143 research outputs found
Vacancy-assisted domain-growth in asymmetric binary alloys: a Monte Carlo study
A Monte Carlo simulation study of the vacancy-assisted domain-growth in
asymmetric binary alloys is presented. The system is modeled using a
three-state ABV Hamiltonian which includes an asymmetry term, not considered in
previous works. Our simulated system is a stoichiometric two-dimensional binary
alloy with a single vacancy which evolves according to the vacancy-atom
exchange mechanism. We obtain that, compared to the symmetric case, the
ordering process slows down dramatically. Concerning the asymptotic behavior it
is algebraic and characterized by the Allen-Cahn growth exponent x=1/2. The
late stages of the evolution are preceded by a transient regime strongly
affected by both the temperature and the degree of asymmetry of the alloy. The
results are discussed and compared to those obtained for the symmetric case.Comment: 21 pages, 9 figures, accepted for publication in Phys. Rev.
Evolution of Microstructure and Texture during Warm Rolling Of a Duplex Steel
The effect of warm rolling on the evolution of microstructure and texture in a duplex stainless steel (DSS) was investigated. For this purpose, a DSS steel was warm rolled up to 90 pct reduction in thickness at 498 K, 698 K, and 898 K (225 °C, 425 °C, and 625 °C). The microstructure with an alternate arrangement of deformed ferrite and austenite bands was observed after warm rolling; however, the microstructure after 90 pct warm rolling at 498 K and 898 K (225 °C and 625 °C) was more lamellar and uniform as compared to the rather fragmented and inhomogeneous structure observed after 90 pct warm rolling at 698 K (425 °C). The texture of ferrite in warm-rolled DSS was characterized by the presence of the RD (〈011〉//RD) and ND (〈111〉//ND) fibers. However, the texture of ferrite in DSS warm rolled at 698 K (425 °C) was distinctly different having much higher fraction of the RD-fiber components than that of the ND-fiber components. The texture and microstructural differences in ferrite in DSS warm rolled at different temperatures could be explained by the interaction of carbon atoms with dislocations. In contrast, the austenite in DSS warm rolled at different temperatures consistently showed pure metal- or copper-type deformation texture which was attributed to the increase in stacking fault energy at the warm-rolling temperatures. It was concluded that the evolution of microstructure and texture of the two constituent phases in DSS was greatly affected by the temperature of warm rolling, but not significantly by the presence of the other phas
Metalurgi Fisik Modern dan Rekayasa Material edisi 6
ilus, 479 hlm, 25c
Metalurgi Fisik Modern dan Rekayasa Material, ed. 6/ Smallman
ix, 479 hal. : ill. ; 25 c
Metalurgi Fisik Modern dan Rekayasa Material, ed. 6/ Smallman
ix, 479 hal. : ill. ; 25 c
Metalurgi Fisik Modern dan Rekayasa Material, ed. 6/ Smallman
ix, 479 hal. : ill. ; 25 c
- …