Search for dissertations about: "prior particle boundaries"

Showing result 1 - 5 of 8 swedish dissertations containing the words prior particle boundaries.

2. 1. Influence of Segregants on Creep Fracture in Powder Metallurgical Martensitic Stainless Steel

   Author : Mats Norell; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; AES; creep; segregants; powder metallurgy; prior particle boundaries; atomisation; SIMS; martensitic stainless steel; ESCA; cavities; powder surfaces;

   Abstract : This thesis deals with the behaviour of segregants in Powder Metallurgical (PM) 10%Cr steel and their impact on creep fracture. Particular interest is taken in determining the reaction products involved in creep cavitation and how these are connected to the powder surface reactions during the gas atomisation and consolidation (hot isostatic pressing). READ MORE

4. 2. Microstructure and Fatigue Analysis of PM-HIPed Alloys : A Focus on Inconel 625 and High-Nitrogen Tool Steel

   Author : Faezeh Javadzadeh Kalahroudi; Mikael Grehk; Mattias Calmunger; Karlstads universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; powder metallurgy; hot isostatic pressing; Inconel 625; high-nitrogen tool steel; microstructure; fatigue behavior; inclusions; Materialteknik; Materials Engineering;

   Abstract : Nickel-based superalloys and tool steels are well-known high-performance alloys due to their extensive use in many different industries. Nickel-based superalloys have found their way into aircraft, aerospace, marine, chemical, and petrochemical industries owing to their excellent high-temperature corrosion and oxidation resistance. READ MORE

5. 3. Tailoring of Liquid Phase Sintering and Microstructure of Sintered Steel

   Author : Walid Khraisat; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermodynamics and persistent liquid; ferrous powder; liquid forming additives; liquid phase sintering; high speed steel powder;

   Abstract : The present study intends to interpret the effects of alloying elements on microstructure and mechanical properties via liquid phase sintering of iron and steel powders. The tools involved are thermodynamic modelling, tailoring of powder properties and processing, and optimisation of sintering. READ MORE

6. 4. Dynamic and meta-dynamic recrystallization of Ni-based superalloy Haynes 282

   Author : Emil Eriksson; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hot compression; EBSD; dynamic recrystallization; meta-dynamic recrystallization; Ni-base superalloys;

   Abstract : Thermomechanical processes are a crucial manufacturing step because they can “reset” the microstructure, and set the starting point for all following steps. In turn, the microstructure can be used to tailor the mechanical properties of the material. READ MORE

7. 5. Micromechanical modeling of cleavage fracture in polycrystalline materials

   Author : Mateusz Stec; Jonas Faleskog; Andre Pineau; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cleavage fracture; probabilistic modeling; brittle to ductile transition; cohesive zone; visco-plastic material; Engineering mechanics; Teknisk mekanik; Other technology; Övriga teknikvetenskaper;

   Abstract : Cleavage fracture in ferritic steels can be defined as a sequence of few critical steps. At first nucleation of a microcrack takes place, often in a hard inclusion. This microcrack then propagates into the surrounding matrix material. The last obstacle before failure is the encounter of grain boundaries. READ MORE