International Journal of Applied Ceramic Technology
·
2022
·Vol. 20
·期 2
·906-916
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IF 2.328
Lingyu Jia,Peigang He,Dechang Jia,Jingkun Yuan,Delong Cai,Daxin Li,Xiaoming Duan,Zhihua Yang,Yu Zhou
Sr-containing ceramic products produced from geopolymer, (Na, Sr)-GP, have been reported as excellent candidate materials for the immobilization of radionuclide 90Sr, despite sintering temperature at 1200°C. In this work, the product possessing the best immobilization performance (leaching rate of 1.29% for Sr 2+ ) can be produced at 1000°C in the method of liquid-phase sintering via the addition of fluxing agent B 2 O 3 at 2.0 wt% in the geopolymer precursor. The mechanical properties of the geopolymer precursor (Na, Sr)-GP were also enhanced via the promotion role of B 2 O 3 to geopolymerization. It was revealed that the overall anti-leaching ability of the Sr-containing ceramic product not only depends on the microstructure of the loading substrate but also can be affected by the chemical state of radioactive strontium retention in the loading matrix.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2018
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IF 2.606
Te Qi,Zhihao Zhao,Yongqiang Sun,Hangyuan Zhao,Xiaolei Li,Huiming Ji
Porous Si 3 N 4 ceramics with a unique interlocking microstructure have been fabricated by pressureless liquid-phase sintering with YbF 3 and CaF 2 sintering additives at a relatively low temperature (1550 °C). Phase transition and mass diffusion in the low-temperature sintering process are facilitated by YbF 3 and CaF 2 producing plenty of liquid phase owing to their extremely low melting points. As the content of YbF 3 increases from 8.0 wt% to 9.5 wt% and the CaF 2 decreases from 2.0 wt% to 0.5 wt%, the conversion rate of the phase transition from α-Si 3 N 4 to β-Si 3 N 4 increases from 71.1% to 81.2% and the largest average aspect ratio of the β-Si 3 N 4 grains reaches 10.05. At the same time, the porosity declines from 40.4% to 34.9% and the flexural strength increases from 168.5 MPa to 232.1 MPa.
研究领域:
材料科学
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陶瓷工程
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DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2022
·
IF 4.969
He Zhang,Jun-Ru Liu,Zhi-Bo Li,Xiao-Chun Deng,Guo-Hua Zhang,Kuo-Chih Chou
In this study, high-performance fine-grained W-Cu sintered blocks with the addition of dispersed Al 2 O 3 particles were successfully produced by low temperature liquid-phase sintering, using the raw material of ultrafine W-Cu alloy powder. The ultrafine W-Cu alloy powder was obtained by a two-step reduction process composed of stages of carbothermal reaction and hydrogen deep deoxidation. The fine Al 2 O 3 grains with uniform distribution in W-Cu alloy were introduced by spray method, leading to the decrease of W grain size and W-W connectivity. The relative densities of all sintered blocks were>97%, and a higher degree of densification ensures that the alloy has excellent comprehensive properties. With the increase of Al 2 O 3 content, W grain size and W-W connectivity of sintered W-Cu samples decrease from 664 nm to 472 nm and 0.2 to 0.14, respectively. The W-Cu alloy with the ultimate tensile strength of 415 MPa and the highest elongation of 7.22% was obtained when the addition amount of Al 2 O 3 was 0.5 wt%. At the same time, it also possessed the maximum bending strength of 1028 MPa and microhardness of 312 HV, respectively. In addition, due to the good network structure of Cu and uniform three-phase distribution, the sintered samples had excellent conductivity and compressive strength.
研究领域:
材料科学
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冶金工程
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DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2024
·
IF 1.8
Yiming Yu,Yaowu Wei,Kui Liu,Bo Chen,Junfeng Chen
This paper aims to improve the density and thermal shock resistance of Y 2 O 3 ceramics for the preparation of ultra-pure high-temperature alloy crucible materials. The doping effect of MgF 2 content on the densification behavior, physical properties, and thermal shock resistance of Y 2 O 3 ceramics was systematically investigated in this paper. The results suggested that the presence of MgF 2 greatly promoted the growth of Y 2 O 3 grains and the transformation of the pore structure by liquid-phase sintering. And the mechanical properties of the MgF 2 -doped Y 2 O 3 ceramics were significantly improved. Besides, the marked improvement in the thermal shock resistance of MgF 2 -doped Y 2 O 3 ceramics was attributed to the synergistic action resulting from the growth of grain size and the enhancement of the crack deflection effect. In particular, the relative density of Y 2 O 3 ceramics doped with 1.5 wt% MgF 2 reached 96.4% and the residual flexural strength ratio after thermal shock achieved 45.0%, showing an excellent application prospect.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
Crystals
·
2023
·Vol. 13
·期 7
·1099
·
IF 2.7
Li He,Niansheng Huang,Donglin Lu,Pengfei Sheng,Wenjing Zou
Due to its high bonding energy and low self-diffusion coefficient, silicon nitride (Si3N4) ceramics cannot form a dense structure with prolonged high-temperature insulation or by raising the sintering temperature. To improve the density of the sintered Si3N4ceramics, additives are added to promote the rearrangement–dissolution–precipitation process of the crystal grains. However, the liquid phase formation temperature of different sintering aid chemical compositions varies, making it challenging to isolate the mechanism and the effect of liquid phase formation temperatures on sintering. Hence, we developed three sintering aids, namely Y2O3-Al2O3(YA), Y2Si2O7(Y2S), and Y2Si2O7-Al6Si2O13(Y2SM), with homologous elements and different liquid phase formation temperatures. These sintering aids can form a liquid phase with SiO2on the surface of Si3N4at varying temperatures. We analyzed the sintered Si3N4ceramic’s density, volume shrinkage rate, and microstructure to verify the YA’s lower liquid phase formation temperature effect, providing more rearrangement time and increasing sintering density. Conversely, sintering aids with too low liquid phase formation temperatures are more prone to volatilize during high-temperature sintering stages, thereby reducing sintering density. This research found that different liquid phase formation temperatures do not affect the α→β phase transition temperature of Si3N4ceramics. We also evaluated the Y2S sintering aid contents’ effect on Si3N4ceramics sintering. The results revealed that aiding sintering with too little Y2S content is insufficient for liquid phase production, and hence does not improve sintering density. Conversely, excessive liquid phase can improve density and refine grain size but increases weight loss rate during sintering due to volatilization.Keywords:liquid phase sintering;liquid phase formation temperature;sintering aids;silicon nitride sintering
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2023
·Vol. 21
·期 2
·829-843
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IF 2.1
Yang Yang,Jiaqi Yan,Shujia Cheng,Gang Liu,Bensong Chen,Kang Zheng,Lin Chen,Xingyou Tian
Cordierite ceramic is usually used for diesel particulate filter owing to its excellent low thermal expansion coefficient and high thermal shock resistance properties. However, the co-exited intermediate spinel phase can deteriorate the thermal and mechanical performances of cordierite ceramic product, because the spinel phase has much higher thermal expansion coefficient comparing to that of cordierite. In this study, two methods are utilized to reduce the spinel impurity in the cordierite ceramic. On the one hand, rational reaction resources were introduced to decrease spinel production. The formation of intermediate spinel phase is systematically researched by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman characterizations and the results clarified the preference of path “Enstatite + Mullite → Cordierite” for less spinel production in comparison to path “Enstatite + Al 2 O 3 → Cordierite + Spinel.” Additionally, MgO was introduced as fluxing agent to promote liquid-phase sintering, thus facilitating the conversion of spinel. On the other hand, the sintering schedule was improved by introducing a holding temperature gradient to promote the diffusion of Si 4+ and further promote the conversion of spinel into cordierite. With these methods, the residual spinel phase is minimized, the resulting high-purity cordierite has a 47% reduction in the thermal expansion coefficient from 3.07 × 10 −6 /K to 1.63 × 10 −6 /K compared to the original cordierite sample.
研究领域:
材料科学
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陶瓷工程
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DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 12
·2904
·
IF 3.1
Xin Yang,Kaihua Li,Jun Li,Zhuo Sheng,Ying Liu
In this work, the preparation of titanium sponge by magnesium thermal method is regarded as the liquid-phase sintering process of titanium, and powder-metallurgy sintering technology is utilized to simulate the aggregation–growth and densification behavior of titanium particles in a high-temperature liquid medium (the molten Mg-MgCl2system). It was found that compared with MgCl2, Mg has better high-temperature wettability and reduction effect, which promotes titanium particles to form a sponge titanium skeleton at lower temperature. The aggregation degree of titanium particles and the densification degree of a sponge titanium skeleton can be improved by increasing the temperature and the relative content of Mg in the melting medium. The kinetics study shows that with the increase in temperature, the porosity of the titanium particle aggregates and the sponge titanium skeleton decreases, and their density growth rate increases. With the extension of time, the aggregation degree of titanium particles and the densification degree of sponge titanium gradually increase. This work provides a theoretical reference for controlling the density of titanium sponge in industry.
研究领域:
材料科学
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冶金工程
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产品关联
DOI
PubMed
高影响因子
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
·
2023
·
IF 6.4
He Zhang,Xiao-Chun Deng,Guo-Hua Zhang
In this study, high performance W–Mo–Cu–Ni–Fe alloy samples with additions of Mo (0–6 wt%), Ni and Fe (total content: 2.5 wt% and 5 wt%) were obtained through liquid-phase sintering at lower temperature, with the raw material of ultrafine W–Mo–Cu–Ni–Fe composite powder. Ultrafine W–Mo–Cu–Ni–Fe alloy powder with strong sintering activity and uniform composition was obtained by two-stage reduction means composed of carbothermic pre-reduction and hydrogen deep deoxidation steps. Significantly, the bonding ability of W/Cu phase interface and the wettability of two phases are greatly improved due to the presences of Ni and Fe. Moreover, the addition of appropriate Mo content was advantageous to the formation of W–Mo solid solution . All alloy samples achieved higher densification degrees to guarantee that the sintered blocks possess outstanding overall performances. Especially, by adjusting Ni/Fe ratio, the highest tension strength and elongation of were achieved by W-2wt.%Mo-1.75 wt%Ni-0.75 wt%Fe-27.5 wt%Cu sintered block, which were 567 MPa and 10.37%, respectively. Moreover, owing to the presences of W–Mo and Cu–Ni–Fe solid solutions, this alloy also had the highest microhardness and bending strength of 446 HV and 1473 MPa, respectively. As increasing Mo content from 0 wt% to 6 wt%, the compression strength of sintered blocks was improved, and failure strains of all the sintered blocks are close to 100%, respectively. However, even though the Cu matrix network structure is more evenly distributed as a result of the existences of added Ni and Fe, the electronic movement ability of the sintered blocks was reduced, leading to a significant decrease in conductivity.
研究领域:
材料科学
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冶金工程
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产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2025
·
IF 6.6
Yuhua Heng,Yiwei Mao,Kunhao Feng,Jianan Zheng,Yingmi Xie,Qingsong Wei
Binder jetting (BJ) possesses considerable potential in forming complex tungsten heavy alloy components. Nonetheless, it is also confronted with challenges such as low green density. Achieving densification typically requires stringent sintering conditions, such as high temperatures or extended durations, which often result in coarse grains and diminished performance in sintered components. This paper introduced a novel inorganic metal salt binder that could generate nanoparticles in situ among the substrate powders. Clearly, the nanoparticles (average size: 360 nm) generated in situ, occupied the interparticle voids between the substrate powders after pretreatment, thereby enhancing the green and pretreated density and reducing the sintering temperature. The pretreated density binder jetted with the novel binder increased by 7.76% compared to that with the commercial binder. Furthermore, surface quality and compressive strength were also improved. The sintered samples could achieve densification at a lower sintering temperature (1500 °C). The increase of capillary force and the elevated solubility of nanoparticles were the primary reasons for densification, which facilitated pore filling and dissolution-reprecipitation during liquid phase sintering, respectively. The ultimate tensile strength, yield strength, and elongation of the sintered samples were 871.06 ± 14.23 MPa, 606.71 ± 9.84 MPa, and 11.00 ± 0.28%, which were 9.50%, 4.30%, and 5.49% higher than those of the sintered samples binder jetted with the commercial binder, respectively. The utilization of inorganic metal salt binders provides a novel approach to the densification and enhancement of the mechanical properties of BJ metallic materials.
研究领域:
材料科学
·
增材制造
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Misganaw Alemu Zeleke,Dong-Hau Kuo
The quaternary chalcogenide Cu 2 Zn(Sn 1-x Ge x )(S,Se) 4 bulks, where x is G e / [ G e + S n ] molar ratios of 0, 0.15, 0.30, and 0.45 were synthesized via reactive liquid phase sintering at 600 °C for 30 min in the tube furnace and characterized systematically. Together with Sb 2 S 3 as a reactive liquid phase sintering aid, the effects of Ge incorporation on densification, grain boundary, crystal phase purity, crystalline size, and electrical properties were studied. The morphology of the resulted Cu 2 Zn(Sn 1-x Ge x )(S,Se) 4 bulk was found to be more densified and compacted at G e / [ G e + S n ] molar ratio of 0.15 compared to the rests. The X-ray diffraction peaks were shifted towards a higher angle as Ge fraction was increased. The hole concentrations for the entirely p-type bulks were determined to be 3.67 × 10 18 , 1.40 × 10 18 , 1.28 × 10 18 , and 8.90 × 10 17 cm −3 at G e / [ G e + S n ] molar ratios of 0, 0.15, 0.30, and 0.45, respectively. The effects on conductivity and mobility were consistent with their interrelations. Hence, the synthesis and study of Ge incorporated Cu 2 ZnSn(S,Se) 4 bulk using powder technique allows identifying the composition which is expectedly more important for the fabrication of thin film solar cells.
研究领域:
材料科学
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太阳能电池技术
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 4
·2116-2124
·
IF 2.779
Li Chen,Hou Jiale,Ye Zijun,Muhammad Raz,Li Aihua,Ma Mingtao,Wu Guofa,Song Kaixin,Zhou Tao,Mao Minmin,Liu Bing,Bafrooei Hadi Barzegar,Taheri-nassaj Ehsan,Luo Shaojin,Shi Feng,Sun Shikuan,Wang Dawei
In this study, Mg x Y 3- x Al 5- x Si x O 12 ( x = 0–0.6) ceramics were prepared via a high-temperature solid state method. Mg 2+ and Si 4+ replacing Y 3+ ions at A-site and Al 3+ at C-site in garnet-type Y 3 Al 5 O 12 (YAG) ceramics were designed to discuss the effects of crystal structure, microstructure on microwave dielectric properties for the first time. Liquid phase sintering induced by doping of Mg 2+ -Si 4+ , significantly decreased the sintering temperature and time for the densification of YAG ceramics. X-ray diffraction of the samples showed single phase for x ≤ 0.5, while a secondary phase of MgAl 2 O 4 formed for x = 0.6. From the Rietveld analysis, a decrease in lattice dimensions, bond length and valence and rattling effect were observed, while Raman results showed a change in FWHM of the Eg mode. Based on these parameters, a structure–property relation was developed for Mg x Y 3- x Al 5- x Si x O 12 ceramics. Specially, Mg 0.1 Y 2.9 Al 4.9 Si 0.1 O 12 showed a good set of microwave dielectric properties sintered at 1575 °C for 4 h with ε r = 10.67, Q × f = 58,799 GHz, τ f = -29.5 ppm/°C.
研究领域:
材料科学
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物理学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2022
·
IF 6.371
He Zhang,Jun-Ru Liu,Guo-Hua Zhang
In this paper, excellent performance W-Cu-Ni-Fe alloys with the addition of Ni and Fe (total content: 5 wt%) were successfully prepared by low temperature liquid-phase sintering, using the raw material of ultrafine W-Cu-Ni-Fe composite powder. Ultrafine W-Cu-Ni-Fe composite powder with high sintering activity and uniform composition distribution was prepared by a two-stage reduction method consisting of carbothermal reaction and hydrogen deep deoxidation. Additions of Ni and Fe not only improved the wettability between W and Cu two phases, but also improved the bonding strength of two-phase interface. All sintered samples had higher relatively densities to ensure that the samples have great comprehensive properties. When Ni and Fe were co-added in appropriate proportions, the highest tensile strength and elongation of W-Cu-Ni-Fe alloy samples were 497 MPa and 9.12 % for the composition: W-3.5 wt%Ni-1.5 wt%Fe-25 wt%Cu, respectively. Meanwhile, with increasing Ni content from 0 wt% to 5 wt%, the compressive strength and failure strain of alloy samples increased from 1160 MPa to 2376 MPa and from 53 % to 98 %, respectively. In addition, with the enhancement of the solid solution strengthening effects of Ni and Fe on Cu matrix, the bending strength and microhardness of the alloy samples increased to 1174 MPa and 361 HV for composition: W-3.5 wt%Ni-1.5 wt%Fe-25 wt%Cu, respectively. Although the additions of Ni and Fe made the Cu matrix network structure have a uniform distribution, it led to a decrease in the electron transfer ability of the alloy, and thus, there was a decrease in electrical conductivity .
研究领域:
材料科学
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冶金工程
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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）