ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01299.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYThose aspects of quantitative X‐ray microanalysis of thin films which either differ from, or do not exist in, bulk specimen analysis are reviewed. Special emphasis is placed on electron trajectory‐linked effects, and on surface polishing fi

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01300.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYA VG Microscopes' HB5 STEM has been used to study supported ruthenium catalysts provided by ICI Ltd. They consist of small ruthenium particles 3–10 nm in diameter and have been imaged using a variety of detectors. The signal combining strongest contrast from the particles with minimum contrast variations due to diffraction effects is from a high angle annular detector. The detector is particularly useful with crystalline supports. For microanalysis purposes, X‐ray spectra, electron energy loss spectra, and microdiffraction patterns have been recorded and together show conclusively that even the smallest particles are hexagonal ruthenium me

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01301.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYSTEM X‐ray microanalysis has been used to determine the redistribution of chromium and nickel during the austenite to ferrite and reverse ferrite to austenite transformation. This paper reports results concerning three particular systems which are representative of a large number of alloy steels and iron‐base alloys. It is shown that, in general, no partitioning of the substitutional solute is observed in the transformable alloy steel or the carbon‐free iron‐base alloy such that during the austenite to ferrite transformation the austenite maintains the same chemical composition. Conversely, for the duplex stainless steel, partitioning of the solute does occur within certain temperature ranges.The results also suggest that solute enrichment may occur at the austenite/ferrite interface which can be interpreted in terms of the existence of a ‘solute dra

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01302.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYAn interactive computer program which allows the quantitation of electron energy loss spectra is described. The program performs a standardless analysis using hydrogenic cross‐section models. The accuracy of the results obtained for a wide range of experimental conditions is typically within 20% of expected values for well characterized samples. The lack of agreed thin film standards is a limit to the improvement of the cross‐section models, but under most practical operating conditions the largest errors arise from instrumental factors such as the effect of finite beam convergence and chromatic errors in the coupling opt

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01303.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYElectron energy loss spectroscopy (EELS) has been used in conjunction with high resolution microscopy (HREM) to identify second phase regions in polycrystalline SiC ceramic compacts. Most inclusions were graphitic and contained no boron, though some borides were also identified. Boron could not be detected at grain boundaries, so its role in sintering remains unclear.

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01304.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYThe atomic number dependence of electron backscattering can be used as the basis of a microanalysis technique. The operating procedures and condition for quantitative measurements of specimen atomic number are outlined and an expression relating the accuracy of composition to the atomic number sensitivity has been derived. Some measurements of the spatial resolution of backscattered electron microanalysis are also presented and compared with the resolution of X‐ray microanalysis.Although the range of application of this technique is limited, where it can be applied it has the following advantages: (i) higher spatial resolution than X‐ray microanalysis for bulk specimens; (ii) very rapid measurement; (iii) can be applied to compounds of low atomic number elements, (e.g. borides, carbides, nitrides, etc.); (iv) specimen preparation is often relatively straightforw

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01305.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYThe use of a simple electronic switch to convert the video signal from a scanning electron microscope to a series of pulses is described. A multichannel pulse height analyser may then be used to perform quantitative image analysis. Examples are given showing how composition analysis, area fraction measurement and image contouring may be performed using the atomic number contrast signal from a back‐scattered electron detector. Other detector systems such as scintillators or specimen current imaging could also be use

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01306.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYA system for the quantitative analysis of stereo‐pairs of photomicrographs has been devised using a Commodore ‘PET’ microcomputer coupled to a digitizing pad, plotter and printer. The system need not use any form of stereo‐viewer and does not require any particular alignment of the photographs. Height differences, derived from parallax measurements, can be obtained quickly even by operators who might normally experience difficulties with stereoscope‐based systems due to either poor stereo vision or inexperience. Three‐dimensional coordinates, input from point‐pairs, are stored inside the computer and may be sorted to draw line profiles along any operator‐selected line. Such profiles may be referred to either the projection of the median plane of the two images or rotated (‘levelled’) to the 0° tilt plane.The operation of the system is described and illustrated using both specially‐constructed left‐ and right‐hand ‘images’ from test contours and also real SEM stereo pairs. Finally, both the potential and limitations of such a system for development

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01307.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYThe particles in sediment from condensation aerosols of zinc and cadmium were exposed to hot, inert gas or radiant heat to investigate the structure revealed by evaporation. The smallest prisms retained their shape but the larger ones evaporated back to the dendritic form characteristic of an earlier stage in their development. It is concluded that large prisms grow with a flawed structure because of strain present in the dendritic skeleton.On spheres, the curved surface surrounding the basal flat tends to become smoother on evaporation of the vapour‐grown layer texture although deep pits develop eventually. The texture opposite the flat, where the growth helix emerges from the solidifying melt, is more persistent. The basal flat remains flat, indicating that the high degree of crystalline perfection achieved in the slowly‐growing basal raft is retained after solidificat

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01308.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY