Ceramics International最新文献_第3页

The comparative effects of cobalt and/or iron ions as dopants into Ba(Zr, Y)O3-δ-based perovskite cathodes for intermediate-temperature SOFCs 钴和/或铁离子作为掺杂剂加入中温 SOFC 的 Ba(Zr, Y)O3-δ 基包晶石阴极的比较效应

IF 5.1 2区材料科学 Q1 MATERIALS SCIENCE, CERAMICS

Ceramics International

Pub Date : 2024-09-25 DOI: 10.1016/j.ceramint.2024.09.260

Baofeng Tu, Aokai Sun, Xiaojing Wang, Huiying Qi, Tonghuan Zhang, Peng Qiu, Di Liu

The development of highly active cathode is crucial to promote the electrochemical performance of intermediate-temperature solid oxide fuel cells (IT-SOFCs). Here, it is reported the cobalt and/or iron ions as dopants into Ba(Zr, Y)O_3-δ with the nominal chemical formulae of BaCo_0.4Fe_0.4Zr_0.1Y_0.1O_3-δ (BCFZY), BaCo_0.8Zr_0.1Y_0.1O_3-δ (BCZY), and BaFe_0.8Zr_0.1Y_0.1O_3-δ (BFZY), which all form the main cubic perovskites in addition to a small amount of co-assembled hexagonal D-Ba(Co, Fe)O_3-δ, D-BaCoO_3-δ, and D-BaFeO_3-δ under the same preparing condition. Among three samples, BCZY composite shows the highest capacity of O₂ adsorption, lower thermal expansion coefficient (19.1 × 10⁻⁶ K⁻¹), and highest electrical conductivity of 2.73 S cm⁻¹ (750 °C). The symmetric cell with BCZY composite cathode exhibits excellent ORR activity with the lowest area specific resistance of 0.10 Ω cm² at 700 °C, which is 0.71 and 0.67 times those of BCFZY composite and BFZY composite cathodes. Accordingly, the single cell with BCZY composite cathode shows the lowest R_P of 0.16 Ω cm² and the highest peak power density of 2.24 W cm² at 700 °C. The distribution of relaxation times (DRT) analysis reveals that BCZY composite cathode shows the superior surficial oxygen exchange and charge transfer activity.

开发高活性阴极对于提高中温固体氧化物燃料电池（IT-SOFC）的电化学性能至关重要。在此，报告了钴和/或铁离子作为掺杂剂加入 Ba（Zr，Y）O3-δ 的情况，其化学式分别为 BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY)、BaCo0.8Zr0.1Y0.1O3-δ (BCZY) 和 BaFe0.8Zr0.1Y0.1O3-δ（BFZY），在相同的制备条件下，它们除了形成主要的立方包晶外，还形成了少量共组装六方的 D-Ba（Co，Fe）O3-δ、D-BaCoO3-δ 和 D-BaFeO3-δ。在这三种样品中，BCZY 复合材料吸附 O2 的能力最强，热膨胀系数较低（19.1 × 10-6 K-1），电导率最高，为 2.73 S cm-1（750 °C）。采用 BCZY 复合阴极的对称电池具有优异的 ORR 活性，在 700 ℃ 时的面积比电阻最低，为 0.10 Ω cm2，分别是 BCFZY 复合阴极和 BFZY 复合阴极的 0.71 倍和 0.67 倍。因此，采用 BCZY 复合阴极的单电池在 700 ℃ 时的 RP 最低，为 0.16 Ω cm2，峰值功率密度最高，为 2.24 W cm2。弛豫时间分布（DRT）分析表明，BCZY 复合阴极显示出卓越的表面氧交换和电荷转移活性。

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引用次数: 0

Tuning the local structure of (Sm, Co) Co-doped Al2O3 system for optical band gap and low dielectric loss 调整（Sm, Co）共掺杂 Al2O3 系统的局部结构以实现光带隙和低介电损耗

IF 5.1 2区材料科学 Q1 MATERIALS SCIENCE, CERAMICS

Ceramics International

Pub Date : 2024-09-25 DOI: 10.1016/j.ceramint.2024.09.267

Hassan Wahab , Rao Tahir Ali Khan , Mudassar Iqbal

This study is about the qualitative description of the high dielectric constant (>10³) and low dielectric loss in a two co-existing phases. According to earlier beliefs, a material with high dielectric constant will exhibit high dielectric loss. However, this study gives the opposite, where a material with high dielectric constant can exhibit low loss. Herein, we report on the effect of tetrahedral – octahedral interaction in a γ- Al₂O₃ and CoAl₂O₄ biphasic system. Phase identification was carried out using Synchrotron x-ray carrying a wavelength of 0.7 Å. The disorder caused by varying cobalt (Co) concentration results in a two co-existing phase system with varying local polarizability due to mixing of cations in a host matrix. In addition, a decreasing trend in the band gap energy has been observed for both the phases as a function of increasing Co concentration, which is attributed to the intra-gap localized density of states determined from the UV–Vis diffuse reflectance spectroscopy (DRS).

本研究是关于高介电常数（>103）和低介电损耗两相共存的定性描述。根据以前的观点，高介电常数的材料会表现出高介电损耗。然而，这项研究却给出了相反的结论，即高介电常数的材料可以表现出低介电损耗。在此，我们报告了γ- Al2O3 和 CoAl2O4 双相体系中四面体-八面体相互作用的影响。钴（Co）浓度变化引起的无序导致了两个共存相体系，由于阳离子在主基体中的混合，其局部极化率各不相同。此外，随着钴浓度的增加，两种相的带隙能都呈下降趋势，这归因于通过紫外-可见漫反射光谱（DRS）测定的隙内局部态密度。

引用次数: 0

Waste electric porcelain-based refractory bricks with significantly enhanced mechanical properties: Preparation, characterization and mechanism 机械性能显著增强的废电瓷基耐火砖：制备、表征和机理

IF 5.1 2区材料科学 Q1 MATERIALS SCIENCE, CERAMICS

Ceramics International

Pub Date : 2024-09-25 DOI: 10.1016/j.ceramint.2024.09.314

Yukun Cao , Zhenfei Lv , Ke Zhang , Chong Lan , Mengke Fan , Xu Lu , Yanghui Ke , Wenbo Guo , Yixian Yang , Xin Wang , Xiulin Shen

Using waste electric porcelain to produce refractory bricks is a viable technology. However, these bricks currently have lower mechanical strength compared to those made from mineral raw materials. This study optimized the proportions and sintering process to develop high-strength refractory bricks from waste electric porcelain. The impact of physical phase, crystallinity, sintering temperature, and fly ash content on the bricks properties was examined. The research found that low crystallinity in waste electric porcelain leads to disorganized growth of mullite nano whiskers at high temperatures, reducing mechanical strength due to insufficient support structures and stress concentration zones. The addition of fly ash promotes the formation of uniformly dispersed mullite columns through non-uniform nucleation, significantly improving mechanical properties by creating a collective tetrahedral structure. Bricks with 20 wt% fly ash sintered at 1440 °C achieved a flexural strength of 77.3 MPa, a compressive strength of 156 MPa, and an apparent porosity of 10.89 %. High-temperature simulations indicate that these bricks exhibit good compressive strength and deformation resistance, with no adhesion observed. These high strength refractory bricks have promising potential for use in various high-temperature applications, including kiln linings, high-temperature flue, high-temperature support components and other industrial processes where durability and thermal stability are critical.

利用废电瓷生产耐火砖是一项可行的技术。然而，与矿物原料制成的耐火砖相比，目前这些耐火砖的机械强度较低。本研究通过优化配比和烧结工艺，利用废电瓷生产出了高强度耐火砖。研究了物相、结晶度、烧结温度和粉煤灰含量对耐火砖性能的影响。研究发现，废电瓷中的低结晶度会导致莫来石纳米晶须在高温下无序生长，由于支撑结构和应力集中区不足而降低机械强度。粉煤灰的加入通过非均匀成核作用促进了均匀分散的莫来石柱的形成，通过形成集体四面体结构显著改善了机械性能。在 1440 °C 下烧结的含 20 wt% 粉煤灰的砖的抗折强度达到 77.3 MPa，抗压强度达到 156 MPa，表观孔隙率为 10.89 %。高温模拟结果表明，这些砖具有良好的抗压强度和抗变形能力，且未观察到粘结现象。这些高强度耐火砖有望用于各种高温应用，包括窑炉内衬、高温烟道、高温支撑部件和其他对耐久性和热稳定性要求较高的工业流程。

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引用次数: 0

High purity H2 resource from methanol steam reforming at low-temperature by spinel CuGa2O4 catalyst for fuel cell 燃料电池用尖晶石 CuGa2O4 催化剂低温蒸汽转化甲醇产生的高纯度 H2 资源

IF 5.1 2区材料科学 Q1 MATERIALS SCIENCE, CERAMICS

Ceramics International

Pub Date : 2024-09-25 DOI: 10.1016/j.ceramint.2024.09.319

Gaokui Chen, Qiuwan Shen, Xin Zhang, Tianyun Zhao, Kuanyu Zhu, Shian Li

Methanol steam reforming (MSR) is an effective way to provide high purity hydrogen for PEMFCs, however the main challenge is the toxic effect of CO. In this study, CuGa₂O₄ spinel catalyst was applied first for MSR at low temperature. The properties of catalysts were characterized by various techniques, the MSR catalytic performance was also studied in deeply. The surface of the catalyst is composed of particle chains that are interconnected, forming high-volume pores that increase the specific surface area. The catalyst also has a rich porous structure, exposing more active sites. Furthermore, the presence of oxygen vacancies facilitates the adsorption of reactive oxygen species, reducing CO generation. A possible pathway for methanol dehydrogenation has been determined using DFT calculations. The relatively low overall energy barrier on the catalyst surface facilitates methanol activation. Among the steps, formaldehyde dehydrogenation is the rate-determining step in the methanol dehydrogenation process. The CuGa₂O₄ catalyst exhibits good gas selectivity, with a hydrogen selectivity of 98 % and CO selectivity of 0. and no deactivation occurred within 50 h, demonstrating outstanding durability. These features allow it to serve as an efficient catalyst for MSR online hydrogen production and direct supply to PEMFCs.

甲醇蒸汽转化（MSR）是为 PEMFC 提供高纯度氢气的有效方法，但主要挑战在于 CO 的毒性效应。本研究首先将 CuGa2O4 尖晶石催化剂用于低温 MSR。通过各种技术对催化剂的特性进行了表征，并对 MSR 催化性能进行了深入研究。催化剂表面由颗粒链组成，颗粒链之间相互连接，形成大体积孔隙，增加了比表面积。催化剂还具有丰富的多孔结构，暴露出更多的活性位点。此外，氧空位的存在有利于吸附活性氧，从而减少 CO 的生成。利用 DFT 计算确定了甲醇脱氢的可能途径。催化剂表面相对较低的总能障有利于甲醇的活化。其中，甲醛脱氢是甲醇脱氢过程中决定速率的步骤。CuGa2O4 催化剂具有良好的气体选择性，氢气选择性为 98%，一氧化碳选择性为 0.0%，且在 50 小时内未发生失活现象，表现出卓越的耐久性。这些特点使其成为 MSR 在线制氢和直接供应 PEMFC 的高效催化剂。

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引用次数: 0

Fluorite-like phases in the La2MoO6 – Sm2MoO6 – MoO3 system: Homogeneity region, crystal structure, and conductive properties La2MoO6 - Sm2MoO6 - MoO3体系中的萤石样相：均质区、晶体结构和导电特性

IF 5.1 2区材料科学 Q1 MATERIALS SCIENCE, CERAMICS

Ceramics International

Pub Date : 2024-09-25 DOI: 10.1016/j.ceramint.2024.09.323

T.S. Berezhnaya, K.A. Chebyshev

Samples in the La₂MoO₆ – Sm₂MoO₆ – MoO₃ system were obtained using the solid-state synthesis method. The phase formation in the given compositional section was firstly studied, and the homogeneity region of the fluorite-like lanthanum-samarium molybdate was determined, as confirmed by XRD analysis including Rietveld refinement and SEM with energy-dispersive microanalysis. The fluorite-like phase contains less molybdenum than the isostructural neodymium molybdate Nd₅Mo₃O_16+δ. The homogeneity region of fluorite-like solid solutions has been determined, which corresponds to the La_5-xSm_xMo_2.75O_15.75 section in the composition range 2.5 ≤ x ≤ 3.5. The crystal structure is characterized by the splitting of cation positions and the presence of excess oxygen in the octahedral voids of the structure. Oxygen atoms in the octahedral positions are displaced from the center of the voids and enter into the molybdenum coordination sphere. The density of single-phase ceramic samples increases with the increase in samarium content. The conductive properties of single-phase ceramics were investigated in an air atmosphere using impedance spectroscopy. The total conductivity was ∼10⁻² S cm⁻¹ for La_2.5Sm_2.5Mo_2.75O_15.75 at 800 °C. The grain bulk conductivity exhibits a break at a temperature of approximately 600 °C, which may be explained by the depletion of charge carriers in the structure.

采用固态合成法获得了 La2MoO6 - Sm2MoO6 - MoO3 体系的样品。首先研究了给定成分段中的相形成，并确定了类萤石钼酸镧钐的均质区域，这一点已通过包括里特维尔德细化在内的 XRD 分析和带有能量色散显微分析的 SEM 扫描仪得到证实。类萤石相的钼含量低于等结构钕钼酸盐 Nd5Mo3O16+δ。已经确定了类萤石固溶体的均匀性区域，该区域对应于成分范围为 2.5 ≤ x ≤ 3.5 的 La5-xSmxMo2.75O15.75 截面。该晶体结构的特点是阳离子位置分裂和八面体空隙中存在过量氧。八面体位置上的氧原子从空隙中心移出，进入钼配位层。单相陶瓷样品的密度随着钐含量的增加而增加。利用阻抗光谱法研究了单相陶瓷在空气环境中的导电特性。在 800 °C 时，La2.5Sm2.5Mo2.75O15.75 的总电导率为 ∼10-2 S cm-1。晶粒体导电率在大约 600 °C 的温度下出现断裂，这可能是由于结构中电荷载流子的耗竭造成的。

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引用次数: 0

Effects of laser shock peening on silicon nitride ceramic with varying sintering additive ratios 激光冲击强化对不同烧结添加剂比例氮化硅陶瓷的影响

IF 5.1 2区材料科学 Q1 MATERIALS SCIENCE, CERAMICS

Ceramics International

Pub Date : 2024-09-24 DOI: 10.1016/j.ceramint.2024.09.298

Seongguk Bae , Haneul Kim , Jaepil Lee , Sungho Jeong

Silicon nitride ceramic (Si₃N₄) for industrial applications is conventionally manufactured with sintering additives, and the properties of Si₃N₄ change significantly based on the contents of these additives. In this study, we investigate the effects of laser shock peening (LSP) on Si₃N₄ sintered with varying ratios of sintering additives.

The Si₃N₄ samples were sintered with a mixture of Y₂O₃, MgO, and SiO₂ sintering additives at 5, 7, 9, and 11 wt%. A Nd:YAG laser (wavelength = 532 nm, maximum pulse energy = 1.4 J, repetition rate = 10 Hz, pulse duration = 8 ns, beam diameter = 11 mm, top-hat profile) was used to irradiate the Si₃N₄ samples. The samples were coated with a protective layer (100 μm thick aluminum foil) and a water layer to confine plasma. LSP of Si₃N₄ with 5 % sintering additives resulted in a slight change in surface hardness but a 77 % decrease in surface compressive residual stress. In contrast, LSP of Si₃N₄ with 11 % sintering additives led to a simultaneous increase in surface hardness (7.3 %) and surface compressive residual stress (67 %), indicating a significant difference in the effectiveness of LSP depending on the ratio of sintering additives. Additionally, the surface of Si₃N₄ with 11 % sintering additives showed evidence of grain refinement after LSP. It was demonstrated that the bending strength of Si₃N₄ with 11 % sintering additives increased by 15.2 %, and the depth of the fracture origin was significantly deepened.

用于工业应用的氮化硅陶瓷（Si3N4）在生产过程中通常会添加烧结添加剂，这些添加剂的含量不同，Si3N4 的性能也会发生显著变化。在本研究中，我们研究了激光冲击喷丸（LSP）对使用不同比例烧结添加剂烧结的 Si3N4 的影响。Si3N4 样品使用 Y2O3、MgO 和 SiO2 混合烧结添加剂烧结，烧结添加剂的重量分别为 5、7、9 和 11%。使用 Nd:YAG 激光器（波长 = 532 nm，最大脉冲能量 = 1.4 J，重复频率 = 10 Hz，脉冲持续时间 = 8 ns，光束直径 = 11 mm，顶帽轮廓）照射 Si3N4 样品。样品上涂有保护层（100 μm 厚的铝箔）和水层，以限制等离子体。使用 5% 烧结添加剂的 Si3N4 低辐照度辐照使表面硬度略有变化，但表面压缩残余应力减少了 77%。与此相反，使用 11% 烧结添加剂的 Si3N4 低温等离子体沉积法同时提高了表面硬度（7.3%）和表面压缩残余应力（67%），这表明低温等离子体沉积法的效果因烧结添加剂的比例不同而存在显著差异。此外，含有 11% 烧结添加剂的 Si3N4 表面在 LSP 之后显示出晶粒细化的迹象。研究表明，含有 11% 烧结添加剂的 Si3N4 的抗弯强度提高了 15.2%，断裂源深度明显加深。

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引用次数: 0

Low permittivity germanate LaAlGe2O7 ceramics: Synthesis, sintering behavior, spectral characteristics and microwave dielectric properties 低介电常数锗酸盐 LaAlGe2O7 陶瓷：合成、烧结行为、光谱特性和微波介电性能

IF 5.1 2区材料科学 Q1 MATERIALS SCIENCE, CERAMICS

Ceramics International

Pub Date : 2024-09-24 DOI: 10.1016/j.ceramint.2024.09.325

Qinglan Yang, Yinghan He, Xiaoli Wei, Xiuli Chen, Huanfu Zhou

Novel low permittivity LaAlGe₂O₇ ceramics was prepared by a solid-state reaction method, and the relationship between microstructure and microwave properties was revealed. XRD and Rietveld refinement confirmed that the crystal structure of LaAlGe₂O₇ is monoclinic P2₁/c space group. Raman spectroscopy reflects the trend of internal structural order and phonon-damping behavior of LaAlGe₂O₇ ceramics. The ceramic sintered at 1250 °C exhibited the best surface morphology and optimum microwave dielectric properties of ε_r = 9.22, Q × f = 33417 GHz, τ_f = −71.68 ppm/°C. The lattice energy and packing fraction are used to explain the change of Q × f value. The relationship between phonon damping behavior and microwave dielectric properties was revealed. The temperature stability was studied by bond valence. The LaAlGe₂O₇ ceramics is a strong candidate for the substrate material of millimeter wave communication.

采用固态反应法制备了新型低介电常数 LaAlGe2O7 陶瓷，并揭示了微观结构与微波特性之间的关系。XRD 和 Rietveld 精炼证实 LaAlGe2O7 的晶体结构为单斜 P21/c 空间群。拉曼光谱反映了 LaAlGe2O7 陶瓷内部结构秩序和声子阻尼行为的变化趋势。在 1250 °C 下烧结的陶瓷具有最佳的表面形貌和最佳的微波介电性能：εr = 9.22，Q × f = 33417 GHz，τf = -71.68 ppm/°C。晶格能和堆积分数用于解释 Q × f 值的变化。揭示了声子阻尼行为与微波介电性能之间的关系。通过键价研究了温度稳定性。LaAlGe2O7 陶瓷是毫米波通信基底材料的有力候选材料。

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引用次数: 0

Effect of Zn substitution on structural, magnetic and electric transport properties in inverse spinel NiFe2O4 锌替代对反向尖晶石 NiFe2O4 结构、磁性和电传输特性的影响

IF 5.1 2区材料科学 Q1 MATERIALS SCIENCE, CERAMICS

Ceramics International

Pub Date : 2024-09-24 DOI: 10.1016/j.ceramint.2024.09.304

Biman Kar , Pawan Kumar , Simanchalo Panigrahi , Durga Prasad Sahu , Subhankar Mishra

In the present investigation, we report a comparative study of structural, magnetic and electric transport properties in bulk NiFe₂O₄ and Ni_0.7Zn_0.3Fe₂O₄ ceramics. The materials were synthesized by solid state reaction method. X-ray diffraction analysis confirmed the cubic spinel structure of the ferrite samples belonging to the Fd

\overline{3}

m space group. The structural analysis of the ceramics was comprehensively evaluated from Rietveld refinements of the XRD data and Raman studies. An increased grain size in the Ni_0.7Zn_0.3Fe₂O₄ microstructure was noticed due to Zn substitution. Both structural and microstructural modifications led to a significant change in the magnetic and electric properties of the Ni_0.7Zn_0.3Fe₂O₄ ceramic. A large increase in saturation magnetization with decreased coercivity was noticed in the Ni_0.7Zn_0.3Fe₂O₄ system due to Zn substitution. DC resistivity was observed to decrease in the Zn-substituted nickel ferrite ceramic due to increased grain size and larger electron hopping between Fe³⁺ and Fe²⁺ ions, as verified by the XPS analysis. Further, a remarkable dielectric relaxation has been observed in the Ni-Zn ferrite owing to greater charge hopping and interfacial polarization. Complex impedance spectra of Ni_0.7Zn_0.3Fe₂O₄ revealed evidence of surface polarization contribution with grain and grain boundary effect on the electric transport properties.

本研究报告对块状 NiFe2O4 和 Ni0.7Zn0.3Fe2O4 陶瓷的结构、磁性和电传输特性进行了比较研究。这些材料是通过固态反应法合成的。X 射线衍射分析证实了铁氧体样品的立方尖晶石结构属于 Fd 3‾ m 空间群。通过对 X 射线衍射数据的里特维尔德细化和拉曼研究，对陶瓷的结构分析进行了全面评估。由于锌的替代，Ni0.7Zn0.3Fe2O4 微结构中的晶粒尺寸增大。结构和微观结构的改变使 Ni0.7Zn0.3Fe2O4 陶瓷的磁性和电性发生了显著变化。由于锌的替代，Ni0.7Zn0.3Fe2O4 体系的饱和磁化率大幅提高，矫顽力下降。XPS 分析证实，由于晶粒尺寸增大，Fe3+ 和 Fe2+ 离子之间的电子跳跃增大，在 Zn 取代的镍铁氧体陶瓷中观察到直流电阻率下降。此外，由于电荷跳跃和界面极化加剧，在镍锌铁氧体中观察到了明显的介电弛豫。Ni0.7Zn0.3Fe2O4 的复合阻抗谱显示了表面极化与晶粒和晶界对电传输特性的影响。

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引用次数: 0

Fabrication of microchannels on silica glass by femtosecond laser multi-scan: From surface generation mechanism to morphology control 利用飞秒激光多扫描在硅玻璃上制作微通道：从表面生成机制到形态控制

IF 5.1 2区材料科学 Q1 MATERIALS SCIENCE, CERAMICS

Ceramics International

Pub Date : 2024-09-24 DOI: 10.1016/j.ceramint.2024.09.308

Kai Liao , Wenjun Wang , Chunjin Wang , Chi Fai Cheung

Femtosecond laser processing has become a critical technique for the microfabrication of hard and brittle materials, particularly in microfluidic device applications. This study focuses on the fabrication of microchannels with controllable cross-sectional profiles in silica glass, a material known for its excellent physical and chemical properties. Through a combination of experimental research and theoretical analysis, the surface generation mechanisms governing microchannel morphology are investigated, alongside the influence of various processing parameters on the surface roughness at the microchannel bottom. A comprehensive optimization method is developed to control sidewall taper and surface roughness by adjusting laser scanning paths and modes. Utilizing a composite scanning approach, the study achieves near-rectangular microchannels with average sidewall taper angles below 5° and surface roughness (Sa) of 2.53 μm. These results provide a new strategy for precise control of microchannel morphology in silica glass, offering significant potential to enhance the efficiency and precision of microfluidic device fabrication, with broad applications in both industrial and research settings.

飞秒激光加工已成为硬脆材料微加工的关键技术，尤其是在微流控设备应用中。本研究的重点是在硅玻璃中制造具有可控截面轮廓的微通道，硅玻璃是一种以其优异的物理和化学特性而著称的材料。通过实验研究和理论分析相结合，研究了微通道形态的表面生成机制，以及各种加工参数对微通道底部表面粗糙度的影响。开发了一种综合优化方法，通过调整激光扫描路径和模式来控制侧壁锥度和表面粗糙度。利用复合扫描方法，该研究实现了近乎矩形的微通道，其平均侧壁锥角低于 5°，表面粗糙度 (Sa) 为 2.53 μm。这些结果为精确控制硅玻璃中的微通道形态提供了一种新策略，为提高微流体设备制造的效率和精度提供了巨大的潜力，在工业和研究领域都有广泛的应用。

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引用次数: 0

High-temperature oxidation behavior of multi-phase ceramic particles-reinforced TiAl composites with different microstructures 具有不同微观结构的多相陶瓷颗粒增强 TiAl 复合材料的高温氧化行为

IF 5.1 2区材料科学 Q1 MATERIALS SCIENCE, CERAMICS

Ceramics International

Pub Date : 2024-09-24 DOI: 10.1016/j.ceramint.2024.09.306

Genhua Zeng , Tengfei Ma , Yupeng Wang , Xiaohong Wang , Hongze Fang , Ruirun Chen

The high-temperature oxidation behaviors of multiphase ceramic particle-reinforced TiAl composites with different microstructures were investigated. The TiAl composites were prepared via spark plasma sintering by introducing 0.5 wt % graphene oxide and 0.3 wt% SiC into Ti-48Al-2Nb-2Cr. The near-γ equiaxed microstructure, dual-phase microstructure, and nearly fully lamellar microstructure were obtained by sintering at 1200, 1250, and 1300 °C, respectively. Moreover, multiphase ceramic particles were uniformly distributed in the TiAl matrix. Cyclic oxidation was conducted at 950 °C in air for 100 h. The TiAl composite with the nearly fully lamellar microstructure exhibited the best oxidation resistance (mass gain of 1.83 mg/cm²) and that with the near-γ microstructure exhibited the worst oxidation resistance (2.47 mg/cm²). The superior oxidation resistance of the TiAl composite with the nearly fully lamellar microstructure is attributed to the uniform distributions of Ti₂AlC particles at the α₂/γ lamellae interfaces and Ti₅Si₃ particles at the lamellae colony boundaries, which hinder atomic diffusion. Moreover, the α₂/γ lamellae colonies facilitate the formation of Nb-rich and Cr-rich phases at the interface of the oxide layer and substrate, which act as a protective barrier against atomic diffusion.

研究了具有不同微观结构的多相陶瓷颗粒增强 TiAl 复合材料的高温氧化行为。在Ti-48-Al-2Nb-2Cr中引入0.5 wt%的氧化石墨烯和0.3 wt%的SiC，通过火花等离子烧结制备了TiAl复合材料。在 1200、1250 和 1300 °C 下烧结分别获得了接近γ等轴的微观结构、双相微观结构和近乎完全片状的微观结构。此外，多相陶瓷颗粒均匀地分布在钛铝基体中。在 950 ℃ 的空气中循环氧化 100 小时后，具有近全片状微结构的 TiAl 复合材料表现出最佳的抗氧化性（质量增益为 1.83 mg/cm2），而具有近γ 微结构的 TiAl 复合材料表现出最差的抗氧化性（2.47 mg/cm2）。具有近完全层状微观结构的 TiAl 复合材料具有较好的抗氧化性，这归因于在 α2/γ 层状界面上均匀分布的 Ti2AlC 颗粒和在层状菌落边界上均匀分布的 Ti5Si3 颗粒阻碍了原子扩散。此外，α2/γ薄片菌落还有助于在氧化层和基底界面形成富含 Nb 和 Cr 的相，从而起到防止原子扩散的保护作用。

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引用次数: 0