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The theory of transformations in metals and alloys

TL;DR: In this paper, the authors present a general introduction to the theory of transformation kinetics of real metals, including the formation and evolution of martensitic transformations, as well as a theory of dislocations.
Abstract: Part I General introduction. Formal geometry of crystal lattices. The theory of reaction rates. The thermodynamics of irreversable processes. The structure of real metals. Solids solutions. The theory of dislocations. Polycrystalline aggregates. Diffusion in the solid state. The classical theory of nucleation. Theory of thermally activated growth. Formal theory of transformation kinetics. Part II Growth from the vapour phase. Solidification and melting. Polymorphic Changes. Precipitation from supersaturated solid solution. Eutectoidal transformations. Order-disorder transformations. Recovery recrystalisation and grain growth. Deformation twinning. Characteristics of martensic transformations. Crystallography of martensitic transformations. Kinetics of martensitic transformations. Rapid solidification. Bainite steels. Shape memory alloys.
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TL;DR: In this paper, a simple model incorporating a temperature-dependent equilibrium proportion of the phases is proposed and shown to lead to a good correlation between experimental and theoretical results, and it is also shown to be compatible with the thermodynamics of irreversible processes.
Abstract: n this paper, the kinetics of anisothermal structural transformations are first discussed. Classical models are shown to raise difficulties because they do not take into account the existence of a temperature–dependent equilibrium proportion of the phases. A very simple model incorporating this factor is proposed and shown to lead to a good correlation between experimental and theoretical results it is also shown to be compatible with the thermodynamics of irreversible processes. The model can be extended to include the possibility of isothermal kinetics of the Johnson–Mehl type, as well as the influence of austenite grain size. The influence of the transformations on plastic behaviour (transformation plasticity) is next discussed. A simple model is described using first purely heuristic considerations, then a more microscopic and physical approach. Possible improvements to this model are suggested, especially the inclusion of the fact that the microscopic plasticity generated by volume differenc...

97 citations

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TL;DR: The theory of deformation twinning is developed and applied to superlattice structures as mentioned in this paper, and the experimental results are discussed and shown to be in general agreement with the theory; however, some variants of the usual disordered mode correspond to true twins whereas others give pseudo twins.

96 citations

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TL;DR: In this paper, the authors observed that discontinuous gold films exhibit temperature-dependent morphological changes following deposition and observed that the initial deposited nuclei are nearly circular and have a doubled peaked size distribution.
Abstract: Vacuum‐deposited discontinuous gold films are observed to exhibit temperature‐dependent morphological changes following deposition This effect is observed on both carbon and silicon monoxide substrates For substrate temperatures between approximately 450° to 750°K the initial deposited nuclei are nearly circular and have a doubled‐peaked size distribution Because of resolution limitations only the part of the distribution with the large sizes is quantitatively examined and discussed Analysis of the distributions at different time intervals following deposition shows a shift in both the mean radius and the dispersion and a decrease in the number of nuclei per unit area These changes are discussed in terms of possible mass transfer along the surface

96 citations

Journal ArticleDOI
TL;DR: A novel clinical PJI model system involving both in vitro and in vivo use of methicillin-resistant Staphylococcus aureus ST239 is established to systematically evaluate the antibacterial properties of the hybrid surface against planktonic and sessile bacteria.
Abstract: Periprosthetic joint infection (PJI) is one of the formidable and recalcitrant complications after orthopedic surgery, and inhibiting biofilm formation on the implant surface is considered crucial to prophylaxis of PJI. However, it has recently been demonstrated that free-floating biofilm-like aggregates in the local body fluid and bacterial colonization on the implant and peri-implant tissues can coexist and are involved in the pathogenesis of PJI. An effective surface with both contact-killing and release-killing antimicrobial capabilities can potentially abate these concerns and minimize PJI caused by adherent/planktonic bacteria. Herein, Ag nanoparticles (NPs) are embedded in titania (TiO2) nanotubes by anodic oxidation and plasma immersion ion implantation (PIII) to form a contact-killing surface. Vancomycin is then incorporated into the nanotubes by vacuum extraction and lyophilization to produce the release-killing effect. A novel clinical PJI model system involving both in vitro and in vivo use of methicillin-resistant Staphylococcus aureus (MRSA) ST239 is established to systematically evaluate the antibacterial properties of the hybrid surface against planktonic and sessile bacteria. The vancomycin-loaded and Ag-implanted TiO2 nanotubular surface exhibits excellent antimicrobial and antibiofilm effects against planktonic/adherent bacteria without appreciable silver ion release. The fibroblasts/bacteria cocultures reveal that the surface can help fibroblasts to combat bacteria. We first utilize the nanoarchitecture of implant surface as a bridge between the inorganic bactericide (Ag NPs) and organic antibacterial agent (vancomycin) to achieve total victory in the battle of PJI. The combination of contact-killing and release-killing together with cell-assisting function also provides a novel and effective strategy to mitigate bacterial infection and biofilm formation on biomaterials and has large potential in orthopedic applications.

95 citations