TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2022
·
IF 3.752
He ZHANG,Zhi-bo LI,Xiao-chun DENG,Ben CHEN,Guo-hua ZHANG,Kuo-Chih CHOU
Ultrafine oxide dispersion strengthening (ODS)-Mo and ODS-W alloy powders containing different types of oxide nanoparticles were successfully synthesized by spraying method (solid−liquid mixing method) combined with the reductions with carbon black and hydrogen in sequence. It is concluded that the solution concentration and type of rare earth oxide have no effect on the grain size of ODS-Mo alloy powder, but have obvious effect on that of ODS-W alloy powder. The higher the concentration of rare earth solution is, the smaller the average grain size of ODS-W alloy powder is. Furthermore, compared with doping with CeO 2 , the grain sizes of reduction products of La 2 O 3 and Y 2 O 3 doped WO 3 are relatively larger. Compared with the undoped case, there is almost no change for grain size of ODS-Mo alloy powder, while the grain size of ODS-W alloy powder becomes much larger. This is probably due to the appearance of the composite oxide (such as La 2 WO 6 ) formed by the reaction between tungsten oxide and rare earth oxides, which promotes the heterogeneous nucleation and growth of tungsten grains during the reduction process of ODS-W, while there is no complex oxide composed of molybdenum and rare earth oxides in the reduction process of ODS-Mo.
研究领域:
材料科学
·
冶金学
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
·
2024
·
IF 5.8
Jiabao Zhu,Shuo Wang,Weiqiang Xiong,Jun Wang,Xiaodong Li,Meishuai Zou
Aluminum-lithium alloy powder exhibits better thermal properties and combustion performances than aluminum , thus showing promising applications in the field of energetic materials such as explosives and propellants. However, the high activity of lithium also raises issues of stability and compatibility with propellant components, deteriorating the powder's overall performance. In this study, a facile coating method is presented using 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTS) as a surfactant to coat hydroxyl‑terminated polybutadiene (HTPB) on the surface of Al-5Li powder, forming the core-shell composite Al-5Li@HTPB. The microstructure and chemical composition characterized by SEM, EDS , XPS , FT-IR, and nano-CT demonstrated that a uniform and dense layer was successfully coated on the surface. The thermal analysis results showed a significant improvement in the thermal properties and stability compared to pure Al-5Li. In addition, ignition tests were conducted, and the results showed that Al-5Li@HTPB could reduce the ignition delay time and significantly reduce agglomeration. Overall, our strategy provides a novel method to solve the stability issues of Al-Li powders and simultaneously enhance combustion performance.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2024
·
IF 5.5
Yapeng Kong,Longdi Ma,Heng Zhang,Xiwen Chen,Xuemin Liang,Liqiang Wang,Yangyang Fan,Yuran Chen
Aluminum-tantalum powders are emerging as new raw materials for additive manufacturing (AM) technologies, but their preparation in bulk quantities and in powder form via conventional metallurgical methods is challenging. In this study, we report a one-step synthesis of spherical Al 3 Ta powder by direct electrolyzing solid Ta 2 O 5 cathode ( vs . a graphite anode) in molten Na 3 AlF 6 -K 3 AlF 6 -AlF 3 -LiF-Al 2 O 3 . Cyclic voltammetry and constant potential electrolysis techniques were employed to characterize the electrochemical reaction process, along with X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for the structural and morphological analyses. The process involves an initial Ta 2 O 5 electro-deoxygenation process, the subsequent electrodeposition of Al 3+ on the formed Ta particles and an in-situ alloying process. The innovative use of Ta 2 O 5 cathodes with a novel hierarchical porous structure allows for a controlled transformation of cathode particle morphology and facilitates the rapid generation of nanoscale tantalum particles. Al 3+ from the electrolyte is then electrodeposited onto these particles, initiating an in-situ alloying reaction. This is an exothermic process that facilitates the diffusion of aluminum atoms into tantalum, and reduces the interfacial energy promoting the formation of spherical Al 3 Ta particles. Such powders are in demand for AM techniques. The findings may now guide the way to establishing the electrochemical route for the short-process preparation of other high-temperature alloy powders.
研究领域:
材料科学
·
电化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Hao Yu,Ce Zhang,Xin Lu
Titanium and its alloy powders are highly sensitive to oxygen, and the limited development of deoxygenation processes restricts the recycling of powders with elevated oxygen levels. In this study, we employed calcium hydride as a deoxygenating reductant and implemented a normal pressure solid-state deoxygenation technique, the in-situ reactions of Ca and H 2 generated from the decomposition of calcium hydride, along with partial gaseous CaH, effectively reduce the oxygen content in the powders. By performing the deoxygenation above the β-transition temperature, we successfully reduced the oxygen content in titanium alloy powder from 3593 ppm to 839 ppm. The deoxygenated powder retained the original appearance, size, and morphology of the initial powder, with no residual impurity elements. The thickness of the surface oxide film was reduced to 3.5 nm, and the interstitial oxygen content was lowered to 300 ppm. In comparison with the current deoxidation in solid-state process, this method significantly reduced the total process time while achieving an equivalent oxygen reduction rate.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
JOM
·
2020
·Vol. 72
·期 3
·1279-1285
·
IF 2.054
Xia Yang,Zhao Jinlong,Dong Zhaowang,Guo Xueyi,Tian Qinghua,Liu Yong
Cobalt-chrome-molybdenum (Co-Cr-Mo) alloy possesses outstanding strength, wear, and corrosion resistance and is a good material candidate for making dental and orthopedic implants. Spherical Co-Cr-Mo powder for additive manufacturing is usually costly due to the high-temperature melting processes and low yield of the powder with desirable particle size in the conventional melt-atomization process. A novel process for making spherical Co-Cr-Mo alloy powder through a simple meltless granulation and sintering process is described herein. The results indicate that the compositional segregation problem can be overcome and high-temperature operation avoided. Segregation-free powder was obtained after sintering above 1200°C. The powder was purified during sintering in a hydrogen atmosphere. The hydrogen purification mechanism is discussed with the aid of thermodynamic modeling using HSC Chemistry software. The oxygen content in the final powder can be controlled to < 0.2 wt.% for powder with particle size < 107 µ m. The final powder retained good spherical morphology.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Central South University
·
2022
·Vol. 29
·期 6
·1811-1822
·
IF 2.392
Dong Zhao-wang,Xia Yang,Guo Xue-yi,Liu Han-ning,Liu Pei-dong
Ti-6Al-4V alloy powder was prepared through a two-step reduction of a mixture of TiO 2 , V 2 O 5 and Al 2 O 3 in this study. The oxide mixture was first reduced by Mg in MgCl 2 at 750 °C in argon, where oxygen was reduced to 2.47 wt% from 40.02 wt%. The oxygen content in the final powder was eventually reduced to an extremely low level (0.055 wt%) using calcium at 900 °C in argon, and the final powder had the composition of 90.12 wt% Ti, 5.57 wt% Al, and 3.87 wt% V, which meets the standard specification of Ti-6Al-4V (ASTM F1108-09). Between the two reductions, a heat treatment step was designed to help controlling the specific surface area and particle size. The effect of the heat treatment temperature on the morphology, and composition uniformity of the powder was investigated in detail. Heat treatment above 1300 °C attributed to a dense powder with a controlled specific surface area. Thermodynamic modeling and experimental results indicated that only α -Ti enriched with Al and β-Ti enriched with V exist in the final powder, and other possible phases including Al-Mg and Al-V were excluded. This study also offers a triple-step thermochemical process for producing high-purity Ti-based alloy powder.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Haiyang Wang,Shuo Wang,Xuanyan Liu,Youqi Zhu,Tinglu Song,Haiyue Yu,Hongdi Fu,Kangcheng Xu,Huaqiang Zhu,Yonghao Zhao,Siyuan Tang,Meishuai Zou
Aluminum-lithium alloy powders receive extensive concern as metal fuel in propellants for high heat value and coefficient of combustion. However, the presence of highly active metal lithium leads to the instability of alloy powder, limiting its application in propellants. Herein, the fluorination-energetic modification is developed to solve the activity problem of aluminum–lithium alloy (Al-5Li, Li 5 wt%) powders and increase their energy level. The first fluorinated layer is constructed by fluorosilane and epoxy silane coating to achieve the modifiable and functional aluminum–lithium alloy (Al-5Li@FS). Afterwards, the energetic layer is coated on Al-5Li@FS surface by glycidyl azide polymer (GAP) to obtain the fluorination-energetic composite powders (Al-5Li@FSG). The microstructural and chemical composition characterizations of Al-5Li@FSG are performed by SEM, FTIR, XPS, TEM, and TOF-SIMS. TG-DSC results show that the coated alloy powders can exhibit excellent thermal properties with remarkably enhanced exothermic enthalpy and thermal weight gain. The Al-5Li@FSG shows significantly improved combustion performances with reduced ignition delay time and repressed agglomeration phenomenon. Furthermore, hydrophobicity, water-reactivity, and compatibility with propellant components are also well modified of the Al-5Li@FSG. This work provides a guideline for preparing aluminum–lithium alloy powders with remarkable stability, excellent combustion performance, compatibility, and high energy level.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Wei Le,Wanjun Zhao,Yanli Zhu,Ziting Wei,Zhigang Liu,Dazhi Liu,Qingjie Jiao
As a highly reactive metal fuel, aluminum–lithium (Al-Li) alloy is an ideal candidate for replacing Al powders in solid propellants. However, the Li solid solution and AlLi compounds on the surface of Al-Li alloy powders display high reactivity, which can react with a large number of organic and inorganic reagents. Thus, the incompatibility of Al-Li alloy with other components of propellants makes it difficult to be further applied in propellants. In this study, surface-modified Al-Li alloy powders (Li content of 5 wt%) with 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (FAS17) were prepared by a facile self-assembly method, which made the alloy powders super-hydrophobic. The results of SEM, XPS and FIB-TEM show that the surface of Al-Li alloy powder is well-coated by an evenly distributed FAS17 layer. Due to the fluoroalkyl on the surface of the powders, the water contact angle increased by 91°and the intensity of the reaction between alloy powders and water is significantly reduced, which results in improved compatibility with other components of propellants. Meanwhile, the propellant grain of surface-modified powders had fewer defects than the sample before coating, and showed original excellent combustion performance. The average combustion pressure and pressurization rate increased by ∼114 kPa and ∼8613 kPa/s, and the steady burning rate increased by 0.24 mm/s. Therefore, the surface-modified Al-Li alloy powders with FAS17 are expected to be an attractive candidate as a highly active and stable fuel in solid propellants.
研究领域:
材料科学
·
化学工程
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2020
·Vol. 45
·期 7
·1141-1152
·
IF 1.544
Zhengyu Cao,Aobo Hu,Bin Xia,Ai-min Pang,Shuizhou Cai
Aluminum-lithium alloy powder has broad application prospects in the field of energetic materials due to its good thermal performance. However, the high reactivity of lithium and the incompactness of the surface oxide layer result in the continuous oxidation of the active metal during storage, thereby deteriorating the thermal performance of the powder. In this paper, a layer of polystyrene (PS) was successfully coated on the surface of Al-10Li (10 wt.%) alloy powder by in-situ polymerization of styrene (St). According to an orthogonal test, the optimum coating conditions for protection factor were as follows: m(St)/m(Al-10Li) was 1 : 1; m(AIBN)/m(St) was 5 %; the reaction temperature was 75 °C; the reaction time was 4 h. The structure, surface morphology and thermal properties were characterized by XPS, FTIR, SEM and TG-DTA. Furthermore, the aging stability of powders were studied by TG-DTA. The results showed that the decay rate of the weight increase of the active metal of Al-10Li alloy powder decreased significantly after coating, which demonstrated that the polystyrene coating effectively protected the active metal of Al-10Li alloy powder, prevented pre-oxidation of Al-10Li alloy powder in air and improved its storage stability.
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
Additive Manufacturing
·
2021
·
IF 10.998
Yubei Zhang,Shan Li,Yantong Zhao,Wenyan Duan,Bingshan Liu,Tongcai Wang,Gong Wang
This paper proposed a kind of aluminum alloy powder additive manufacturing technology through surface modification of AlSi10Mg particles and digital light processing (DLP) printing. Firstly, AlSi10Mg particles were coated by styrene through suspension polymerization . The TEM results showed that the coating thickness is approximately 200 nm to 400 nm. Secondly, printing slurry was prepared by mixing photocurable acrylate resin with AlSi10Mg powder. The printing experiments showed that the curing depth of the printing slurry was obviously improved after surface coating of AlSi10Mg power. And the reason was discussed in detail. Then, the photocuring behavior and viscosity of the printing slurry were tested and analyzed. Finally, complex structures of AlSi10Mg material were successfully fabricated by digital light processing. It is demonstrated that surface modification is a feasible method for the photocurable printing of ultrafine alloy powder, which can also be expanded to the additive manufacturing of other alloy systems .
研究领域:
材料科学
·
增材制造
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Hongdi Fu,Shuo Wang,Tinglu Song,Weiqiang Xiong,Xuanyan Liu,Kangcheng Xu,Xiaodong Li,Meishuai Zou
The superior combustion heat, lower ignition temperature, and enhanced combustion efficiency of aluminum–lithium (Al-Li) alloy powders have garnered significant research attention in relation to Al powders. However, the inadequate compatibility between Al-Li alloy powders (especially when Li > 3 wt%) and propellant components limits its application in the development of composite solid propellants. This study focuses on the surface-coating active Al-4.3Li (wt.%) alloy powder using a composite fluorosilane coupling agent to improve compatibility and combustion performance. A coating layer with a thickness of 30–40 nm was successfully formed on the surface of Al-4.3Li alloy powder through interactions involving Al-F, Al-O-Si, and Li-O-Si bonds, thereby achieving remarkable hydrophobicity. The heat release increased by 7.5 %, while the ignition delay time of the alloy powder decreased by nearly 200 ms, resulting in a significantly enhanced combustion performance in relation to that of the original Al-4.3Li alloy powder. Moreover, the modified Al-4.3Li alloy powder exhibited better compatibility, and no cracks or bubbles were observed in the cross-section of the propellant containing modified Al-4.3Li metal fuel. This study provides an effective approach for utilizing Al-Li alloy powders in solid propellants, which is of great significance for the development of high-energy propulsion systems.
研究领域:
材料科学
·
推进工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Mingyuan Zhang,Taotao Cai,Weiliang Lu,Shili Zheng,Ying Zhang,Yi Zhang
Given the high cost of fabricating the Ti-6Al-4V alloy powder by the traditional hydriding-dehydriding and atomization methods, a novel sintering-deoxygenation process was proposed and studied in this research. With the help of the developed deoxygenation treatment, value-added raw materials such as Ti sponge can be substituted by low-cost and low-grade materials with high oxygen content. In addition, sintering in a solid state saves a significant amount of processing energy compared to alloying above the melting point of Ti in the conventional alloy production process. This paper prepared six sintering precursors with different initial compositions and oxygen contents using the low-valued raw materials of crude titanium, crude vanadium, V 2 O 3 , Al powder, and Al 2 O 3 powder. These precursors' sintering performances on shrinkage, phase composition, microstructure, and porosity were investigated. The results show that the sintering shrinkage is positively correlated with the sintering temperature and holding time and is also affected by the raw materials. The pellet made by mixed crude titanium and AlV master alloy showed the largest shrinkage and the densest bulk. The various combinations of the raw materials led to the changes in the oxygen contents in the precursors, the alpha-beta phase ratio, and the shift of the diffraction peaks of the α-phase. The dissolving of the AlV master alloy and the formation of the Ti 3 Al intermediate phase took place during sintering due to diffusion. Sintering at 900–1000 °C is critical for elemental diffusion and densification, and sintering at higher temperatures is decisive for microstructure homogenization and further densification. Using the hydrogen-assisted Mg deoxygenation method, all the sintered samples could be treated to an oxygen level of around 0.4 wt% regardless of oxygen content in precursors. The contents of Ti, Al, V, and Fe in the obtained Ti-6Al-4V powders met the requirements of GB/T 34486-2017. This research has demonstrated the feasibility of fabricating Ti-6Al-4V alloy powder by the novel sintering-deoxygenation process.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）