Bierwisch, C., Kraft, T., Riedel, H., Moseler, M.
Rapid granular flow from a moving container and angle of repose formation were investigated by numerical simulations using the discrete element method (DEM) and experiments. Grain models of various...
Prakash, A., Weygand, S.M., Riedel, H.
The development of a strong basal texture upon processing has proven to be a major impediment in commercial applications of wrought magnesium alloys. The basal texture hampers further processing of...
Texture induced tension-compression asymmetry of drawn tungsten wires (2009)
Ripoll, M.R., Reisacher, E., Riedel, H.
The stress-strain curves of drawn tungsten wires exhibit a strong tension-compression asymmetry. which is demonstrated experimentally for a series of wires drawn to different diameters. The...
Three-dimensional discrete element models for the granular statics and dynamics of powders (2009)
Moseler, M., Bierwisch, C., Kraft, T., Riedel, H.
A novel coarse graining scheme for the discrete element method (DEM) was developed which allows for the representation of a given granular system using artificially enlarged grains. Based on the...
Wonisch, A., Kraft, T., Moseler, M., Riedel, H.
Simulations based on the discrete element method (DEM) are used to investigate the relationship between the distribution of particle sizes and the macroscopic sintering behavior of ceramic powders....
Prakash, A., Weygand, S.M., Riedel, H.
Computational Materials Science, 45(2009) S.744-50
Simulation in powder technology, in (2008)
This chapter describes micromechanical and macroscopic material models for granular and porous materials and applications to powder technological processing steps. The emphasis lies on powder...
Twinning models in self-consistent texture simulations of TWIP steels (2008)
Prakash, A., Hochrainer, T., Reisacher, E., Riedel, H.
The high work hardening rate and ductility of high manganese austenitic steels is mainly attributed to the strong twinning induced plasticity (TWIP) effect found in the material. With a low stacking...
Simulation of die filling in 3D with special emphasis on vibration supported filling (2008)
Bierwisch, C., Kraft, T., Moseler, M., Riedel, H.
Modelling die filling with focus on density distribution is a key component in establishing a continuous virtual process chain for the die compaction and sintering processing route. A discrete...
Finite element modelling of PM surface densification process (2008)
Yazici, B.A., Kraft, T., Riedel, H.
The developments in the field of powder metallurgy (PM) enable production of complex shapes in a cost competitive way especially for automotive industry. Surface densification of sintered gears...
Discrete element simulations of constrained ceramic powder sintering (2008)
Wonisch, A., Kraft, T., Moseler, M., Riedel, H.
A particle-based simulation approach employing the discrete element method (DEM) is presented for ceramic powder sintering under geometric constraints. The grain-scale approach allows investigating...
Numerical homogenisation of elasto-plastic granule assemblies using discretised particles (2008)
Schmidt, I., Kraft, T., Riedel, H.
In this contribution, the finite element method is used to investigate the deformation mechanisms in- and the macroscopic response of an assembly comprised of elasto-plastic spherical granules....
Rechnerische Methoden zur Lebensdauervorhersage von gegossenen Hochtemperaturbauteilen (2008)
Eisengusswerkstoffe weisen aufgrund der Graphitausscheidungen ein asymmetrisches Verhalten in Zug und Druck auf. Es wurde ein Werkstoffmodell entwickelt, das die Fähigkeiten des Chaboche Modells und...
Linear Phase Filtering of Early Auditory Evoked Potentials (2007)
Granzow Riedel, H. Riedel, B. Kollmeier, Ag Medizinische Physik
One of the major experimental obstacles to unambiguous interpretation of early auditory evoked potentials is the usually poor signal-tonoise ratio of the averaged data. For responses to stimuli well...
Simulations of the influence of rearrangement during sintering (2007)
Henrich, B., Wonisch, A., Kraft, T., Moseler, M., Riedel, H.
A three-dimensional application of the discrete element method to free, constrained and pressure-assisted solid-state sintering of powders is presented. Special emphasis is laid on the generation of...
Modeling texture evolution during hot rolling of magnesium alloy AZ31 (2007)
The texture evolution during hot rolling of the magnesium alloy AZ31 is simulated using a visco-plastic self-consistent model including crystallographic slip, twinning and recrystallization. This...
Korrelation zwischen zyklischer Rissspitzenöffnung und Lebensdauer (2007)
Schweizer, C., Seifert, T., Schlesinger, M., Riedel, H.
Under LCF and TMF loading the lifetime is often determined by the growth of microcracks, which generally nucleate during the first cycles. Assuming the crack growth rate per cycle to be approximately...
Multi-grain finite element model for studying the wire drawing process (2007)
Ocenasek, J., Ripoll, M.R., Weygand, S.M., Riedel, H.
Wire drawing of tungsten wires leads to a special microstructure which is characterized by elongated curled grains and a sharp (1 1 0) texture. At this moment the computational power does not allow...
Stress-induced anisotropy of sintering alumina: Discrete element modelling and experiments (2007)
Wonisch, A., Guillon, O., Kraft, T., Moseler, M., Riedel, H., Rödel, J.
Simulations based on the discrete element method are employed to investigate the anisotropic sintering of alumina. The results are compared with accompanying experiments. It is shown that during...
Twinning models in self-consistent simulations of TWIP steels (2007)
Prakash, A., Hochrainer, T., Riedel, H., Helm, D., Reisacher, E.
The high work hardening rate and ductility of high manganese steels is due to the strong twinning induced plasticity (TWIP) effect in addition the more common dislocation plasticity observed in...
Simulation von Prozessfolgen mit der Diskrete-Elemente-Methode (2007)
Riedel, H., Wonisch, A., Bierwisch, C., Kraft, T., Moseler, M.
Finite-Elemente basierte Methoden sind gut geeignet, um Herstellungsprozesse von Bauteilen auch mit komplexen Formen zu modellieren. In der Zwischenzeit wurden die Simulationsmöglichkeiten durch die...
Multi-grain finite element model for studying the wire drawing process (2007)
Ocenasek, J., Rodriguez Ripoll, M., Weygand, S.M., Riedel, H.
Wire drawing of tungsten wires leads to a special microstructure which is characterized by elongated curled grains and a sharp (1 1 0) texture. At this moment the computational power does not allow...
Kawalla, R., Schmidt, C., Riedel, H., Prakash, A.
Due to the deformation mechanisms of magnesium and the typical basal texture rolled magnesium sheets show a significant asymmetry of flow stress in tension and compression which is disadvantageous...
Prakash, A., Weygand, S.M., Riedel, H.
17th Internat.Workshop 'Computational Mechanics of Materials', Paris, August 22-24, 2007
Wonisch, A., Korn, K., Kraft, T., Riedel, H.
Sintering green bodies made by typical industrial production processes like uniaxial compaction, tape casting or extrusion may exhibit a significant anisotropic microstructure, which in turn leads to...
Krasowsky, A., Schmitt, W., Riedel, H.
In this paper, a novel experimental-numerical methodology for an accurate prediction of springback after sheet forming is presented. An advanced phenomenological material models is implemented in the...
Walde, T., Gumbsch, P., Riedel, H.
A self-consistent texture model is implemented in the finite-element code ABAQUS /Explicit. Hardening of the slip systems is described by evolution laws for dislocation densities, and the Bauschinger...
Numerical simulation of the drawing process of tungsten wires (2006)
Weygand, S.M., Riedel, H., Eberhard, B., Wouters, G.
Tungsten wires for lamp filaments sometimes develop longitudinal cracks of substantial length during processing, mainly during wire drawing. In this work, the drawing process is analysed with a...
Multi-scale simulations of rearrangement effects and anisotropic behavior during sintering (2006)
Wonisch, A., Kraft, T., Riedel, H.
Numerical modeling of sintering by continuum mechanical simulations is successfully applied today to predict e.g. the distortions developing during sintering. Several examples that demonstrate the...
Thermo-mechanical material models for components of engines and power plants (2006)
Seifert, T., Mohrmann, R., Hartrott, P. Von, Tandler, M., Riedel, H.
In this paper material models are presented that have been developed at the Fraunhofer Institute for Mechanics of Materials (IWM) for thermo-mechanical applications. One the one hand deformation...
Kawalla, R., Schmidt, C., Riedel, H., Prakash, A.
The present research work has been concentrated on the clarification of selected problems of deformation mechanisms for the aspired deformation-recrystallization model. The model at the current state...
Krasowsky, A., Schmitt, W., Riedel, H.
In this paper, a novel experimental-numerical methodology for an accurate prediction of springback after sheet forming is presented. An advanced phenomenological material models is implemented in the...
Numerical simulation of the drawing process of tungsten wires (2006)
Weygand, S.M., Riedel, H., Eberhard, B., Wouters, G.
Tungsten wires for lamp filaments sometimes develop longitudinal cracks of substantial length during processing, mainly during wire drawing. In this work, the drawing process is analysed with a...
Aktaa, J., You, J.H., Hickel, T., Pyzalla, A.R., Schreyer, A., Riedel, H.
Workshop der HGF-Allianz Hybrid Materials for High Performance Systems (HYPER), Darmstadt, 12.-13.Oktober 2006
Computation of macroscopic yield surfaces by particle methods (2005)
Schmidt, I., Wonisch, A., Henrich, B., Moseler, M., Riedel, H.
The essential ingredient for the simulation of the cold compaction of powders by the finite element method is the provision of yield surface and ist evolution with deformation. Usually isotropic...
Interactive texture- and finite-element simulation including the Bauschinger effect (2005)
In this paper we describe a rolling simulation considering the main sources of plastic anisotropy, namely the Bauschinger effect and crystallopgraphic texture. For this purpose we coupled the...
Moseler, M., Riedel, H., Gumbsch, P., Stäring, J., Mehlig, B.
We study the shock-induced phase transformation from fullerite to a dense amorphous carbon phase by tight-binding molecular dynamics. For increasing hydrostatic pressures P, the C60 cages are found...
Modeling texture evolution during rolling of magnesium alloy AZ31 (2005)
Due to crystallographic texture rolled magnesium sheets exhibit strongly aniso-tropc and asymmetric plastic behavior. Therefore the simulation of texture evolution during manufacturing is a...
Riedel, H., Andrieux, F., Walde, T.
Mit Hilfe von Plasizitätsmodellen für poröse Werkstoffe wird das Grenzformänderungsschaubild berechnet und das Walzen von Aluminiumband modelliert. Dabei zeigt sich die Überlegenheit...
Simulation von Rissbildung und Verzug in der Mikroelektronik (2005)
Kraft, T., Riedel, H., Schwanke, D., Müller, E.
Ein wesentlicher Prozessschritt bei der Herstellung von keramischen Mehrlagenschaltungen ist das Sintern. Beim Sintern bildet sich unter dem Einfluss hoher Temperatur aus dem vorgeformten Grünling...
Multi-scale modeling and simulation of sintering (2005)
Kraft, T., Henrich, B., Moseler, M., Riedel, H.
Simulation methods to study sintering based on finite elements as well as discrete particle dynamics are presented. Both methods have their application focus on different length scales. The particle...
Modelling and simulation of processing steps in powder technology using particle dynamics (2005)
Kraft, T., Henrich, B., Bierwisch, C., Moseler, M., Riedel, H.
A simulation method based on discrete particle dynamics is presented and applied to die filling, compaction and sintering. The method is computationally very efficient so that three dimensional...
Modelling of anisotropic shrinkage during liquid phase sintering (2005)
Korn, K., Kraft, T., Riedel, H.
Green bodies made by tape casting, extrusion or uniaxial die compaction may ehib it appreciable sintering anisotropy. To account for this, a micromechanical liquid phase sintering model was extended...
Computer simulation as a tool in PM material science and technology (2005)
Kraft, T., Riedel, H., Gumbsch, P.
This article describes the simulation of different powder technological processing steps. Among many routes the die compaction processing route is selcted as a demonstration example. From the process...
3D-modeling of die filling (2005)
Bierwisch, C., Henrich, B., Kraft, T., Moseler, M., Riedel, H.
Using three-dimensional meso-particle dynamics (MPD) simulations we investigate die filling processes. In contrast to continuum methods this approach automatically takes into account the...
Modelling and numerical simulation of powder die compaction with a particle code (2004)
Coube, O., Henrich, B., Moseler, M., Riedel, H.
While powder compaction has usually been described by continuum mechanics models like the Drucker-Prager-Cap model, it is now modelled by a self-developed particle dynamics code. The interaction...
Numerical simulation of the double-step pressing of a simplified gear (2004)
Coube, O., Andrieux, F., Riedel, H.
The double step pressing of a gear is numerically simulated with the goal to predict the density distribution and the final shape after unloading of the part. The first powder die compaction step is...
Assessment of fatigue lifetime of PM-parts (2004)
For predicting the fatigue lifetime of a P/M component not only the loading history must be considered, but also the porosity distribution, which can influence the material behaviour significantly...
Beim Sintern bildet sich unter dem Einfluss hoher Temperatur aus dem vorgeformten Grünling das feste Bauteil. Die treibende Kraft für das Zusammenwachsen der Pulverteilchen und die Verdichtung des...
Simulation in powder technology (2004)
This chapter describes micromechanical and macroscopic material models for granular and porous materials and applications to powder technological processing steps. The emphasis lies on powder...
In this paper a constitutive model for porous ductile metals with spheroidal voids is investigated. The constitutive model used to describe void growth prior to void coalescence is the...
Reiterer, M., Kraft, T., Riedel, H.
Sinter forming is a recently developed process for the production of advanced ceramic components. It combines pressure-supported sintering and superplastic deformation, and allows RBAO (Reaction...
Finite element simulation of cold isostatic pressing and sintering of SiC components (2004)
Reiterer, M., Kraft, T., Janosovits, U., Riedel, H.
Finite element simulations were performed for cold isostatic pressing of SiC powder. To describe the compaction behaviour, the Drucker-Prager-Cap model implemented in ABAQUS/Explicit® computer...
Krasowsky, A., Walde, T., Schmitt, W., Andrieux, F., Riedel, H.
The ambition to reduce development time and consts in the metal forming industr y has led to a wide application of finite element (FE) codes. Commercial FE-programs for sheet forming simulation give...
Springback simulation in metal sheet forming (2003)
Krasowsky, A., Schmitt, W., Andrieux, F., Haas, E., Riedel, H.
Springback prediction is an important issue for the sheet metal forming industry. The application of new materials, including high strength steel, for light weight structures in the automotive...
Processing techniques for functionally graded materials (2003)
Kieback, B., Neubrand, A., Riedel, H.
An overview of the achievements of the German priority program "Functionally Grades Materials (FGM)" in the field of processing techniques is given. Established powder processes and techniques...
Krasowsky, A., Riedel, H., Schmitt, W., Benevolenski, O.
The application of new sheet materials is often impeded by the insufficient predictability of the spring-back complicated by the Bauschinger effect. The prediction of spring-back during sheet forming...
Compaction and sintering of a ceramic seal: Modeling and experimental response (2003)
Kraft, T., Riedel, H., Rosenfelder, O.
The delivery time of a new powder-metallurgical component is controlled by the tooling design, manufacture and commissioning. Cracking of the part in the production process must be avoided, and close...
To predict the fatigue lifetime of a P/M component not only the loading history must be considered, but also the porosity distribution, which can influence the material behavior significantly and...
In this work, we couple a texture model with the commercial finite element (FE) program ABAQUS/Explicit by implementing it as user supplied material subroutine (VUMAT) in the FE-code. The texture...
Riedel, H., Mohrmann, R., Schmitt, W., Hauss, R.
Modern exhaust systems must withstand severe cyclic mechanical and thermal loads throughout the whole life cycle. Up to now, highly loaded parts of exhaust syst ems are predominantly designed...
Prediction of fatigue lifetime of PM-parts (2003)
For predicting the fatigue lifetime of a P/M component not only the loading history must be considered, but also the porosity distribution, which can influence the material behavior significantly and...
Modelling of the fatigue life of automobile exhaust components (2002)
Schmitt, W., Mohrmann, R., Riedel, H., Dietsche, A., Fischersworring-Bunk, A.
Numerical simulation of die compaction and sintering (2002)
A method to simulate die compaction and sintering is presented. By implementing user defined routines for both processes into the general purpose finite element program ABAQUS quantitative...
Simulation of hot forming processes of refractory metals using porous metal plasticity models (2002)
Distortions and cracking of graded components during sintering (1999)
The aim of the project is to develop methods for predicting distortions and cracking during the fabrication of gradient materials, and to apply them to simple geometries (tubes, beams and plates)....
Modelling of powder die compaction (1998)
The most economic and most frequently used production route in powder technology is uniaxial die pressing of the powder at ambient temperature and subsequent sintering of the powder compact at high...
A liquid phase sintering model: Application to Si N and WC-Co (1997)
A model for liquid phase sintering is examined. The model accounts for solid densification during sintering by particle rearrangement and contact flattening, with large pore fitting and grain...
Kriechen von Keramik unter statischer und wechselnder Belastung (1997)
Ziel der Arbeit ist die Erklärung und Beschreibung der ausgeprägten Zug-Druck-Asymmetrie. Als wesentlicher Faktor für die Asymmetrie wird Porenbildung unter Zugbelastung angesehen. Die Kriechraten...
Pressing and sintering in powder technology (1996)
Two of the major problems in powder technology are cracking of the parts during die pressing and shape distortions during sintering, the latter being more severe the more the material shrinks....
Numerische Simulation des Pressens und Sinterns in der Pulvertechnologie (1996)
Riedel, H., Coube, O., Gaebel, R.
Der Vortrag beschreibt den Stand der Arbeiten zur numerischen Simulation des Pressens und Sinterns. Zum Thema Rißbildung beim Pressen werden Modellversuche und begleitende Simulationsrechnungen...
A model for liquid phase sintering (1996)
Svoboda, J., Riedel, H., Gaebel, R.
A quantitative model for liquid phase sintering is developed based on the following ideas. During heating a liquid phase forms, which is easily mobile, wets the solid particles completely, dissolves...
Riedel, H., Coube, O., Gaebel, R., McHugh, P.E., Svoboda, J.
Mit Hilfe der numerischen Simulation des Pressens und Sinterns können Gründichteverteilung, Sinterverzug und in Zukunft auch Rißbildung vorhergesagt werden. Damit steht ein numerisches Werkzeug...
To calculate shape distortions of powder compacts during sintering, both die pressing and sintering processes were simulated for two hard metal parts by using the finite element method. The modified...
The mechanical behaviour of sintering powder compacts (1995)
Micromechanical models for the sintering of Powders are described and macroscopic constitutive equations are derived from them. While the first model can be regarded as the sintering of long wires...
Numerical simulation of die pressing and sintering-development of constitutive equations (1994)
Riedel, H., Meyer, D., Svoboda, J., Zipse, H.
This paper summarizes recent studies on solid-state sintering with the goal of developing constitutive equations for use in finite element simulations of the sintering process. The assumed transport...
Numerical simulation of die pressing and sintering-development of constitutive equations (1994)
Riedel, H., Svoboda, J., Zipse, H.
This paper summarizes recent studies on solid-state sintering with the goal of developing constitutive equations for use in finite element simulations of the sintering process. The assumed transport...
Micromechanical models for brittle and ductile fracture (1994)
The present paper summarizes the principles of brittle and ductile material behavior and describes the progress made in two selected areas of modeling fracture processes. The classical problem of the...
Riedel, H., Svoboda, J., Zipse, H.
Constitutive equations for the intermediate and late stages of sintering are derived assuming grain boundary diffusion to be the controlling transport mechanism. The surface of the pore space is...
Svoboda, J., Riedel, H., Zipse, H.
The intermediate stage of sintering is characterized by equilibrium surfaces of the open pore space between the grains. These doubly curved surfaces are determined numerically for the three cubic...
A theoretical study of grain growth in porous solids during sintering (1993)
The processes of grain boundary migration, pore drag and pore/boundary separation are described on the basis of the phenomenological equations for boundary migration and surface diffusion....
Numerical simulation of die pressing and sintering-development of constitutive equations (1993)
Riedel, H., Meyer, D., Svoboda, J., Zipse, H.
Micromechanical models for the pressing and sintering of powders are described and macroscopic constitutive equations are derived from them. The effects of cohesion and friction between powder...
The fracture mechanisms operating in metallic and ceramic materials are summarized and the ranges of stress and temperature in which each of them dominates are shown on a fracture map. Cleavage...
Fatigue behavior of silicon-nitrides at elevated temperatures.: Vortrag. (1993)
Gehrke, E., Riedel, H., Berweiler, W., Siebels, J.
The macroscopic crack growth and the dynamic and cyclic fatigue behavior of two commercial silicon- nitrides are investigated in the temperature range up to 900 degree C. The correlation between...
Constitutive equations for the mechanical behavior of powder compacts during sintering (1993)
Riedel, H., Svoboda, J., Zipse, H., Gäbel, R.
Constitutive equations for the mechanical behaviour of porous solids during sintering are derived for equilibrium configurations of open and closed prosity. In a first step equilibrium surfaces are...
Simulation of die pressing and sintering of powder metals, hard metals and ceramics (1992)
Constitutive equations for die pressing and sintering are developed and implemented in the finite-element program ADINA (copyright). As an example, the production of a hard-metal tool is simulated...
The retardation of grain boundary migration by a pore is analyzed numerically and by an analytical approximation, which becomes exact in the limiting case of small velocities. At high velocities, the...
Mechanismen des Kriechbruchs und daraus abgeleitete Lebensdauermodelle (1992)
Komponenten von Kraftwerken werden bei Inspektionen der Anlage auf Kriechschädigung untersucht. Ziel der Arbeit ist es, aus dem beobachteten Grad der Porenbildung möglichst quantitativ auf die...
Simulation of pressing and sintering of powders. (1991)
Inhomogeneities in green density or in the temperature distribution during sintering may cause cracking, internal stresses or distortions of the sintered specimen. As a prerequisite for a numerical...
Gehrke, E., Berweiler, W., Siebels, J., Riedel, H.
Im Hinblick auf den Einsatz von Hochleistungskeramiken in Verbrennungsmachinen wurde das makroskopische Rißwachstum (Doppeltorsionsmethode und das Ermüdungsverhalten (4-Punkt-Biegeprüfung) an zwei...
Numerische Analyse eines Materialmodelles für Sintern (1990)
Ein auf Korngrenzendiffusion basierendes Materialgesetz für Sintern wurde in das FE-Programm ADINA implementiert. Dabei wurde ein implizites Zeitintegrationsverfahren (alpha-Methode) zur Bestimmung...
Crack growth and cyclic fatigue behaviour of sintered silicon nitride and syalon. (1990)
Gehrke, E., Berweiler, W., Riedel, H.
In the past years, various high-performance ceramics were developed, but their technical application is still limited. In order to extend the applicability of the high-performance ceramics, the...
Photovoltaic lead-chalcogenide IR-sensor arrays on Si for thermal imaging applications (1990)
Masek, J., Maissen, C., Zogg, H., Platz, W., Riedel, H., Königer, M., ...
Linear arrays of photovoltaic infrared sensors for thermal imaging applications are fabricated in narrow gap semiconductor layers grown heteroepitaxially on Si. Epitaxy is achieved using stacked...
A life prediction method for constrained grain boundary cavitation (1990)
The purpose of this paper is to provide a theoretical model to predict the remaining lifetime of a high-temperature component, which exhibits a given degree of cavitation damage.
Creep crack growth under small-scale creep conditions. (1990)
Two different constitutive models are employed to describe creep crack growth under small-scale creep conditions theoretically. The first model combines elastic/nonlinear viscous deformation fields...
Constitutive equations for the mechanical behavior of a sintering solid are derived from a microscopic model. The shrinkage and shear deformation of a microstructure with hexagonal grains and pores...
Recent advances in modelling creep crack growth (1989)
At the time of the previous International Conference on Fracture, the C integral had long been recognized as a promising load parameter for correlating crack growth rates in creep-ductile materials....
Recent advances in modelling creep crack growth (1989)
At the time of the previous International Conference on Fracture, the C-asterisk integral had long been recongnized as a promising load parameter for correlating crack growth rates in creep-ductile...
Life prediction methods for constrained grain boundary cavitation. (1989)
This paper summarizes the experimental evidence and the theoretical models that appear to be relevant for the nucleation and growth of grain boundary cavities in piping systems of fossil-fired power...
Lebensdauervorhersage bei behindertem Porenwachstum (1989)
Die Arbeit faßt die experimentellen Befunde und die theoretischen Modelle zusammen, die für die Keimbildung und das Wachstum von Kriechsporen in Rohrleitungen von Kohlekraftwerken wesentlich zu...
On the background of the historical evolution of the subject area, the current knowledge on creep crack growth is reviewed. The discussion is grouped around the C-integral, which is the appropriate...
Processing defects and strength of alumina substrates (1987)
Berweiler, W., Varner, J.R., Riedel, H., Harbach, F., Weiler, L.
Two sets of commercial alpha-alumina plates with a mean grain size of 1 to 2 mym were tested using the concentric-ring test. All specimens were taken from the same batch of material. The two sets of...
Fracture at high temperatures (1987)
The book is intended to summarize our present knowledge of intergranular fracture at elevated temperatures. The main subject is grain boundary cavitation under conditions of creep, creepfatigue and...
Berweiler, W., Mohrmann, R., Hollstein, T., Riedel, H.
Im modernen Maschinenbau werden immer hoehere Betriebstemperaturen angestrebt. Waehrend metallische Hochtemperaturlegierungen zur Zeit nur bis zu ca. 1000 Grad C einsetzbar sind, liefern die...
Creep fatigue of steels in various environments (1987)
Renner, E., Vehoff, H., Riedel, H., Neumann, P.
The interaction between fatigue and creep in X6CrNi1811 and X8CrNiNb1613 has been investigated in air and in vacuum at 873 K and 973 K using smooth specimens. A new damage parameter for creep-fatigue...
Creep crack growth in ductile, creep-resistant steels (1987)
Creep crack growth in two of the commonly used creep-resistant ferritic steels was investigated. Both steels were tested in the as-processed condition and after many years of service in electric...
Proefschrift Freiburg i.d. Schweiz.