A.A.El-Meligi
材料科学技术（英）
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
Jong-Kyu Baek
,
Hae-Wook Kwon
材料科学技术（英）
The effects of processing variables on the fluidity of hypereutectic Al-Si alloy melt during squeeze casting were investigated. The maximum fluidity of Al-16.0%Si alloy during squeeze casting was obtained under the applied pressure of 30 MPa. The fluidity increased with superheat. The fluidity increased with silicon content in the range from 12.0% to 20.0%. That was decreased respectively by eutectic modification and primary silicon refinement.
关键词:
Squeeze casting
,
null
,
null
,
null
弓满锋
,
乔生儒
,
梅芳
,
袁月清
材料导报
假设薄膜和基体界面处于理想结合状态,基于应变协调理论,采用有限元软件(ANSYS 8.0)分析了不同膜基比(hc/hs)和开孔对氧化铝薄膜/铝合金基体系统热屈曲变形、热应力的影响.结果表明,当矩形薄板发生热屈曲时,曲率和热应力均随膜基比非线性变化.随着膜基比的增加,曲率不断减小,而薄膜和基体中的热应力表现出不同的变化趋势,基体中的热应力随膜基比的增加而增加,薄膜中的热应力随膜基比的增加而减小.当hc/hs<0.005时,曲率受膜基比的影响非常大且曲线较陡;当hc/hs>0.005时,曲率随膜基比的增加而缓慢减小.开孔能在一定程度上缓解系统的热屈曲变形,但是这种缓解程度相对较小.无孔时系统中的热残余应力在面内基本上都是均匀分布的,而开孔时系统中的热残余应力分布不再均匀,特别是在小孔附近产生了严重的应力集中现象,膜基比越小则应力集中现象越严重.
关键词:
氧化铝薄膜
,
铝合金
,
热屈曲
,
变形
,
应力
,
有限元
林化强
,
段文超
,
孙琳
,
史洪微
,
刘常升
,
刘福春
,
韩恩厚
腐蚀科学与防护技术
doi:10.11903/1002.6495.2016.187
通过对比商业化的抑制剂颜料铬酸锶和改性多聚磷酸锶铝,研究了新型绿色抑制剂颜料-肉桂酸铈对轨道交通用7XXX铝合金的腐蚀抑制行为和含肉桂酸铈环氧涂层的腐蚀防护行为.浸泡实验的结果表明,肉桂酸铈和铬酸锶对铝合金的腐蚀具有优秀的抑制作用.极化曲线(PDS)的结果表明,改性多聚磷酸锶铝在浸泡初期对铝合金具有较强的腐蚀抑制能力,而这种腐蚀抑制能力在浸泡后期弱于肉桂酸铈和铬酸锶.研究了含有1％(质量分数)以上3种抑制剂颜料环氧漆的腐蚀行为,电化学阻抗谱(EIS)结果表明,含有1％肉桂酸铈的环氧涂层具有优秀的腐蚀防护能力.
关键词:
肉桂酸铈
,
铝合金
,
抑制剂颜料
,
电化学阻抗谱
,
腐蚀抑制
