透射电镜像转角的测定及应用

论述了完全标定透射电镜像转角所需拍摄的二次曝光电子显微像的数量,推导了由已测的像转角间接计算其它像转角的一般公式,以Philips Cm200电镜为实例,说明了测定像转角的基本步骤,并以实例说明怎样利用像转角,把衍射花样的晶体学信息传递给电子显微像。     

Inner Surface Modification of a Tube by Magnetic Glow-Arc Plasma Source Ion Implantation

A new method named the magnetic glow-arc plasma source ion implantation （MGA-PSⅡ） is proposed for inner surface modification of tubes. In MGA-PSⅡ, under the control of an axial magnetic field, which is generated by an electric coil around the tube sample, glow arc plasma moves spirally into the tube from its two ends. A negative voltage applied on the tube realized its inner surface implantation. Titanium nitride （TIN） films are prepared on the inner surface of a stainless steel tube in diameter 90mm and length 600mm. Hardness tests show that the hardness at the tube centre is up to 20 GPa. XRD, XPS and AES analyses demonstrate that good quality of TiN films can be achieved.     

蝶状马氏体的自促发相变

采用复变函数方法计算了蝶状马氏体周围的应力场分布.计算结果表明,在蝶状马氏体的凸部存在很强的张应力,而在两翼结合的凹部存在很大的压应力.新的蝶状马氏体容易在张应力处被应变诱发生成,即应变诱发蝶状马氏体多出现在先生成的蝶状马氏体的凸部.但在两翼结合的凹部,即压应力处,也可能诱发新的蝶状马氏体.张应力场诱发的蝶状马氏体的尺寸比压应力场诱发的蝶状马氏体大.在一串自促发蝶状马氏体中,第2个蝶状马氏体多在第1个蝶状马氏体凸部大约2μm处出现.以上计算结果与实验观察符合较好.     

DIFFUSIVE AGGREGATION ON ION IMPLANTED THIN FILMS

Diffusive aggregation on-ion implanted thin films is studied. It is revealed that aggregation is realized mainly by atoms or clusters in the film matrix. The implanting ions play the role of triggering them into motion and supplying the kinetic energy for their diffusion. The aggregation process is characterized by finite density of aggregating particles, random triggering, and limited diffusion distance. The aggregate observed shows scaling or fractal property.     

MICROSTRUCTURE AT THE INTERFACE OF TITANIUM CARBIDE AND NICKEL ALUMINIDES

Microstructure at the interface of titanium carbide and nickel aluminides in the samples obtained by infiltration of molten Ni₃Al alloy has studied by a scanning electron microscopy (SEM) and an analytical transmission electron microscopy (ATEM) with an energy dispersive spectrometer (EDS). It is found that the morphology at the interfaces between hard phase skeleton of TiC_0.7 and metallic phases depends on the ratio of Ti/C in carbide. Some periodic zigzag fringes are observed at a smooth interface between metallic phase and carbides in the sample of Ni₃Al/TiC_0.7. The results of analysis using EDS show that Ti in TiC_0.7 carbide is easier than that in TiC_0.7 to dissolve into the molten alloy during solid-liquid reaction. The formation of this periodic zigzag fringe,which may be a growth zone of a new Ti-Ni-Al phase,in the interface of TiC_0.7/Ni₃Al would occur during the initial stage of solidification.