JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2013
·Vol. 28
·期 5
·882-887
·
IF 0.484
Li Liang,Zhou Aiguo,Xu Lin,Li Zhengyang,Wang Libo
Titanium aluminum carbide (Ti 3 AlC 2 and Ti 2 AlC) powders were synthesized from TiH 2 powders instead of Ti powders as Ti source by a tube furnace under argon atmosphere without preliminary dehydrogenation. 95 wt% pure Ti 3 AlC 2 powders were synthesized from TiH 2 /1.1Al/2TiC at 1 450 °C for 120 min. High-purity Ti 2 AlC powders were also prepared from 3TiH 2 /1.5Al/C and 2TiH 2 /1.5Al/TiC powders at 1 400 °C for 120 min. The as-synthesized samples were porous and easy to be ground into powders. Sn or Si additives in starting materials increased the purity of synthesized Ti 3 AlC 2 obviously and expanded the temperature range for the synthesis of Ti 3 AlC 2 . With Si or Sn as additives, high pure Ti 3 AlC 2 was synthesized at 1 200 °C for 60 min from TiH 2 / x Si/Al/2TiC and TiH 2 / x Sn/Al/2TiC ( x = 0.1, 0.2), respectively.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Jian Yang,Yu Cong,Junrong Ling,Wentao Xu,Ye Zhang,Youfu Zhou,Maochun Hong
Aluminum oxynitride (AlON) powders were synthesized by a novel carbothermal reduction and nitridation (CRN) method. Homogenous and fluffy AlOOH/C core-shell nanoparticle precursor was hydrothermally synthesized with aluminum nitrate hydrate, sucrose and urea as starting materials. Then single-phase AlON powders were synthesized by CRN method at 1700 °C for 2 h. The phase transition and growth of Al 2 O 3 particles was effectively retarded by the amorphous carbon nano-layers on the surface of precursor, resulting in significantly lower reaction temperature and further smaller particle size. Based on above fine AlON raw material, transparent AlON ceramic was prepared by pressureless sintering at 1880 ℃ with the in-line transmittance above 80 %.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2023
·
IF 10.9
Hailing Yang,Ji Zou,Zhimin Xiong,Jingjing Liu,Weimin Wang,Zhengyi Fu
Hexagonal BN-coated powders have been widely used in various engineering sectors, however, their productions are restricted by the complexity of gas-solid reactions. In this study, guided by thermodynamics, a novel approach to synthesize Layer-structured hexagonal BN ( h BN)-coated high entropy diboride powders in vacuum was developed, using metal salt Zr(NO 3 ) 4 ·5H 2 O, HfCl 4 , NbCl 5 , TaCl 5 , C 16 H 36 O 4 Ti, boric acid, and sucrose as raw materials. By adjusting the ratio of carbon to metal source (C/M), powders only consisting of two boride solid solutions and h BN were finally obtained, under an optimal processing condition of C/ M = 5.5 and synthesis temperature of 1400 °C. Parts of h BN were found to coat on high-entropy metal diborides ceramic (HEB) particles, corresponding formation mechanism for core-shell structured powders was investigated, together with the liquid precursor assisted boro/carbothermal reduction process. Starting from as-synthesized core-shell powders, (Ti 0.2 Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2 )B 2 –11 vol% h BN ceramics were densified at 1900 °C under 50 MPa without holding, with a high relative density of 97.3%.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Jian Yang,Haitao Zhang,Yanan Li,Wentao Xu,Youfu Zhou,Maochun Hong
Single-phase aluminum oxynitride (AlON) powders were synthesized by improved direct nitridation (DN). The improved DN method is to obtain high quality powder by adding high nitrogen pressure on the basis of ordinary DN method. Compared with the ordinary DN method, the average particle size of the synthesized powder is reduced by about 20 μm, the morphology tends to be spherical and the sintering activity is higher. Using different particle size α-Al 2 O 3 precursor, a modified DN method was adopted to synthesize spherical, good dispersibility and fine AlON powders. The influence of particle size of raw material α-Al 2 O 3 on sintering properties was investigated. Transparent AlON ceramics with dimensions of φ 103mm × 3 mm with in-line transmittance greater than 80%were fabricated by pressureless sintering from above AlON powders. In addition, the effects of different nitrogen pressure on the morphology, particle size distribution and average particle size of synthetic powder were investigated. On this basis, the differences between DN method and improved DN method on synthetic powder and the possible synthesis mechanism were proposed.
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
·
2022
·
IF 6.364
Baoqiang Li,Chang Liu,Zheng Fang,Zongxian Yang,Fei Ding,Liuyang Bai,Chun Wang,Fangli Yuan
Preparation of high-entropy carbides in bulk quantities and in powder form via simple methods at relatively low temperature is challenging. Here, we report the first synthesis of (ZrTiTaNbMo)C high-entropy carbide (HEC) powders via magnesiothermic reduction process. In this, a mixture of individual metallic oxides , graphite and magnesium is treated at a temperature of 1350 °C under Ar atmosphere. The (ZrTiTaNbMo)C powders are obtained after acid leaching, deionized water cleaning and drying process, and synthesized powders shows single-phase face-centered cubic ( fcc ) structure with the oxygen content of only 0.35 wt% and particle-size range of 5–60 µm. Such powders are in potential demand for additive manufacturing techniques, while high dense HEC bulk ceramic is fabricated by hot pressing sintering using ball-milled HEC powders in preliminary researches. The successful synthesis of (ZrTiTaNbMo)C powders may guide the way towards synthesis of many other high-entropy carbide powders via magnesiothermic reduction process.
研究领域:
材料科学
·
化学工程
·
制造工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Hongbin An,Ruoyu Chen,Saisai Li,Lingfeng Huang,Wenbao Jia,Qianfang Wu,Aiqing Mao
Powder synthesis is crucial for achieving the densification and facilitating widespread applications of high entropy carbide (HEC). Specifically, the production of fine particle-size powders is essential to enhance the densification of HECs. Consequently, this paper proposes the molten salt method for synthesizing HEC powders. The synthesis process successfully yielded (Ta Nb Ti V) C powders with a particle size of only 0.44 µm at 1400°C, exhibiting a uniform distribution of each element. Subsequent densification of (Ta Nb Ti V) C within the 1700–1900°C temperature range was carried out using spark plasma sintering. It was observed that as the densification temperature increased, the densification and mechanical properties of HEC significantly improved. This study presents innovative ideas for the preparation of HEC at lower temperatures.
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 ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Pengbo Zhao,Jinpeng Zhu,Mingliang Li,Gang Shao,Hailong Wang,Jilin He
High-entropy monoborides (HEMBs) are promising materials for use in cutting tools and wear-resistant coatings owing to their super hardness. Because of the scarcity of reports on powder synthesis , extensive application of HEMBs is limited. To address this problem, a molten-salt-assisted strategy for synthesising HEMB powders is proposed herein. High-entropy (V 0.2 Cr 0.2 Mo 0.2 W 0.2 Ni 0.2 )B powders with CrB-type orthogonal crystal structures were successfully synthesised at 1500 °C and examined by using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy . Subsequently, the mechanism of powder synthesis using molten salt and the advantages of powders prepared by employing molten salt for the densification and hardness enhancement of ceramics were comprehensively evaluated. The (V 0.2 Cr 0.2 Mo 0.2 W 0.2 Ni 0.2 )B powders were densified by applying spark plasma sintering to study the microstructural evolution of bulk ceramics with a super hardness of 42.19 ± 2.66 GPa. This work has expanded the family of superhard HEMBs and provides a strong support for the further application of HEMBs.
研究领域:
材料科学
·
陶瓷工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2016
·
IF 0
Qi Huang Deng,Zhi Hui Ding,Xiang Feng Shen,Shi Yu Du,Qing Huang
Zirconium diboride (ZrB2) nanoparticles were synthesized by polymer template method using zirconyl (ZrOCl2∙8H2O), boric acid (H3BO3), Chitosan and Mannitol (C6H14O6) with microwave sintering method. SEM and other analytic methods were used to study the phase composition and the microstructure of the nanoparticles.The influence of the ratio of zirconium to boron and carbon on the purity of ZrB2 powders, as well as the synthesis temperature and the holding time were studied. Pure ZrB2 at the molar ratio of C/Zr/B=10/5.2/1 can be obtained. The optimum parameter for microwave sintering is 1320 °C for 1h, which is about 300°C lower than conventional carbonization reduction to obtain ZrB2 powders. The synthesized powders have small particle sizes (50nm) with nearly spherical morphology.
研究领域:
材料科学
·
陶瓷
·
纳米材料
·
粉末合成
·
微波处理
✓ 已验证
DOI
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2013
·Vol. 96
·期 10
·3296-3303
·
IF 2.107
Kuo Jiang,Songbai Liu,Chuanchao Li
Powders composing of La 2 Zr 2 O 7 (LZ) and (Zr 0.8 Y 0.2 )O 1.9 (10YSZ) phases (volume ratio = 1:1) were synthesized by using a sol-spray pyrolysis method. The effects of annealing temperature on the grain size and lattice parameter of the LZ–10YSZ powders were investigated. XRD results showed that the grain size of LZ and 10YSZ phases gradually grew from 10 to 95 nm and from 5 to 65 nm as the annealing temperature elevated from 900°C to 1200°C. The relative decreasing percentage of grain size comparing to that of the single-phase LZ and 10YSZ powders were in the range 9%–36% and 37%–86%. The activation energy for grain growth of LZ and 10YSZ phases in the composite powders were 225 ± 12 and 382 ± 17 kJ/mol, which were 20% and 183% higher than that of the single-phase counterparts. Obvious lattice contraction and lattice expansion for LZ and 10YSZ phases were observed at temperatures below 1100°C, respectively. SEM results revealed that LZ and 10YSZ phases were homogeneously distributed in the sintered bulk. The TEM results suggested that the grain growth was affected by the interaction on nanometer length scales of grain boundaries between LZ and 10YSZ phases in the composite.
研究领域:
材料科学
·
陶瓷
·
纳米材料
·
粉末合成
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）