Ji-Juan Liu
,
Ran Li
,
Lian-Xiang Fang
,
Ju Wang
,
Tao Zhang
金属学报(英文版)
doi:10.1007/s40195-016-0368-3
Unexpected facture without any room-temperature plasticity severely limits potential structural applications of bulk metallic glasses (BMGs), especially La-, Mg- and Fe-based ones. In this study, a simple free corrosion method was provided to improve the plasticity of a brittle (La, Ce)-based BMG by the introduction of high-density corrosion defects on the surface. The influences of immersing time in 0.1 mol/L H2SO4 aqueous solution on the surface morphology and mechanical properties of the BMG were evaluated. With increasing immersing time from 5 to 30 min, the degree of surface corrosion increased obviously, and the distribution of corrosion defects became more homogenous. In the samples, the yielding phenomenon and certain plasticity appeared up to 0.3% after the surface treatment. The yielding and plasticity can be attributed to easier nucleation of shear bands on the defect surface rather than on the glabrous surface. The results provided a novel method to improve the plasticity of BMGs.
关键词:
Metallic
,
glasses
,
Corrosion
,
plastic
,
deformation
,
mechanism
,
Rapid
,
solidification
,
Microstructure
徐群杰
,
朱律均
,
齐航
,
曹为民
,
周国定
金属学报
用光电化学方法研究了Cu在不同浓度NaCl的硼酸--硼砂溶液中的腐蚀以及缓蚀剂聚天冬氨酸(PASP)对Cu的缓蚀作用. Cu在硼酸--硼砂缓冲溶液中, 表面的Cu2O膜为p型半导体. 当Cu所在的溶液中存在少量NaCl (小于0.5 g/L)时, Cu表面Cu2O膜会受轻微Cl-掺杂但不会改变半导体性质; 当溶液中存在较多NaCl (0.5-15 g/L)时, Cu2O膜会受Cl-较严重的侵蚀, Cl-掺杂使Cu2O膜部分转成n型; 当溶液中存在大量NaCl (大于15 g/L)时, Cu$_{2}$O膜完全被Cl-掺杂而转型成n型. 缓蚀剂PASP的加入能够对Cu起到缓蚀作用：当NaCl浓度为2 g/L时, PASP与溶液中的Cl-在Cu表面竞争吸附, 明显抑制了Cl-对Cu2O膜的掺杂, Cu2O受到了保护仍为p型; 在NaCl浓度为30 g/L时, PASP与Cl-竞争吸附只能削弱Cl-对Cu2O膜的掺杂, Cu2O膜仍受Cl-掺杂而转成n型, 但n型性质变弱. 对Cu2O膜性质的Mott-Schottky测试结果与光电化学结果一致.
关键词:
Cu
,
Photoelectrochemistry
,
Corrosion
,
Inhibitor
,
PASP
张金涛
,
胡吉明
,
张鉴清
,
曹楚南
金属学报
通过电化学阻抗谱(EIS)技术研究了LY12铝合金/钝化膜/环氧涂层复合电极在NaCl水溶液中的腐蚀行为.结果表明, 随浸泡时间的延长, 复合电极体系的阻抗不断增大；在浸泡初期, 复合电极体系的阻抗谱中即出现了低频扩散阻抗, 认为该阻抗由金属表面钝化膜的溶解产物的传质引起. 扫描电镜(SEM)观察表明铬酸盐钝化膜呈现明显的裂纹形貌; 利于溶解的铬盐通过裂纹到达合金基体使其钝化,是复合电极阻抗不断增大的原因所在.
关键词:
铝合金
,
Passivation
,
Epoxy coatings
,
Corrosion
唐咸燕
中国腐蚀与防护学报
对于市政排污管道而言,硫酸杆菌往往是造成其腐蚀的一个主要原因.本文总结了近年来混凝土硫酸杆菌腐蚀的研究进展.归纳认为针对混凝土硫酸杆菌腐蚀的研究大致可以分为两种实验研究方法:细菌模拟测试和现场暴露测试.同时还介绍了混凝土硫酸杆菌的腐蚀机理以及硫酸杆菌侵蚀与化学硫酸侵蚀的区别;总结了在评价混凝土抗硫酸杆菌侵蚀性能时使用的各种参数以及提高混凝土抗侵蚀性能的措施.最后认为虽然对混凝土的硫酸杆菌腐蚀的研究取得了一些进展,但是该领域在国内尚属起步研究阶段,在腐蚀程度的评价、预测模型的建立、细菌与母体的关系以及是否可以利用细菌活动来提高混凝土的抗腐蚀能力等方面的研究还很欠缺,建议尽快加强这些方面的研究
关键词:
混凝土
,
Concrete
,
Corrosion
,
Durability
,
Advances
程学群
,
李晓刚
,
杜翠薇
中国腐蚀与防护学报
采用特制高压釜设备，研究304L不锈钢、316L不锈钢、317L不锈钢和镍基合金（Incoloy 800）在高温高压醋酸溶液中的腐蚀，初步探讨了不锈钢和镍基合金在醋酸溶液中的腐蚀机理及Ni和Mo元素对提高不锈钢耐蚀性能的影响。结果表明，温度对不锈钢和镍基合金耐蚀性有显著影响，随着温度的升高，腐蚀速率逐渐增大，当温度升高到一定值，不锈钢的耐蚀性会急剧下降。在低温醋酸溶液中，Ni对于提高不锈钢耐蚀性是有益的；在高温醋酸溶液中，Ni对于提高不锈钢耐蚀性没有显著影响。在低温醋酸溶液中，Mo对于提高不锈钢耐蚀性没有显著影响；在高温醋酸溶液中，Mo对于提高不锈钢耐蚀性是有益的。
关键词:
醋酸
,
Stainless steel
,
Nickel Based Alloy
,
Corrosion
A.A.El-Meligi
材料科学技术（英文）
Al-alloy (AA5022) corrosion penetration (CP) and crystal structure were investigated after running static immersion corrosion tests in 1 mol/L HCl solution and different concentrations of rare earth elements (La3+), (Ce3+) and their combination, at different temperatures. X-ray diffraction (XRD) was used to examine the surface structure before and after immersion, and secondary electron detector (SED) was operated to study surface morphology. In 1 mol/L HCl solution the corrosion penetration increased with increasing temperature and immersion time. The increase of La3+ concentrations up to 1000×10-6 g/L led to the decrease in the corrosion penetration, and the decrease in Ce3+ concentrations up to 50×10-6 g/L decreases the corrosion penetration of the alloy. Mix3 (combination of La3+ and Ce3+) dramatically reduced the corrosion penetration. This suggests that a synergistic effect exists between La3+ and Ce3+. The reaction kinetics both in absence and presence of La3+ and Ce3+ and their combination would follow a parabolic rate law. The XRD patterns revealed that the intensities of certain hkl phases are affected. The crystalline structure has not been deformed either before or after testing and there are no additional peaks except that of the as-received alloy. In the case of accelerating CP, the surface morphology shows that the roughness and voids of surface are increased.
关键词:
Al-alloy
,
Corrosion
,
penetration
,
Crystal
,
s
Haitao Wang
材料科学技术（英文）
A cellular automata model was used to study the diffusion characteristics in the corrosion film at a mesoscopic scale. The model focused on a metal/film/electrolyte system, including a series of local evolution rules. The effect of diffusion rate on the film growth and metal corrosion was investigated. The result showed that the growth rate of the film followed a power law with the diffusion steps, and the corrosion rate had the same law as that of the film growth in the model with the feedback effect. There existed a diffusing plane in the film, where the concentration of the diffusing species did not depend on time. The diffusion steps were found to have a great influence on the position and species concentration of the diffusing plane.
关键词:
Corrosion
