Searched for: contributor:"Sietsma, J. (promotor)"
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Kumar, A. (author)
In this PhD thesis, we investigate the microstructural evolution and damage in different steel grades used in railway applications such as switches, crossings and curved tracks, which are the key components in the rail transportation industries around the world. The damage in these components leads to a maintenance cost of billions of Euros per...
doctoral thesis 2019
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Peelman, S. (author)
The rare earth elements (REEs) are a material group that is becoming increasingly important in modern day technologies, with applications in electronics (e.g. FeNdB magnets and luminescent phosphors), chemical industry (e.g. REE catalysts), energy industry (e.g. NiMH batteries and windmills) and medicine (e.g. Gd MRI contrast fluid). Considering...
doctoral thesis 2019
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Venkatesan, P. (author)
Rare earth elements (REEs), along with other metals, will play a pivotal role in the transition towards a low-carbon economy. Primary mining of REEs consists of multiple steps, is energy intensive and has an adverse environmental impact. Thus, the current scenario of “use and throw” of REEs after a single use in a product is untenable....
doctoral thesis 2019
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Wu, J. (author)
The microstructural aspects of rolling contact fatigue in rails were studied. The rail track is a critical component of the railway system and its long-term performance contributes crucially to the sustainable development of the railway system. The increasing demands of trains with a higher speed/capacity impose more severe load conditions on...
doctoral thesis 2018
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Abbasalizadeh, A. (author)
Electrochemical metal extraction in molten salts is the dominant industrial method for production of Rare Earth (RE) metals from their oxides. Two major challenges pertaining to RE metals extraction using this technology are a) low solubility of RE oxides in molten salts and b) carbon monoxide or carbon dioxide generation and possibility of...
doctoral thesis 2018
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Bojack, A. (author)
This thesis studies in-situ the phase transformations during heat treatment of two advanced steels: a supermartensitic stainless steels (SMSS), on which the main focus of this work is, and Fe-C-Mn-Si steels. A magnetic technique, based on the analysis of saturation magnetization, is utilized as the primary analysing tool. The scientific aim of...
doctoral thesis 2018
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Goulas, C. (author)
This Ph.D. thesis investigates the substitution of quenching and tempering treat-
ments by isothermal bainitic treatments in automotive spring production. An isothermal bainitic treatment has benefits mainly in terms of energy savings, but it can also prevent quench cracking, distortion and residual stresses, commonly found in quenched and...
doctoral thesis 2018
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Ou, X. (author)
The aim of this PhD. thesis is to use molecular dynamics (MD) simulations to comprehend the mechanisms governing nucleation and growth of martensite phase in austenitic phases in iron. In view of this objective, the thesis is divided into five parts: Chapter 2 reviews previous investigations of the fcc-to-bcc transformation in iron by MD...
doctoral thesis 2017
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Nienhuis, J. (author)
The different phases in the life of archaeological objects can be described by artefact biography. This dissertation defines an updated version: artefact biography 2.0, and the life phases of Early Iron Age bronze studs from Oss-Zevenbergen, the Netherlands, are elaborated. Throughout the thesis, the research revolves around information value....
doctoral thesis 2017
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van Liempt, P. (author)
doctoral thesis 2016
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Monteiro de Sena Silvares de C, I. (author)
These days, climate change and its consequences regularly make the news. Sea levels are rising, poles are defrosting, species are becoming extinct, the ozone layer is being destroyed and the earth's temperature is increasing. These symptoms convey a clear call to action: the preservation of the environment needs to be of the highest concern. In...
doctoral thesis 2016
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HajyAkbary, F. (author)
This Ph.D. thesis investigates the relation between microstructural and mechanical properties of Advanced High Strength Steels (AHSS), with the goal of developing a microstructure with optimised mechanical properties. Among different grades of AHSS, Quenching and Partitioning (Q&P) steel which is composed of thin films of retained austenite...
doctoral thesis 2015
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Öhlund, C.E.I.C. (author)
The research presented in this thesis aims to deepen our understanding of the effect of micro-alloying on the microstructure and mechanical property evolution during tempering of martensitic steel for fasteners. The ongoing trend of engine down-sizing has led to the need for stronger and more temperature resistant fasteners than currently...
doctoral thesis 2015
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Den Ouden, D. (author)
Steels with higher strength and better formability are increasingly required by the automotive industry because they can provide higher safety, reduce energy consumption and thus lead to a better environmental protection. To meet these requirements, it is a sustainable effort for steel industry to develop high strength formable steels. One of...
doctoral thesis 2015
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Van Tol, R.T. (author)
This thesis studies the effect of plastic deformation on the stability of the austenitic microstructure against martensitic transformation and diffusional decomposition and its role in the phenomenon of delayed fracture in austenitic manganese (Mn)-based TWinning Induced Plasticity (TWIP) steels. The transformation to alpha’-martensite upon...
doctoral thesis 2014
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McGarrity, K.S. (author)
Microstructural banding is explored in 2D and 3D using serial sectioned micrographs. The banding is quantified using two parameters called the Band Continuity Index Cb and the Perpendicular Continuity Index Cp. The indexes determined from the 2D micrographs is shown to be sufficient for estimating the distribution of the bands in 3D. A...
doctoral thesis 2013
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Dere, E.G. (author)
The research presented in this thesis aims at deepening our understanding of the formation of the microstructure of steel during thermal processing in order to control the microstructure and thereby improve the fire-resistance of low-alloy steel. The strength of steel decreases during a fire mainly due to the following changes in the...
doctoral thesis 2013
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Galindo Nava, E.I. (author)
This work aims to describe plastic deformation and microstructure evolution of metals at various scales in terms of dislocation behaviour. The theory is based on statistical thermodynamics, where the entropy is proposed to incorporate the possible paths for dislocation motion. Other than estimating the velocity gradients a dislocation may reach,...
doctoral thesis 2013
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Ghodrat, S. (author)
Cast iron components in combustion engines, such as cylinder blocks and heads of trucks, are exposed for long periods of time to elevated temperatures. Moreover, the engines are started and stopped frequently during their operational life, constituting a large number of heating and cooling cycles. In geometrical complex components the sudden...
doctoral thesis 2013
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Bahrami, A. (author)
Al-Mg-Si alloys are heat treatable alloys in which strength is obtained by precipitation hardening. Precipitates, formed from a supersaturated solid solution during ageing heat treatment, are GP-zones, B", B´ and B-Mg2Si. Precipitation kinetics and strength vary with alloy composition and process parameters. There is still a need for property...
doctoral thesis 2010
Searched for: contributor:"Sietsma, J. (promotor)"
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