Sökning: "Engineering and Technology Materials Engineering Metallurgy and Metallic Materials"

Visar resultat 21 - 25 av 579 avhandlingar innehållade orden Engineering and Technology Materials Engineering Metallurgy and Metallic Materials.

1. 21. Study of pyrolysis and gasification of biomass from the self-organization perspective

   Författare :Aliaksandr Alevanau; Ersson Mikael; Weihong Yang; Pär Jönsson; Sylwester Kalisz; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; pyrolisys; pellets; hydrogen; gasification; Materials Science and Engineering; Teknisk materialvetenskap; Chemical Engineering; Kemiteknik;

   Sammanfattning : This thesis focuses on the analysis of kinetics of i) low-temperature pyrolysis of gaseous hydrocarbons, ii) high-temperature steam gasification of char of wood pellets (>700oC), iii) high temperature pyrolysis of straw pellets in an atmosphere of argon and steam, and iv) high temperature pyrolysis of slices of transversally cut wooden sticks. The results of the kinetic measurements in the high-temperature cases are approximated using a least-square based optimization software, which was specially developed to analyse kinetics prone for deviation from the Arrhenius law. LÄS MER

3. 22. Thermo-Mechanical-Metallurgical Modelling of Pearlitic Steels and Railhead Repair Welding

   Författare :Björn Andersson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pearlitic steels; Railhead repair; Welding simulations; Phase transformations; Cyclic plasticity; Finite element analysis; Homogenisation;

   Sammanfattning : The efficiency of rail transport is attributed to low rolling resistance, which comes at the cost of high contact pressures between rail and wheel. Consequently, both the rail and wheel can be susceptible to fatigue crack initiation and propagation due to the resulting high stresses and large number of load cycles in service. LÄS MER

4. 23. Microstructure development and mechanical properties of cast and thermo-mechanically treated eutectic high-entropy alloys

   Författare :Adrianna Lozinko; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; strength-ductility trade-off; eutectic alloys; recrystallization; EBSD; heterogeneous structure; high-entropy alloys;

   Sammanfattning : The recently emerging high-entropy alloys (HEAs) present a novel alloying strategy, significantly expanding the scope of metal alloy design. Single-phase HEAs, nevertheless, suffer from the strength-ductility trade off as seen in conventional metallic materials. LÄS MER

5. 24. Weldability and Testing Methodology in Precipitation Hardening Superalloys

   Författare :Jonny Jacobsson; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Weldability; Alloy 718; ATI® 718Plus™ and Haynes® 282®; Superalloys; Varestraint; Waspaloy®;

   Sammanfattning : Usable weldability data is desired in the manufacturing industry, especially within the aerospace industry where fabrication of structural jet engine components are realized. Welding of precipitation hardening superalloys such as Waspaloy®, Alloy 718, ATI® 718Plus™ and Haynes® 282® in particular can lead to solidification cracking in the fusion zone, liquation cracking in the heat affected zone and/or to solid state cracking. LÄS MER

7. 25. On Surface Characteristics and Microstructural Development of Soft Magnetic Composite Powder and Components

   Författare :Christos Oikonomou; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; X-ray photoelectron spectroscopy; compaction; annealing; X-ray diffraction; soft magnetic composites; high resolution scanning electron microscopy; surface layers; magnetic testing; powder metallurgy; depth profiling; electron backscatter diffraction; focused ion beam; thickness determination; energy dispersive X-ray spectroscopy; microstructure;

   Sammanfattning : Soft Magnetic Composite (SMC) products manufactured by traditional Powder Metallurgical (PM) techniques, are strong candidate materials for electromagnetic applications. Their advantages are based on cost and energy efficient production methods, shape complexity realization and uniquely uniform and isotropic three dimensional (3D) magnetic properties. LÄS MER