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Visar resultat 1 - 5 av 16 avhandlingar som matchar ovanstående sökkriterier.
1. Weld Cracking of Precipitation Hardening Ni-based Superalloys - Investigation of repair welding characteristics and susceptibility towards strain age cracking
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
2. Weldability of Cast Superalloys - Effect of homogenization heat treatments on hot cracking susceptibility of cast Alloy 718, ATI® 718Plus®, and Haynes® 282®
Sammanfattning : Precipitation hardened Ni- and Ni–Fe-based superalloys are used in high-temperature sections of aero engines owing to their superior mechanical properties compared to those of the other alloys. However, their better mechanical performance is accompanied by its own challenges during the manufacturing process. LÄS MER
3. Weldability of Precipitation Hardening Superalloys – Influence of Microstructure
Sammanfattning : Superalloys and in particular the precipitation hardened Ni-based superalloys havealways been used extensively in the hot sections of jet engines. Large hot structuralengine components with complex geometry have preferably been cast as single piececomponents since the large scale vacuum investment casting process becameavailable about fifty years ago. LÄS MER
4. Modeling the Microstructure Evolution During and After Hot Working in Martensitic Steel
Sammanfattning : In this study, the goal is to predict the microstructure evolution during and after the hot working of a martensitic stainless steel with 13% chromium using a physically-based model in the form of a MATLAB toolbox. This model is based on dislocation density theory and consists of coupled sets of evolution equations for dislocation, vacancies, recovery, recrystallization, and grain growth. LÄS MER
5. Thermomechanical Processing of Nickel-Base Alloy 825
Sammanfattning : Alloy 825 material was studied using a Gleeble-3800 thermosimulatorby performing single-hot compression experiments.Optical microscopy and electron backscatter diffraction wereutilized to characterize the microstructure. Dynamicrecrystallization is not considerable in the as-cast alloy anddislocation recovery is deemed to be dominant. LÄS MER