查找使用阿拉丁产品的科研文献

Defect Analysis of Rare-Earth (Y, La, Sm) Oxide Doped AlN Ceramics for Electronic Device Applications

Bowen Yin,Haoran Ren,Weijia Guo,Chongyang Zhang,Xingchen Zhang,Yutian Lu,Hui Zhang,Zhenxing Yue

Aluminum nitride (AlN) ceramics are widely used in high-power electronic devices due to their excellent electrical insulation, high thermal conductivity, and chemical stability. Doping with rare-earth oxides is a common modification method for AlN ceramics that enhances sintering behavior and thermal conductivity but simultaneously alters defect states, thereby affecting electrical properties. The evolution of these defects and their influence on electrical transport and heat conduction remain unclear. Herein, the defect behavior, electrical insulation, and thermal conduction of Y 2 O 3 , La 2 O 3 , and Sm 2 O 3 -doped AlN ceramics are systematically compared. A combination of direct current (DC) conductivity, electrochemical impedance spectroscopy (EIS), dielectric spectroscopy, and thermally stimulated depolarization current (TSDC) analyses confirms a pronounced defect “cleaning effect” induced by rare-earth dopants, with an efficiency ranking of Sm > La > Y. The results reveal that oxygen substituting for nitrogen sites and aluminum vacancies dominate the low- and high-temperature conduction processes, respectively. The influence of rare-earth doping on thermal conductivity is also evaluated. Notably, the samples doped with 4 wt% Y 2 O 3 exhibit the best electrical insulation and the highest thermal conductivity. This work provides important insights into achieving synergistic optimization of the electrical and thermal properties of AlN ceramics through defect engineering.

Effect of ball-milling time on the properties of AlN ceramics fabricated via digital light processing

Haiman Xu,Rongzhen Liu,Chonggao Bao,Na Huang,Pan Li,Hao Li

Aluminum nitride (AlN) ceramics are widely utilized in various applications due to their exceptional properties. However, fabricating complex AlN components using conventional machining techniques remains challenging. To address this issue, Digital Light Processing (DLP) is proposed as a viable technique for manufacturing intricate AlN ceramics. A key challenge in this process is the moisture absorption and hydrolysis of AlN powders, which significantly increase slurry viscosity and affect the layer-by-layer accumulation of AlN slurry. This study systematically investigated the particle size distribution, rheological behavior, and curing kinetics of AlN slurry processed with different ball-milling times. At a ball-milling time of 8 h, the slurry with a 54 vol% solid loading exhibited a viscosity of 21.1 Pa.s at a shear rate of 27 s −1 and a curing depth of 83 μm at an energy dose of 74.4 mJ/cm². Following debinding and sintering, the sintered AlN ceramics achieved a flexural strength of 98.7 MPa, a bulk density of 2.74 g/cm³ , and an open porosity of 12.82 %. These findings provide critical insights into optimizing slurry preparation and processing parameters for the DLP-based fabrication of AlN ceramics.

Mechanistic insights into high-efficiency polishing of AlN single crystals: synergistic effects of abrasives and oxidants

Shitong Liu,Baoguo Zhang,Wenhao Xian,Yijun Wang,Sihui Qin,Yang Liu

Chemical mechanical polishing (CMP) of aluminum nitride (AlN) requires a balance between high material removal rates (MRR) and atomic-level surface quality. This study systematically investigates the synergistic effects of abrasives (CeO 2 , Al 2 O 3 ) and oxidants (K 2 S 2 O 8 , KMnO 4 , H 2 O 2 ) on AlN polishing efficiency and interfacial mechanisms. Experimental results show that the combination of Al 2 O 3 abrasive and K 2 S 2 O 8 oxidant at pH 2.0 achieves an optimal MRR of 2.1 μm/h, outperforming KMnO 4 by 153%. Zeta potential and oxidation–reduction potential (ORP) analysis reveal strong specific electrostatic adsorption between negatively charged persulfate ions (S 2 O 8 2 ⁻) and positively charged Al 2 O 3 surfaces. Density functional theory (DFT) calculations further confirm that S 2 O 8 2 ⁻ exhibits the highest adsorption energy on Al 2 O 3 (−9.5 eV/molecule) and AlN (001) surfaces (−9.87 eV/molecule), promoting the formation of Al-O bonds. X-ray photoelectron spectroscopy (XPS) and differential charge density analyses demonstrate that K 2 S 2 O 8 treatment maximizes Al-O bonding (21.03%), facilitating oxidative removal. This work provides fundamental insights into abrasive-oxidant interactions for AlN CMP, enabling ultra-smooth AlN surface finishing (Sq < 0.18 nm, Ra < 0.05 nm) and thereby laying a theoretical foundation for high-efficiency AlN surface machining.

Effect of Anti-Hydrolysis AlN Microspheres on the Electrical Insulation and Thermal Conductivity of PMIA Paper

Fangcheng Lü,Rui Yang,Haoou Ruan,Shenghui Wang,Xiang Yu

D-GQDs Modified Epoxy Resin Enhances the Thermal Conductivity of AlN/Epoxy Resin Thermally Conductive Composites

Duanwei Zhang,Fusheng Liu,Sheng Wang,Mengxi Yan,Xin Hu,Mengying Xu

This article proposes a method of increasing thermal conductivity (λ) by improving the λ value of a matrix and reducing the interfacial thermal resistance between such matrix and its thermally conductive fillers. D-GQDs (graphene quantum dots modified by polyetheramine D400) with a π–π-conjugated system in the center of their molecules, and polyether branched chains that are rich in amino groups at their edges, are designed and synthesized. AlN/DG-ER (AlN/D-GQDs-Epoxy resin) thermally conductive composites are obtained using AlN as a thermally conductive and insulating filler, using D-GQDs-modified epoxy resin as a matrix. All of the thermal conductivity, electrically insulating and physical–mechanical properties of AlN/DG-ER are investigated in detail. The results show that D-GQDs linked to an epoxy resin by chemical bonds can increase the value of λ of the epoxy–resin matrix and reduce the interfacial thermal resistance between AlN and DG-ER (D-GQDs–epoxy resin). The prepared AlN/DG-ER is shown to be a good thermally conductive and insulating packaging material.Keywords:thermal conductivity;graphene quantum dots;AlN;epoxy resin;thermally conductive composites

Enhanced shear strength of Cu/AlN/Cu gradient materials with continuous and quasi-continuous interfacial structures

Fei Chen,Binhua Xiang,Mingyong Jia,Yueqi Wu,Zhifeng Huang,Qiang Shen

In the electronic industry, the composite of copper (Cu) and aluminum nitride (AlN) is widely used, but obtaining Cu/AlN/Cu functionally gradient materials (Cu/AlN/Cu FGMs) in a single step using traditional laminated sintering processes has proven challenging due to significant differences in their physical properties. To address this issue, molybdenum (Mo), with a high melting point and low expansion, was involved in creating a continuous gradient structure with AlN and a quasi-continuous interfacial structure with Cu. The continuous interfacial structure of Mo/AlN gradient materials was obtained by hot pressing at 1650°C. Subsequently, the quasi-continuous interfacial structure of Cu/Mo heterogeneous metal joints with high shear strength was achieved by utilizing the diffusion welding method at 700–950°C. The results indicated that the optimum shear strength of Cu/AlN/Cu FGMs is around 90 MPa. However, Cu/AlN/Cu FGMs with different diffusion interlayers failed in different ways when shear occurred, which greatly depends on the phase compositions at the joint. The challenges are overcome by utilizing Mo to construct the continuous and quasi-continuous interfaces, resulting in Cu/AlN/Cu FGMs with improved shear properties.

High-temperature composite phase change materials with superior thermal storage performance enabled by hierarchical AlN aerogel ceramics

Tianze Ren,Yimin Xuan,Xianglei Liu

High-temperature phase change materials (HT-PCMs) play a crucial role in latent heat storage systems for renewable power generation. Integrating HT-PCMs with high-thermal-conductivity porous ceramic skeletons to form composite PCMs (CPCMs) effectively mitigates limitations such as low thermal conductivity, leakage, and supercooling. However, most skeletons fail to achieve both high thermal conductivity and ideal porosity (>85 %) simultaneously, resulting in a trade-off in CPCMs between high latent heat (>300 J/g) and fast thermal response (>10 W/(m·K)). Herein, we developed high-performance CPCMs through the synergistic integration of a tailored AlN aerogel ceramic (AlN-AC) and two distinct HT-PCMs, enabling efficient thermal storage performance from 500 to 900 °C. The hierarchical AlN-AC was fabricated via the spontaneous coagulation casting method, exhibiting 90 % porosity and a thermal conductivity of approximately 10 W/(m·K). Leveraging its exceptional infiltration capacity and highly conductive network, two CPCMs were developed by incorporating Al Si alloy (CPCM-AlSi) and NaCl (CPCM-NaCl), respectively. The resulting composites achieved a maximum latent heat of 402 J/g with CPCM-NaCl and a maximum thermal conductivity of 22 W/(m·K) with CPCM-AlSi. Meanwhile, the CPCMs also achieved a high total energy storage density of 625 J/g and 1791 J/cm 3 within a narrow 200 °C range, with reliable performance over 800 thermal cycles. The CPCMs successfully combine high thermal energy density with efficient heat transfer, outperforming the overall performance of previously reported CPCMs. Additionally, a novel micro-CT-based method was developed for predicting thermal storage performance, offering significantly improved accuracy over conventional approaches. This study presents an integrated strategy from material design to performance prediction for advanced high-temperature CPCMs.

Optimization of dispersants for high solid content AlN suspensions in digital light processing-based vat photopolymerization technology

Qingzhi Xu,Fei Liu,Yuntao Huang,Jianping Ma,Lifu Lin

Vat photopolymerization (VPP) technology based on digital light processing offers unparalleled advantages for manufacturing complex aluminum nitride (AlN) ceramic components. However, the thermal conductivities of AlN ceramic components fabricated using VPP typically exhibit significant discrepancies compared to those produced using traditional forming processes. The main reason for this is the limitation of the solid content in the AlN ceramic suspensions reported in previous studies, which is usually constrained within 50 vol%. This study systematically investigates the effects of the dispersants KOS110 and KOS163 on the rheological behavior , curing kinetics, and stability of AlN ceramic suspensions. By optimizing the type and concentration of the dispersants, a photocurable AlN ceramic suspension with a high solid content of up to 60 vol% and excellent flow properties is achieved. Using the optimized AlN suspension, high-resolution complex AlN ceramic components are successfully fabricated, exhibiting outstanding thermal conductivity and flexural strength of 183 W/(m·K) and 331 ± 8 MPa, respectively. This research will provide theoretical guidance and feasible technical routes for the preparation of complex structure AlN ceramic components with high thermal conductivity .

Influence of heat treatment on the lattice oxygen migration behavior, thermal and mechanical properties of AlN ceramics

Chang-quan Li,Kuan-kuan Li,Xiao-feng Zeng,Xi Long,Peng-zhao Gao,Xin-lin Ren,Jian-li Wang,Hui-ying Tang,Hang Qin,Han-ning Xiao

This study systematically investigates the effect of heat-treatment temperature (600-1200 °C) in air on the oxidation behavior, lattice oxygen migration, and thermal and mechanical properties of AlN ceramics. The results show that when the heat-treatment temperature is ≤ 800 °C, no detectable oxide layer forms on the surface of AlN ceramics; however, lattice oxygen begins to diffuse toward grain boundaries. At 1000 °C, a continuous and dense Al 2 O 3 layer (∼2.55 μm) forms on the surface. The thermal expansion mismatch between this oxide layer and the AlN matrix induces a residual compressive stress (-749.78 MPa) in the AlN substrate. Concurrently, XPS, EDS line scanning, and hot-gas extraction collectively confirm that lattice oxygen has sufficiently migrated to grain boundary regions. The resulting lattice purification reduces phonon scattering centers, while the residual compressive stress lowers interfacial thermal resistance at grain boundaries and suppresses crack propagation. These two mechanisms act synergistically, leading to the highest flexural strength (451.48 MPa) and thermal conductivity (211.73 W·m -1 ·K -1 ) among all samples. When the temperature is further increased to 1200 °C, the oxide layer thickens sharply to approximately 30.95 μm. Cracks and pores develop due to the thermal expansion mismatch, causing a marked decrease in both thermal conductivity and flexural strength. Finally, a kinetic equation for predicting the oxide layer thickness on AlN ceramics is established based on the Hou-Chou kinetic model. A comprehensive model describing lattice oxygen migration and oxidation behavior during heat treatment is also constructed. This work provides a theoretical basis for optimizing the heat-treatment process and enhancing the performance of AlN ceramics.

Sintering behavior, flexural strength, thermal conductivity and dielectric properties of novel Y2O3-LiF co-doped AlN ceramics

Deyin Liang,Xiaoqiang Li,Wenlong Yin,Chaoyang Zhang,Bo You,Shengquan Yu

This study systematically investigates the influence of Y 2 O 3 content on the microstructure, thermal conductivity, flexural strength, and dielectric properties of AlN ceramics co-doped with 2 wt% LiF. XRD and Rietveld refinement confirmed the hexagonal crystal structure for all compositions, with the Y2F2 sample exhibiting a distinct lattice contraction. SEM analysis revealed a steady​ decrease in grain size and a morphological evolution​ of the secondary phase at grain boundaries from a discontinuous to a continuous state with increasing Y 2 O 3 . TEM further demonstrated that the Y2F2 composition yielded the most favorable microstructure, characterized by minimal interface defects and a well-ordered transition zone at the grain boundary triple junctions. Consequently,​ the sample with 2 wt% Y 2 O 3 (Y2F2) delivered optimal overall performance:​ a thermal conductivity of 231.26 W m −1  K −1 , a bending strength of 302 MPa, a dielectric constant of 8.396 (at 1 MHz) with a low loss factor of 1.4 × 10 −3 , and an activation energy of 1.04 eV. These results identify 2 wt% as the critical Y 2 O 3 content that balances oxygen gettering and lattice incorporation, leading to a synergistic optimization of properties.

AlN reinforced polyethersulfone composite with stable high-energy-density via synergizing thermal management and suppressed electrical treeing

Yue Zhang,Guowei Hao,Kunjun Jiang,Changhai Zhang,Yongquan Zhang,Tiandong Zhang,Huajie Yi,Qi Wang,Tao Shen

Polymer-based dielectrics have attracted considerable attention due to their high energy storage density ( U ) and flexibility in processing. However, polymer dielectrics suffer from conduction losses under high fields and temperatures, which reduces the discharge energy density ( U e ) and charge-discharge efficiency ( η ), therefore, effective heat dissipation and maintaining performance at elevated temperatures remain critical challenges that require immediate solutions. In this study, we developed composite materials using polyethersulfone (PESU) as the matrix, incorporating varying mass fractions (1 wt%, 3 wt%, 5 wt%, and 7 wt%) of aluminum nitride (AlN) filler. Simultaneously, we systematically analyzed the thermal conductivity, electric field distribution, and electric tree evolution behavior of the composite material through finite element simulation. Experimental results indicate that, at room temperature, the composite material with 1 wt% AlN in PESU achieves a discharge energy density of 7.39 J/cm 3 at 520 kV/mm, while maintaining a charge-discharge efficiency exceeding 93.5 %. The breakdown strength ( E b ) of this composite reaches 531 kV/mm, representing a 28.9 % improvement compared to pure PESU. At elevated temperatures of 60 °C and 100 °C, the E b of 1 wt% AlN-PESU increases by 42.1 % and 75.4 %, respectively, compared to PESU. Furthermore, simulation results confirm that the introduction of AlN filler significantly improves the thermal conductivity of the composite material, effectively suppresses local temperature rise and electric field distortion, contributing to the suppression of electric tree initiation and retards the progression toward electrical breakdown. This study provides theoretical foundation and engineering route for high-performance polymer-based dielectric materials with broad application value.

An “All-in-One” Strategy to Reconstruct Temporomandibular Joint Osteoarthritic Microenvironment Using γ-Fe2O3@TA@ALN Nanoparticles

Xiao Cen,Junjie Deng,Xuefeng Pan,Rufang Wei,Zhimao Huang,Rong Tang,Shengkai Lu,Rong Wang,Zhihe Zhao,Xinqi Huang

Current clinical strategies for the treatment of temporomandibular joint osteoarthritis (TMJOA) primarily target cartilage biology, overlooking the synergetic effect of various cells and inorganic components in shaping the arthritic microenvironment, thereby impeding the effectiveness of existing therapeutic options for TMJOA. Here, γ-Fe 2 O 3 @TA@ALN magnetic nanoparticles (γ-Fe 2 O 3 @TA@ALN MNPs) composed of γ-Fe 2 O 3 , tannic acid (TA), and alendronate sodium (ALN) are engineered to reconstruct the osteoarthritic microenvironment and mitigate TMJOA progression. γ-Fe 2 O 3 @TA@ALN MNPs can promote chondrocytes’ proliferation, facilitate chondrogenesis and anisotropic organization, enhance lubrication and reduce cartilage wear, and encourage cell movement. Magnetic-responsive γ-Fe 2 O 3 @TA@ALN MNPs also exhibit pH sensitivity, which undergoes decomposition within acidic environment to release ALN on demand. Under a 0.2 T static magnetic field, γ-Fe 2 O 3 @TA@ALN MNPs accelerate the synthesis of cartilage-specific proteins, and suppress catabolic-related genes expression and reactive oxygen species generation, affording additional protection to TMJ cartilage. In TMJOA mouse models, articular injection of γ-Fe 2 O 3 @TA@ALN MNPs effectively alleviates cartilage degeneration and subchondral bone loss in short and long terms, offering promising avenues for the development of therapeutic interventions for TMJOA.