Sökning: "Frank Mücklich"
Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Frank Mücklich.
1. Eutectic Modification of Al-Si casting alloys
Sammanfattning : Aluminum alloys with silicon as the major alloying element are the most widely used aluminum casting alloys. The eutectic phase in these alloys is formed by hard and brittle silicon plates in an aluminum matrix. Such silicon plates can act as crack propagation paths deteriorating the toughness of the material. LÄS MER
2. Synthesis and characterization of nanocarbons as reinforced particles in metal composites
Sammanfattning : In this work, several scientific problems related to high pressure–high temperature (HP–HT) synthesis of new materials using fullerite as a precursor were studied: first, the mechanism of the transformation of C60 crystal into a nano-clustered graphene phase (NGP) at a pressure of 8 GPa; and second, the effect of disorder introduced into C60 crystals by ball milling prior to HP–HT synthesis on the structure and properties of the NGP. A separate set of experiments was devoted to compression of C60 precursor at unexplored before pressure of 25 GPa and elevated temperatures in search for new type of disordered carbon-based materials. LÄS MER
3. Increasing phase transformation rate in advanced high strength steel applications
Sammanfattning : The bainite transformation rate has been shown to increase by starting the heat treatment with partial martensite transformation after austenitization. Based on this fact, a process very similar to “Quenching and Partitioning” (Q&P) is used to produce a fine-grained complex microstructure of martensite, bainite and retained austenite with outstanding mechanical properties in a very short time. LÄS MER
4. Defect-engineered (Ti,Al)N thin films
Sammanfattning : This thesis investigates the effect of point defects (nitrogen vacancies and interstitials) and multilayering ((Ti,Al)N/TiN) on the phase transformations in cathodic arc-evaporated cubic (Ti,Al)N thin films at elevated temperatures. Special attention is paid to the evolution of the beneficial spinodal decomposition into c-TiN and c-AlN, the detrimental formation of wurtzite AlN and the potential application as hard coating in cutting tools. LÄS MER
5. Vibrations in solids : From first principles lattice dynamics to high temperature phase stability
Sammanfattning : In this thesis I introduce a new method for calculating the temperature dependent vibrational contribution to the free energy of a substitutionally disordered alloy that accounts for anharmonicity at high temperatures. This method exploits the underlying crystal symmetries in an alloy to make the calculations tractable. LÄS MER
