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Development of Lead Free Crystal Glass Using Silica Sand from Gong Belibis Setiu, Terengganu 被引量:1
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作者 Mohamad Haniza Mahrnud Mohd Idham Mustaffar Abdul Hadi Abdul Rahman 《Journal of Geological Resource and Engineering》 2016年第3期137-141,共5页
The silica sand deposit located at km 55 Jalan Pantai Kuala Terengganu-Kuala Besut in the District of Setiu, North Terengganu consists of loose sand of fine to coarse grain size which is developed over the raised beac... The silica sand deposit located at km 55 Jalan Pantai Kuala Terengganu-Kuala Besut in the District of Setiu, North Terengganu consists of loose sand of fine to coarse grain size which is developed over the raised beaches of marine origin. The underlying bedrock is believed to be either metasediment of Late Paleozoic age or intrusive granitic rocks. The average content of SiO2 is 99.3% while for the Fe2O3, Al2O3 and TiO2, their average content are 0.1%, 0.3% and 0.2% respectively. The screen analyses show that more than 90 percent of the silica sand is within 150 to 1,180 micron size range. The total area underlain by potential silica sand is about 1.9 million sq. metres with total measured reserve about 2.6 million tonnes. According to Malaysian Standard, MS 701:1981 and British Standard BS 2975:1988, silica sand for making crystal glass should meet the grade B specification in which the purity of silica sand is not less than 99.5% with only a small amount of iron oxide (0.015%), alumina (0.05%), chromium oxide (maximum 2 ppm) and other mineral oxides. In the production of crystal glass, a front loading furnace was used and maximum melting temperature was 1400 ℃. After melting process, physical evaluation on the crystal glass products were performed pertaining to complete accomplishment of melting such as existing of bubbles inside crystal glasses. In order to ensure that crystal glass quality meets the international standard, specification for crystal glass published by British standard BS 3828:1973 was taken as a guideline. Some of the parameters are density, surface hardness and refractive index. In general, silica sand from Gong Belibis, Setiu Terengganu is suitable as a raw material for making crystal glass product. 展开更多
关键词 Silica sand attrition scrubbing crystal glass and refractive index.
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The Effect of Sm_2O_3 on the Chemical Stability of Borosilicate Glass and Glass Ceramics 被引量:3
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作者 张永强 WANG Mitang +2 位作者 LI Mei WANG Ming 刘全生 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第4期692-697,共6页
Sm2O3 containing zinc-borosilicate glass and glass ceramics were prepared by melt quenching method, and the effect of Sm2O3 and micro-crystallization on the chemical stability of borosilicate glass was explored. DTA a... Sm2O3 containing zinc-borosilicate glass and glass ceramics were prepared by melt quenching method, and the effect of Sm2O3 and micro-crystallization on the chemical stability of borosilicate glass was explored. DTA analysis showed that the endothermic peak and exothermic peak of basic glass changed from 635 ℃ and 834 ℃ to 630 ℃ and 828 ℃ respectively as a result of the doping of Sm2O3. XRD analysis showed the promoting effect of Sm2O3 on crystallization ability of this glass. The cumulative mass loss of base glass, Sm2O3 containing glass, glass ceramic and Sm2O3 containing glass ceramic was 0.289, 0.253, 0.329, 0.269 mg/mm2 respectively after 26 days corrosion in alkali solution, and 1.293, 1.290, 0.999, 1.040 mg/mm2 respectively in acidic erosion medium. Micro-crystallization decreased and improved the alkali and acid resistance of borosilicate glass respectively, the addition of Sm2O3 increased the alkali resistance of base glass and glass ceramics, and the slight effect of Sm2O3 on the acid resistance of borosilicate glass was also observed. 展开更多
关键词 borosilicate glass chemical durability crystallization Sm2O3
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PREPARATION AND PROPERTIES OF CRYSTAL GLASSES WITHOUT LEAD CONTENT
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作者 王为 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1999年第3期53-58,共6页
BaO is the most common consideration in the preparation of newcrystal glass for getting rid of lead content in the glass andceramic wares to protect hu- man health and environment. But forkeeping the glass products... BaO is the most common consideration in the preparation of newcrystal glass for getting rid of lead content in the glass andceramic wares to protect hu- man health and environment. But forkeeping the glass products' properties to meet the requirements ofthe tradi- tional crystal glass, B_2O_3, Al_2O_3, TiO_2, SrO and ZnOetc (at a special ratio) had been researched with BaO to con- stitutea mixture to replace the lead content in the glass compositions. 展开更多
关键词 crystal glass lead poison glass composition and preparation
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Crystallization Mechanism of Na_2O-CaO-Al_2O_3-SiO_2-F Glass Containing Cr_2O_3
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作者 Lidong Teng Fuming Wang Wenchao Li(Department of inorganic Materials, Shandong Institute of Light Industry, Jinan 250100, China)(Applied Science School, University of Science and Technology Beijing, Beijing 100083, China) 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 1999年第3期214-218,共5页
The effect of Cr2O3 on the nucleation and crystallization of Na2O-CaO-Al2O3-SiO2-F- glass has been investigated by means of ESR(Electron Spin Resonance), SEM(Scanning Electron Microscope), EDS(Energy Dispersive Specro... The effect of Cr2O3 on the nucleation and crystallization of Na2O-CaO-Al2O3-SiO2-F- glass has been investigated by means of ESR(Electron Spin Resonance), SEM(Scanning Electron Microscope), EDS(Energy Dispersive Specrometer) and so on. Computer pattern recognition is applied to optimize the heat-treatment schedules. The experimental results show that the base glass containing more than 1 .5 % (mass fraction) Cr2O3 can be nucleated internally and converted to spheroidal crystal glass materials. The spheroidal crystal consisted of fibrous wollastonite crystals radiating from a center. The residual glass phase filled in the interstices between the fibers and between the spherulites. During heat treatment process, the valence states ofchromium changed from Cr6- to Cr3-, and the Cr-spinel solidsolution [CaCr2O4] precipitated followed this valence change. At the primary stage of crystallization, the Cr-spinel could act as a nucleating center on which the principal or}stalline phase β-CaSiO3 grew epitaxially. 展开更多
关键词 crystallized glass Na_2O-CaO-Al_2O_3-SiO_2 Cr_2O_3 pattern recognition
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PHASE SEPARATION AND CRYSTALLIZATION OF CHALCOGENIDE GLASSES
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作者 程继健 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1993年第4期1-12,共12页
In this paper the experimental results associated until the phase separation and nucleation and crystallization of chalcogenidc glasses are described. Experi-ments demonstrate that the phas separation may be affected ... In this paper the experimental results associated until the phase separation and nucleation and crystallization of chalcogenidc glasses are described. Experi-ments demonstrate that the phas separation may be affected by small amount of additives. It has been found that some chalcogenide glasses could be converted into glass-ceramics without phase separation. The different mechanisms of nucleated crystallization of chalcogenide glasses are discussed and propossed. 展开更多
关键词 PHASE SEPARATION AND CRYSTALLIZATION OF CHALCOGENIDE glassES AS HEAT
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Micromechanism of Crystallization in Multicomponent Metallic Glass
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作者 Jianmin LP Mingxiu QUAN and Zbuangqi HU (National Key Lab. of RSA, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, China)(To whom correspondence should be addressed) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1996年第6期401-408,共8页
A micromechanism in an atomic level of crystallization of transition metal-metalloid TM(80)M(20) metallic glass is thermodynamically proposed by taking Bernal polyhedra as the starting structure of metallic glass. It ... A micromechanism in an atomic level of crystallization of transition metal-metalloid TM(80)M(20) metallic glass is thermodynamically proposed by taking Bernal polyhedra as the starting structure of metallic glass. It is composed of two competitively processes: (i) densification process of atom cluster leads to the formation of the precursor in amorphous matrix; (ii) the growth of atom cluster leads to the decreasing packing density. The preferential precipitation sequence of metastable phase is bcc, bet, cpc (close-packed crystal, hcp or fee structure). A metastable phase decomposition (Fe,Mo)(23)B-6 (fcc)-Fe2B highly strained bet phase was observed during crystallization of (Fe(0.99)M(0.01))(78)Si9B13 metallic glass, which is related to the occurrence of nanocrystalline. 展开更多
关键词 Si MO REV Micromechanism of Crystallization in Multicomponent Metallic glass NATURE
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Preparation,Structures,Thermal Properties and Sintering Behaviors of B_2O_3-SiO_2-ZnO-BaO-Al_2O_3 Glass 被引量:3
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作者 丁阚俊杰 chen nan +1 位作者 杜国平 zhang aisheng 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2016年第6期1323-1328,共6页
B_2O_3-SiO_2-ZnO-BaO-Al_2O_3 glass with different Al_2O_3 contents(1mol%, 3mol%, 5mol%, and 7mol%) was prepared, and it was intended to be used as lead-free and low-melting glass sealants for solid oxide fuel cells.... B_2O_3-SiO_2-ZnO-BaO-Al_2O_3 glass with different Al_2O_3 contents(1mol%, 3mol%, 5mol%, and 7mol%) was prepared, and it was intended to be used as lead-free and low-melting glass sealants for solid oxide fuel cells. The effects of Al_2O_3 content on the structures, thermal properties, and sintering behaviors of the B_2O_3-SiO_2-ZnO-BaO-Al_2O_3 glass were investigated in detail. The Al_2O_3 content largely influenced the structures and thermal properties of the glass. When the Al_2O_3 content 5mol%, the transition temperature of the glass decreased with the Al_2O_3 content, while the crystallization temperature increased with the Al_2O_3 content. However, higher Al_2O_3 content degraded the stability of the glass. The B_2O_3-SiO_2-ZnO-BaO-Al_2O_3 glass with 5 mol% Al_2O_3 content exhibits the optimal sintering densification characteristics and can be used as glass sealants for solid oxide fuel cells. 展开更多
关键词 B2O3-SiO2-ZnO-BaO-Al2O3 glass thermal properties sintering behavior densification crystallization
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Ultra-broadband modulation instability gain characteristics in As_2S_3 and As_2Se_3 chalcogenide glass photonic crystal fiber
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作者 王河林 吴彬 王肖隆 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第6期259-263,共5页
Based on the designed As2Se3 and As2S3 chalcogenide glass photonic crystal fiber(PCF) and the scalar nonlinear Schrdinger equation,the effects of pump power and wavelength on modulation instability(MI) gain are co... Based on the designed As2Se3 and As2S3 chalcogenide glass photonic crystal fiber(PCF) and the scalar nonlinear Schrdinger equation,the effects of pump power and wavelength on modulation instability(MI) gain are comprehensively studied in the abnormal dispersion regime of chalcogenide glass PCF.Owing to high Raman effect and high nonlinearity,ultra-broadband MI gain is obtained in chalcogenide glass PCF.By choosing the appropriate pump parameter,the MI gain bandwidth reaches 2738 nm for the As2Se3 glass PCF in the abnormal-dispersion region,while it is 1961 nm for the As2S3 glass PCF. 展开更多
关键词 ultra-broadband modulation instability Raman effect high nonlinearity chalcogenide glass photonic crystal fiber
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Crystal Growth and Nucleation in Glasses in the Lithium Silicate System 被引量:1
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作者 Galina A. Sycheva 《Journal of Crystallization Process and Technology》 2016年第4期29-55,共27页
The crystal growth and nucleation in glasses in the lithium silicate system have been investigated. Phase separation in ultimately homogenized glasses of the lithium silicate system xLi<sub>2</sub>O·(... The crystal growth and nucleation in glasses in the lithium silicate system have been investigated. Phase separation in ultimately homogenized glasses of the lithium silicate system xLi<sub>2</sub>O·(100 ﹣ x)SiO<sub>2</sub> (where x = 23.4, 26.0, 29.1, and 33.5 mol% Li<sub>2</sub>O) has been studied. The glasses of these compositions have been homogenized using the previously established special temperature-time conditions, which make it possible to provide a maximum dehydration and removal of bubbles from the glass melt. The parameters of nucleation and growth of phase separated in homogeneities and homogeneous crystal nucleation have been determined. The absolute values of the stationary nucleation rates I<sub>st</sub> of lithium disilicate crystals in the 23.4Li<sub>2</sub>O·76.6SiO<sub>2</sub>, 26Li<sub>2</sub>O·74SiO<sub>2</sub> and 29.1Li<sub>2</sub>O·70.9SiO<sub>2</sub> glasses with the compositions lying in the metastable phase separation region have been compared with the corresponding rates I<sub>st</sub> for the glass of the stoichiometric lithium disilicate composition 33.51Li<sub>2</sub>O·66.5SiO<sub>2</sub>. It has been found that the crystal growth rate has a tendency toward a monotonic increase with an increase in the temperature, whereas the dependences of the crystal growth rate on the time of low temperature heat treatment exhibit an oscillatory behavior with a monotonic decrease in the absolute value of oscillations. The character of crystallization in glasses with the compositions lying in the phase separation region of the Li<sub>2</sub>O-SiO<sub>2</sub> system is compared with that in the glass of the stoichiometric lithium disilicate composition. The conclusion has been made that the phase separation weakly affects the nucleation parameters of the lithium disilicate and has a strong effect on the crystal growth. 展开更多
关键词 Phase Separation Crystal Nucleation Stationary Nucleation Crystal Growth in Phase Separated and Non-Phase Separated glasses
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Ce^(3+):Lu_(3)Al_(5)O_(12)–Al_(2)O_(3) optical nanoceramic scintillators elaborated via a low-temperature glass crystallization route 被引量:3
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作者 Jie FU Shaowei FENG +5 位作者 Yongchang GUO Ying ZHANG Cécile GENEVOIS Emmanuel VERON Mathieu ALLIX Jianqiang LI 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2023年第2期268-278,共11页
Transparent Ce:lutetium aluminum garnet(Ce:Lu_(3)A_(l5)O_(12),Ce:LuAG)ceramics have been regarded as potential scintillator materials due to their relatively high density and atomic number(Zeff).However,the current Ce... Transparent Ce:lutetium aluminum garnet(Ce:Lu_(3)A_(l5)O_(12),Ce:LuAG)ceramics have been regarded as potential scintillator materials due to their relatively high density and atomic number(Zeff).However,the current Ce:LuAG ceramics exhibit a light yield much lower than the expected theoretical value due to the inevitable presence of LuAl antisite defects at high sintering temperatures.This work demonstrates a low-temperature(1100℃)synthetic strategy for elaborating transparent LuAG–Al_(2)O_(3) nanoceramics through the crystallization of 72 mol%Al_(2)O_(3)–28 mol%Lu_(2)O_(3)(ALu28)bulk glass.The biphasic nanostructure composed of LuAG and Al_(2)O_(3) nanocrystals makes up the whole ceramic materials.Most of Al_(2)O_(3) is distributed among LuAG grains,and the rest is present inside the LuAG grains.Fully dense biphasic LuAG–Al_(2)O_(3) nanoceramics are highly transparent from the visible region to mid-infrared(MIR)region,and particularly the transmittance reaches 82%at 780 nm.Moreover,LuAl antisite defect-related centers are completely undetectable in X-ray excited luminescence(XEL)spectra of Ce:LuAG–Al_(2)O_(3) nanoceramics with 0.3–1.0 at%Ce.The light yield of 0.3 at%Ce:LuAG–Al_(2)O_(3) nanoceramics is estimated to be 20,000 ph/MeV with short 1μs shaping time,which is far superior to that of commercial Bi_(4)Ge_(3)O_(12)(BGO)single crystals.These results show that a low-temperature glass crystallization route provides an alternative approach for eliminating the antisite defects in LuAG-based ceramics,and is promising to produce garnet-based ceramic materials with excellent properties,thereby meeting the demands of advanced scintillation applications. 展开更多
关键词 glass crystallization garnet antisite defects Lu_(3)Al_(5)O_(12)-Al_(2)O_(3)(LuAG-Al_(2)O_(3))transparent ceramics NANOCERAMICS scintillation
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Pressureless crystallization of glass toward scintillating composite with high crystallinity for radiation detection 被引量:2
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作者 Junzhou Tang Shichao Lv +9 位作者 Ziyu Lin Guanxin Du Manyun Tang Xu Feng Junpeng Guo Xiang Li Junfeng Chen Lei Wei Jianrong Qiu Shifeng Zhou 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第34期173-180,共8页
The construction of scintillating ceramics is of great technological importance for various fundamental applications, including medical diagnostic, security inspection, resource exploration and particle physics. The c... The construction of scintillating ceramics is of great technological importance for various fundamental applications, including medical diagnostic, security inspection, resource exploration and particle physics. The chief challenge is the facile and scalable synthesis of scintillating ceramics with the desirable combination of pore-free, reliable mechanical properties and excellent scintillating performance. Here we present a pressureless glass crystallization strategy for the construction of scintillating composite with high crystallinity. The fabricated scintillating composites are featured by small optical turbidity, excellent mechanical properties, and efficient scintillating luminescence with the scintillating light yield of 15,000 pH/MeV and about 2.46 times higher than that of the commercial BGO single crystal. Moreover, the scintillating composite derived radiation detector device is successfully elaborated. The practical application for monitoring gamma ray is demonstrated and the precision of the device is less than that of the tolerable deviation of 30%. Our results suggest an innovative approach for expanding the category of scintillating material candidates, pointing to practical application in the field of radiation detection. 展开更多
关键词 glass glass crystallization Optical materials COMPOSITE LUMINESCENCE
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Coherent supercontinuum generation in soft glass photonic crystal fibers 被引量:3
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作者 MARIUSZ KLIMCZAK BARTLOMIEJ SIWICKI +1 位作者 ALEXANDER HEIDT RYSZARD BUCZYNSKI 《Photonics Research》 SCIE EI 2017年第6期229-246,共18页
An overview of the progress on pulse-preserving, coherent, nonlinear fiber-based supercontinuum generation is presented. The context encompasses various wavelength ranges and pump sources, starting with silica photoni... An overview of the progress on pulse-preserving, coherent, nonlinear fiber-based supercontinuum generation is presented. The context encompasses various wavelength ranges and pump sources, starting with silica photonic crystal fibers pumped with 1.0 μm femtosecond lasers up to chalcogenide step-index and microstructured fibers pumped from optical parametric amplifiers tuned to mid-infrared wavelengths. In particular, silica and silicatebased all-normal dispersion(ANDi) photonic crystal fibers have been demonstrated for pumping with femtosecond lasers operating at 1.56 μm with the recorded spectra covering 0.9–2.3 μm. This matches amplification bands of robust fiber amplifiers and femtosecond lasers. The review therefore focuses specifically on this wavelength range, discussing glass and nonlinear fiber designs, experimental results on supercontinuum generation up to the fundamental limit of oxide glass fiber transmission around 2.8 μm, and various limitations of supercontinuum bandwidth and coherence. Specifically, the role of nonlinear response against the role of dispersion profile shape is analyzed for two different soft glass ANDi fibers pumped at more than 2.0 μm. A spatio-temporal interaction of the fundamental fiber mode with modes propagating in the photonic lattice of the discussed ANDi fibers is shown to have positive effects on the coherence of the supercontinuum at pump pulse durations of 400 fs. Finally, the design and development of graded-index, nanostructured core optical fibers are discussed.In such structures the arbitrary shaping of the core refractive index profile could significantly improve the engineering flexibility of dispersion and effective mode area characteristics, and would be an interesting platform to further study the intermodal interaction mechanisms and their impact on supercontinuum coherence for subpicosecond laser pumped setups. 展开更多
关键词 PCF Coherent supercontinuum generation in soft glass photonic crystal fibers SC
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Crystallization of a Ti-based Bulk Metallic Glass Induced by Electropulsing Treatment 被引量:3
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作者 Yong-jiang HUANG Xiang CHENG +3 位作者 Hong-bo FAN Shi-song GUAN Zhi-liang NING Jian-fei SUN 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2016年第1期69-73,共5页
The effect of electropulsing treatment(EPT)on the microstructure of a Ti-based bulk metallic glass(BMG)has been studied.The maximum current density applied during EPT can exert a crucial role on tuning the microst... The effect of electropulsing treatment(EPT)on the microstructure of a Ti-based bulk metallic glass(BMG)has been studied.The maximum current density applied during EPT can exert a crucial role on tuning the microstructure of the BMG.When the maximum current density is no more than 2 720A/mm^2,the samples retains amorphous nature,whereas,beyond that,crystalline phases precipitate from the glassy matrix.During EPT,the maximum temperature within the samples EPTed at the maximum current densities larger than 2 720A/mm^2 is higher than the crystallization temperature of the BMG,leading to the crystallization event. 展开更多
关键词 bulk metallic glass electropulsing transmission electron microscopy crystallization microstructure
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Migration of Paramagnetic Ions in Glass Melts Under Influence of a Magnetic Field
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作者 SCHADEWALD Uwe HALBEDEL Bernd 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2012年第S2期1068-1071,共4页
Magnetic forces are widely used to influence the properties of materials.The main focus of recent investigations concerning oxide melts mainly was on the use of Lorentz forces either to mix glass melts to avoid an imp... Magnetic forces are widely used to influence the properties of materials.The main focus of recent investigations concerning oxide melts mainly was on the use of Lorentz forces either to mix glass melts to avoid an improved inhomogeneity or to measure the flow of these melts.In the last years also the use of magnetic gradient forces has become an object of research mainly in electrochemistry.On the basis of preliminary investigations the influence of these forces on paramagnetic ions such as Fe;in oxide melts is investigated to examine the potential of magnetic gradient forces as a tool to create defined gradient materials. 展开更多
关键词 magnetic gradient force glass crystallization paramagnetic ions
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Direct TEM Observation of Phase Separation and Crystallization in Cu_(45)Zr_(45)Ag_(10)Metallic Glass
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作者 Hui Wang Shang-Gang Xiao +5 位作者 Tao Zhang Qiang Xu Zeng-Qian Liu Meng-Yue Wu Frans Tichelaar Henny Zandbergen 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2016年第6期538-545,共8页
The structural evolution of Cu_(45)Zr_(45)Ag_(10) metallic glass was investigated by in situ transmission electron microscopy heating experiments. The relationship between phase separation and crystallization wa... The structural evolution of Cu_(45)Zr_(45)Ag_(10) metallic glass was investigated by in situ transmission electron microscopy heating experiments. The relationship between phase separation and crystallization was elucidated. Nucleation and growth-controlled nanoscale phase separation at early stage were seen to impede nanocrystallization, while a coarser phase separation via aggregation of Ag-rich nanospheres was found to promote the precipitation of Cu-rich nanocrystals.Coupling of composition and dynamics heterogeneities was supposed to play a key role during phase separation preceding crystallization. 展开更多
关键词 Bulk metallic glass Phase separation In situ TEM heating Crystallization glass forming ability
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An experimental study on grinding of Zr-based bulk metallic glass
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作者 Mustafa Bakkal Erdinc Serbest +3 位作者 Ilker Karipcin Ali T. Kuzu Umut Karaguzel Bora Derin 《Advances in Manufacturing》 SCIE CAS CSCD 2015年第4期282-291,共10页
There are limited studies in the literature about machinability of bulk metallic glass (BMG). As a novel and promising structural material, BMG material machining characteristics need to be verified before its utili... There are limited studies in the literature about machinability of bulk metallic glass (BMG). As a novel and promising structural material, BMG material machining characteristics need to be verified before its utilization. In this paper, the effects of cutting speed, feed rate, depth of cut, abrasive particle size/type on the BMG grinding in dry conditions were experimentally investigated. The experimental evaluations were carried out using cubic boron nitride (CBN) and A1203 cup wheel grinding tools. The parameters were evaluated along with the results of cutting force, temperature and surface roughness measurements, X-ray, scanning electron microscope (SEM) and surface roughness analyse. The results demonstrated that the grinding forces reduced with the increasing cutting speed as specific grinding energy increased. The effect of feed rate was opposite to the cutting speed effect, and increasing feed rate caused higher grinding forces and substantially lower specific energy. Some voids like cracks parallel to the grinding direction were observed at the edge of the grinding tracks. The present investigations on ground surface and grinding chips morphologies showed that material removal and surface formation of the BMG were mainly due to the ductile chip formation and ploughing as well as brittle fracture of some particles from the edge of the tracks. The roughness values obtained with the CBN wheels were found to be acceptable for the grinding operation of the structural materials and were in the rangeof 0.34-0.58 lam. This study also demonstrates that con- ventional A1203 wheel is not suitable for grinding of the BMG in dry conditions. 展开更多
关键词 Bulk metallic glass (BMG) - Grinding - Crystallization X-ray analysis . Surface morphology
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Biphasic (Lu,Gd)_(3)Al_(5)O_(12)-based transparent nanoceramic color converters for high-power white LED/LD lighting 被引量:1
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作者 Jie Fu Ying Zhang +10 位作者 Shaowei Feng Mathieu Allix Cécile Genevois Emmanuel Veron Zhibiao Ma Wenlong Xu Linghan Bai Ruyu Fan Yafeng Yang Hui Wang Jianqiang Li 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2023年第12期2331-2344,共14页
Ce doped Lu_(3)Al_(5)O_(12)(Ce:LuAG)transparent ceramics are considered as promising color converters for solid-state lighting because of their excellent luminous efficiency,high thermal quenching temperature,and good... Ce doped Lu_(3)Al_(5)O_(12)(Ce:LuAG)transparent ceramics are considered as promising color converters for solid-state lighting because of their excellent luminous efficiency,high thermal quenching temperature,and good thermal stability.However,Ce:LuAG ceramics mainly emit green light.The shortage of red light as well as the expensive price of Lu compounds are hindering their application for white lighting.In this work,transparent(Lu,Gd)_(3)Al_(5)O_(12)–Al_(2)O_(3)(LuGAG–Al_(2)O_(3))nanoceramics with different replacing contents of Gd^(3+)(10%–50%)were successfully elaborated via a glass-crystallization method.The obtained ceramics with full nanoscale grains are composed of the main LuGAG crystalline phase and secondary Al_(2)O_(3) phase,exhibiting eminent transparency of 81.0%@780 nm.After doping by Ce^(3+),the Ce:LuGAG–Al_(2)O_(3) nanoceramics show a significant red shift(510 nm→550 nm)and make up for the deficiency of red light component in the emission spectrum.The Ce:LuAG–Al_(2)O_(3) nanoceramics with 20%Gd^(3+)show high internal quantum efficiency(81.5%in internal quantum efficiency(IQE),96.7%of Ce:LuAG–Al_(2)O_(3) nanoceramics)and good thermal stability(only 9%loss in IQE at 150℃).When combined with blue LED chips(10 W),0.3%Ce:LuGAG–Al_(2)O_(3) nanoceramics with 20%Gd^(3+)successfully realize the high-quality warm white LED lighting with a color coordinate of(0.3566,0.435),a color temperature of 4347 K,CRI of 67.7,and a luminous efficiency of 175.8 lm·W^(−1).When the transparent 0.3%Ce:LuGAG–Al_(2)O_(3) nanoceramics are excited by blue laser(5 W·mm^(−2)),the emission peak position redshifts from 517 to 570 nm,the emitted light exhibits a continuous change from green light to yellow light,and then to orange-yellow light,and the maximum luminous efficiency is up to 234.49 lm·W^(−1)(20%Gd^(3+)).Taking into account the high quantum efficiency,good thermal stability,and excellent and adjustable luminous properties,the transparent Ce:LuGAG–Al_(2)O_(3) nanoceramics with different Gd^(3+)substitution contents in this paper are believed to be promising candidates for high-power white LED/LD lighting. 展开更多
关键词 glass crystallization (Lu Gd)_(3)Al_(5)O_(12)(LuGAG)-Al_(2)O_(3)nanoceramics high-power WLEDs/LDs white lighting
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