Sökning: "Solidification cracking"

Visar resultat 11 - 15 av 18 avhandlingar innehållade orden Solidification cracking.

  1. 11. Modelling microstructural changes in pulsed weldments

    Författare :P. Ravi Vishnu; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik;

    Sammanfattning : Microstructural changes in pulsed weldments have been studied in mild steel, a quenched and tempered steel and in two austenitic stainless steels. A heat flow model has been developed to compute the thermal cycles at different locations in the pulsed welds. LÄS MER

  3. 12. Challenges in Resistance Welding of Ultra High Strength Steels

    Författare :Erik Tolf; Arne Melander; Zuheir Barsoum; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Resistance welding; spot welding; surface cracks; nut welding; UHSS; projection welding; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : Increasing the use of Ultra High Strength Steels (UHSS) in vehicle bodystructures is important for reducing weight and cutting CO2 emissions. This thesis investigates challenges in resistance welding that can be a barrier to implementing UHSS as a replacement for low strength steels in vehicle structures. LÄS MER

  4. 13. 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

  5. 14. On the Microstructures and Anisotropic Mechanical Behaviours of Additively Manufactured IN718

    Författare :Dunyong Deng; Johan Moverare; Ru Lin Peng; Jian Zhang; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Additive manufacturing (AM), also known as 3D printing, offers great design flexibility for manufacturing components with complex geometries, and has attracted significant interest in the aero and energy industries in the past decades. Among the commercial AM processes, selective laser melting (SLM) and electron beam melting (EBM) are the two most widely used ones for metallic materials. LÄS MER

  7. 15. Problems in the Aluminium DC Casting Process Associated with Melt Treatment Operations

    Författare :Ghadir Razaz; Torbjörn Carlberg; Arne.K Dahle; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The quality of DC cast Al alloys is highly dependent on melt batch composition and impurity level in the molten alloy. The chemical composition and cleanliness of a melt is controlled through the melt treatment operations, carried out while the melt is still in the furnace before casting starts. LÄS MER