Sökning: "Precipitation hardening"

Visar resultat 11 - 15 av 40 avhandlingar innehållade orden Precipitation hardening.

1. 11. 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. 12. Development of a new generation of 12% Cr steels: Z-phase strengthened steels

   Författare :Masoud Rashidi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; atom probe tomography; Z-phase; 9-12% Cr steels; martensitic steels; transmission electron microscopy; precipitation hardening; creep;

   Sammanfattning : Fossil-fuel fired steam power plants provide more than 60% of the electricity generated worldwide, and account for about one third of the global CO2 emissions. The thermal efficiency of the steam power plants is limited by the maximum allowed steam temperature and pressure, which in turn are determined by the long-term corrosion and creep resistance of economically viable materials. LÄS MER

4. 13. Aspects of precipitation in alloy Inconel 718

   Författare :Saied Azadian; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materialteknik; Engineering Materials;

   Sammanfattning : A study was made of the microstructure of the Ni-base alloy Inconel 718 with emphasis on the precipitation and stability of intermetallic phases as affected by heat treatments. In addition the effect of the precipitation on selected mechanical properties namely hardness, creep notch sensitivity and hot ductlity were investigated. LÄS MER

5. 14. Weld Cracking of Precipitation Hardening Ni-based Superalloys - Investigation of repair welding characteristics and susceptibility towards strain age cracking

   Författare :Fabian Hanning; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gleeble; Haynes 282; Waspaloy; welding; ATI 718Plus®; weldability; post-weld heat treatment; weld cracking; strain age cracking; hot cracking; Nickel-based superalloys;

   Sammanfattning : High temperature resistance and strength requirements make nickel-based superalloys the material of choice for the hot section of aero engines. Fabrication in terms of combining wrought and cast parts in the manufacturing of hot structural components enables component optimisation via the use of wrought high-strength parts, where geometrical constraints allow, and cast parts to produce complex geometries. LÄS MER

7. 15. High Performance Aluminium Alloys for Laser Powder Bed Fusion: Alloy Design and Development

   Författare :Bharat Mehta; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Additive Manufacturing; Precipitation Kinetics; Integrated Computational Materials Engineering; Laser Based Powder Bed Fusion; Heat Treatment; Aluminium Alloys;

   Sammanfattning : Additive Manufacturing (AM), particularly Laser Based Powder Bed Fusion (LB-PBF) has proven to be a notable technology to produce novel microstructures and expand the ceiling of product design. However, the development of novel alloys in metal LB-PBF has not followed the same pace as development of product design. LÄS MER