Nanoscale toughening of low carbon Al2O3-C refractories by means of SiCnw/Al2O3 composite reinforcement

To improve the thermal shock resistance of low carbon Al₂O₃-C refractories, SiC nanowires (SiC_nw) containing SiC_nw/Al₂O₃ composite reinforcement were introduced. The specific fracture energy of the Al₂O₃-C refractory matrix was obtained by statistical grid nano-indentation. The reinforcement mechanism of SiC_nw/Al₂O₃ on thermal shock resistance of refractories was investigated. The results revealed that the matrix-specific fracture energy of A6 (6 wt% SiC_nw/Al₂O₃ added) was 217 N/m, which was 58.4% higher than reference sample A0 (137 N/m) and 18.6% higher than MA6 (183 N/m, 6 wt% SiC/Al₂O₃ added). A6 showed the highest residual strength ratio of 49.8%, which was 114.7 % higher than A0 (23.2%) and 82.4 % higher than MA6 (27.3%). The components with different morphology in SiC_nw/Al₂O₃ cluster, especially SiC nanowires, promote the generation of microcracks, crack multi-deflection, and branching, which toughen the matrix and improve the thermal shock resistance of refractories. In comparison to the literature, A6 showed a higher rising in residual strength ratio than those with higher graphite content (4 wt% and 20 wt%), which will greatly reduce the consumption of carbon-containing refractories and contribute to the reduction of CO₂ emission.     

Effect of alumina bubbles with and without Al2O3 coatings on the performance of lightweight Al2O3-MgAl2O4 refractories

In this work, the effect of alumina bubbles with Al₂O₃ coatings (CABs) and without coatings (ABs) on the performance of lightweight refractories was investigated. It showed that the addition of either ABs or CABs was beneficial to improve mechanical properties of refractories. The compressive strength for the specimens with 1 wt% ABs and CABs addition increased from ~50.5 to ~60.9 and ~70.2 MPa. The refractoriness under load was enhanced from ~1589 to ~1617 and ~1623°C. Furthermore, the results of three-point bending tests showed significant improvement was achieved in thermal shock resistance in terms of the value of residual strength ratio from 16% to 43% for specimens with CABs addition. Meanwhile, the results of ultrasonic pulse velocity measurement indicated that there is a good consistency between two evaluation methods. In order to achieve the trade-off between lightweight and overall performance, the introduction of CABs into lightweight refractories is feasible and effective.     

Enhanced mechanical properties of lightweight Al2O3-C refractories reinforced by combined one-dimensional ceramic phases

We prepared a new lightweight Al₂O₃-C refractory material with a higher strength by using microporous corundum aggregates instead of dense tabular corundum aggregates, which was reinforced by in situ formed SiC whiskers, multi-walled carbon nanotubes (MWCNTs), and mullite rods. A comparative study of the microstructure, mechanical properties, and fracture behavior was carried out for dense and lightweight Al₂O₃-C refractories coked at 1200°C and 1400°C, respectively. By using the microporous corundum aggregates, a better aggregate/matrix interface bonding and an optimized distribution of SiC whiskers were obtained. The SiC whiskers formed inside the microporous corundum aggregates and simultaneously in the matrix by a vapor-solid reaction mechanism, resulting in an enhancement at the microporous aggregate/matrix interface. Furthermore, the in situ formed MWCNTs and well-developed mullite rods at 1200°C in the matrix also contributed to the better interface structure. Thus, due to the improved microporous aggregate/matrix interface, the crack propagation along the aggregate/matrix interface was suppressed, resulting in an increased crack propagation within the aggregates. Consequently, the synergy between microporous corundum aggregates and combined one-dimensional ceramic phases caused a lower bulk density but a markedly higher strength, a higher fracture energy, and a higher toughness of lightweight Al₂O₃-C refractories compared to the dense ones. Overall, our study allows to overcome the traditional concept that a higher strength of refractories is reached by a higher density.     

Microstructures and properties of novel lightweight refractory aggregates with microporous MgO@MgAl2O4 core-shell structures

Microporous aggregates are the key to the lightweight design and preparation of refractories for the working linings of the high temperature furnaces. In this work, the lightweight MgO-MgAl₂O₄ refractory aggregates with core-shell structures were prepared by in-situ decomposition synthesis technology using Mg(OH)₂ and nano-size Al₂O₃ as raw materials. The influence of the nano-size Al₂O₃ content on the microstructures and properties was thoroughly studied. The results demonstrated that the microporous MgO core structures were formed after the decomposition of Mg(OH)₂, and the MgAl₂O₄ bonds between the microporous MgO core structures were formed through the reaction between the nano-size Al₂O₃ and MgO. When the nano-size Al₂O₃ contents were less than 9 wt%, the MgAl₂O₄ bonds were discontinuous. With the increase of the nano-size Al₂O₃ contents to 9–15 wt%, more continuous MgAl₂O₄ bonds (i.e. MgAl₂O₄ shell structures) were formed at the surface of the microporous MgO core structures. Overall, the optimized specimens were lightweight MgO-MgAl₂O₄ refractory aggregates with the addition of 9 wt% nano-size Al₂O₃, which exhibited the microporous MgO@MgAl₂O₄ core-shell structures, a median pore size of 268 nm, a high compressive strength of 105 MPa, and a low thermal conductivity of 4.1 W/(m·K) at 800 ℃.     

Comparative evaluation investigation of slag corrosion on Al2O3 and MgO-Al2O3 refractories via experiments and thermodynamic simulations

Al₂O₃- and MgO-based refractories are widely used in the steel industry as lining materials for many metallurgical reactors. Due to their direct contact with slag and steel, they suffer corrosion and degradation, especially in the slag-line position, which limits their service performance. The purpose of this article is to obtain a better understanding of the corrosion behavior of the two refractories with different compositions of virtual steelmaking slags (wt%CaO/wt%SiO₂ = 3.0–7.0, Al₂O₃: 18–35 wt%) using laboratory experiments and FactSage thermodynamic modeling. Pure Al₂O₃ and MgO-Al₂O₃ crucibles were adopted to simulate the two refractories, respectively, during the experiment. The results show that the degree of corrosion of both crucibles increases with an increase in slag basicity and a decrease in Al₂O₃ content in the slag. The Al₂O₃ crucible is more susceptible to corrosion than the MgO-Al₂O₃ crucible, which is attributed to the effect of the slag penetrating through the Al₂O₃ crucible matrix and substituting part of its matrix. For the MgO-Al₂O₃ crucible, there was no obvious slag substitution, but a transition layer was found in the contact region between the crucible and the slag. The Al₂O₃ in the crucible matrix reacts with slag to produce calcium alumina (CaAl₁₂O₁₉, CaAl₄O₇) and other complex oxides, while the MgO particles at the MgO-Al₂O₃ crucible-slag interface were only surrounded by liquid slag without an obvious chemical reaction between them. The mechanism of corrosion was studied by experiments combined with thermodynamic calculations and with the establishment of a new corrosion model. This study is expected to provide a guide for the design of related refractories and slags in industrial applications.     

Densification and Properties of Fe2O3 Nanoparticles added CaO Refractories

Up to 8 wt. % of Nano-iron oxide was added to CaO refractory matrix. The crystalline phases and microstructure characteristics of specimens sintered at 1650 °C for 5 h in an electric furnace were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The physical properties are reported in terms of bulk density, apparent porosity and hydration resistance. The mechanical behavior was studied by a cold crushing strength (CCS) and flexural strength at 1200 °C test. As a result, it was found that the presence of Nano-iron oxide in the CaO refractory matrix induced 2CaO.Fe₂O₃ (C₂F), CaO.Fe₂O₃ (CF) and 3CaO.Al₂O₃ (C₃A) phase’s formation, which improved the sintering process. Nano-iron oxide also influenced the bonding structure through a direct bonding enhancement. On the Other hand, the presence of Nano-iron oxide resulting in improvement properties of CaO refractory matrix refractories such as bulk density, hydration resistance and cold crushing strength. The maximum flexural strength at 1200 °C is achieved by the samples containing 4 wt. % nano-Fe₂O₃.     

A novel approach to lightweight alumina-carbon refractories for flow control of molten steel

Functional refractory materials for flow control devices of molten steel in continuous casting used to be prepared from Al₂O₃–C refractories containing dense corundum aggregates. According to the traditional concept, the denser the refractories, the higher the strength of refractories. However, we prepared a new lightweight Al₂O₃–C refractory material using microporous corundum aggregates instead of dense corundum aggregates, which were reinforced by in situ formed SiC whiskers. A comparative analysis of microstructures and properties was carried out for conventional and lightweight Al₂O₃–C refractories with and without Si powder addition. We showed that microporous aggregates formed a better aggregate/matrix interface bonding and an improved distribution of SiC whiskers. The SiC whiskers formed not only in the matrix, but also inside of the microporous aggregates and at the aggregate/matrix interface by a vapor-solid reaction mechanism. Due to the formation of a microporous aggregate/matrix interface reinforced by SiC whiskers, the crack propagation along the aggregate/matrix interface was suppressed, whereas the percentage of cracks propagating within the aggregates was enhanced. Thus, the synergy between in situ formed SiC whiskers and microporous aggregates resulted in a significant higher strength of lightweight Al₂O₃–C refractories compared to conventional ones. The results therefore provide an original strategy to strengthen Al₂O₃–C refractories.     

Enhanced performance of low-carbon MgO–C refractories with nano-sized ZrO2–Al2O3 composite powder

Low-carbon MgO–C refractories are facing great challenges with severe thermal shock and slag corrosion in service. Here, a new approach, based on the incorporation of nano-sized ZrO₂–Al₂O₃ composite powder, is proposed to enhance the thermal shock resistance and slag resistance of such refractories in this work. The results showed that addition of ZrO₂–Al₂O₃ composite powder was helpful for improving their comprehensive performances. Particularly, the thermal shock resistance of the specimen containing 0.5 wt% composite powder was enhanced significantly which was related to the transformation toughening of zirconia and in-situ formation of more spinel phases in the matrix; also, the slag resistance of the corresponding specimen was significantly improved, which was attributed to the optimization of pore structure and formation of much thicker MgO dense layer.     

Effect of Alumina Reactivity on the Densification and Properties of Al2O3–Cr2O3 Refractories

Alumina‐chrome (Al₂O₃–Cr₂O₃) refractories with Al₂O₃:Cr₂O₃ molar ratio 1:1 were synthesized in the temperature range of 1400–1700°C by conventional solid–oxide reaction route. The effect of different aluminas (viz., hydrated and calcined) on the densification, microstructure, and properties of Al₂O₃–Cr₂O₃ refractories was investigated without changing the Cr₂O₃ source. The starting materials were analyzed to determine the chemical composition, mineralogy, density, surface area, and particle size. Sintered materials were characterized in terms of densification, phase assemblage, and mechanical strength at room temperature and at higher temperatures. Microstructural evolution at different sintering temperature was correlated with sintering characteristics. It can be concluded that the Al₂O₃–Cr₂O₃ refractories prepared with hydrated alumina as Al₂O₃ source show better densification and hot mechanical strength than corresponding calcined variety.     

Vacuum impregnation treatment of microporous Al2O3-MgAl2O4 refractory raw materials with sub-micron pores and high strength

In the present work, we propose a novel method to decrease the pore size as well as to enhance the strength of microporous Al₂O₃-MgAl₂O₄ refractory raw materials, which were prepared by the vacuum impregnation treatment of porous Al₂O₃ powders with at MgCl₂ solution. The effect of the MgCl₂ content (0–32.5 wt%) on the phase distribution, microstructures, and physical properties of the refractory raw materials was thoroughly investigated. The results demonstrated that the sub-micron pore structure inside the pseudomorph particles was effectively preserved due to the volume expansion effect of spinel and the spinel sintering neck formation between Al₂O₃ microcrystallites. With the MgCl₂ content increasing from 0 to 11.9 wt%, the pseudomorph particles contained many sub-micron pores resulting from the introduction of the MgCl₂ solution, resulting in the decrease of the intra-particle pore size as well as the development of spinel sintering necks between pseudomorph particles. The strength of the aggregates was therefore enhanced. With a further increase of MgCl₂ content to 24.2 and 32.5 wt%, the inter-particle pore sizes increased due to the volume expansion and Kirkendall effect associated with the spinel formation between pseudomorph particles, which were responsible for the progressive decrease of the strength. Overall, the optimized samples were microporous Al₂O₃-MgAl₂O₄ refractory aggregates with the addition of 11.9 wt% MgCl₂, which exhibited an apparent porosity of 45.0%, a high compressive strength of 45.6 MPa, a median pore size of only 1.49 µm, and a high sub-micron pore volume content of 42.5 vol%. Meanwhile, it is possible to obtain the porous Al₂O₃-MgAl₂O₄ powders with a large number of sub-micron pores by crushing and sieving the optimized aggregates.     

Combustion synthesis of B4C/Al2O3/C composite powders and their effects on properties of low carbon MgO-C refractories

To improve the dispersity and oxidation resistance of nano carbon black (CB) in low carbon MgO-C refractories, B₄C/Al₂O₃/C composite powders were prepared by a combustion synthesis method using B₂O₃, CB and Al powders as the raw materials. The phase compositions and microstructures of the synthesized products were characterized by X-ray diffraction (XRD), Raman spectroscopy, and a scanning electron microscopy/energy dispersive spectrometry (SEM/EDS). The results show that an 80 wt% excess of CB is the maximum amount of CB that can be added under the condition of a self-propagating combustion wave, and the phase compositions of the products are B₄C, α-Al₂O₃ and CB. B₄C particles with uniform sizes and cubic polyhedral structures are embedded in the Al₂O₃ matrix. The combustion-synthesized B₄C/Al₂O₃/C powders and mechanically mixed B₄C/Al₂O₃/C powders were added to the low carbon MgO-C refractories, and their corresponding properties were compared. The apparent porosity (AP) of the refractories with the synthesized powders (labelled as M3) is lower than those of the refractories with mechanically mixed powders (labelled as M2) and without composite powders (labelled as M1). The oxidation ratio and slag erosion depth of M3 were lower than those of M2 and M1. The thickness of the decarburized layer of M3 was 10.2% and 22.4% less than that of M2 and M1, respectively. The penetration depth of M3 was 12.0% and 27.9% less than that of M2 and M1, respectively. The thermal shock resistance of M3 was better than that of M2 and M1. The residual strength ratio of M3 was 15.8% and 17.2% more than that of M2 and M1, respectively. These results suggest that the combustion-synthesized B₄C/Al₂O₃/C composite powders can be used as new and promising additives for low carbon MgO-C refractories.     

Effect of Al2O3@CaCO3 spherical particles on microstructures,phase compositions and performances of lightweight MA spinel-corundum refractories

The lightweight spinel-corundum refractory was prepared using the Kirkendall effect when spherical particles Al₂O₃@CaCO₃ were introduced into the ingredient. The mechanism of pore formation through in-situ pore formation combined with the Kirkendall effect to reduce the bulk density of the refractory to the lightweight has been investigated in detail. The properties of the lightweight spinel-corundum refractory have also been studied. The results showed that the calcium at the center of the spherical particle spreads outwards and reacts with Al₂O₃ in the shell to form calcium hexaluminate (CA₆). After which a portion of CA₆ reacts with spinel in the matrix to manufacture a solid solution phase (CM₂A₈). At the same time, the hollow structure forms at the center of the spherical particle due to the buildup of the Kirkendall pore. With the additional amount of the Al₂O₃@CaCO₃ spherical particles reaches 30%, the samples fired in 1650 °C for 3 h can gain high compressive strength (119.8 MPa), high refractoriness under load (>1700 °C), low bulk density (2.76 g cm⁻³) and low thermal conductivity (1.36 W·(m·K) ⁻¹).     

Comprehensive study on corrosion protection properties of Al2O3, Cr2O3 and Al2O3–Cr2O3 ceramic coatings deposited by plasma spraying on carbon steel

In this study, individual Al₂O₃ and Cr₂O₃ coatings and Cr₂O₃-25, 50, 75 wt% Al₂O₃ composite coatings were applied on carbon steel by atmospheric plasma spraying method. Corrosion experiments were performed on as-sprayed and epoxy resin sealed coatings including potentiodynamic polarization, electrochemical impedance spectroscopy and long-term immersion in 3.5 wt% NaCl solution. Phase composition and microstructure of the coatings were investigated by x-ray diffraction, optical microscopy and scanning electron microscopy, before and after the corrosion experiment. The results showed that the Cr₂O₃ coating exhibited the best corrosion resistance, due to the densest microstructure and highest adhesion strength. The Cr₂O₃-25 wt% Al₂O₃ coating had the highest interconnected porosities and thus had the least corrosion resistance compared to other coatings. In general, the as-sprayed coatings induced a maximum increase of 3.93 times the polarization resistance (R_p) in the polarization experiment and a 3.5 times increase in the charge transfer resistance (R_ct) in the EIS experiment, which was not significant. Stresses caused by increased volume of corrosion products in the coating-substrate interface resulted in the spallation of Cr₂O₃-25, 50 wt% Al₂O₃ coatings from the substrate over long-term of immersion. The adhesion strength of the coatings was a determining criterion for the long-term durability of the coatings. The sealing treatment resulted in a significant increase in R_p and R_ct.     

An approach for matrix densification based on particle packing and its effect on lightweight Al2O3-MgO castables

For lightweight refractory containing lightweight aggregates, the properties of the matrix are decisive to its performance. In the present work, Dinger–Funk equation was adopted to calculate the theoretical packing density of a castables matrix based on Stovall linear packing model and to design its particle size distribution. Four lightweight Al₂O₃-MgO castables with different particle size distribution (represented by q-value) were prepared and examined. Results show that a suitable q-value was needed to ensure acceptable properties including sintering characteristics, strength and slag resistance, which deteriorated distinctly at high q (>=0.31). For the sample with q=0.28, the matrix showed dense and uniform mirostructure, and the properties of castable reached a favourable compromise among sintering characteristics (apparent porosity=14.8%, bulk density=3.02 g cm⁻³, permanent linear change<0.6%), strength (cold modulus of rapture=12.4 MPa, cold crashing strength=155.5 MPa), and resistance against both slag corrosion (I_c=22.4%) and penetration (I_p=11.5%). The sample with q=0.25 showed the highest strength and resistance against slag corrosion (matrix dissolved in slag), but its slag penetration resistance was lower due to the existence of cracks between aggregates and matrix.     

Eco-friendly tape casting of borosilicate glass/Al2O3 sheets for LTCC applications

This work reports the innovative development of a borosilicate glass/Al₂O₃ tape for LTCC applications using an eco-friendly aqueous tape casting slurry. Polyvinylpyrrolidone (PVP) and polyacrylic acid (PAA) were the respective dispersants, while carboxymethyl cellulose (CMC) and styrene acrylic emulsion (SA) were the respective binders. The results showed that PVP was more suitable than PAA as the dispersant for the aqueous casting slurry, and that 1.5 wt% PVP would achieve well dispersion of CABS glass/Al₂O₃ powder in the aqueous slurry. Moreover, a small amount of 2.0 wt% CMC binder could yield smooth CABS glass/Al₂O₃ tapes crack free. A high-quality CABS glass/Al₂O₃ tape with a smooth surface was made from an aqueous slurry containing 1.5 wt% PVP dispersant, 2.0 wt% CMC binder, and 2.0 wt% PEG-400 plasticizer. The density, tensile strength, and surface roughness of the green tape were 2.05 g/cm³, 0.87 MPa, and 148 nm, respectively. The resulting CABS glass/Al₂O₃ composites sintered at 875 °C exhibited a bulk density of 3.14 g/cm³, a dielectric constant of 8.09, a dielectric loss of 1.0 × 10^?3, a flexural strength of 213 MPa, a thermal expansion coefficient of 5.30 ppm/^°C, and a thermal conductivity of 3.2 W m^?1 K^?1, thus demonstrating its broad prospects in LTCC applications.     

High-strength and corrosion-resistant Al2O3 ceramics with excellent closed-cell structure

As a lightweight refractory, porous Al₂O₃ ceramics are advocated in the iron and steel smelting industry because of their excellent resource-saving and low heat loss. However, the severely poor slag corrosion resistance and low mechanical strength caused by open pores shorten their service life. To solve this problem, Al₂O₃ ceramics with excellent closed-cell structure were fabricated by combining β-SiC pore-foaming and gel-casting techniques, and their pore structure and properties were tailored by tuning the content of β-SiC and sintering temperature. It is noted that the closed pores introduced in the dense Al₂O₃ matrix play a pivotal role in improving the corrosion resistance and mechanical strength while maintaining the lightweight. And the sample with closed porosity of 20.6% exhibited compressive strength of 640 MPa and flexural strength of 272 MPa. Meanwhile, its corrosion and penetration indices were at a low level, 6.3% and 54.8%, respectively.     

B4C mineralizing role for mullite generation in Al2O3-SiO2 refractory castables

Based on refractory end-users’ requirements, continuous efforts have been made to design engineered products able to withstand high temperatures (800–1500 °C) and severe thermal gradients. One alternative to enhance the mechanical properties of alumina-based compositions consists of inducing in situ generation of phases with platelet or acicular shape within their matrix fraction, which may improve crack deflection and grain bridging mechanisms. Mullite and Al₁₈B₄O₃₃ are some compounds that present such interesting features. Thus, this work addresses the evaluation of alumina refractory castables bonded with SioxX-Zero and/or microsilica, containing 0 or 1 wt% of B₄C (sintering additive), aiming to: (i) induce transient liquid sintering, (ii) point out which silica source could favor a more effective mullite formation at high temperatures, and (iii) analyze the influence of B₄C in the phase transformation and thermo-mechanical properties of the designed compositions. Comparing SioxX-Zero and microsilica-bonded refractories, the latter showed more likelihood to give rise to the mullite phase during the samples’ thermal treatments. Moreover, adding B₄C to the castables containing 3 wt% of SiO₂ induced the generation of a boron-rich liquid phase with transient features during the samples’ firing step, favoring earlier sintering and faster mullite and Al₁₈B₄O₃₃ formation. These transformations resulted in refractories with enhanced creep, thermal shock resistance and HMOR behavior in a broader temperature range (600–1550 °C), which may enable them to be used in various industrial applications (petrochemical, steel-making, etc.).     

Enhanced thermal shock resistance of low-carbon Al2O3-C refractories with direct CVD synthesis of nano carbon decorated oxides

Novel low carbon Al₂O₃-C refractories were prepared through adopting chemical vapour deposition (CVD) synthesized nano carbon decorated Al₂O₃ powder. The phase compositions, microstructures, mechanical properties and thermal shock resistance of Al₂O₃-C refractories were characterized and evaluated. The results show that the morphologies of nano carbon composites are mainly dominated by the concentration of catalyst. Specifically, the growth of MWCNTs is preferred with a Ni²⁺ concentration at 0.1?mol/L, while higher concentrations e.g. 0.3?mol/L would stimulate the formation of nano-onion like carbon. With the introduction of nano carbon decorated Al₂O₃ additives, the residual strength after thermal shock can reach 12.4?MPa, which is much higher than the 2?wt% nano carbon black containing specimens (6.4?MPa). The enhanced thermal shock resistance should be attributed to that the nano onion-like carbon reduces the cohesion between the matrix and the Al₂O₃ particles and decreases the thermal expansion coefficient.     

High strength and hardness BNNSs/Al2O3 composite ceramics prepared by hot-press sintering of in-situ composite BNNSs/Al2O3 powder

In this paper, BNNSs/Al₂O₃ composite powder was prepared by in-situ reaction using borate nitridation method and BNNSs/Al₂O₃ composite ceramics were prepared by hot-pressing sintering. This method achieves uniform mixing of BNNSs and Al₂O₃ ceramic matrix and reduces the introduction of impurities in the processing process. The BNNSs/Al₂O₃ composite ceramics have excellent bending strength (549.4 MPa), fracture toughness (5.18 MPa m^1/2) and hardness (21.3 GPa). The high hardness of composite ceramics is attributed to high grain boundary strength and density. The reinforcing mechanisms of ceramics include BNNSs pull-out, BNNSs bridging, crack deflection as well as the transgranular fracture and intergranular fracture of Al₂O₃ matrix.     

Enhanced mechanical strength and bactericidal activity of macro-porous Al2O3 ceramics through the introduction of Cu for membrane support application

Enhancing the mechanical strength of macro-porous ceramics and simultaneously endowing them with bactericidal activity are considered to be beneficial for their application as membrane support materials for water and wastewater treatment. In this study, Cu-containing Al₂O₃ porous ceramics were prepared by powder mixing, cold pressing and subsequent sintering. The microstructures of as-fabricated ceramics consisted of large α-Al₂O₃ particles as matrix, as well as inter-particle NaAlSiO₄, CuAl₂O₄ and CuO phase. With increased sintering temperature from 1430 to 1560 °C, the proportion of band-shaped CuO phase, which exhibited stronger binding tendency with Al₂O₃ than NaAlSiO₄, gradually increased, while that of particle-shaped CuAl₂O₄ phase decreased. Increasing the Cu content from 2 to 8 wt% at a fixed sintering temperature of 1500 °C resulted in the presence of more band-shaped CuO phase in Al₂O₃ matrix which tightly bonded Al₂O₃ particles together. The increase of sintering temperature and Cu content could both lead to enhanced bending strength and reduced porosity, while the later factor showed stronger modulatory effects than the former one. Moreover, the bactericidal rates of Cu-containing Al₂O₃ porous ceramics towards Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were found to increase with increased Cu content in a Cu content-dependent manner. Together, the Cu-containing Al₂O₃ porous ceramic added with 8 wt% Cu and sintered at 1500 °C exhibited the highest bending strength and strongest bactericidal activity, which could be a promising candidate material for membrane support application.