Scanning electron microscopic inspection

A method used to prevent charging of the sample during scanning electron microscopic inspection is to coat the sample with a conducting metal such as gold, which is a destructive process as the metal caimot be removed from the surface of the substrate. Conducting polymers that can be spin-appKed onto the sample and subsequently removed cleanly are ideal. Polyanfline has been demonstrated to provide such a solution. 

Morphological and fractographic inspection of the materials were performed on cryogenic fractured surfaces taken from the central region of tested and untested DDENT specimens, using a Jeol JSM 6400 Scanning Electronic microscope (SEM). 

X-ray residual stress determination was performed on the surface of the samples prepared by HIP sintering. The measured residual stress was compared with the results calculated by the finite element method (FEM). The electrical resistivity was measured by the four probes method on the slices cut from the cylinder samples. In order to inspect the thermal stability, the samples were annealed at 900 °C for 24 hour in vacuum. The microstructure on the section was observed by scanning electron microscope. 

Solutions of acid copper sulfate (containing only chloride and carrier) were used as the copper electroplating bath. A piece of titanium mesh (diameter = 55 mm) coated with iridium oxide was used as an insoluble anode. The bath was pumped through the anode to the cathode under 1 l/min and controlled at 25 °C. The cathode rotating speed was maintained at 165 rpm. The copper electrodeposition tests were conducted under different electric field waveforms with an average cathodic current density of 25 to 32 ASF, which was controlled by the cell voltage. Samples were cross-sectioned with a focused ion beam scanning electron microscope (FIB-SEM) to inspect both the quality of the copper deposits in the trenches or via-holes. 

Optically this may involve filling the pores with a material such as black wax or Wood s metal, sectioning and inspecting with a microscope or scanning electron microscope. 

After oxidation or electrolysis corrosion tests, the working surface of the alloy samples was inspected by X-ray diffraction (XRD) using a M2 IX diffractometer with Cu Ka radiation. The cross-section of the anode samples were examined using a JSM-6480LV scanning electron microscope (SEM) and the compositions of the oxide layers on the anode samples after polishing were also determined by energy dispersive X-ray spectroscopy (EDS). 

Fracture surfaces of the cracked spouts were examined using a Hitachi S-3500N scanning electron microscope (SEM). The specimens were cleaned ultrasonically in a mixture of isopropanol and deionized water. Prior to the inspection the surfaces were gold sputter coated to enhance the imaging. 

In reality, the identification of one or more forms of corrosion requires visual observation, nondestructive inspection methods, optical microscopic examination, and sometimes electron scanning microscopy, etc. The first study of the corrosion appearance of a case should divide corrosion into uniform and localized corrosion. Localized corrosion can be further identified as macroscopic or microscopic local corrosion. Microscopic attack refers to a minute amount of dissolved metal, accompanied by considerable damage, before the phenomenon becomes visible to the naked eye. 

---