CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Weide Wang,Dongxu Yao,Hanqin Liang,Yongfeng Xia,Kaihui Zuo,Jinwei Yin,Yu-Ping Zeng
The effect of the GdH 2 on the shrinkage behavior, microstructure, thermal conductivity , and flexural strength was investigated. The pre-sintering enables the elimination of native SiO 2 and the simultaneous formation of Gd 2 O 3 . The N/O ratio in the liquid phase was increased because of the increasing Gd 2 O 3 /SiO 2 ratio, resulting in the restricted shrinkage during gas pressure sintering. The high N/O ratio in the liquid phase benefits not only the nucleation and growth of β-Si 3 N 4 but also the removal of lattice oxygen, leading to the increase of thermal conductivity . Although the replacement of Gd 2 O 3 by GdH 2 leads to enhanced flexural strength at low temperature, it tends to reduce the flexural strength at high temperature. This variation related largely to the exaggerated bimodal microstructure. This work signifies that GdH 2 is an effective sintering additive for obtaining Si 3 N 4 ceramics with both high flexural strength and high thermal conductivity.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Yun Liu,Ruixiang Liu,Yuanhang Zheng,Jixue Zhao,Tianyi Sui,Xiaolei Li,Bin Lin
To investigate the mechanism of the influence of the sintering additive ratio on the microstructure evolution of silicon nitride (Si 3 N 4 ) ceramics, Si 3 N 4 ceramics were prepared by gas pressure sintering using different ratios of Y 2 O 3 /MgSiN 2 as additives. Varying the ratio of Y 2 O 3 /MgSiN 2 changed the composition of the liquid phase, thereby affecting the densification process and phase transformation rate of Si 3 N 4 ceramics, and ultimately changing their microstructure. The reduction in the Y 2 O 3 /MgSiN 2 ratio raised the N/O and Si/O ratios in the system, which increased the liquid phase viscosity. The Si 3 N 4 grain distribution varied from "normal to bimodal". In the case of increasing the proportion of MgSiN 2 and prolonging the sintering time, more of the glass phase evaporated, which reduced the content of the low thermal conductivity phase and increased the continuity of Si 3 N 4 /Si 3 N 4 . Therefore, Si 3 N 4 ceramics with 1 wt% Y 2 O 3 and 5 wt% MgSiN 2 exhibited excellent properties after sintering at 1900 °C for 12 h, with thermal conductivity, bending strength , and fracture toughness of 106.7 Wm −1 K −1 , 776 MPa, and 11.66 MPa m 1/2 , respectively.
研究领域:
材料科学
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陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2024
·
IF 1.8
Dian Zhang,Xuan Liu,Yijun Liu
Conventional aluminum nitride (AlN) ceramics exhibited insufficient mechanical properties expected from their potential applications in the presence of dynamic loads and intensive stresses caused by thermal shock. In this study, the mechanical properties of AlN ceramics were enhanced by toughening them using AlN whiskers (AlN w ) via gel casting followed by low-temperature sintering at 1650°C. The addition of AlN w simultaneously increased the bending strength, toughness and thermal conductivity of the AlN ceramics. The maximum values of the bending strength, toughness, and thermal conductivity of 9.0 wt% AlN w /AlN were 303.92 MPa, 3.92 MPa·m 1/2 and 186.53 W·m −1 ·K −1 , respectively, which were higher than those of the AlN ceramics by 39.93%, 61.31% and, 15.61%, respectively. The AlN w in AlN w /AlN ceramics tightly bonded with the ceramic matrix, leading to two characteristic toughening mechanisms in the ceramics: crack pinning and deflection at irregular grain boundaries caused by doped whiskers, as well as bridging and stress relaxation caused by whiskers incorporated with the grains. Moreover, the one-dimensional morphology of AlN w can provide a channel for quick photon transport, thereby enhancing the thermal conductivity of AlN w /AlN.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Zhouxi Tan,Mingkang Zhang,Shuai Zhao,Yihua Huang,Zhengren Huang
Low strength and poor performance of SiC–WC composite for seals, attributable to the use of a large amount of liquid phase sintering additives, limit the application prospects of these materials. This study focuses on preparing high-strength, high-toughness, and wear-resistant SiC–WC composite using a small amount of aluminum and carbon black as sintering additives. The results revealed that the specimen containing 50 wt% WC exhibited the maximum flexural strength and fracture toughness of 645.9 MPa and 7.49 Mpa m 1/2 , respectively. These improvements were attributed to the deoxidizing and solid-solution effects of Al and the reinforcing effect of the WC second phase. Moreover, the specific wear rate was measured at 8.06 × 10 −7 mm 3 N −1 m −1 , which was 56.9 % lower than that of monolithic SiC. Results from Raman spectral analysis provided evidence of the presence of W–O bonds on the wear surface, indicating that the SiO 2 film could be successfully replaced by a WO 3 film.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Liang Wang,Wei-Ming Guo,Peng-Fei Sheng,Li-Fu Lin,Xiao Zong,Shang-Hua Wu
A new type of non-oxide sintering additive of YH 2 was introduced for the fabrication of AlN ceramics with high thermal conductivity and flexural strength . The effects of YH 2 addition (0–5 wt%) on the phase composition, densification, microstructure, thermal conductivity and flexural strength of pressureless sintered AlN ceramics were investigated and compared with those Y 2 O 3 -added samples (1–5 wt%). The addition of 1 wt% YH 2 led to an in-situ reduction reaction with oxygen impurities, the formation of Y 2 O 3 and finally the formation of yttrium aluminate, which in turn improved densification and microstructure. A high flexural strength (408.69 ± 28.23 MPa) was achieved. The addition of 3 wt% YH 2 increased the average grain size and purified the lattice. All these effects are believed to help achieve a high thermal conductivity of 184.82 ± 1.75 W·m −1 ·K −1 . Although the thermal conductivity was close to the value of 3 wt% Y 2 O 3 -added sample, its strength was much increased to 381.53 ± 43.41 MPa. Meanwhile, it demonstrated a good combination of the thermal conductivity and flexural strength than the values reported in some literature. However, further increasing the YH 2 addition to 5 wt% resulted in a high N/O ratio that inhibited the densification behavior of AlN ceramics. The current study showed that AlN ceramics with excellent thermal and mechanical properties could be obtained by the introduction of a suitable YH 2 additive.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Tao Feng,Wanbo Hou,Mingde Tong,Hejun Li,Hongjiao Lin,Shifeng Wen
SiC nanowires (SiC nws ) modified SiC f /HfC-SiC composites were prepared by precursor infiltration and pyrolysis (PIP) and chemical vapor infiltration (CVI) methods. The microstructure, flexural strengths, impact and impact-ablation tests of the composites with and without SiC nws were investigated. The results showed that after introducing SiC nws , not only the retention rate of HfC ceramic produced by PIP was increased obviously, but also the fracture displacement of the modified composites was reduced due to the enhancement effect of SiC nws at interface between SiC fiber and matrix. After impact and impact-ablation, the strength retention of SiC nws modified composites was 91.6 % and 69.1 % respectively, higher than that of the composites without SiC nws (85.2 % and 54.8 %). As the impact resistance of the modified composites was improved by the pull-out and bridging of SiC nws , the ablation resistance of the impacted composites was enhanced as well.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Ning Sun,Tengpeng Wang,Yuhang Du,Xiaojun Ma,Wenkai Xin,Haochen Dang,Xuqiu Xie,Tao Wei,Qinggang Li
Si 3 N 4 ceramics pose a challenge when it comes to the preparation of light-curing pastes with high depth of cure, elevated solid content, and low viscosity. This challenge is primarily attributed to their inherent characteristics, including high absorbance, a high refractive index, and suboptimal sphericity. Consequently, the application of Si 3 N 4 ceramics in 3D printing remains a complex endeavor. To address the intricacies associated with 3D printing using Si 3 N 4 ceramics, our research focuses on the utilization of Tetramethylammonium Hydroxide (TMAH) for pH adjustment in Si 3 N 4 ceramics. This adjustment aims to enhance the stability, curing depth, and viscosity of the slurry. Subsequently, we employ this Si 3 N 4 light-curing slurry for 3D printing, followed by sintering the printed materials. The evaluation includes testing for porosity, density, and flexural strength of the samples. Notably, our efforts yield porous silicon nitride ceramics boasting an impressive density of 1.8299 g/cm 3 , porosity measuring 43.718%, and remarkable flexural strength amounting to 275 MPa.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2013
·
IF 1.789
Chao Jiang,Dou Zhang,Xueping Gan,Rui Xie,Fuqiang Zhang,Kechao Zhou
A new processing technique was proposed for preparing aluminum nitride (AlN)/Hydantion interpenetrating network composites. The technique comprised gelcasting AlN green bodies, degreasing, and infiltrating Hydantion epoxy resin and hardener into the AlN skeleton under a vacuum condition. The effects of AlN contents on the viscosities of AlN slurries and the flexural strength , thermal conductivity , dielectric constant of the AlN/Hydantion composites were evaluated. The highest thermal conductivity and flexural strength of the AlN/Hydantion composites reached 3.56 W/mK and 101.3 MPa, respectively. The fracture surface of the composite revealed that an interpenetrating polymer network in the AlN ceramic skeleton was formed. The AlN/Hydantion composite exhibited the dielectric constant of 7.3 at 1 MHz.
研究领域:
材料科学
·
工程学
✓ 已验证
产品关联
DOI
高影响因子
JOM
·
2021
·Vol. 73
·期 11
·3451-3459
·
IF 2.474
Chen Ben,Li Zhi-Bo,Zhang Guo-Hua,Chou Kuo-Chih
To improve the performance of Mo-based cermets, Mo-(Ni)-Al 2 O 3 cermets were prepared with raw materials of nano-sized Al 2 O 3 powder. The effects of Al 2 O 3 and Ni additions on the densification behavior, microstructure, bending strength, and hardness of the Mo-(Ni)-Al 2 O 3 cermets were experimentally analyzed. The results showed the content of Al 2 O 3 had a great influence on the degree of densification of Mo-Al 2 O 3 cermets at the sintering temperature of 1600°C. In addition, the Al 2 O 3 particles were distributed evenly in the matrix of Mo-based cermets, which refined the grains of Mo and increased the hardness of cermets. Because of the weak interfacial bonding strength between Al 2 O 3 ceramic phase and Mo metal phase, the bending strength decreased continuously with increasing Al 2 O 3 content. However, Ni addition improved the wetting and adhesion of Al 2 O 3 and Mo. With the addition of Ni, the relative density increased, and thus hardness and bending strength were improved.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xiao Zong,Shuangshuang Wu,Kunji Lin,Jintao Zhang,Yehua Li,Donglin Lu,Xin Deng,Shengguo Lu,Jihua Qiu,Yuanzhi Shao,Shanghua Wu
Improving the thermal conductivities and bending strengths of ceramic substrates is crucial for their applicability as key components of integrated chips. Herein, we report the latest study in which the thermal conductivity and bending strength of aluminum nitride (AlN) ceramics were systematically predicted using high-precision prediction model approached with a machine learning (ML) method based on extreme gradient enhancement method (XGBoost). The ML model was used to rank the effects of the process parameters, and SHapley Additive exPlanations (SHAP) was employed to quantify the contributions of different factors. Sintering additives were found to have the predominant influence on the thermal conductivity and bending strength; particularly, those with cationic radii within 0.085–0.105 nm enhance both properties. By using Pr 2 O 3 as the sintering additive and adopting the preparation conditions recommended by the ML model, we prepared AlN ceramics with thermal conductivity as high as 195.63 W m −1 K −1 and bending strength of 371.60 ± 9.31 MPa, thus satisfying the application requirement of high thermal conductivity . The proposed model is also applicable to alumina and silicon nitride ceramics. This study provides a practicable and once-for-all strategy to realize the entire process from the ML prediction design to the preparation of ceramic materials exhibiting superior thermal conductivity and high strength.
研究领域:
材料科学
·
人工智能
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Hongbo Zhao,Renjun Pei,Pei-Xi Wang
The teeth of limpets, consisting of orderly aligned hard goethite (iron oxyhydroxide) nanocrystals and flexible chitin microfibers, are one of the hardest and stiffest biomaterials found in nature. However, the replication of their composition and ordered microstructures to artificial biomimetic materials remains a challenge. Here, we fabricated large-sized limpet tooth analogues with hierarchically ordered structures by applying long-range orientational control to the short-scale self-assembly of hybrid colloidal liquid crystals formed by chitin nanocrystals and goethite nanorods. The obtained composite laminates exhibited excellent bending resistance compared to biomaterials, cement, and ceramics. These results suggest that the mass production of structurally ordered materials with high strength and toughness may be achieved by using lyotropic liquid crystals.
研究领域:
材料科学
·
生物学
✓ 已验证
产品关联
DOI
高影响因子
CORROSION SCIENCE
·
2020
·
IF 6.479
Tao Feng,Mingde Tong,Shuotian Yao,Hejun Li,Hongjiao Lin,Shifeng Wen,Peipei Wang
The B-modified SiC/HfC-SiC composites were prepared by the combination of precursor infiltration and pyrolysis (PIP) and chemical vapor deposition (CVD) methods. The microstructure, cyclic ablation and bending strength tests of the SiC/HfC-SiC composites with and without B were investigated. The results showed that the B-modified composites had a better cyclic ablation resistance than that of the composites without B. The effective residual thickness of the B-modified composites was also higher than that of the composites without B after cyclic ablation. The residual bending strength of the B-modified composites was slightly lower than that of the composites without B.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）