WANG Deyong
,
ZHANG Zhixiang
,
WANG Huihua
,
JIANG Maofa
钢铁研究学报(英文版)
This present paper focused on the formation reasons of solidified crust when a basic tundish flux was used to cast the Al-killed steel. Crust samples were taken in an actual tundish, and analyzed by the methods of XRD, SEM and EDX. It was found that the main compositions of crystallization phases existing in tundish crust are Ca12Al4O33, Ca2SiO4 and a little spinel. Spinel and Ca2SiO4 distributed at grain boundaries of Ca12Al4O33, which increased the connection strength of crystallization phases by pinning the grain boundary, density or hardness of tundish crust will also significantly increased. When an initial composition of tundish flux was in spinel region of CaO-SiO2-Al2O3-10%MgO phase diagram, it was easier to form spinel in crust. Three approaches for spinel formation in crust were summarized. When flux is nearly saturated with magnesia, on the metal/flux interface, MgO in flux reduced by dissolved Al and formed the spinel. Inside molten steel and on the interface of steel/refractory, with a feasible Al content it is also easy to form spinel and spinel inclusions will float and captured by flux.
关键词:
tundish flux;crust;Spinel;formation reasons
LIU Chengjun
,
SHI Peiyang
,
ZHANG Dayong
,
JIANG Maofa
钢铁研究学报(英文版)
A great amount of ferrous tailings and slag cause severe damage to the ecological environment, which must be reclaimed and utilized. The composition, type, and characteristics of ferrous tailings and slag in China were introduced. The research status and the application outlook of glass ceramics made from ferrous tailings and slag were discussed. Glass ceramics made from ferrous tailings and slag can be applied to various fields, and it will be environmentally conscious materials in the 21st century.
关键词:
glass ceramics;ferrous tailings;slag
李尊
,
吴谨
,
刘劲
,
吴秋红
液晶与显示
doi:10.3788/YJYXS20153002.0353
在经典 Criminisi 图像修复算法框架的基础上，针对优先权可靠性低和全局搜索最佳模板效率低、错误匹配率大的缺点进行改进。改进的算法为基于萤火虫算法(FA)的快速 Criminisi 图像修复算法。首先从数学的角度引入正规化函数至置信度，以此提升优先权计算的可靠性；然后引入 FA 到最佳模板的搜索与填充中，能够有效地将全局搜索与局部搜索有效地结合，鲁棒性较高，提高效率且错误匹配率低。实验结果表明：采用本文的改进算法能在保证修复质量的基础上降低时耗，提高效率。
关键词:
Criminisi算法
,
优先权
,
最佳匹配模板
,
FA
Applied Surface Science
A novel kind of micro-arc oxidation (MAO) coating was prepared on magnesium alloy surface coated with rare earth conversion film (RE-film) in an alkaline aluminum oxidation electrolyte by AC power source. Inspection of scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) microspectroscopy, the structure and composition of MAO coating formed on AZ91D with RE-film under different applied voltages were investigated and the performance of the optimized MAO coating compared with the MAO coating directly formed on magnesium alloy. As the pretreatment of magnesium alloy with RE-film, the cerium oxides can be incorporated into the MAO coatings, reduce porosity of the MAO coating surface and enhance the thickness of MAO coating. These structure features and the cerium oxides incorporated into the MAO coating result in greatly improved corrosion resistance. Base on electrochemistry impedance spectroscopy (EIS) measurement, the electronic structure and composition analysis of the MAO coating, a double-layer structure, with a compact inner layer and a porous outer layer, of the coating was proposed for understanding its corrosion process. (C) 2010 Elsevier B.V. All rights reserved.
关键词:
Magnesium alloy;Rare earth conversion film;Micro-arc oxidation;Porosity;az31 magnesium alloys;micro-arc oxidation;mg-al alloys;electrolyte;resistance;cerium;phosphate
Science China-Technological Sciences
Product/metal ratio (PMR) was introduced as a novel criterion for the evaluation of electrolytes on micro-arc oxidation (MAO) of Mg and its alloys. The criterion initially sprang from Pilling-Bedworth ratio (PBR), focused on the roles of electrolytes for the compactness of the fabricated coatings, and took attention on properties of reactants/products during MAO. Meanwhile, based on our experiments as well as the results from literatures, the effects of electrolyte additives on morphologies and compositions of the fabricated MAO coatings of Mg alloys were exploited for verification and supplement of the initial criterion. In combination of the initial PMR criterion and experimental verification, PMR could be represented by special mode (PMR (s)=V (oxide products)/V (alloy substrates)) and general mode (PMR (g)= PMR (s)+ PMR (d)). The ideal PMR (s) should be between 1 and 2, while PMR (d) is related to the coating deposition during MAO. PMR (d) is a supplement to PMR (s) when the effect of the overlaying property (O) of the coatings and the effective deposition (D) of electrolyte composites are considered (PMR (d)=f(O, D). O is related to the melting point (MP) and boiling point (BP) of the MAO products. D is related to the effective reactions between alloy substrates and electrolytes during MAO.
关键词:
micro-arc oxidation;Mg alloys;Pilling-Bedworth ratio;product/metal;ratio;az91d magnesium alloy;electrochemical corrosion behavior;silicate-containing electrolytes;ceramic coatings;potassium fluoride;resistance;films;surface;microstructure;technology
周筠
,
吴勇生
,
李如燕
,
孙可伟
,
王敏
硅酸盐通报
以粉煤灰(FA)、铸造旧砂热法再生粉尘(DHRS)为原料,在水玻璃型碱性激发液的激发作用下研究制备了DHRS-FA地质聚合物材料(铸造旧砂热法再生粉尘-粉煤灰基地质聚合物材料).为了探讨不同的养护工艺对DHRS-FA地质聚合物材料强度的影响,研究了自然养护、湿养养护、高温蒸养(40℃、60℃、80℃)养护对地质聚合物强度的影响.结果表明:试样在高温养护工艺下,其早期抗压强度形成较快,且优于自然养护和湿养养护工艺下试样形成的抗压强度;试样在高温养护工艺下,中期和后期抗压强度趋于自然养护试样的抗压强度;而湿养条件下养护的试样抗压强度最差.
关键词:
粉煤灰
,
铸造旧砂热法再生粉尘
,
地质聚合物材料
,
高温养护工艺
Electrochimica Acta
Protective composite coatings were prepared on magnesium alloy AZ91D by micro-arc oxidation (MAO) treatment plus a top coating with sealing agent using multi-immersion technique under low-pressure conditions. The corrosion resistance of AZ91D alloy with composite coatings was superior evidently to that with merely MAO film. SEM observations revealed that the sealing agent was integrated with MAO film by physically interlocking; therewith covered uniformly the surface as well as penetrated into pores and rnicro-cracks of MAO film. The anti-corrosion properties in 3.5% NaCl solution of the composite coatings were evaluated by using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. Based on the results of chronopotentiometric (E similar to t) and EIS measurements for long time immersion in 3.5% NaCl solution, appropriate equivalent circuits for the composite coatings system were proposed. It follows that due to the blocking effect of the sealing agent in pores and cracks in MAO film, the composite coatings can suppress the corrosion process by holding back the transfer or diffusion of electrolyte and corrosion products between the composite coatings and solution during immersion. (c) 2005 Elsevier Ltd. All rights reserved.
关键词:
composite coatings;MAO film;sealing;magnesium alloy AZ91D;EIS;micro-arc oxidation;impedance spectroscopy;interfacial factors;phosphate coatings;alkaline-solutions;aluminum-alloys;nacl solution;anodic films;mg alloys;part 2
邓海文
,
檀柏梅
,
张燕
,
高宝红
,
王辰伟
,
顾张冰
功能材料
doi:10.3969/j.issn.1001-9731.2016.06.038
在化学机械抛光(CMP)过程中,加入苯并三氮唑(BTA)抑制 Cu 界面和布线条的腐蚀.但同时,会与Cu发生化学反应生成的Cu-BTA钝化膜是CMP后主要的清洗对象之一.采用FA/OⅡ型螯合剂作为清洗液的主要成分,采用接触角测试仪及原子力显微镜来表征BTA的去除效果.通过改变 FA/OⅡ型螯合剂的浓度完成一系列对比实验,确定最佳的清洗效果.通过对比实验得知,当清洗液中螯合剂的浓度为1．50×10－4~200×10－4时,此时清洗液的pH 值＞10,能有效去除Cu-BTA 钝化膜以及其它残留的有机物,接触角下降到29°,表面的粗糙度较低.
关键词:
CMP后清洗
,
FA/OⅡ螯合剂
,
Cu-BTA钝化膜
,
接触角
,
粗糙度
Materials and Corrosion-Werkstoffe Und Korrosion
A rapid and convenient anodization technology with AC power source to obtain the MAO films formed on magnesium alloy AZ91D in phosphate bath (base electrolyte + Na3PO4) with or without aluminate and silicate was studied. The corrosion resistance of the anodic films was studied by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques and the microstructure and composition of films were examined by SEM and XRD. The results show that Na3PO4 can promote the occurrence of sparking during the MAO process, while abundant heat generated by sparking might enhance the formation of the glassy phase of the compound when the electrolyte contains the additives of NaAlO2 and Na2SiO3 simultaneously. The optimized MAO film is ivory-white smooth by naked eye, while presents porous and microcracks in microscopic scale. The anodic film formed in the alkaline solution with optimized parameters possesses superior corrosion resistance by electrochemical test. The XRD pattern shows that the components of the anodized film consist of MgO, MgAlO2, and MgSiO3. No oxide crystal with P element can be found.
关键词:
micro-arc oxidation;electrochemical impedance spectroscopy;koh-aluminate solutions;corrosion protection;ceramic coatings;alloys;anodization;parameters;resistance;behavior
