

Abstract. Currently, additive manufacturing technologies develop actively. This requires creation of computational methods to describe physical processes occurring at the time of manufacturing. One of the methods used for the production of metal powder parts is the method of selective laser melting. This paper presents an SPH-based numerical technique for modeling the process of powder sintering under the influence of a laser beam. The flow of liquid formed as a result of melting is described by the Navier-Stokes equations. Pressure forces, viscous effects and surface forces at the interface are included in the force balance. The thermal state is determined from the energy conservation law, which takes into account thermal processes, volumetric absorption of laser radiation energy, convective heat exchange with the external environment and radiation. Phase transitions between solid and liquid phases are described in the framework of the generalized formulation of the Stefan problem. The calculation method is verified on tests specific to the class of problems under consideration. A comparison is made with the analytical solution, as well as with solutions obtained by other modifications of the SPH method, and with experimental data.

Developing Microporous Transport Layers for Polymer Electrolyte Membrane (PEM) Water Electrolyzer Anodes

Polymer electrolyte membrane water electrolysis (PEMWE) is a promising technology for the production of hydrogen from fluctuating renewable energies [1]. Due to the scarcity of iridium that is commonly used as anode catalysts for the oxygen evolution reaction (OER), low anode loadings have become increasingly important [2]. Some low iridium loaded electrodes come with the drawback of a low electrical conductivity, which can be mitigated if the adjacent porous transport layer (PTL) has a similarly fine pore structure as that of the carbon black based microporous layers (MPL) used in PEM fuel cells [3]. First developments of titanium MPLs for PEMWE were based on vacuum plasma spraying [4, 5]. In recent work, titanium MPLs have also been fabricated by powder sintering, however these MPLs are very thick (200-300 µm) [6] and thus are almost as thick as the complete PTL used in other work.In this work, we present a method to produce microporous layers for PEMWE anodes by a titanium powder sintering process. For this, we coat a titanium slurry on top of a commercial powder-sintered PTL substrate. The successive sintering step solidifies the MPL coating and forms a single component from the two layers. The effects of the sintering temperature on the surface morphology are investigated by scanning electron microscopy (SEM) top-view and cross-sectional imaging (see Figure 1). An analysis of the pore structure of the developed MPL/PTL composite through mercury intrusion porosimetry (MIP) reveals pore-sizes of approximately one order of magnitude below those of the PTL substrate. Electrochemical characterization is carried out in 5 cm2 PEMWE single-cells with low-iridium loadings (0.2 mg/cm2), measuring polarization curves up to 6 A/cm2 and performing electrochemical impedance spectroscopy (EIS) measurements. Our study demonstrates the benefits of MPLs for highly efficient PEM water electrolyzers with low-iridium loadings, as a 15% lowered HFR and a slightly improved iR-free cell voltage can be observed for our MPL compared to the pristine PTL substrate without MPL. Further analysis will be conducted to disentangle the contribution of the MPL (surface) morphology and of its surface properties to the observed performance benefits.

(K, Na)NbO3 lead-free piezoceramics prepared by microwave sintering and solvothermal powder synthesis

Low temperature and short processing time are favorable for fabricating (K, Na)NbO3 (KNN) lead-free piezoelectric ceramics with a drawback of easy alkali metal volatilization during the powder synthesis and sintering processes. This study revealed that microwave sintering (MS) in addition to microwave solvothermal synthesis (MSS) of powder can lead to short-time fabrication of KNN ceramics with high density and fine grains. It was found that when the concentration of KOH/NaOH exceeds 1 M, KNN powder with single perovskite structure can be synthesized successfully by MSS method, which can be densified by MS to a high relative density close to 97% at 1050 °C even using 2/9 shorter time than conventional sintering (CS) at the same temperature. Importantly, the MSed KNN ceramics show better piezoelectric and ferroelectric properties than CSed counterparts. Without any dopants, the piezoelectric coefficient (d33) of the MSed pure KNN ceramics is 132 pC/N, and the remnant polarization (Pr) is 26.3 μC/cm2. The results show that the MS method is a promising method for preparing KNN-based ceramics.

Effect of calcination and sintering temperature on porosity and microstructure of porcelain tiles

Abstract Porcelain tiles are prepared from kaolin, silica sand, feldspar, clay raw materials, and various additives. Ceramic powders are calcined at different temperatures after grinding, drying, and sieving. After the powders are formed and dried, they are sintered at different temperatures. Firing shrinkage (FS), water absorption (WA), and three-point flexure tests of the samples are compared. The mineralogical definitions are completed by performing a phase analysis via X-ray diffraction (XRD). After the microstructural investigations, pore-sizes and distributions are examined by the Barrett–Joyner–Halenda (BJH) method. The powder sintering process increases the crystallization of the compact material. Low porosity and high strength structures are obtained for the samples with powder calcination temperatures of 800 and 900 °C and a compact sintering temperature of 1200 °C. The pore volume increases by increasing the powder calcination temperature in samples compact-sintered at 1200 °C. When the powder calcination temperature of these samples is increased to 1000 °C, the flexural strength decreases. Therefore, the powder sintering temperature of 900 °C is the critical value.

Origin of coercivity in an anisotropic Sm(Fe,Ti,V)12-based sintered magnet

We have demonstrated an anisotropic bulk SmFe12-based sintered magnet with sufficiently large coercivity of μ0Hc=1.0 T and a remanence ratio (Mr/Ms) of 0.84 using conventional liquid sintering process of nitrogen jet-milled powders with the nominal composition of Sm8Fe73.5Ti8V8Ga0.5Al2 (at.%). The moderate saturation magnetization of μ0Ms =0.74 T is due to the dissolution of a large amount of stabilizing elements, Ti, V, and Al, in the 1:12 phase. The anisotropy field of the main 1:12 phase was determined to be µ0HA=10.2 T. Detailed multi-scale microstructure characterizations by scanning electron microscope (SEM) and scanning transmission electron microscope (STEM) showed the magnet consists of Sm(Fe,Ti,V,Al)12 grains with the ThMn12-type crystal structure with a size distribution of ~3 − 15 µm that are enveloped by ~3 nm thick Sm-rich amorphous intergranular phase. Secondary phases including metallic (Sm,Ga)-rich, SmOx, and Fe2(Ti,V) phases coexist with the 1:12 phase. Measured angular dependence of coercivity follows Kondorsky type magnetization reversal, suggesting the coercivity arises due to the pining of magnetic domain walls. Magneto-optical Kerr effect (MOKE) microscopy revealed magnetization reversal starts at the grain boundaries and interphase interfaces and thin amorphous intergranular phases act as the pinning sites against magnetic domain wall propagation. Small micromagnetic parameter α~0.164 estimated by fitting to the Kronmüllar equation suggest that the reduction of the grain size and engineering of the intergranular phase to an Fe-lean composition are necessary to improve the coercivity toward µ0HA/3 = 3.4 T. This work provides guidelines on an optimum microstructure to develop an anisotropic bulk SmFe12-based sintered magnet with a sufficiently large coercivity.

One-Step Enameling and Sintering of Low-Carbon Steels

Powder technology allows manufacturing complex components with small tolerances, saving material without subsequent machining. There is a growing trend in using sintered steel components in the automotive industry. Within 2020, about 2544 million US dollars was invested for manufacturing sintered components. Not only does this industry uses steel components, but the gas cooker industry also uses steel in its burners since they are robust and usually demanded by Americans, with forecasts of 1097 million gas cookers in 2020. Steel gas burners have a ceramic coating on their surface, which means that the burner is manufactured in two stages (casting and enameling). This work aims to manufacture the gas burners by powder metallurgy, enameling and sintering processes in a single step. To achieve this aim, the ASC100.29 iron powder has been characterized (flow rate, relative density and morphology); subsequently, the most suitable parameters for its compaction and an adequate sintering temperature were studied. Single-step sintering and enameling was achieved by compacting iron powder at 500 MPa and sintering at 850 °C for 5 min. The necessary porosity for mechanical anchoring of the coating to the substrate is achieved at this sintering temperature. Bending resistance tests, scratching, degradation under high temperature and basic solution and scanning electron microscopy were used to characterize and validate the obtained samples.

The set Up of an Experimental Testing Rig to Measure Time and Space Temperature Profiles in Laser Sintering of Polymeric Powders

Selective Laser Sintering (SLS) is the most common type of Additive Manufacturing (AM) process using granular materials which has the potential to revolutionize the manufacturing industry. However, in the layer-wise build-up of the three-dimensional specimen, the complex laser-material interactions and the poor selection of associated process parameters can give rise to an increase to a number of defects of the artifacts. In fact, the temperature distribution along the surface and in depth at the laser spot, which are strongly affected by the thermal conductivity of the powder bed, do affect the hatch distance and the thickness of the powder layer, as well as on the quality of the final artifact. In this study, a laser sintering experimental set-up, equipped with an Infra-red thermographic camera and a K-type thermocouple, is built to measure the temperature distribution at the surface and 1mm below the surface in a special Polyamide 12 (PA12) powder bed. A one-watt stationary diode laser is used as heat source on samples characterized by various particle size distributions (PSD). Using the set-up, an accurate in-situ thermal characterization of the powder bed along with heat distribution study can be performed. Preliminary tests were conducted and the pixelwise temperature profile along the surface and temperature at the depth of 1mm below the surface of the powder bed has been reported. On the basis of the results, it is possible to provide good estimates of the global energy balances on the system, which are essential in evaluating the energy required to optimize the sintering and melting process of the polymeric powders.

Effects of sintering temperature on the microstructural properties of Al2O3–Y2O3 powder mixtures

Abstract In this study, YAlO3 (YAP) was produced at low temperatures by a powder sintering process. Al2O3–Y2O3 powder mixtures were subjected to heat treatment at different temperatures. The relationship between the sintering temperature and the emergence of new phases was investigated via X-ray diffraction, and supported by energy dispersive X-ray spectroscopy. The crystallization of the monoclinic yttrium aluminum oxide (Y4Al2O9) occurred at 1 000 °C, whereas the yttrium aluminum perovskite (YAlO3) crystallization occurred at 1 100°C. Energy dispersive X-ray spectroscopy analysis showed yttrium content in the sample containing Al2O3–YAlO3 powder sintered at 1100 °C, associated with the YAlO3 phase formed at this temperature. Brunauer–Emmett–Teller surface analysis showed a significant decrease in the pore volume of the sample sintered at 1 100°C.