The effect of hydrogen on the corrosion and stress corrosion cracking of the magnesium AZ91 alloy has been investigated in aqueous solutions. Hydrogen produced by corrosion in water diffuses into, and reacts with the ...The effect of hydrogen on the corrosion and stress corrosion cracking of the magnesium AZ91 alloy has been investigated in aqueous solutions. Hydrogen produced by corrosion in water diffuses into, and reacts with the Mg matrix to form hydride. Some of the hydrogen accumulates at hydride/Mg matrix （or secondary phase） interfaces as a consequence of slow hydride formation and the incompatibility of the hydride with the Mg matrix （or secondary phase）, and combines to form molecular hydrogen. This leads to the development of a local pressure at the hydride/Mg matrix （or secondary phase） interface. The expansion stress caused by hydride formation and the local hydrogen pressure due to its accumulation result in brittle fracture of hydride. These two combined effects promote both the corrosion rate of the AZ91 alloy, and crack initiation and propagation even in the absence of an external load. Hydrogen absorption leads to a dramatic deterioration in the mechanical properties of the AZ91 alloy, indicating that hydrogen embrittlement is responsible for transgulanar stress corrosion cracking in aqueous solutions.展开更多
通过气相外延技术生长了Au掺杂的Hg_(1-x)Cd_xTe薄膜材料。利用傅里叶光谱仪和金相显微镜对外延材料进行了表征。通过二次离子质谱(Secondary Ion Mass Spectroscopy,SIMS)技术分析了Au在Hg_(1-x)Cd_xTe外延层以及CdZnTe衬底中的纵向分...通过气相外延技术生长了Au掺杂的Hg_(1-x)Cd_xTe薄膜材料。利用傅里叶光谱仪和金相显微镜对外延材料进行了表征。通过二次离子质谱(Secondary Ion Mass Spectroscopy,SIMS)技术分析了Au在Hg_(1-x)Cd_xTe外延层以及CdZnTe衬底中的纵向分布趋势。利用SIMS技术还分析了Ⅰ、Ⅱ族和Ⅵ、Ⅶ族杂质在Hg_(1-x)Cd_xTe外延层以及CdZnTe衬底中的纵向分布趋势,发现衬底和外延层的过渡区具有吸杂作用。研究结果对提高探测器的性能具有指导意义。展开更多
基金supported by the Hundred Talent Program of the Chinese Academy of Sciences,the National Natural Science Foundation of China(No.50499336)the National Basic Research Program of China(No.2007CB613705)
文摘The effect of hydrogen on the corrosion and stress corrosion cracking of the magnesium AZ91 alloy has been investigated in aqueous solutions. Hydrogen produced by corrosion in water diffuses into, and reacts with the Mg matrix to form hydride. Some of the hydrogen accumulates at hydride/Mg matrix （or secondary phase） interfaces as a consequence of slow hydride formation and the incompatibility of the hydride with the Mg matrix （or secondary phase）, and combines to form molecular hydrogen. This leads to the development of a local pressure at the hydride/Mg matrix （or secondary phase） interface. The expansion stress caused by hydride formation and the local hydrogen pressure due to its accumulation result in brittle fracture of hydride. These two combined effects promote both the corrosion rate of the AZ91 alloy, and crack initiation and propagation even in the absence of an external load. Hydrogen absorption leads to a dramatic deterioration in the mechanical properties of the AZ91 alloy, indicating that hydrogen embrittlement is responsible for transgulanar stress corrosion cracking in aqueous solutions.
文摘通过气相外延技术生长了Au掺杂的Hg_(1-x)Cd_xTe薄膜材料。利用傅里叶光谱仪和金相显微镜对外延材料进行了表征。通过二次离子质谱(Secondary Ion Mass Spectroscopy,SIMS)技术分析了Au在Hg_(1-x)Cd_xTe外延层以及CdZnTe衬底中的纵向分布趋势。利用SIMS技术还分析了Ⅰ、Ⅱ族和Ⅵ、Ⅶ族杂质在Hg_(1-x)Cd_xTe外延层以及CdZnTe衬底中的纵向分布趋势,发现衬底和外延层的过渡区具有吸杂作用。研究结果对提高探测器的性能具有指导意义。
