【摘 要】
:
Hydrophobic Mg(OH)2/calcium myristate (Ca[CH3(CH2)12COO]2,CaMS) and Mg(OH)2/magnesium myristate(Mg[CH3(CH2)12COO]2,MgMS) composite coatings were prepared on the alkali-treated AZ31 substrates via both elec-trodeposition and dipping methods.The morphologie
【机 构】
:
Corrosion Laboratory for Light Metals,College of Materials Science and Engineering,Shandong Universi
论文部分内容阅读
Hydrophobic Mg(OH)2/calcium myristate (Ca[CH3(CH2)12COO]2,CaMS) and Mg(OH)2/magnesium myristate(Mg[CH3(CH2)12COO]2,MgMS) composite coatings were prepared on the alkali-treated AZ31 substrates via both elec-trodeposition and dipping methods.The morphologies,compositions,and constitutes of the coatings were investigated by using field-emission scanning electron microscopy (SEM),X-ray photoelectron spectroscopy (XPS),and Fourier transform infrared spectrometry (FTIR) together with X-ray diffractometer (XRD).Furthermore,electrochemical (polarization and impedance spectroscopy) and hydrogen evolution tests were applied to evaluate the corrosion resistance.The wettability and adhesive strength of the composite coatings were characterized through water static contact angle (CA),sliding angle(SA),and nano-scratch tests.Results indicated that the better super-hydrophobicity,corrosion resistance,and adhesion were achieved via an electrodeposited process.The corrosion current density (icorr) and hydrogen evolution rate (HER) of the electrodeposited coating were three and one orders of magnitude smaller than the substrate,implying a significantly improved corrosion resistance.This scenario was ascribed to the super-hydrophobicity of electrodeposited composite coating with a contact angle (CA) and slide angle (SA) of 159.2° ± 0.8° and 5.2° ± 0.8°,respectively.However,the dipped composite coat-ing was adverse to the improvement of corrosion resistance and adhesion due to the dissolution of the underlying Mg(OH)2 layer and smooth surface with less organic fatty acid salt (MgMS).
其他文献
介绍了黏附性能对电梯钢丝绳使用功能产生的重要影响,分析了影响油脂黏附性能的主要因素.根据电梯钢丝绳的运动特征,自制了钢丝绳的离心试验装置,对不同油脂在不同温度下的黏附性能开展研究.油脂离心试验量化了油脂的黏附性能,为电梯钢丝绳油脂的选型提供重要的试验依据.
介绍国际标准化组织钢丝绳技术委员会(ISO/TC 105)组成架构、职责范围以及现行国际标准.1980年我国以观察员身份第一次参与钢丝绳领域国际标准化工作,2010年我国承担ISO/TC 105的秘书处工作,之后开始主导多项国际标准.分析ISO/TC 105标准在实际运用中存在的问题,提出对今后ISO/TC 105工作的思考.
对42CrMo大型轴加工表面缺陷进行焊接修补,选用型号ER55-G的Φ1.2 mm JM-68实心焊丝,工件焊前预热温度为350℃,层间温度控制在400℃以内,焊接线能量在1 KJ/mm以内,焊后进行620℃去应力退火处理,修补后的工件表面无缺陷并满足荷载要求.
铁路工程用接触网立柱Q355B地脚螺栓安装过程中出现断裂失效.对断裂螺栓进行化学成分分析、碳当量值验算、断口宏观及微观形貌观察、非金属夹杂物检验、金相组织检验等.结果 表明:地脚螺栓局部出现了过热熔融现象,且碳当量值较高,螺栓局部受热后在冷却过程中产生针状马氏体淬硬组织,受到外力冲击时萌生裂纹源并迅速扩展断裂.
ER70S-6盘条生产焊丝出现拉拔断裂,通过对断裂样品进行电镜扫描以及金相分析,发现贝氏体和马氏体复合相组织是造成断裂的直接原因.根据该组织形成机制从元素偏析和轧后控冷两个方面分析,提出并实施延长盘条出罩时间、强化盘条保温效果等措施,改善盘条基体组织,解决了断丝问题.
20CrMnTiH (O)60mm热轧圆钢制造副箱中间轴,车削加工后中间轴外圆表面存在光亮环,且在光亮环中出现细小“黑点”缺陷.为研究此现象,对中间轴的化学成分、缺陷部位宏观和微观形貌、金相组织、非金属夹杂物等进行检测分析.结果 表明,由于缺陷处存在非金属夹杂物,夹杂物中含有的Al2 O3及MgO·Al2O3成分,颗粒材质较硬,在车削加工时Al2O3及MgO·Al2O3夹杂物颗粒被刀尖带出,在车刀痕表面刮擦出线状痕迹,在环境光线下造成此处与正常车刀痕表面亮度有差异,从而导致所谓“光亮环”产生.
The indentation size effect (ISE) was studied by instrumented nanoindentation and Vickers hardness measurements on poly-crystalline copper,β CuAlBe pseudoelastic and age-hardenable CuBe alloys.Variations in the load-depth curves at different loads would s
In this study,high density electric current pulse (ECP) treatment was introduced instead of the conventional solution treat-ment,and the γ\'phase was completely dissolved under the ECP treatment within only several milliseconds at 1148 ℃.Due to the extr