Materials Today Communications
·
2021
·
IF 3.383
Shi Tian,Wenchao Guo,Qianglong He,Aiyang Wang,Tian Tian,Chun Liu,Lanxin Hu,Zhixiao Zhang,Hao Wang,Weimin Wang,Zhengyi Fu
TiN–TiB 2 –hBN composite powders were synthesized by a nitride boronizing process using TiN and amorphous boron as the raw materials, and the reaction process of TiN–B powder mixture was investigated by heat treatment at elevated temperatures. At 1400 °C in a vacuum, TiN–TiB 2 –hBN composite powders with a core-shell structure of layered hBN-wrapped TiB 2 were obtained, which can be used to prepare ceramic composites with excellent properties. The results showed that B atoms began to diffuse into TiN and replace the N atoms to form TiB 2 at high temperature; then, the substituted N escaped outwards, and upon contacted with B, formed hBN at the surface of the TiB 2 particles. The relative density, bending strength , and fracture toughness of the 70 vol% TiN–17.6 vol% TiB 2 –12.4 vol% hBN (TB73) composite prepared by reactive sintering were 98.90%, 521 MPa, and 4.22 MPa m 1/2 , respectively, which were much higher than that of fabricated via conventional method (TBN73: 88.02%, 198 MPa, and 2.58 MPa m 1/2 ).
研究领域:
材料科学
·
陶瓷工程
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产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2022
·Vol. 19
·期 6
·3255-3266
·
IF 2.328
Jiakun Wu,Haikuo Wang,Zhicai Zhang,Zhiqiang Hou,Dazhuan Wu,Xiaoping Ouyang
Al 2 O 3 -cBN-hBN self-lubricating ceramics were synthesized by using a high-pressure sintering method. The mapping relationships between sintering thermodynamic conditions, component content, and mechanical properties were established using the response surface method. The main factors influencing the mechanical properties are clarified. The formation mechanism of the excellent mechanical properties is explained. It is found that the undesired phase transformation from cBN to soft hBN can be effectively inhibited by using a low-temperature and high-pressure sintering process. Sintering temperatures improve the relative densities and elastic modulus of self-lubricating ceramic but have little effect on the hardness and fracture toughness. cBN content is the main factor affecting the mechanical properties of the composites. The microcracks developed during the high-pressure sintering process contribute to the fracture toughness of the composites.
研究领域:
材料科学
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陶瓷
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机械工程
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DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2022
·
IF 9.879
Chenglin Li,Hao Zhang,Xiaowen Zhang,Zechao Zhang,Nan Li,Ying Liu,Xiuting Zheng,Dali Gao,Daming Wu,Jingyao Sun
With the continuous development of modern electronic equipment, thermal management of electronic devices has become the focus of attention due to the energy consumption. As an important part of thermal management system, it is necessary to develop an electrical equipment shell with both superior thermal conductivity and mechanical properties for better thermal management performance. However, it is very difficult to balance the relationship between thermal conductivity and mechanical properties of thermal conductive polymer composites . Increasing filling content of thermal conductive fillers would lead to heavy damage of mechanical properties. In this paper, we construct a bi-continuous structure to solve this problem. The ABS phase provides thermal conductivity enhancement, while the PC phase is responsible for mechanical property maintaining. A highest thermal conductivity of 0.476 W/(m⋅K), 138% higher than that of pure PC, can be obtained after optimum design of formulation and processing conditions. Meanwhile, the mechanical properties of PC/ABS composite are also enhanced comparing with filled-PC. Moreover, the reported PC/ABS composite has excellent electrical insulation and dielectric properties . Overall, our PC/ABS composites with simultaneous enhanced thermal conductivity and mechanical properties are of great prospect as electrical equipment shells for efficient thermal dissipation .
研究领域:
材料科学
·
热管理工程
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产品关联
DOI
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2018
·
IF 3.316
Chen Pan,Kaichang Kou,Yu Zhang,Ziyu Li,Tiezheng Ji,Guanglei Wu
Porous polymer materials have been widely used for the preparation of low dielectric constant materials, but they also suffer from high moisture absorption and decreased thermal conductivity. In this study, core–shell structured hexagonal boron nitride coated hollow glass microsphere (HGM@hBN) particles were prepared using an electrostatic-assembly process and incorporated into poly(tetrafluoroethylene) (PTFE). The composites exhibited decreased dielectric constants due to the implantation of air, which is mainly encapsulated in HGM . The hBN layer on the surface of HGM effectively enhanced composite thermal conductivity due to its special core-shell form. The 30 vol% HGM@hBN/PTFE composites had a low dielectric constant of 1.68, low moisture absorption of 0.11%, and thermal conductivity (0.276 W/mK) was improved by 43% compared with that of 30 vol% HGM/PTFE composites. This study provides a facile and cost-effective strategy for fabricating polymer composites with low dielectric constant, low moisture absorption and no deteriorated thermal conductivity simultaneously.
研究领域:
材料科学
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复合材料
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高分子科学
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电气工程
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热能工程
✓ 已验证
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2016
·
IF 3.85
Chen Pan,Kaichang Kou,Qian Jia,Yu Zhang,Guanglei Wu,Tiezheng Ji
To achieve polymer-based composites for electronic packaging with low dielectric constant, low dielectric loss tangent and high thermal conductivity , silane coupling agent KH550 modified hexagonal boron nitride (hBN) platelets were introduced into PTFE matrix via a cold pressing and sintering method. The effect of surface treatment on the morphology, thermal conductivity and dielectric properties of the composites was investigated. The results revealed that after surface treatment, the interfacial adhension between hBN platelets and PTFE matrix was improved and the in-plane orientation degree of hBN platelets in PTFE matrix decreased, which effectively improvd the thermal conductivity of the composites. The thermal conductivity of hBN-KH550/PTFE composite with 30 vol% filler content is 0.722 W/mK, which is 2.7 folds of pure PTFE. Moreover, the enhanced interfacial adhension and reduced surface hydrophilicity of hBN platelets significantly decreased the interfacial polarization , resulting in not only lower dielectric constant and dielectric loss tangent but also weaker frequency-dependence.
研究领域:
材料科学
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复合材料
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电子封装
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热管理
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DOI
高影响因子
Advanced Electronic Materials
·
2024
·
IF 5.3
Zi-hao Dong,Qi-hang Zhang,Kai Liu,Shao-jie Fu,Xu-Hao Hong,Qian-jin Wang,Yan-qing Lu,Yong-yuan Zhu,Xue-jin Zhang
Two-dimensional (2D) materials are widely used in various optical, electronic, and optoelectronic devices. However, the realization of visible light emission and near-infrared photodetection functions in a single device remains a challenge. Here, an integrated dual-functional device is developed by manipulating the excitons of WS 2 within a graphene/hBN/WS 2 /graphene heterostructure. When operating as a photodetector at low external bias, the dark current is well suppressed by the hBN layer. With the excellent two-photon absorption (TPA) property of monolayer WS 2 , the photoresponse range of the photodetector can be extended to the near-infrared region, achieving a responsivity of up to 0.19 mA/W at 1145 nm. At high external bias, the device can work in light-emitting mode, in which the electroluminescence (EL) wavelength can be tuned via gate voltage. This atomically thin device opens up possibilities for applications in miniaturized display, sensing, and monitoring systems.
研究领域:
材料科学
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光电子学
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纳米技术
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产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2022
·
IF 9.417
Jiakun Wu,Haikuo. Wang,Chao Wang,Zhicai Zhang,Yao Tang,Zhiqiang Hou,Shun Wan,Dazhuan Wu,Zhongjun Tan,Xiaoping Ouyang
Al 2 O 3 -based self-lubricating ceramics are cutting tool materials that meet the extreme working conditions of dry cutting. However, due to the soft lubricating components, the mechanical properties of composites are dramatically reduced. In this paper, Al 2 O 3 -cBN-hBN self-lubricating material was designed. High density, fine grain ceramics were synthesized by high-pressure technology. The influence of thermodynamic condition, cBN/hBN addition on mechanical and thermal properties of sintered composites was analyzed. Friction and wear tests were carried out. It is found that the addition of cBN particles can significantly improve the mechanical and thermal properties of the composites. However, the truss effect caused by excessive volume fraction of cBN can reduce the pressure transfer efficiency, and then affect the properties of sintered composites. The different hBN content can change the wear mechanism of the composites. The release efficiency of hBN particles in composites was enhanced due to the large modulus difference between cBN and hBN. The well-sintered Al 2 O 3 -cBN-hBN bulks present an excellent mechanical property. The hardness of the composites is improved at least by 54% compared with the traditional self-lubricating material on the premise of ensuring fracture toughness and lubrication performance.
研究领域:
材料科学
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陶瓷
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摩擦学
·
高压加工
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DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2025
·
IF 4.7
Yaxi Liu,Mingyang Fang,Xiaofei Zhu,Ning Wang,Lishi Wang
To address mass heat flux and hazardous hot spots in high-power devices, the phase-change thermal interface materials (TIMs) have attracted intense interest. However, the leakage issue of the organic phase-change materials in the TIMs is still a great challenge to be addressed. Herein, a newly designed phase-change TIMs was constructed with inorganic phase-change VO 2 . In the construction, a 3D hBN–OH–VO 2 oriented thermal network was constructed via ice-templating, followed by epoxy resin (EP) vacuum infiltration. Polyvinyl alcohol (PVA) aqueous solution and tert -butyl alcohol (TBA) solvent were comparatively investigated as inducers for dual-performance channel engineering. Characterization revealed an optimal hBN-OH:VO 2 mass ratio of 4:1. At a low total filler loading of ∼10 wt%, the PVA-assisted TIM achieved thermal conductivities of 0.29 W/m·K (25 °C) and 0.33 W/m·K (80 °C), while the TBA-assisted system exhibited thermal conductivities of 0.34 W/m·K and 0.39 W/m·K, respectively. Additionally, the thermal interface material exhibits a latent heat of up to 1.98 J/g without any component leakage. This study provides a novel strategy for designing highly reliable phase-change TIMs.
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 27
·1-11
·
IF 2.8
Wang Haohuan,Gong Wen,Yuan Ying,Wu Jinsuo,Wen Sen,Liu Xianghua
The overall performance of 3D printed epoxy resin falls short of meeting the demands for the production and advancement of insulating components in electrified transportation equipment. This article introduces an approach for enhancing the dielectric characteristics of a composite epoxy resin oriented with hexagonal boron nitride by incorporating nano-alumina. Consequently, a 3D printed composite epoxy resin comprising nano-alumina and hexagonal boron nitride is successfully fabricated, demonstrating exceptional physical, chemical, and dielectric properties. The research findings unveil that, when the filler content reaches 3 wt% for nano-alumina and 27 wt% for hexagonal boron nitride, the micro-nano composite epoxy resin exhibits impressive mechanical characteristics while maintaining a significant degree of thermally conductive anisotropy. Specifically, at this precise filler content, the interlayer compatibility within the micro-nano composite epoxy resin experiences a substantial improvement, ultimately resulting in outstanding dielectric performance with a maximum volume resistivity of 5.5 × 10 15 Ω∙cm and a surface resistivity of approximately 6.2 × 10 14 Ω. Furthermore, the micro-nano composite epoxy resin, with in-plane-oriented hBN, exhibits the highest dielectric strength, achieving a peak value of 35.7 kV∙mm −1 at the mentioned filler content. This investigation offers valuable insights into the development of high-performance 3D printed insulation components.
研究领域:
材料科学
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电气工程
·
复合材料研究
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产品关联
DOI
高影响因子
Materials Research Express
·
2022
·Vol. 9
·期 4
·046303
·
IF 2.025
Fengmei Ren,Zizheng Yang,Haihong Ma,Zhengfa Zhou,Weibing Xu
High integration and miniaturization of electronic systems require thermal conductivity and mechanical damping materials. In this study, hexagonal boron nitride (hBN) particles were modified by vinyltrimethoxysilane (V171) and hexadecyltrimethoxysilane (N3116) for comparing, and described as V171-hBN and N3116-hBN, respectively. The pristine and surface modified hBN were filled in vinylmethylpolysiloxane (VMQ), and then vulcanized to fabricate hBN/silicone rubber composites. The damping properties of V171-hBN/silicone rubber composites were significantly higher than that of pristine hBN/silicone rubber composites, while N3116-hBN/silicone rubber composites were in contrast. The strong interfacial action in V171-hBN/silicone rubber composites came from the chemical bond by vinyl groups on the surface of V171-hBN taking part in the vulcanization of VMQ. This strong interfacial action led the deformation of hBN, and the internal friction between layers of hBN significantly increased to dissipate more energy. As a result, V171-hBN/silicone rubber composites with excellent damping and thermal conductivity as well as good mechanical properties were obtained.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-10
·
IF 4.259
Zhou Ying,Wang Yao,Liu Tengfei,Xu Gang,Chen Guangming,Li Huayi,Liu Lichun,Zhuo Qiqi,Zhang Jiaoxia,Yan Chao
The world faces severe environmental, human and ecological problems when major oil spills and organic discharges are released into the environment. And so it is imperative to develop tools and high performance innovative materials that can efficiently absorb these organic discharges. Furthermore, green, facile methods to produce these advanced materials are also needed. In this paper, we demonstrate a novel porous supersponge based on melamine coated with hBN. This superhydrophobic sponge (with a contact angle >150°) exhibits excellent absorption performance for oils and organic solvents, including good selectivity, high capacity (up to 175 g·g −1 ) and extraordinary recyclability (less than 20% decline after 30 cycles of absorption/squeezing). The synthetic procedure required only ultrasonication and immersion of the sponge in aqueous hBN solution, being a green, cost-effective and scalable production methodology. By virtue of the straightforward and cost-effective fabrication method, along with the excellent absorption performance, hBN-decorated sponges have great promise for real world practical application in the field of oil spills and organic leakage cleanup.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Li Yin,Kai Zhao,Yu Ding,Yuxin Wang,Zhen He,Saifang Huang
This work aims to investigate the effect of hBN on the friction and wear resistance of Sialon composite. Sialon and its composite with 10 wt% hBN were fabricated by SPS sintering. The effect of hBN additive on the phase composition, microstructure, densification behavior, mechanical and dry sliding tribological properties of Sialon material was studied. Being sintered at 1600 °C for 10 min, compared to monolithic Sialon, Sialon-hBN composite has more refined β-Sialon grains with smaller aspect ratios and slightly declined relative density. The hardness of the Sialon-hBN composite was reduced due to the weak bonding between Sialon and hBN grains. Nevertheless, its fracture toughness increased ascribing to the toughening mechanisms, including crack deflection and crack bridging. hBN had an essential impact on the tribological performances of the composite due to its lower friction coefficient and good lubrication action. Under the same densification level (i.e., with a relative density of around 97.5%), the friction and wear resistance of Sialon-hBN composite were much better than monolithic Sialon. The main wear mechanisms were tribolayer formation, oxidized wear, and abrasive wear.
研究领域:
材料科学
·
力学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）