| 1. |
- Bengtsson, B., et al.
(författare)
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Quantitative STEM chemical analysis
- 1978
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Ingår i: Scanning electron microscopy. - AMF O'Hare, Ill : Scanning Electron Microscopy, Inc.. ; , s. 655-662
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Konferensbidrag (refereegranskat)
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| 2. |
- Bengtsson, B., et al.
(författare)
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Quantitative STEM microanalysis
- 1978
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Ingår i: Scandinavian journal of metallurgy. - 0371-0459 .- 1600-0692. ; 7:2, s. 57-59
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Easterling, K.E.
(författare)
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Metallurgical applications of scanning transmission electron microscopy
- 1977
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Ingår i: Journal of Materials Science. - 0022-2461 .- 1573-4803. ; 12:5, s. 857-868
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Tidskriftsartikel (refereegranskat)abstract
- It is shown that scanning transmission microscopy (STEM) has followed two main lines of development, the pure STEM based upon a field emission electron source in which the emphasis is given to high resolution, and a combined system in which STEM is an attachment to a conventional transmission microscope (TEM+STEM). When used in combination with an energy dispersive X-ray spectrometer, the combined TEM+STEM system is shown to be extremely versatile and possibly the more useful for the applied metallurgist. The high vacuum requirements of pure STEM, however, make this system suitable to be used in conjunction with an Auger spectrometer. Examples of the various microanalysis facilities of STEM are given in the article, including micro-diffraction, rocking-beam channelling patterns, qualitative and quantitative X-ray spectroscopy analysis, particle analysis, and in situ experimentation. The controversial subject of whether thicker specimens can be studied in STEM compared with conventional TEM is also discussed
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| 4. |
- Easterling, K. E.
(författare)
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Recent developments in quantitative electron microscopy
- 1977
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Ingår i: International Metals Review. - : Informa UK Limited. - 0308-4590. ; 22:1, s. 1-24
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Tidskriftsartikel (refereegranskat)abstract
- Recent developments across the whole field of electron microscopy and associated equipment and techniques are reviewed with particular emphasis on quantitative measurements and analysis. The review is intended to cover a wide field embracing transmission, scanning, and scanning transmission microscopy as well as X-ray spectroscopy, on-line image analysis, and in situ experimentation, with the object of seeing how and to what effect quantitative electron microscopy is serving materials technology.
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| 5. |
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| 6. |
- Easterling, K.E., et al.
(författare)
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Some recent developments in powder metallurgy in Sweden
- 1979
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Ingår i: Science of Sintering. - 0350-820X. ; 11:spec, s. 105-120
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Tidskriftsartikel (refereegranskat)abstract
- The authors concentrate on some recent scientific and technological developments in the two main areas of activity in Sweden, i.e. cemented carbides and steel powder metallurgy. They also give a few details of some interesting preliminary work on the hot isostatic pressing of silicon nitride and the development of sintered oxide containers for storing nuclear waste materials
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| 7. |
- Easterling, K.E., et al.
(författare)
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The nucleation of martensite in steel
- 1976
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Ingår i: Acta Metallurgica. - : Elsevier BV. - 0001-6160. ; 24:4, s. 333-341
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Tidskriftsartikel (refereegranskat)abstract
- Calculations of the total energy for transforming austenite to martensite in the form of thin ellipsoidal plates, fully coherent with the austenite, show that the process may be spontaneous in the presence of pre-existing dislocations. It is found that dislocations, or groups of dislocations, in the austenite are suitable sites for martensite nucleation in that their strain fields may interact favourably with the strain field associated with the Bain deformation thereby eliminating the energy barrier to nucleation. The driving force for twinning to occur virtually simultaneously with nucleation is large and when this happens energy is released for thickening and growth of the nucleus. It is also found that the strain energy of coherent plates of martensite, whether twinned or untwinned, is a function of their orientation in the austenite, although the lowest strain energy case occur nevertheless over a relatively wide range of orientations
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| 8. |
- Porter, D.A., et al.
(författare)
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Dynamic studies of the deformation and fracture of pearlite using 200 kV SEM
- 1978
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Ingår i: Electron microscopy 1978. - Toronto : Microsopical Soc. of Canada. - 0920622062 ; , s. 578-579
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Konferensbidrag (refereegranskat)abstract
- Summary form only given, as follows. The influence of interlamellar spacing on the mechanics of deformation was studied and the materials examined ranged from coarse pearlite, with a mean interlamellar spacing λ~0.4 μm, to fine pearlite with λ~0.1 μm. The problems of ex post facto reasoning regarding the modes of deformation were avoided by continuously following deformation with the TV monitor and recording high resolution slow scan micrographs from the same area both before and after straining. The results of this investigation have shown that there are large differences in the deformation and fracture mechanisms between coarse and fine pearlites, especially when the cementite lamellae are aligned close to the tensile axis
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| 9. |
- Porter, D.A., et al.
(författare)
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Dynamic studies of the tensile deformation and fracture of pearlite
- 1978
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Ingår i: Acta Metallurgica. - : Elsevier BV. - 0001-6160. ; 26:9, s. 1405-1422
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Tidskriftsartikel (refereegranskat)abstract
- High resolution 200 kV scanning electron microscopy has been used to study in situ the tensile deformation and fracture of a range of pearlites, from relatively coarse mean interlamellar spacing of about 400 nm, to very fine mean spacing of about 90 nm. It was found that there were considerable differences in the tensile deformation behaviour between fine and coarse pearlites. A model is proposed to account for the differences based upon a combination of pile-up and fibre loading stresses, in which the operating deformation mode is largely determined by which type of mechanism is dominant
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| 10. |
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| 11. |
- Sotkovszki, P., et al.
(författare)
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Secondary ion analysis of segregation in welded steels
- 1979
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Ingår i: Metal Science. - : Maney Publishing. - 0306-3453. ; 13:10, s. 597-601
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Tidskriftsartikel (refereegranskat)abstract
- The role of weld defects, such as root cracks, or cold cracking in helping to initiate fatigue failure or reducing the impact toughness of welded constructions is now fairly well established. In the case of cold cracking, it is now standard procedure to use the basic (low-hydrogen) electrodes when welding high-strength micro alloyed fine grained or quenched and tempered steels. However, it has to be acknowledged that the mechanism of cold cracking and its relation to the dispersion of inclusions or the amount of hydrogen in steels is not well understood. It has been established that cold cracking may arise in welds containing martensite due evidently to the fact that hydrogen has a lower solubility in martensite than ferrite. However, whether the expelled hydrogen then congregates at the martensite/ferrite phase boundary or elsewhere has not been clarified. It was thus the object of the present work to consider some of the metallurgical consequences of using basic or rutile electrodes when welding high-strength steels, with particular reference to the segregation of the various alloying elements around inclusions. For this purpose the relatively new technique of secondary ion analysis was employed in conjunction with light and electron microscopy. The unique feature of secondary ion analysis is that hydrogen can be detected even when present in relatively small amounts.
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| 12. |
- Åström, H., et al.
(författare)
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Hot cracking and micro-segregation in 18-1 0 stainless steel welds
- 1976
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Ingår i: Metal Science. - : Maney Publishing. - 0306-3453. ; 10:7, s. 225-234
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Tidskriftsartikel (refereegranskat)abstract
- Advanced quantitative chemical and image analysis techniques based on scanning and scanning-transmission electron miCroscopy have been used to study hot cracking and micro-segregation in an 18%Cr-10%Ni weld metal. It is found that the main cause of hot cracking is sulphur segregation. In fully austenitic welds, manganese remains in solution and when the last of the S-rich 'melt solidifies Mn is simply not available to break up the sulphide films. The present practice of substantially increasing the amount of Mn in austenitic welds, or adding cerium, would thus seem to be justified. Phosphorus also aggravates the problem of hot cracking, but fortunately it does not appear to segregate so markedly as sulphur, being much more soluble in austenite. If the weld metal is so alloyed that solidification to the two-phase austenite plus ferrite occurs, hot cracking does not occur. The two main reasons are concluded to be: (1) manganese is less soluble in ferrite than austenite and a sufficient quantity of Mn is evidently released to combine with S and form inclusions; (2) the structural refinement of two-phase structures, compared to the single-phase austenite, results in a more even distribution of Sand P throughout the weld metal, and marked segregation is thus avoided.
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