| 1. |
- Borgenstam, Annika, et al.
(författare)
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Bainite in the light of rapid continuous cooling information
- 1996
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Ingår i: Metallurgical and Materials Transactions. A. - 1073-5623 .- 1543-1940. ; 27:6, s. 1501-1512
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Tidskriftsartikel (refereegranskat)abstract
- Rapid continuous cooling of pure iron can produce three different transformations yielding acicular structures: Widmanstätten a, lath martensite, and lenticular martensite. The information on their extensions into binary systems with carbon, nickel, and chromium has been reviewed, and admittedly rough methods have been used for estimating growth rates in order to examine the role of diffusion. The effect of alloying elements on their plateau temperatures and growth rates indicates that Widmanstätten a in Fe-C alloys grows under conditions close to local equilibrium for carbon, and it is suggested that the same should hold for edgewise growth of bainite. In Fe-Ni alloys, there are indications that Widmanstätten α grows under a considerable solute drag, an effect which may also occur for bainite. In Fe-Cr alloys, the solute drag effect seems to be weaker but may increase with the carbon content.
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| 2. |
- Wei, L.Y., et al.
(författare)
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Intergranular microstructure of cast Mg-Zn and Mg-Zn-rare earth alloys
- 1995
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Ingår i: Metallurgical and Materials Transactions. A. - 1073-5623 .- 1543-1940. ; 26A:8, s. 1947-1955
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Tidskriftsartikel (refereegranskat)abstract
- The solidification path and microstructure of cast Mg-9Zn and Mg-8Zn-1.5 MM (misch metal) alloys have been investigated by a combination of thermal analysis and analytical electron microscopy. The addition of 1.5 wt pct MM had a strong influence on the as-cast microstructure with the introduction of new `ternary' interdendritic phases and structural modification of known binary phases. The temperature ranges for formation of these phases from the melt were identified, their crystal structures determined, and their compositions analyzed. Products from eutectoidal decomposition of the interdendritic phase in the binary Mg-9Zn alloy were also identified
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| 3. |
- Wei, L.Y., et al.
(författare)
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Precipitation hardening of Mg-Zn and Mg-Zn-RE alloys
- 1995
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Ingår i: Metallurgical and Materials Transactions. A. - 1073-5623 .- 1543-1940. ; 26A:7, s. 1705-1716
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Tidskriftsartikel (refereegranskat)abstract
- The age-hardening response of two cast Mg-Zn-RE alloys has been investigated and compared with that of a binary Mg-Zn alloy. The microstructures of the aged specimens were examined by analytical electron microscopy. Formation of a fine dispersion of rodlike β prime 1 precipitates is the main cause for age hardening, while extensive precipitation of disc-shaped β prime 2 coincides with the onset of overaging. Rare earth additions retard the formation of β prime 2 precipitates and thus postpone overaging. Four different orientation relationships between β prime 2 precipitates and matrix were found and explained in terms of the near-CSL model.
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| 4. |
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