Sökning: "DICTRA"

Visar resultat 1 - 5 av 16 avhandlingar innehållade ordet DICTRA.

1. 1. Multicomponent diffusional reactions in tool steels : Experiment and Theory

   Författare :Greta Lindwall; Malin Selleby; Karin Frisk; John Ågren; Carelyn Campbell; KTH; []
   Nyckelord :hot-work tool steel; precipitation hardening; DICTRA; coarsening; mobilities; CALPHAD; cobalt; PM tool stees; nitrogen; compound materials;

   Sammanfattning : Many phenomena determining the microstructure of a tool steel and consequently the properties of the material, are governed by multicomponent diffusion. The diffusion driven reactions that take place during, for example, tempering of a hot-work tool steel or when the microstructure develops during hot isostatic pressing of cold-work tool steel, are dependent on the types and amounts of alloying elements. LÄS MER

3. 2. ICME guided development of cemented carbides with alternative binder systems

   Författare :Martin Walbrühl; John Ågren; Annika Borgenstam; Henrik Larsson; Claudio Miguel Lousada Patricio; Jan Qvick; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cemented carbide; ICME; Materials Design; alternative binder; hardness; AIMD; liquid diffusion; frozen-in solubilities; DICTRA; surface gradients; labyrinth factor; Materials Science and Engineering; Teknisk materialvetenskap;

   Sammanfattning : The development of alternative binder systems for tungsten carbide (WC) based cemented carbides has again become of relevance due to possible changes in EU regulations regarding the use of Cobalt (Co). A framework for the ICME (Integrated Computational Materials Engineering) based Materials Design is presented to accelerate the development of alternative binder systems. LÄS MER

4. 3. Evolution of Microstructure in Two Austenitic Alloys at High Temperatures

   Författare :Jenny M Erneman; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; N ; Thermo-Calc; Nb C; gamma prime; DICTRA; APFIM; quantitative metallography; AISI 347; Alloy 800; energy filtered TEM; sigma phase;

   Sammanfattning : A niobium stabilised AISI 347 austenitic stainless steel was investigated after static ageing and creep deformation at temperatures between 500°C and 800°C for times up to 88 000 h. Coarse and fine NbX precipitates and also s-phase precipitates were formed in the temperature range 500-700°C. LÄS MER

5. 4. Aspects of microstructural evolution in chromium steels in high temperature applications

   Författare :Åsa Gustafson; KTH; []
   Nyckelord :Cr-steels; nucleation; coarsening; model; DICTRA; precipitates; carbides; carbo-nitrides; MX; VN; M23C6; TiC; TEM; EFTEM; Curie-temperature;

   Sammanfattning : In this thesis 9-12 % Cr steels, used for high-temperaturecomponents in fossil-fired power plants are considered. Thecreep strength of thees steels depend on their microstructurethat consists of a matrix of tempered lath martensite withdensely distributed precipitates. LÄS MER

7. 5. Development of Composition Gradients in Cemented Carbides

   Författare :Robert Frykholm; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; EPMA; DICTRA; functionally graded materials; gradient sintering; diffusion; APFIM; thermodynamic modelling; SEM; surface zones;

   Sammanfattning : This thesis concerns the formation of tough surface zones, depleted of cubic carbo-nitrides, in cemented carbides. Several materials with varied phase compositions, binder phase volume fraction, and carbon content have been investigated. LÄS MER