Metallurgy and Foundry Engineering
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ISSN 1230-2325
e-ISSN: 2300-8377
Issue Date
2007
Volume
Vol. 33
Number
No. 1
Description
Journal Volume
Metallurgy and Foundry Engineering
Vol. 33 (2007)
Projects
Pages
Articles
Laser melted steel free surface formation
(2007) Siwek, Aleksander
Two-dimensional mathematical model of recasting steel by laser was presented in this paper. Surface velocity and liquid temperature for several powers of laser beams and sulfur contents were obtained as results of numerical modeling of liquid flow and heat exchange processes. The shape of free surface in a melted zone was computed with the use of iterative method proposed in this paper.
The application of fuzzy logic analysis to assessing the significance of mixing parameters for the PM metal-ceramic composite
(2007) Wojtaszek, Marek; Durak, Jarosław
An attempt to implement the fuzzy logic to quick and economic analysis of the mixing process in two component system (alumina powder-ceramic fibres) was made. An experiment with composites made by the powder metallurgy method and the determination of its selected properties were carried out. To obtain samples cold moulding and coextrusion were used. The forming process was made with constant parameters of mixing and forming. The influence of fibrę volume fraction in the matrix on the selected properties and the microstructure of the product was investigated. Experimental results and experts' knowledge were the input information for numerical computations and were represented by linguistic variables, fuzzy sets and fuzzy rules. Obtained or estimated in such way information from the technical point of view must be treated as an incomplete and uncertain knowledge. It means the mathematical description verified by experiments is not available. This knowledge was used to analyse the mixing parameters by the fuzzy logic. To implement inference the Fuzzy Logic Toolbox from Matlab package was used.
Estimation of materials microstructure parameters using computer program SigmaScan Pro
(2007) Matusiewicz, Piotr; Czarski, Andrzej; Adrian, Henryk
Possibilities of SigmaScan Pro computer program applications in quantitative characterization of materials microstructure are described in this paper. The studies were carried out for microstructures of different types, i.e. granular single phase, dispersed and lamellar. Furthermore possibilities of shape factors utilization in quantitative studies of microstructure, particularly in range of microstructure sta-bility are presented in details.
Influence of orientation relationship between ferrite and cementite in pearlite on stability of cementite plates
(2007) Czarski, Andrzej; Skowronek, Tadeusz; Osuch, Władysław
The aim of the studies performed was to assess an influence of crystallographic orientation relationship (OR) between pearlitic ferrite and cementite on a stability of cementite plates. Diffraction analysis made with an electron microscope showed the existence of the Bagaryatski OR and the Pitsch OR both in the pearlite structure after eutectoid transformation and after each tested time of the sphe-roidization annealing. The obtained results indicate that the crystallographic orientation relationship does not influence the stability of cementite showing lamellar morphology.
Strain in the upsetting process
(2007) Kajtoch, Jerzy
In the paper strain distribution in materials commonly referred to as soft materials (electrolytic copper 99,9 % Cu, annealed) and hard ones (steel 20, containing 0,2 % C) produced during hot upsetting process. Numerical calculations were performed with a use of commercial software QForm2D/3D. Significance of the influence of friction forces in the head surface on the free surface profile and distor-tion of rectangular coordination grid of deformations, as well as, effective strain distribution, in various stages of the process was investigated. The results indicate changes in nonuniformity of strain in obtained forgings.