| 1. |
- Gault, B., et al.
(författare)
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Atom probe microscopy characterization of as quenched Zr-0.8 wt% Fe and Zr-0.15 wt% Cr binary alloys
- 2013
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Ingår i: Materials letters (General ed.). - : Elsevier BV. - 0167-577X .- 1873-4979. ; 91, s. 63-66
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Tidskriftsartikel (refereegranskat)abstract
- Two binary Zr-alloys with a β-quenched structure were analysed by atom probe tomography to provide a better understanding of how Fe and Cr perform in industrial Zr alloys. In a Zr-0.8 Fe (wt%) alloy, we observed a dispersion of precipitates with a composition close to Zr3Fe, and Fe segregated to a grain boundary. In a Zr-0.15 Cr (wt%) alloy, Cr was observed in solid solution in the Zr-matrix and segregated to grain boundary where it formed small spherical particles or elongated atmospheres.
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| 2. |
- Li, Wen-Bin, et al.
(författare)
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On the Zener drag pressure by cubic shaped particles
- 1988
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Ingår i: Strength of metals and alloys. - Amsterdam : Elsevier. - 0080348041 ; , s. 1345-1350
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Konferensbidrag (refereegranskat)abstract
- All models of the Zener drag effect, in which precipitate particles hinder the movement of migrating grain boundaries, are based on spherical or ellipsoidal particles. Zener drag by cubic shaped particles is modelled. It is shown that cubic particles are generally more effective than spherical particles in holding up grain growth, and that coherent particles are better in this respect that incoherent particles
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| 3. |
- Ringer, S.P, et al.
(författare)
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Effect of particle pinning on recrystallization of a titanium-stabilized stainless steel
- 1990
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Ingår i: Recrystallization '90. - Warrendale, Pa : Minerals, Metals & Materials Society. - 0873391241 ; , s. 483-489
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Konferensbidrag (refereegranskat)abstract
- Recent work has shown that maintenance of coherency between stable particles and matrix after the bypassing of grain boundaries during grain growth can occur to reduce the energy of the particle /matrix interface, and that this occurs by a diffusion controlled bodily rotation of the particle. Since coherent particles, in general, offer more resistance to migrating boundaries than incoherent ones, a particle rotation, if it occurs, should tend to help refine grain size following recrystallization. The recrystallization and early stages of grain growth of a deformed Ti-stabilized austenitic stainless steel (321) containing coherent and semicoherent TiC precipitates has been studied by light optical and transmission electron microscopy. Evidence for a particle rotation following recrystallization of this alloy is presented. A model explaining this behaviour is developed and discussed in terms of the likely effects phenomena such as this and particle reversion will have on the recrystallization behaviour of these steels
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| 4. |
- Ringer, S.P., et al.
(författare)
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Liquid film simulation of Zener grain boundary pinning by second phase particles
- 1991
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Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 7:3, s. 193-200
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Tidskriftsartikel (refereegranskat)abstract
- The geometry of the interaction of second phase particles with migrating grain boundaries has been studied using a liquid film simulation. The geometries observed show that the perimeter of intersection between boundary and particle can be complex, often not lying in a single plane through the particle. The curvature of the boundary when in contact with the particle is also complex, sometimes displaying double curvature and often of opposite sign. These observations have been used to modify previous calculations quantifying the grain boundary pinning effect. Measurements from the photographs of these interactions have been applied to a force equilibrium approach for calculating the pinning force and these results are found to be in good agreement with values obtained using an energy analysis based on grain boundary shape change
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| 5. |
- Ringer, S.P., et al.
(författare)
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On the interaction and pinning of grain boundaries by cubic shaped precipitate particles
- 1989
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Ingår i: Acta Metallurgica. - : Elsevier BV. - 0001-6160. ; 37:3, s. 831-841
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Tidskriftsartikel (refereegranskat)abstract
- Previous models of the Zener pinning of migrating grain boundaries by precipitates are all based on spherical or ellipsoidal particles. In this work, theoretical and experimental studies are made of pinning by stable, cubic-shaped particles. It is shown that cubic-shaped particles are generally more effective than spherical particles in holding up grain growth. Pinning is also more effective if particles are fully coherent. Transmission electron microscopy is used to study actual grain boundary/particle interactions in a Ti-microalloyed steel in which the coherent precipitate is a stable, cubic-shaped titanium nitride compound. The interactions observed are discussed in the light of the models developed
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| 6. |
- Ringer, S.P., et al.
(författare)
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On the rotation of precipitate particles
- 1992
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Ingår i: Acta Metallurgica et Materialia. - 0956-7151. ; 40:2, s. 275-283
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Tidskriftsartikel (refereegranskat)abstract
- An energetically unfavourable situation can develop when coherent particles are bypassed by migrating grain boundaries. This is due to the precipitates being exposed to incoherent interfaces in the new matrix. In this work, the rotation of precipitate particles to low energy, coherent orientations in the new matrix is shown to be one of several possible responses to this situation. A physical and kinetic model for the rotation is put forward and the results of calculations of rotation rate presented. It is shown that particle rotation is controlled by interfacial diffusion and depends upon alloy composition, time, temperature and particle size and shape. The possibility of particle rotation occurring during particle/boundary contact is also discussed. This is shown to depend upon the nature of the boundary type. Generally, boundaries moving under large driving pressures with high velocities (e.g. phase transformation interfaces), are less likely to allow rotation during particle/boundary contact than less mobile boundaries such as those in grain growth and recrystallization. Experimental results, from SAD and TEM of a Ti stabilized austenitic stainless steel containing a dispersion of coherent TiC precipitates is also presented and supports the particle rotation model
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