A5076613730- Microstructure and Mechanical Properties of Steels
- High Temperature Alloys and Creep
- Metallurgy and Material Forming
- Microstructure and mechanical properties
- Metallurgical Processes and Thermodynamics
- Material Properties and Failure Mechanisms
- Aluminum Alloy Microstructure Properties
- Metal Alloys Wear and Properties
- Engineering and Materials Science Studies
- Advanced Materials Characterization Techniques
- nanoparticles nucleation surface interactions
- Fatigue and fracture mechanics
- Advanced machining processes and optimization
- Hydrogen embrittlement and corrosion behaviors in metals
- Metal and Thin Film Mechanics
- Non-Destructive Testing Techniques
- Intermetallics and Advanced Alloy Properties
- Advanced Surface Polishing Techniques
- Ultrasonics and Acoustic Wave Propagation
- Metal Forming Simulation Techniques
- Mechanical and Thermal Properties Analysis
- Fire effects on concrete materials
- Material Properties and Applications
- Nuclear Materials and Properties
- Advanced Machining and Optimization Techniques
Johannes Kepler University of Linz
2020-2024
University of Stuttgart
2020-2021
Graz University of Technology
2010-2020
University of Cape Town
2013-2014
Institute of Experimental Physics of the Slovak Academy of Sciences
2014
Materials Center Leoben (Austria)
2006-2011
SIB Swiss Institute of Bioinformatics
2009
École Polytechnique Fédérale de Lausanne
2009
Sulzer (Switzerland)
1981
We demonstrate the in situ measurement of zero-group-velocity Lamb waves and thickness-resonances steel sheet samples using laser-based ultrasound, while changing sample temperature from ambient to 1000 ∘C. The ratio resonance frequencies yields dependent Poisson's its material without requiring knowledge on sheets' thickness. Changes derivative determined reflect changes microstructural constituents. show that additional resonances present response spectrum can be used cross-check...
In this work, microstructural changes during creep of Ni-based alloy 617 at 700 °C and 165 MPa have been investigated by electron microscopy, complementarily modelled. Precipitate types, sizes chemistry were determined transmission- (TEM) scanning microscopy (SEM). Apart from γ' particles, MX carbides, coarse μ-phase was found. Grain size, frequency twins, deformation patterns geometrically necessary dislocations characterized backscatter diffraction (EBSD). Based on measurements literature...
A multi-purpose heating attachment designed primarily for X-ray four-circle diffractometers but applicable also classical powder diffraction is presented. When working in reflection geometry, the air-cooled stage allows studies to be performed on plate-like samples up 1173 K whole orientation space. This paper gives a detailed description of assembly and important technical specifications performance experiments. The characteristics stage, displacement sample from goniometer centre as result...
This work focuses on the characterisation of cavities evolution in a P91 steel pipe three conditions: as received, and after creep at 650°C 60 MPa for 7000 9000 h. A field emission gun scanning electron microscope (FEG-SEM) equipped with focused ion beam (FIB) gun, conventional (SEM) light optical (LOM) have been employed investigation. study reveals two types cavities: pre-existing cavities, which are rare this type heat resistant steels, mean diameter 2·56 μm produced during diameters...
Recently, the high cost and low productivity of machining hard materials such as Ti-6Al-4 V has drawn major attention to development a modular scalable tool system with integrated laser one piece equipment. The present study focuses on new concept laser-assisted milling spindle beam guiding. is located at cutting area moving synchronously cutter. In order optimize process respect force reduction, various conditions were investigated, both experimentally simulation. numerical 3D FEM...
This work deals with the development of a comprehensive mean-field dislocation creep model and its application to martensitic 9% Cr-steel P91. Microstructural data from literature, EBSD measurements results precipitate kinetic simulations serve as input for simulation in addition material- physical constants. The has capability calculating curves depending on their initial microstructure, stress temperature is thus able deduce time-to-rupture diagrams. Side-result microstructural evolution...
Abstract Nanometer‐sized precipitates in tool steels are the most important microstructural constituents determining mechanical and thermophysical properties. For improvement of existing steel grades development new a fundamental knowledge precipitation reactions during heat treatments at application temperature is vital interest. Thus, comprehensive characterization various required. This paper reviews studies performed on complex which hardens by secondary hardening carbides intermetallic...
Abstract Recently, a novel model has been developed for simulation of the evolution spherical precipitates in multi‐component, multi‐phase systems. Contrary to classical approaches, kinetic scales linearly with complexity system and it is, thus, particularly suitable complex industrial applications. In present paper, features capabilities new approach are demonstrated on example heat treatment thermal ageing an tool steel. The predictions compared comprehensive experimental data. Model...
Coherency strengthening plays a major role in precipitation strengthening. The governing mechanism is based on the interaction of dislocations with elastic strain field induced by lattice misfit precipitates and matrix. In case non-spherical precipitates, corresponding stress inhomogeneous depends relative orientation particle respect to Burger's vector dislocation. We evaluate shear increment due fields around an oblate precipitate suggested model for coherency precipitates. results weak...
Precipitates are the key ingredient for strength of heat treatable alloys. To optimize mechanical properties alloys it is important to know response precipitates thermomechanical treatments. In past, application computer models describe evolution in course these processes has proven difficult due complexity problem. this work, a new model based on mean-field representation multicomponent matrix applied treatments steels. Example simulations presented 9- 12% Cr ferritic/martensitic resistant...
Abstract A novel steel grade has been developed recently exhibiting superior thermal stability. This is attributed to the combined precipitation of secondary hardening carbides and intermetallic phases. However, behaviour this not completely understood yet. In study, computer simulations kinetics during heat treatment are performed compared a complementary experimental characterisation precipitate microstructure, which was carried out previously. The employ model for nucleation, growth...