In this work, an analysis of the course of the peritetic transformation L+Al3Fe→α-AlMnFeSi in Al–Fe–Mn–Si alloys containing an increasing Mn content (0–2%) has been presented. The particular steps of the solidification of the examined alloys by peritectic transformation: (1) primary phase precipitation from liquid alloy: L→L1+Al3Fe, (2) peritectic reaction: L+Al3Fe→α-AlMnFeSi, (3) peritectic transformation: Al3Fe→α-AlMnFeSi←L1 and (4) nucleation and growth of the equilibrium phase in liquid: L→L2+α-AlMnFeSi, have been identified and described. The distribution of the transition metals Fe and Mn in the intermetallic phases has been estimated by means of the EDS microanalysis. Composition gradient in the secondary α-AlMnFeSi phase was analysed as a result of the local transport of the alloy components during the precipitation sequence. It was stated that Mn atoms involved mechanism of the analysed peritetic transformation. The formulated equation Δxα2/t=K(Mn, ΔMn) for isothermal conditions of the analysed transformation has represented a good agreement to the experimental data in the range of the low Mn content (Mn≤1%).

In this paper the concept of Virtual Teams creation and model of activity will be described. Examples of application in the modelling and control of alloys crystallisation area related to this concept will be discussed. This work was carried out by the International Science-research Organisations' in charge of international projects. The investigations and numerical simulation of physical processes as a dispersed system were carried out using supercomputers and co-ordinated by Internet. The results, organisation and applicability of the model of Virtual Team will be shown.

The necessary conditions for implementation of intelligent processing to the composite in situ of regular structure production are presented. The basic element of IPM concept is the description of the material dynamics. It represents the mathematical models of the process, which help predict the microstructural evolution of the material towards the goal state during processing. In the case of the investigated process, the mathematical models are bound up with the transport phenomena encountered during the process. The heat transfer model formulated and solved in the microscopic scale is presented. The results achieved for the general case and for the cases connected with the real vertical Bridgman process are discussed. The problem of optimal control is bound up with the formulation of the quality control index. This index is described in the paper. Implementation of intelligent processing to the vertical Bridgman process requires the innovation of the Bridgman system by the control module and the suitable equipment for the non-invasive investigation of the growing structure quality.

In this study, an attempt has been made to describe a two-stage process of making thixotropic castings using a concept of intelligent processing of materials (IPM). The first part of the study gives a characteristic of the thixotropic casting process, its technological fundamentals and methods of obtaining a rheocast structure. Against this background was outlined the possibility of an innovative extension of the technology of making thixotropic castings by application of the simulation control tool known as IPM.To discuss the thixotropic casting in terms of a concept of intelligent processing of materials, some simplifications and general assumptions for a formal description of the phenomena which occur in this process, including mass and heat transport, are required. A relatively simple configuration of the system in which an alloy of rheocast structure is solidifying enables application of equally simple methods of model solution. The second part of the study is expected to cover the presentation of results along with their analysis.

Implementation of Intelligent Processing of Materials (IPM) concept [1] to the vertical Bridgman process requires early information provided by non-invasion factors which are monitoring the critical states during process run. The actual knowledge of the process conditions varying along with changes in process model will indicate measures that should be taken to ensure proper planning and feedback which will finally produce a material characterised by the pre-set complex of properties. The results presented in this paper connected with the control quality index formulated in [2] are the step-by-step realisation of IPM concept being applied to the process of composite in situ formation ([3]).This paper presents the two-stage approximation method of the real temperature microfield for the mathematical models of heat transfer in Bridgman system. The problems bound up with this method are discussed. The illustrations for the two-dimensional problem are presented.

Analytical method for description of the shape of cells observed in 1D experiment is suggested. The shape of cells is treated as a result of wave character perturbation which has appeared on previously planar surface of a crystal. A product of two functions is used to describe it: the first function is related to fundamental undulation of crystal surface and the second is connected with the details of cell's geometry. A description of the fundamental undulation of crystal surface takes into account both: amplitude and frequency of undulation; whereas the geometry of cells includes: tip curvature, groove shape and asymmetry of doublets. The suggested product of two functions allows the shape of cells observed during oriented solidification to be reproduced, namely: some cells growing just above velocity which corresponds to the cellular threshold, the doublets and the cells growing in predendritic region. Additionally, the modification of cellular shape in function of growth rate as well as 3D image of cellular arrays may be shown using the considered formal description.

According to irregular eutectic growth model two characteristic parameters are differentiated within revealed morphology: the first (lambda(i)) - adequate to the formation of lamellar structure in steady-state and the second (lambda(s)(i)) - to extreme development of the perturbation due to marginal wavelength at non-faceted s/l interface. The selection of both above parameters among all the spacings revealed on cross-sections of the Al-Si eutectic alloy solidified directionally is also made. Some values of the lambda(i) and lambda(s)(i) parameters obtained by means of calculation made using the new growth law for the same values of growth rate v and temperature gradient G as those imposed during solidification of the Al-Si eutectic alloy are compared to the spacings selected within oriented morphology. An influence of temperature gradient G(G(x), G(z)) on lamellar structure formation during irregular eutectic growth is emphasized. The analysis is based on existence of two thermodynamic states: stationary state leading to formation of regular structure and rotation around stationary state leading to branching phenomenon due to instability at the s/l interface of non-faceted phase.