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功能梯度材料 1

增材制造 1

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气体雾化 1

电沉积 1

粉末特征 1

纳米颗粒 1

脉冲喷射 1

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Preparation and characterization of nanocrystalline ZrO2-7%Y2O3 powders for thermal barrier coatings

Kirsten BOBZIN, Lidong ZHAO, Thomas SCHLAEFER, Thomas WARDA

《机械工程前沿（英文）》 2011年 第6卷 第2期   页码 176-181 doi: 10.1007/s11465-011-0220-4

摘要：

High-energy ball milling is an effective method to produce nanocrystalline oxides. In this study, a conventional ZrO2-7%Y2O3spray powder was ball-milled to produce nanocrystalline powders with high levels of crystalline disorders for deposition of thermal barrier coatings. The powder was milled both with 100Cr6 steel balls and with ZrO2-3%Y2O3 ceramic balls as grinding media. The milling time was varied in order to investigate the effect of the milling time on the crystallite size. The powders were investigated in terms of their crystallite sizes and morphologies by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that under given milling conditions the powder was already nanostructured after 40 min milling. The crystallite size decreased significantly with increasing milling time within first 120 min. After that, a further increase of milling time did not lead to a significant reduction of the crystallite size. Ball-milling led to lattice microstrains. Milling with the steel balls resulted in finer nano-sized crystal grains, but caused the contamination of the powder. The nano-sized crystal grains coarsened during the heat-treatment at 1250°C.

关键词： nanostrucured powders     yttria stabilized zirconia (YSZ)     high-energy ball milling     thermal barrier coatings    

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Highly selective and green recovery of lithium ions from lithium iron phosphate powders with ozone

《化学科学与工程前沿（英文）》 2023年 第17卷 第6期   页码 749-758 doi: 10.1007/s11705-022-2261-0

摘要： Since lithium iron phosphate cathode material does not contain high-value metals other than lithium, it is therefore necessary to strike a balance between recovery efficiency and economic benefits in the recycling of waste lithium iron phosphate cathode materials. Here, we describe a selective recovery process that can achieve economically efficient recovery and an acceptable lithium leaching yield. Adjusting the acid concentration and amount of oxidant enables selective recovery of lithium ions. Iron is retained in the leaching residue as iron phosphate, which is easy to recycle. The effects of factors such as acid concentration, acid dosage, amount of oxidant, and reaction temperature on the leaching of lithium and iron are comprehensively explored, and the mechanism of selective leaching is clarified. This process greatly reduces the cost of processing equipment and chemicals. This increases the potential industrial use of this process and enables the green and efficient recycling of waste lithium iron phosphate cathode materials in the future.

关键词： lithium iron phosphate powder     stoichiometric number     selective leaching     lithium recovery    

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Preparation and photocatalytic kinetics of nano-ZnO powders by precipitation stripping process

ZHANG Dongxiang, XUE Min, XU Hang, XU Wenguo, TARASOV V

《化学科学与工程前沿（英文）》 2008年 第2卷 第3期   页码 319-324 doi: 10.1007/s11705-008-0051-y

摘要： Ultra-fine zinc oxalate powders were prepared through a precipitation stripping method with bis(2-ethylhexyl) phosphate (HDEHP) diluted by tetrachloride carbon as the extractant, and oxalic acid ethanol aqueous solution as the re-extractant and precipitator. Zinc oxide powders were obtained by decomposing zinc oxalate powders at 450°C. The prepared zinc oxide powders were characterized by transmission electron microscope (TEM), Scanning electron microscope (SEM), Thermogravimetric analysis (TG), X-ray diffraction (XRD) and Fourier transmission infrared (FT-IR) spectrum. The photocatalytic performance of methylene blue by zinc oxide was studied based on the Langmuir model and Photo-Layer model. The results show that some zinc oxide powders were micro-multipore materials with hexagonal crystal. The particle size was around 32 nm. The photocatalytic process was the control step in the chemical reaction. The photo catalytic process followed pseudo-first order kinetics and •OH concentration inside the photo-layer in different reaction condition were calculated according to the Photo-Layer model.

关键词： 2-ethylhexyl     micro-multipore     Photo-Layer     hexagonal     methylene    

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Design of Simulations” approach for exploiting and calibrating discrete element simulations of cohesive powders

《化学科学与工程前沿（英文）》 2022年 第16卷 第6期   页码 874-885 doi: 10.1007/s11705-021-2131-1

摘要： The flow behaviours of cohesive particles in the ring shear test were simulated and examined using discrete element method guided by a design of experiments methodology. A full factorial design was used as a screening design to reveal the effects of material properties of partcles. An augmented design extending the screening design to a response surface design was constructed to establish the relations between macroscopic shear stresses and particle properties. It is found that the powder flow in the shear cell can be classified into four regimes. Shear stress is found to be sensitive to particle friction coefficient, surface energy and Young’s modulus. A considerable fluctuation of shear stress is observed in high friction and low cohesion regime. In high cohesion regime, Young’s modulus appears to have a more significant effect on the shear stress at the point of incipient flow than the shear stress during the pre-shear process. The predictions from response surface designs were validated and compared with shear stresses measured from the Schulze ring shear test. It is found that simulations and experiments showed excellent agreement under a variety of consolidation conditions, which verifies the advantages and feasibility of using the proposed “Sequential Design of Simulations” approach.

关键词： discrete element method     cohesive materials     parameter calibration     ring shear cell     design of experiments    

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电沉积法制备多功能复合材料研究动态与发展趋势

郭忠诚,朱晓云,杨显万

《中国工程科学》 2004年 第6卷 第4期   页码 86-94

摘要：

综述了近年来国内外在复合电沉积制备多功能复合材料方面的研究动态与发展趋势；重点探讨了多元复合电沉积、多元脉冲复合电沉积、脉冲喷射电沉积、纳米复合电沉积以及功能梯度材料的复合电沉积等方面的研究现状和发展趋势。结果表明：这五类复合材料镀层的性能比传统的单金属镀层、合金镀层及其复合镀层更加优异，在今后的发展中将有更广阔的应用前景。

关键词： 电沉积     复合镀层     纳米颗粒     功能梯度材料     脉冲喷射    

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Assessing the effects of different dielectrics on environmentally conscious powder-mixed EDM of difficult-to-machine material (WC-Co)

Jagdeep SINGH,Rajiv Kumar SHARMA

《机械工程前沿（英文）》 2016年 第11卷 第4期   页码 374-387 doi: 10.1007/s11465-016-0388-8

摘要：

Electrical discharge machining (EDM) is a well-known nontraditional manufacturing process to machine the difficult-to-machine (DTM) materials which have unique hardness properties. Researchers have successfully performed hybridization to improve this process by incorporating powders into the EDM process known as powder-mixed EDM process. This process drastically improves process efficiency by increasing material removal rate, micro-hardness, as well as reducing the tool wear rate and surface roughness. EDM also has some input parameters, including pulse-on time, dielectric levels and its type, current setting, flushing pressure, and so on, which have a significant effect on EDM performance. However, despite their positive influence, investigating the effects of these parameters on environmental conditions is necessary. Most studies demonstrate the use of kerosene oil as dielectric fluid. Nevertheless, in this work, the authors highlight the findings with respect to three different dielectric fluids, including kerosene oil, EDM oil, and distilled water using one-variable-at-a-time approach for machining as well as environmental aspects. The hazard and operability analysis is employed to identify the inherent safety factors associated with powder-mixed EDM of WC-Co.

关键词： WC     hazard and operability analysis (HAZOP)     discharging     aerosol concentration     dielectrics     powders    

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用于粉末床增材制造的铬镍铁合金粉末特征研究

Quy Bau Nguyen, Mui Ling Sharon Nai, Zhiguang Zhu, Chen-Nan Sun, Jun Wei, Wei Zhou

《工程（英文）》 2017年 第3卷 第5期   页码 695-700 doi: 10.1016/J.ENG.2017.05.012

摘要：

本研究中使用不同的粉末表征技术对铬镍铁合金的原始粉末和回收粉末在粉末床增材制造（AM）上的流动特性、行为特征进行研究。结果发现，选择性激光熔化（SLM）工艺的粒径分布（PSD）范围通常在15 ～ 63 μm 之间。原始的铬镍铁合粉末的流量约为28 s·(50 g)–1，组装密度是60%。流变测试结果表明，原始粉末与回收粉末相比具有更好的流动性。讨论了两种粉末之间的相互关系。运用铬镍铁合金粉末已经成功打印出了螺旋桨。实验结果表明铬镍铁合金粉末适用于增材制造（AM），本研究为生产增材制造粉末提供参考。

关键词： 增材制造     粉末特征     气体雾化     微观结构     铬镍铁合金    

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标题 作者 时间 类型 操作

Preparation and characterization of nanocrystalline ZrO2-7%Y2O3 powders for thermal barrier coatings

Kirsten BOBZIN, Lidong ZHAO, Thomas SCHLAEFER, Thomas WARDA

期刊论文

Highly selective and green recovery of lithium ions from lithium iron phosphate powders with ozone

期刊论文

Preparation and photocatalytic kinetics of nano-ZnO powders by precipitation stripping process

ZHANG Dongxiang, XUE Min, XU Hang, XU Wenguo, TARASOV V

期刊论文

Design of Simulations” approach for exploiting and calibrating discrete element simulations of cohesive powders

期刊论文

电沉积法制备多功能复合材料研究动态与发展趋势

郭忠诚,朱晓云,杨显万

期刊论文

Assessing the effects of different dielectrics on environmentally conscious powder-mixed EDM of difficult-to-machine material (WC-Co)

Jagdeep SINGH,Rajiv Kumar SHARMA

期刊论文

用于粉末床增材制造的铬镍铁合金粉末特征研究

Quy Bau Nguyen, Mui Ling Sharon Nai, Zhiguang Zhu, Chen-Nan Sun, Jun Wei, Wei Zhou

期刊论文