The present article describes development and testing of a new measurement method that enables nondestructive and in situ monitoring of a vacuum carburizing process. The principle of the method is based on monitoring the carbon diffusion during vacuum carburizing by the in-situ measurement of electrical resistance changes in the carburizing sample. Using this method the electrical resistance changes during vacuum carburizing of pure iron were acquired and analyzed.
COBISS.SI-ID: 13139990
In this paper we propose an evolutionary computation approach for the modelling of yield strength in formed material. One of the most general evolutionary computation methods is genetic programming, which was used in our research. Genetic programming is an automated method for creating a working computer program from a problem’s high-level statement. During our research, material was cold formed by drawing using different process parameters On the basis of a training data set, various different genetic models for yield strength distribution were developed during simulated evolution.
COBISS.SI-ID: 13042966
A multi scale numerical approach for evaluation of crack initiation and propagation in thermally cut structural elements made of martensitic steel is presented. A numerical simulation of micro-crack initiation is based on the Tanaka-Mura micro-crack nucleation model, where individual grains of synthetic microstructure are simulated using the Voronoi tessellation. Three improvements are added to this model (multiple slip bands, micro-crack coalescence and segmented micro-crack) generation). Crack propagation is then solved on a macro scale model using LEFM.
COBISS.SI-ID: 13864982
Numerical simulation of micro-crack initiation that is based on improved Tanaka-Mura micro-crack nucleation model is presented. Numerical simulation of crack-initiation was performed with ABAQUS, using a plug-in that was written specially for handling micro-crack nucleation and coalescence. Since numerical model was directed at simulating fatigue properties of thermally cut steel with martensitic structure, edge properties of specimen were additionally inspected in terms of micro-structural properties, surface roughness and residual stresses.
COBISS.SI-ID: 13864726
The alloy that may be important as a quasicrystal strengthened aluminium alloy was characterised in details. Special attention was devoted to icosahedral quasicrystalline phase. The composition of the i-phase was approximately Al52Mn18Be30. The i-phase was present predominantly in the form of dendrites and a rodlike eutectic phase. The morphology of the i-phase was explained by the predominant growth in threefold directions and the lowest energy of the fivefold planes, leading to the faceting and adopting a pentagonal dodecahedron shape.
COBISS.SI-ID: 13052182