Field emission-scanning electron microscopy(FE-SEM) technique was employed to observe the shape, size and distribution of AlN+MnS inclusions in oriented electrical steels. Specimens used for FE-SEM observation were de...Field emission-scanning electron microscopy(FE-SEM) technique was employed to observe the shape, size and distribution of AlN+MnS inclusions in oriented electrical steels. Specimens used for FE-SEM observation were deeply electrolytic etched at room temperature in non-aqueous acetylacetone(AA) solution. The results indicate that the FE-SEM technique has obvious advantage in specimen preparation. Therefore, it can be easily used to identify the AlN+MnS inclusions and even copper nano-particles in oriented electrical steels with the same analysis accuracy as that by TEM. This technique is a good substitute for TEM and the associated specimen preparation in the observation of inclusions in electrical steels. It will be a powerful technique for routine analysis in the production of grain oriented electrical steels.展开更多
为确保光学麦克风在电气设备内部应用的安全可靠性,文中选定聚氨酯、聚四氟乙烯、环氧树脂、聚醚醚酮和酚醛树脂作为封装材料,进行光学麦克风与电气设备相关的环境相容性试验,并采用扫描电子显微镜(scanning electron microscope,SEM)...为确保光学麦克风在电气设备内部应用的安全可靠性,文中选定聚氨酯、聚四氟乙烯、环氧树脂、聚醚醚酮和酚醛树脂作为封装材料,进行光学麦克风与电气设备相关的环境相容性试验,并采用扫描电子显微镜(scanning electron microscope,SEM)和傅里叶变换红外(Fourier transform infrared,FTIR)光谱仪对试验前后的材料性能进行检测。结果表明:聚氨酯表面易浸润变压器油且有明显颜色变化,不适用于油浸式变压器,但可用于水听器、空气和常温环境中;聚四氟乙烯与变压器油的相容性较好,可用于油浸式变压器、气体绝缘开关设备(gas insulated switchgear,GIS)和温度变化较大的场景;其余材料与电气设备的相容性不佳,适用性有待进一步研究。文中提出的封装材料与环境相容性试验的检测方法可为光学麦克风封装材料选型提供有益借鉴,具有一定的工程实用价值。展开更多
The crystallized mullite composite has been synthesized via sol-gel technique in the presence of transition metal ions such as iron and copper. The electrical resistivity and activation energy of the composites have b...The crystallized mullite composite has been synthesized via sol-gel technique in the presence of transition metal ions such as iron and copper. The electrical resistivity and activation energy of the composites have been measured and their variation with concentration of the metal ion has been investigated. The resistivity of doped mullite decreases rapidly in the shorter temperature range and sharply in the higher temperature range. The decreasing resistivity is due to the 3d orbital electrons and the concentration of metal ions present. X-ray analysis confirms the presence of metal ions in mullite, which entered in the octahedral site. The Fe2+ and Cu2+ ions will substitute Al3+ ion in the octahedral site of mullite structure and most probably will be responsible for reducing the resistivity as well as the activation energy. Transition metal ion doped mullite-based ceramic can be considered as promising material as a substrate in the electronic industry, because of its reasonable atom density, its low activation characteristics, low thermal expansion coefficient and high mechanical strength. The present material we have developed has an activation energy of resistivity/band gap energy, Eg, 1.11 eV at 0.04 M concentration for Cu2+ ion.展开更多
基金Project(50471104) supported by the National Natural Science Foundation of China
文摘Field emission-scanning electron microscopy(FE-SEM) technique was employed to observe the shape, size and distribution of AlN+MnS inclusions in oriented electrical steels. Specimens used for FE-SEM observation were deeply electrolytic etched at room temperature in non-aqueous acetylacetone(AA) solution. The results indicate that the FE-SEM technique has obvious advantage in specimen preparation. Therefore, it can be easily used to identify the AlN+MnS inclusions and even copper nano-particles in oriented electrical steels with the same analysis accuracy as that by TEM. This technique is a good substitute for TEM and the associated specimen preparation in the observation of inclusions in electrical steels. It will be a powerful technique for routine analysis in the production of grain oriented electrical steels.
文摘The crystallized mullite composite has been synthesized via sol-gel technique in the presence of transition metal ions such as iron and copper. The electrical resistivity and activation energy of the composites have been measured and their variation with concentration of the metal ion has been investigated. The resistivity of doped mullite decreases rapidly in the shorter temperature range and sharply in the higher temperature range. The decreasing resistivity is due to the 3d orbital electrons and the concentration of metal ions present. X-ray analysis confirms the presence of metal ions in mullite, which entered in the octahedral site. The Fe2+ and Cu2+ ions will substitute Al3+ ion in the octahedral site of mullite structure and most probably will be responsible for reducing the resistivity as well as the activation energy. Transition metal ion doped mullite-based ceramic can be considered as promising material as a substrate in the electronic industry, because of its reasonable atom density, its low activation characteristics, low thermal expansion coefficient and high mechanical strength. The present material we have developed has an activation energy of resistivity/band gap energy, Eg, 1.11 eV at 0.04 M concentration for Cu2+ ion.
