材料期刊网

Morphologies of Al₄Sr Intermetallic Phase and Its Modification Property upon A356 Alloys

Chengwei Liao , Jianchun Chen , Yang Li , Rui Tu , Chunxu Pan

材料科学技术（英文）

In general, the modification performance of Al−Sr master alloys is primarily dependent upon the morphologies and sizes of the Al4Sr intermetallic phase. In this paper, the crystal structure, morphologies, sizes, hardness and elastic modulus of Al4Sr in Al{Sr master alloys prepared from variant processes were studied by means of optical metallurgical microscope, X-ray diffraction (XRD), scanning electron microscopy (SEM), and nanoindentation system. The results revealed that the microstructures and modi¯cation performance of the Al₄Sr phase were related to the preparation processes. That is to say, when a "direct reaction-hot extrusion" process was used, the Al4Sr phase exhibited a homogeneous distribution in the Al matrix with small size and roundish shapes, which ensured the Al−Sr master alloy wire advantages involving high recovery, good reproducibility, no delitescence of modification, no corrosion on equipments, and good workability. However, in the case of the traditional "direct reaction" process, the Al₄Sr phase was in large size with shapes of rectangular stripe and plates, which limited the Sr content increasing due to the brittleness of the Al−Sr alloy. It was also found that the morphology and size of the Al₄Sr phases changed during heat treatment at high temperature up to 600 °C.

关键词: Intermetallics , null , null , null , null

退火条件对AgCuNi/TU1复合界面的影响

李佩 , 周世平 , 刘少斌 , 刘绍虎 , 陈丽华 , 王健

贵金属 doi:10.3969/j.issn.1004-0676.2010.03.003

采用轧制复合法制备AgCuNi/TU1复合带材,使用EDS能谱仪分析不同退火条件下复合界面元素的扩散情况,利用两端不受扩散影响的扩散偶模型和Arrenius关系计算退火温度在550～750℃下Ag在TU1中的扩散系数、扩散常数与扩散激活能.结果显示:退火温度在550～750℃之间,分钟级退火时间下(退火时间<5 min),AgCuNi/TU1复合界面主要发生表面原子扩散,且扩散系数和扩散常数在同一数量级,而扩散激活能有明显差别.

关键词: 金属材料 , 复合材料 , 扩散系数 , 扩散常数 , 扩散激活能

AgCuCe/TU1层状复合材料扩散退火工艺研究

乔勋 , 王健 , 周世平 , 贺晓燕 , 李林修

贵金属 doi:10.3969/j.issn.1004-0676.2009.02.002

用室温固相轧制复合法制备了AgCuCe/TU1层状复合材料,研究了不同扩散退火工艺对AgCuCe/TU1界面结合性能的影响,测定了复合材料复层和基体的硬度,观察了试样的界面微观组织.结果表明:600 ℃/0.5 h扩散退火可以改善界面结合状态和界面附近组织形貌,获得充分的再结晶组织和致密的界面结合状态;700 ℃/0.5 h扩散退火在界面处形成细晶区和孔洞;750 ℃/0.5 h扩散退火使AgCuCe/TU1在界面处形成氧化物夹杂,严重损害界面结合性能.

关键词: 金属材料 , 复合材料 , 扩散退火 , 界面 , 显微组织

CPB和TU对X70钢在含SO2酸性溶液中的缓蚀作用

何晓英 , 邓海英 , 李容

腐蚀学报（英文） doi:10.3969/j.issn.1002-6495.2005.04.007

采用交流阻抗法和极化曲线法研究了溴代十六烷基吡啶(CPB)和硫脲(TU)在复配前后对X70钢在H2SO3溶液中的缓蚀作用.研究发现:H2SO3的浓度为10 mmol/L、pH=3.7的HAc-NaAc缓冲体系中,溴代十六烷基吡啶(CPB)与硫脲(TU)的缓蚀率随着浓度的增加而增加,溴代十六烷基吡啶(CPB)的浓度达到5×10-6kg/L时的缓蚀性能最佳,而硫脲(TU)的浓度达到50×10-6kg/L时的缓蚀性能最佳.复配实验结果表明:当缓蚀剂的总浓度为25×10-6kg/L,溴代十六烷基吡啶(CPB)和硫脲(TU)复配质量浓度比为1:1时缓蚀效果最好.

关键词: 溴代十六烷基吡啶 , 硫脲 , 协同缓蚀 , X70钢 , 电化学阻抗谱

轧制道次变形量对AgCuNi/TU1复合材料板形的影响

刘少斌 , 王健 , 李佩 , 顾彬 , 卫思璇 , 周世平

贵金属 doi:10.3969/j.issn.1004-0676.2010.02.009

通过改变轧制道次变形量,制备AgCuNi/TU1复合材料样品.样品分剪后测量其侧弯度,利用XRD测定AgCuNi/TU1复合材料残余应力分布情况.结果表明:初始道次变形量对AgCuNi/TU1复合材料分剪后的侧弯度影响较大,在道次轧制压力基本相同的条件下,轧制的复合材料板形较好.基体有复层的部分残余应力为拉应力,而没有复层的部分残余应力为压应力,样品分剪后向有复层的一侧产生侧弯.

关键词: 复合材料 , 轧制道次变形量 , 残余应力 , 侧弯度

EDA-TU的制备及其对碳钢在氨法脱硫浆液中的缓蚀作用

徐海娟 , 谢刚 , 袁靖淞 , 魏无际

材料保护

用乙二胺(EDA)和硫脲(TU)为原料制备缓蚀剂EDA-TU,优化了EDA-TU的合成条件.采用黏度法和红外光谱对合成产物的分子结构进行了表征.采用静态失重法和极化曲线法研究了其在氨法脱硫循环浆液中对Q235钢的缓蚀作用.结果表明:最佳的合成条件为合成温度80℃,反应时间4h,此时反应物的转化率最高;在氨法脱硫液中该缓蚀剂的用量为100 mg/L时,对Q235碳钢的缓蚀率可达75.16％;电化学分析表明该缓蚀剂对Q235碳钢的缓蚀作用是基于对阳极反应的抑制.

关键词: 乙二胺 , 缓蚀剂 , 氨法脱硫浆液 , 碳钢

氧含量对碳钢TU48在高温水中的低周疲劳寿命和表面腐蚀产物状态的影响

王雷明 , 钟义兵 , 朱小明 , 夏元复

中国腐蚀与防护学报

对TU48碳钢在不同溶解氧浓度的水溶液中进行了低周腐蚀疲劳，结合俄歇电子能谱（AES）和Mssbauer谱分析其表面的腐蚀产物.结果表明，随着水中溶解氧含量的增加，碳钢的腐蚀疲劳断裂时间变短，碳钢表面形成的腐蚀产物的成分也有很大的变化，Fe3O4减少，而γ-Fe2O3含量增多；在含氧量很低的条件下，腐蚀还生成α-Fe2O3和铁的氢氧化物.

关键词: 穆斯堡尔谱学 , auger electron spsctroscopy , carbon steel , oxidized film

Influence of Iron Microstructure on Corrosion Inhibitor Performance in Acidic Media

Journal of Physical Chemistry C

Electrochemical measurements employing ac and dc techniques as well as atomic force microscopy were used to study the electrochemical corrosion behavior of ingot iron with two different microstructures: conventional polycrystalline ingot iron (CPII) and bulk nanocrystalline ingot iron (BNII) fabricated from CPII by severe rolling, without and with inhibitors. The corrosive media was 0.1 M H(2)SO(4) solution, while thiourea (TU) was employed as inhibitor, with a concentration of 5.0 mM, as well as a 1:1 combination of TU and KI. Impedance and polarization results show that BNII was more susceptible to corrosion in the uninhibited acid. The presence of TU improved the corrosion resistance of both specimens comparably, while KI reduced the inhibition efficiency of TU. Infrared spectrophotometry revealed that the interfacial species for CPII and BNII in the presence of TU were quite identical and markedly different from that in TU + KI. Molecular dynamics (MD) simulations were performed to illustrate the adsorption process of TU at a molecular level, and the theoretical predictions showed good agreement with the electrochemical results.

关键词: nanocrystalline ingot iron;universal force-field;mild-steel corrosion;sulfuric-acid;electrochemical corrosion;sulfate-solution;behavior;thiourea;derivatives;molecules

Corrosion inhibition and adsorption behavior of imidazoline salt on N80 carbon steel in CO(2)-saturated solutions and its synergism with thiourea

Journal of Solid State Electrochemistry

The inhibition and adsorption behavior of 2-undecyl-1-sodium ethanoate-imidazoline salt (2M2) and thiourea (TU) on N80 mild steel in CO(2)-saturated 3 wt.% NaCl solutions was studied at 25 A degrees C, pH 4, and 1 bar CO(2) partial pressure using electrochemical methods. It was found that inhibition efficiency (eta%) increased with increase in 2M2 concentration but decreased with increase in TU concentration with optimum eta% value at 20 mg l(-1) TU. The data suggest that the compounds functioned via a mixed-inhibitor mechanism. The inhibition process is attributed to the formation of an adsorbed film of 2M2 and TU via the inhibitors polycentric adsorption sites on the metal surface which protects the metal against corrosion. A synergistic effect was observed between TU and 2M2. Potential of unpolarizability, E (u), was observed in the presence of 100 mg l(-1) TU which was shifted positively in the presence of 2M2-100 mg l(-1) TU blends, which suggests that the presence of 2M2 stabilized the adsorption of TU molecules on the surface of the metal. The adsorption characteristics of 2M2 were approximated by Langmuir adsorption isotherm.

关键词: Adsorption;CO(2) corrosion;Imidazoline;Mild steel;Synergism;Thiourea;impedance spectroscopy eis;sulfuric-acid-solution;m hcl solutions;mild-steel;dioxide corrosion;benzimidazole derivatives;anodic-dissolution;chloride solutions;h2so4 solutions;iodide-ions

硫脲对X70钢在含H2S薄层液膜下的缓蚀性能

邓祖宇 , 何晓英

腐蚀与防护

采用极化曲线法和电化学阻抗谱研究了缓蚀剂硫脲(TU)对X70钢在含H2S薄层液膜下的缓蚀作用.结果表明,在含H2S薄层液膜下,TU对X70钢有一定的缓蚀作用;TU属于以抑制阴极过程为主的缓蚀剂,TU的缓蚀性能随其浓度的增加而增加,当TU浓度为10 mg/L时达到最大值;TU浓度进一步增加,缓蚀率减小.TU在X70钢表面为化学吸附,通过氮或硫原子上的孤对电子与表面铁发生键合而化学吸附在钢表面,从而对X70钢产生缓蚀作用.

关键词: 硫脲 , X70钢 , 薄层液膜 , 极化曲线 , 电化学阻抗谱