MATERIALS CHEMISTRY AND PHYSICS
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2018
·
IF 2.21
Zhuang Lu,Limeng Liu,Zhaoping Hou,Guihong Geng,Yujing Wang,Wenzhou Sun,Wanxiu Hai,Yuhong Chen
Tantalum carbide (TaC)-based composites containing 0.1–30 mol% lanthanum hexaboride (LaB 6 ) were prepared by hot pressing at 1900 °C for 30 min under 30 MPa pressure. Effects of LaB 6 content on densification, microstructure and mechanical properties of the consolidated TaC-LaB 6 composites were investigated. Sinter-forge was performed to test creep resistance of the TaC-LaB 6 composites at temperatures up to 1950 °C. Addition of LaB 6 increased densification of the TaC-LaB 6 composites and the compositions with ≥1 mol% LaB 6 almost reached full densities. LaB 6 reacted with TaC and the Ta 2 O 3 impurity to form minor phases of TaB 2 , B 2 O 3 and C. Average size of the TaC grains in the consolidated composites showed a decrease trend with increase in the LaB 6 content. The TaC-LaB 6 composites with 1–2 mol% LaB 6 addition had relatively good flexural strength , Vickers hardness and fracture toughness with a value of 530 MPa, 15.6 GPa and 5.29 MPa m 1/2 , respectively. Addition of LaB 6 modified interfacial bonding strength of the TaC grains, hence increase in creep resistance under sinter-forge up to 1950 °C.
研究领域:
材料科学
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机械工程
·
陶瓷
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DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2018
·
IF 13.325
Lu Zhuang,Liu Limeng
TaC ceramics were prepared by hot pressing at 1900 °C for 30 min under 30 MPa mechanical pressure. The effect of adding 1–10 mol% LaB 6 as a sintering aid on densification, the phase composition, microstructure and mechanical properties of the consolidated materials were investigated. TaC and LaB 6 reacted to form the solid solution. The grain average size decreased from 10 μm at 1 mol% LaB 6 addition to 4 μm at 10 mol% LaB 6 addition. The 5 mol% LaB 6 composition had good flexural strength of 312 MPa. Keywords Ultra high-temperature ceramic Tantalum carbide Hot pressing
研究领域:
材料科学
·
高温陶瓷研究
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产品关联
DOI
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Hui Wang,Dongdong He,Weidong Huang,Xinxi Chen,Yu Wang,Lihong Huang
In this study, LaB 6 -reinforced Ti6Al4V was successfully fabricated by the selective laser melting (SLM) process. TiB and La 2 O 3 with particle-like shapes formed uniformly after the in-situ reaction of LaB 6 and Ti6Al4V. The sizes of the TiB and La 2 O 3 particles were around 1 µm and 200 nm, respectively. Due to a combined strengthening effect of the micrometer-scale and nanoscale reinforcements, the mechanical properties of the LaB 6 /Ti6Al4V samples were enhanced significantly. However, the effect was highly related to the SLM parameters. As the laser power increased, the TiB changed from particle to needle-like shape and La 2 O 3 tended to aggregate and grow into a larger size. Besides, the martensite α-Ti also became coarser, which was disadvantageous to the mechanical performance. The desired inner structure can be obtained by adjusting the processing parameters of the SLM. The best mechanical performance of the SLM LaB 6 /Ti6Al4V samples was achieved at the laser power of 260 W and the scanning speed of 500 mm/s. The maximum tensile strength and Vickers hardness were 1337.1 MPa and 477.62 HV, respectively, which outperformed the other counterparts significantly. Thus, the results suggest that the in-situ reaction of LaB 6 and Ti6Al4V can improve the mechanical properties of the Ti6Al4V alloys effectively.
研究领域:
材料科学
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增材制造
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产品关联
DOI
高影响因子
Applied Materials Today
·
2019
·
IF 8.013
Wentao Dang,Bing Ma,Zhiguang Huan,Rongcai Lin,Xiaoya Wang,Tian Li,JinFu Wu,Nan Ma,Haibo Zhu,Jiang Chang,Chengtie Wu
Bone tumors may lead to osteoporosis. It is of great significance to fabricate functional scaffolds for treating bone tumor, osteoporosis and repairing bone defects. In this study, LaB 6 micro-nanoparticles/poly( d , l -lactide)-modified β-tricalcium phosphate scaffolds (TCP-PDLLA-LB) were successfully prepared. The LaB 6 surface chemistry-reinforced TCP-PDLLA-LB scaffolds were endowed with the following excellent properties: (1) the enhanced mechanical strength. The TCP-PDLLA-5LB scaffolds possessed higher compression resistant capacity than TCP scaffolds owing to the strong adhesive property of PDLLA that bound the LaB 6 micro-nanoparticles and scaffolds tightly; (2) the excellent photothermal performance. TCP-PDLLA-LB scaffolds presented distinct photothermal property because of localized surface plasmon resonance effect of LaB 6 micro-nanoparticles when exposed to the near-infrared (NIR) light (wavelength: 808 nm) and it was flexibly controllable through changing the quantity of LaB 6 micro-nanoparticles, power density of NIR light and environmental humidity; (3) the excellent biological properties in vitro . When culturing with saos-2 bone tumor cells, the TCP-PDLLA-5LB scaffolds effectively killed the saos-2 cells through adjusting power density of NIR light, irradiation duration time of NIR light and irradiation times of NIR light. Additionally, the TCP-PDLLA-5LB scaffolds were able to release bioactive ions which were beneficial to the in vitro osteogenesis of rabbit bone marrow stromal cells (rBMSCs) by supporting the attachment and proliferation of rBMSCs as well as promoting the expressions of osteogenic genes BMP2, RUNX2 and COL 1; and (4) the abilities of effectively ablating bone tumors and supporting bone tissue regeneration in vivo . The bone tumor tissues were significantly ablated and suppressed through hyperthermia due to the existence of LaB 6 micro-nanoparticles on the scaffolds. Simultaneously, TCP-PDLLA-5LB scaffolds implanted in bone defects effectively helped new bone formation regardless of NIR light irradiation. In conclusion, LaB 6 surface chemistry-reinforced scaffolds possess the dual functions of ablating bone tumor and repairing bone defects, which offers a promising therapy strategy for tumor/disease-related bone tissue engineering.
研究领域:
生物医学工程
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材料科学
·
肿瘤学
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DOI
高影响因子
Crystals
·
2024
·Vol. 14
·期 5
·452
·
IF 2.4
Sen Yang,Ruiqing Ba,Jingnan Hong,Jing Li,Jingdong Guo,Xinghui He,Hongwei Zhang,Naihe Yi,Weibing Ma
Pure lanthanum hexaboride (LaB6) ceramics were prepared using powders of different grain sizes. The ceramics could reach a relative density of 98.2% at high temperatures and pressures, but had a low flexural strength (136.9 MPa). LaB6ceramics were synthesized using ZrO2-Al2O3-TiO2(ZAT) as sintering additives. The ceramics demonstrate high density and excellent mechanical properties. The hot pressure sintering (HPS) method was utilized in the synthesis of the ceramics. Investigations were conducted on the effects of ZAT content, as well as the effects of the sintering temperature and pressure on the sintering behavior, microstructure, and mechanical and electrical properties of LaB6ceramics. LaB6ceramics fabricated with a ZAT addition of 6 wt.%, at a sintering temperature of 1700 °C, and under a pressure of 50 MPa, exhibited superior sintering and electrical properties, including a relative density of 97%, a conductivity of 7.2 MS/m, a flexural strength of 281.5 MPa, and a Vickers hardness of 21.2 GPa. The LaB6ceramics synthesized in this research exhibit promising potential as electron-emitting cathodes for field emission applications.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2019
·
IF 4.175
Yu Wang,Chao Fang,Xiang Li,Zhou Peng Li,Bin Hong Liu
LaB 6 is a unique plasmonic material , for which the localized surface plasmon resonance (LSPR) absorption band intrinsically lies in the near infrared (NIR) region. In this work, we synthesized spherical LaB 6 nanoparticles with a tunable size within 50–200 nm. The optical properties of these LaB 6 nanospheres were found to be sensitive to the thickness of surface oxide layer that was formed during the synthesis, purification and dispersion processes. In order to enhance the stability of LaB 6 nanoparticles in aqueous environment, LaB 6 @SiO 2 with a core-shell structure was successfully prepared. Both LaB 6 and LaB 6 @SiO 2 demonstrated low cytotoxity in biomedical tests when their concentrations were limited to 0.2 mg mL −1 . The in vitro photothermal therapy experiment showed that 4T1 cancer cells were eventually apoptotic after being exposed to a 980 nm laser for 5 min at a considerably low power density of 0.82 W cm −2 and a low dose of 0.1 mg mL −1 for LaB 6 @SiO 2 . The results suggest that these LaB 6 nanospheres are viable photothermal agents for biomedical applications.
研究领域:
材料科学
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生物医学工程
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纳米技术
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产品关联
DOI
高影响因子
Metals
·
2023
·Vol. 13
·期 2
·264
·
IF 2.9
Dongdong He,Hui Wang,Weidong Huang,Xinxi Chen,Guofu Lian,Yu Wang
In this study, TiB + La2O3/Ti-6Al-4V composites were successfully prepared by in situ reaction using selective laser melting technology. The effect of LaB6content on the fabrication quality, microstructure evolution and mechanical properties of the composite samples was investigated. The results show that the relative density of the sample gradually decreased from 98.56% to 96.57% as LaB6content increased from 0 wt% to 3 wt%. With increasing LaB6content, TiB precipitates gradually aggregated and grew from a discrete needle-like structure to a dendritic structure, before eventually developing a cell-like structure. The dislocations piled up around the TiB and La2O3reinforcements, which impeded the motion of the dislocations and led to the enhancement of the tensile strength of the samples. Different from the addition of a single reinforcement due to the combined strengthening effect of the micrometer-scale and nanoscale reinforcements, the strength of the samples was increased significantly. The Ti-6Al-4V sample with 3 wt% LaB6addition showed the most significant strengthening effect. Compared to the pure Ti-6Al-4V sample, the 3 wt% LaB6addition sample gained a 35.71% increase in hardness and a 14.5% increase in tensile strength. Additionally, wear volume was reduced by 47.5%. The results revealed that the addition of LaB6was a potential way to improve the mechanical performance of the titanium alloys in the additive manufacturing process.
研究领域:
材料科学
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机械工程
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产品关联
DOI
高影响因子
SUPERLATTICES AND MICROSTRUCTURES
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2014
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IF 1.979
Hongbo Tang,Yuchang Su,Jiang Tan,Te Hu,Jinyu Gong,Lihua Xiao
In this work, LaB 6 @SiO 2 nanoparticle with a core–shell structure was synthesized and doped into Poly(vinyl butyral) (PVB) matrix to prepare LaB 6 @SiO 2 –PVB nanocomposite film. Field emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and ultraviolet–visible–near infrared spectroscopy (UV–vis–NIR) were employed to characterize these materials. The TGA and UV–vis–NIR results show that LaB 6 @SiO 2 nanoparticle contributed to improving thermal stability of PVB in LaB 6 @SiO 2 –PVB film, with an increase of almost 60 °C from the initial decomposition temperature in the case of the neat PVB film; additionally, maximum transmittance in visible region red-shifted from 605 to 645 nm and maximum absorption in near-infrared region moved slightly from 1466 to 1472 nm. In short, the LaB 6 @SiO 2 NPs could be a potential candidate for transparent and heat insulation materials.
研究领域:
材料科学
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纳米技术
·
光学工程
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产品关联
DOI
高影响因子
MATERIALS & DESIGN
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2018
·
IF 4.525
Changcong Wang,Kezhi Li,Qinchuan He,Caixia Huo,Xiaohong Shi
A combined heterogeneous coating composed of LaB 6 -MoSi 2 -TiB 2 (LMT) outer layer and SiC inner layer was fabricated on carbon/carbon (C/C) composites using a two-step method. Among them, the SiC transition layer was in-situ synthesized by pack cementation (PC) in the first step, where-after supersonic atmospheric plasma spraying (SAPS) was devoted to deposit the LMT outer layer. The combined LMT/SiC coating revealed a representative microstructure with limited porosity and adhered well with the C/C substrate. Isothermal oxidation test demonstrated that the combined LMT/SiC coating displayed a better oxidation resistance than the MoSi 2 /SiC coating without the addition of rare-earth La and alloying Ti elements at 1773 K. Oxyacetylene torch experiment showed that the combined LMT/SiC coating could efficiently protect the C/C composites withstand short-term ablation for 60 s. The good oxidation and ablation resistant properties of the combined LMT/SiC coating were ascribed to the integrity of LMT/SiC coating and superior protection of a glassy La-Si-O-B-Ti compound scale formation during oxidation and ablation.
研究领域:
材料科学
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航空航天工程
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产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2016
·Vol. 18
·期 28
·19165-19172
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IF 4.449
Lihong Bao,Xiaoping Qi,Tana,Lumen Chao,O. Tegus
Multiple nanocrystalline rare-earth hexaborides La1−xBaxB6 have been synthesized via a single step solid-state reaction. The Ba doping effects on crystal structure, grain morphology, magnetic and optical absorption properties were investigated using XRD, FESEM, HRTEM, SQUID magnetometry and optical measurements. The results show that all the Ba-doped hexaborides crystallize in the CsCl-type single phase, indicating the Ba atoms occupied the lattice sites of LaB6. The optical absorption results indicate that the absorption valleys of LaB6 are red-shifted from 622 nm to 780 nm when the Ba doping content increases to x = 0.8. The first-principle calculation results reveal that Ba doping reduces the total kinetic energy of the electrons of LaB6, which lead to the absorption valleys moving toward a higher wavelength. Meanwhile, the band gap of BaB6 obtained from optical absorption is in good agreement with the theoretical calculation results. The magnetic measurements results showed that Ba doping lead to room-temperature ferromagnetism of LaB6 due to the different ionic radii of La3+ and Ba2+ causing intrinsic crystal defects, which is directly observed experimentally by HRTEM. This is the first time that we have found the tunable optical and ferromagnetic behavior of Ba doped nanocrystalline LaB6. Thus, nanocrystalline La1−xBaxB6, as multi-functional materials, should open up a new route to extend the optical and magnetic applications of LaB6 nanopowder.
研究领域:
材料科学
·
凝聚态物理
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纳米材料
·
功能材料
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磁学
·
光学材料
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2017
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IF 3.582
Yishan Li,Nianbing Zhong,Qiang Liao,Qian Fu,Yun Huang,Xun Zhu,Qiaoliang Li
A novel photothermal biomaterial , designated GeO 2 -SiO 2 -Chitosan-Medium-LaB 6 (GSCML), was prepared to improve photosynthetic bacteria (PSB) biofilm development and hydrogen production performance. This biomaterial employed spectral beam splitting technology to increase the overall utilization of the incident light spectrum, which LaB 6 nanoparticles (NPs) mainly absorb light at approximately 380–510 and 660–780 nm and convert it into heat energy ; the transmit light is around 590 nm for PSB growth. The temperature increased, and the luminous intensity of the light transmitted through the prepared biomaterial are controlled by adjusting the LaB 6 NPs' content. The average biofilm growth rate and hydrogen production rate of the biofilm on the created biomaterial were 0.05 mg/cm 2 /day and 2.92 mmol/h/m 2 , which were 3.4 and 4.1 times higher than those of the glass slide, respectively. The properties of the GSCML biomaterial provide advantages for applications in immobilized cell technologies and photobioreactors.
研究领域:
生物技术
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新能源研究
·
材料科学
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产品关联
DOI
高影响因子
POWDER TECHNOLOGY
·
2023
·
IF 5.2
Shunyuan Xiao,Shaofu Li,Xuemeng Gan,Yafeng Yang
LaB 6 has been demonstrated as an effective O-scavenger for powder metallurgy (PM) Ti alloys to mitigate the detrimental effect of solid-solution O on the ductility. However, conventional mechanical mixing methods lead to the agglomeration and non-uniform distribution of LaB 6 , resulting in partial deactivation and reduced O-scavenging efficiency during sintering. Aiming at this issue, we propose an electrostatic self-assembly strategy that combined surface functional modification of LaB 6 with solid-liquid fluidized bed powder coating treatment to synthesize a novel LaB 6 -coated Ti composite powder. Compared to traditional LaB 6 additives in powder mixtures, the LaB 6 -coating particles exhibited excellent O-scavenging efficiency and higher utilization rate. Even at a low coating-content of 0.3 wt% LaB 6 , the tensile strength and elongation of the as-sintered Ti samples increased from 461 ± 26 to 579 ± 13 MPa and 5.6 ± 1.4% to 14.2 ± 0.3%, respectively. The achieved improvement rate (∼95%) in tensile elongation was significantly superior to the previously reported data of the rare-earth O-scavengers.
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DOI
高影响因子
危险品化学品经营许可证（带存储）