The CuAl5 single crystal with the initial orientation (I 10)[00I] was cold rolled and subsequently compressed in a channel die in such a way that the new direction of plastic flow was parallel to the transverse direction of initial rolling and the compressed plane was parallel to the former rolling plane. The dislocation slip was the only deformation mechanism during rolling. The dislocation substructure after rolling was uniform. During the compression in a channel die, additionally, the deformation twinning as well as the shear band formation took place. The recrystallization commenced and proceded within the shear bands. After that. the recrystallization proceeded by the nucleation and growth of new grains within the areas with high density of deformation twins. The recrystallized regions of the former shear bands were filled by fine grains while the regions amongst them exhibited much bigger grains. The recrystallization texture was formed according to the theory of the oriented growth.

The paper presents preliminary results of the investigations of the correlations occurring between the rate of the acoustic emission (AE) events and the plastic deformation mechanisms during channel-die compression of Mg-Li and Mg-Li-Al alloys. as well as the corresponding metallic matrix composites reinforced with short ó Al2O3 fibres. Essential qualitative and quantitative differences in the AE behaviour have been observed in the composites and in the pure alloys. The obtained results are discussed on the basis of the possible dislocation and microcracking processes and also on the basis of microstructure observations using the optical microscopy. It is suggested that the highly jumping character of AE behaviour in two-phase (a+ /3) Mg8Li3AI alloys is related to the twinning in a phase and to the microcracking along the interfaces. while in Mg8Li + bAl2O3 composites also to the fibres cracking and debonding processes, i.e. the loss of cohesion between the fibres and the matrix.

The formation of texture and microstructure in polycrystalline Cu and Cu-5 wt. % Al alloy during two modes of homogenous rolling have been compared. Two samples of each metal were rolled. One sample was rolled unidirectionally, while the other by reverse rolling. Some differences in the textures depending on the rolling mode have been observed in the range of deformation of the Cu-5 wt. % Al alloy where intensive twinning took place. It was also found that the texture of reverse rolling was more homogeneous across the thickness of the rolled alloy sheet than the texture of unidirectionally rolled material. No clear effect of the rolling mode on microstructure has been observed.

The subject of investigation is the ridging phenomenon occuring in ferritic stainless chromium steels. The origin of this undesirable surface phenomenon is connected with the observed strips of texture inhomogeneities showing plastic anisotropy. Basing on measurements of crystallographic orientation topography the texture inhomogeneities together with the ridging effects have been investigated in sheets from earlier stages of the production process. The proposed changes in the traditional technological processing of sheets obtained from this steel type are intended to limit the occurrence of the ridging effect.

Deformation of a composite material being compressed between two parallel plates is analyzed from the point of view of changing the relative thickness of particular layers during the process. The three layer composite consists of two different materials: one of them is assumed to be viscoplastic while the other one is perfectly plastic. Variation of the relative thickness of the different layers is investigated with respect to values of material constants, geometrical arrangements of the materials as well as the loading history.

The microtextural changes within macroscopic shear bands (MSBs) in high purity aluminium and copper single crystals with { 112}( I I I) initial orientation, deformed by channel die compression, have been studied in detail. Systematic measurements of single orientations by SEM/EBSD and TEM/CBED clearly show that the investigated crystals are stable only in a global sense. The occurrence of the first set of MSBs is connected with a local lattice rotation towards the { 00 I }(110) orientation. In particular, this process directs the (111) slip plane, towards a shear plane and the activation of new, highly stressed { 111 }( 101) + { 111 }(Ol I)---, ---, CP{ 111 }( 112) slip systems, is documented. The deformed matrix near MSBs represents a relatively more stable behaviour, and the group of the orientations situated near the C{l 12}(1ll)-D{44 11}(11 11 8) positions describes it.

The galvanostatic method used in previous measurements of the chemical diffusion coefficient in the Al-rich aluminium-lithium alloys has given a numerical values of the above coefficient at four imposed temperatures. This directly measured values of diffusion coefficient is compared with the value obtained indirectly from the measurement of the Li-solute redistribution within the Al-3.5Li alloy solidified directionally in the Bridgman system. The adequate theoretical considerations dealing with the description of solute redistribution in eutectic system has been made to calculate the value of back-diffusion parameter for the performed 2D experiment. The definition of back-diffusion parameter has been rearranged to calculate the numerical value of the diffusion coefficient in the solid. It has been shown that back-diffusion parameter plays essential role in the model of solute redistribution which is discussed from the viewpoint of the application of current model for redistribution to calculation of the solidification path.

The suitable structure of an alloy affects its superplastic properties due to a basic mechanisms of superplastic deformation. A fine structure of equiaxial grains appears in the alloy provided there are dispersoids and intermetallic compounds of certain size and distribution. The composition of the 2:XXX - type alloy (with Ni - addition) as well as a special thermomechanical treatment allowed to obtain a suitable structure of 15 μm-grain size and an equiaxial shape. The formation of such microstructure was investigated using optical, scanning and electron microscopy, as well as X-ray phase analysis techniques. The X-ray and electron microscopy with EDAX analyser allowed to determine the type and morphology of the intermetallic compounds, very important to generation the fine-grained structure. The superplastic state regarding quality of the structure was verified in tensile tests performed at the range of deformation rates between 1.4 x 10--4 to 7 x 10-3 s-1 and at temperatures from 789 K to 839 K, which allowed to attain the elongation above 300% and strain rate sensitivity coefficient m = 0.509.

The strain hardening parameters of steel, aluminium and brass sheets were determined by uniaxial and balanced biaxial (hydraulic bulging) tensile tests. Sheet thickness gradation in different points of hemisphere formed in bulge test was analysed. The Ho 11 om o n equation was used to described uniaxial and biaxial strain hardening curves, and a comparison of strain hardening exponent was performed. Both the mean value of strain hardening exponent n (which describe the strain hardening of the whole strain range) and differential n,-value were determined on the base of the results of uniaxial and biaxial testing. The influence of the stress-state on the strain hardening behaviour of the material, as well as strain localization process, under both deformation modes are analysed.

A basic ceramic system was developed by mixing the low temperature form of wollastonite ceramics, sodium silicate and aluminium phosphate. In some cases, UHMW polyethylene powder has been added to the ceramic system during the mixing. The effect of maturation time and aluminium phosphate and polyethylene contents on the mechanical properties has been evaluated. By using four-point bending and double torsion tests the mechanical characterisation has been performed. The mechanical properties, with the exception of the maximum strength, are of the order of human cortical bone. This system allows other constituents to be added to the basic formulation to improve mechanical properties due to the presence of liquid sodium silicate that decreases the interfacial energy of ceramics. Thus, from the mechanical point of view, the materials developed may be suitable for the repair and reconstruction of bone.

Stress and strain state during the curvature change are characterized by great nonuniformity. There are circumferential tensile stresses in the external elongated zone and compressive ones in the internal zone. Both zones are separated by the neutral surface where circumferential stresses equal zero.

Basing on the data of Al2O3 and SiO2 thermodynamic acnvrties in SiO2-containing calcium aluminates of three formulae, CaO · Alz03, I 2CaO · 7Alz03 and 3Ca0 · Alz03 (shortly denoted as C1A" C12A7 and C3A1), at 1873K for the wide range of SiO2 mole fractions [!], we propose their activities expressed as functions of CaO contents provided there is no change in SiO2 mole fraction. The proposed relations allow to follow the change of the inclusions and steel composition during calcium treatment when calcium or calcium-silicon are added. An evolution of inclusion and steel compositions during calcium treatment was investigated starting from the partly modified inclusions C1A1-SiO2 with x;,02 = O.IO and 0.03. It was shown that the change of calcium aluminosilicates composition is slightly different for the pure calcium and calcium-silicon additions. With the calcium treatment the mole fraction of SiO2 in inclusions is decreasing less significant.

The paper presents the results of some preliminary investigations on electrolytic separation of chemical elements contained in anode slimes. A new type of electrolyzer is presented which can enable a continuous transport of the electrolysis products 10 a receiver. Then, both the kinetics and the mechanism of anodic dissolution of powder electrodes, taking as example silver powder are discussed. An empirical formula allowing to control this process by means of such parameters as powder mass, current density, electrolyte concentration and grain structure has also been derived. Finally, a procedure for conducting anodic dissolution so as to reverse passivation and to increase the fraction reacted is suggested.

The chemistry and microstructure of ceramic coatings of Zr02 with 8 and 20 wt% Y2O3 plasma deposited on the NiCrFe substrate with the NiCr25Al6Fe2Y0.4 interlayer were investigated using scanning, analytical microscopy and X-ray phase analysis. An amorphous phase and fine crystalline zone adjacent to the ceramic and metallic layer was detected using transmission electron microscopy. On the other hand, another zone, which was nanocrystalline with some contribution of amorphous phase was observed in the NiCrAIFeY interlayer close to the NiCrFe substrate.

The object of investigations was two-phase steel having the austenitic structure with ferrite precipitates (volume fraction about I 0% ). The material was subjected to cold rolling up to about 85% of deformation and subsequently annealed within the temperature range 750°C+l000°C. X-ray investigations included the phase analysis, measurements of pole figures and calculations of the orientation distribution functions (ODF's) for both component phases. The textures of austenite and ferrite after the final rolling reduction and successive stages of annealing were analysed within the centre and surface layers of the sheets. Examination of the austenite recrystallization texture included additionally the analysis of orientation fibres and transformations of the experimental and ideal ODF's. From the texture analysis it results that the mechanisms controlling the development of the austenite recrystallization texture is the selective growth of twins. Texture simulations indicate that austenite rolling texture can be transformed into the recrystallization texture according to twin relation, i.e. by rotation through an angle of (2n - I) x 60° about < I 11 >poles. A certain contribution of the oriented growth into the texture formation was also found. In that case relation between the recrystallization and deformation textures may be described by rotation 30°+40°/<111>. In both cases a variant selection of the rotation axis takes place. Based on the texture examination and the phase analysis it is additionally assumed that the (a ➔y) phase transformation may exert some effect on the recrystallization textures of both component phases

Recently, new methods for utilization of converter slag have been sought. Slag processing by reduction in an electric arc furnace is one of such methods. However, the state of the relevant investigations is rather poor. This was the reason for carrying out study aimed at developing a new technology of the process under industrial conditions. The study presented allows chemical composition of non-metallic and metal phases and the reduction level of the converter slag components during process run in an electric arc furnace to be determined.

The stored energy e, due to plastic deformation is defined as the change in internal energy measured at stress free state of material, and it characterises the cold-worked state. Both cold-worked state and the stored energy at each instant of deformation depend on the deformation history. Therefore, the instantaneous rate de,f dwP of energy storage seems to be an appropriate measure of the energy conversion process (wP is the work of plastic deformation). The rate of energy storage is important characteristic of the whole energy storage processes. It is a macroscopic quantity that is influenced by many microscopic mechanisms. Each of them is described by the separate internal paramenter H;. In mathematical description, the stored energy is a function of H,, H2, H3 •.• , H,,. Since there exist couplings between different mechanisms the function can not be, in general, written in the from: Le'..° (H;). The similar remark concerns also the energy storage rate. i= I The present paper is devoted an answer if it is possible to distinguish the influence of the change in given internal parameter on the rate of energy storage. In order to find the answer the theoretical analysis of energy storage rate on the basis of phenomenological thermodynamics of plastic deformation was done. The theoretical description of the experimental method od stored energy determination is presented. The results of the analysis have been used to support the additive partitioning of the resultant rate of the energy stored and to show experiment which allows distinguishing the particular components. Each component represents the specific microscopic mechanism. The analysis of preliminary experimental data arrived at the conclusion that in the initial stage of plastic deformation of polycrystalline metal at least two components of the energy storage rate exist. One of them is associated with the rise of dislocation density, and another one is related to the internal stress field due to elastic accommodation of incompatible strains in the vicinity of grain boundaries.

The existing methods of analysis of drawing with a floating plug stated the most favourable angle differences between the drawing die and the plug. In the paper the theoretical analysis is made enabling achieving the possibly minimal diameter reduction at the stated wall thickness reduction. There is discussed tool geometry and a state of stress, which enable stable guidance of the process. The experimental studies with drawing of OF-Cu copper and CuZn37 brass tubes confirmed the results of theoretical consideration.

The paper presents the results of SrSO4 reduction and SrS oxidation with the use of gaseous mixture (CO+CO2) in 1073-1373 K temperature range. On the base of an assumed equation describing the process in the wide range of reaction stage the dependence of constant reaction rates on CO concentration in the gaseous phase. The value of reaction activation energy and its change depending on the composition of the gaseous phase (CO+CO2) has been defined. The boundary value CO concentration in the gaseous phase, above which reductions, and below which oxidation of SrS take place, has been defined.

Constituent binary subsystems Co-Cu, Co-Si and Cu-Si were described briefly, and their calculated phase diagrams were presented and invariant reactions of the liquid phase, as well. Thermodynamic parameters for Co-Si and Cu-Si systems were taken from the former own assessments and coefficients for binary system Co-Cu were accepted from the one of the most recent literature evaluations. Tdb file was then set up by means of binary formalism. Equilibrium calculations resulted in the parameters of all invariant reactions with liquid phase involved, and the Schei l reaction scheme was constructed as well. Graphical representation of the calculated liquidus surface was shown as the projection onto the G i b b s triangle plane.

Przegląd literaturowy stosowanych na świecie technologii do przerobu stopów Zn-Ag-Pb wskazuje, że najefektywniejszą technologią jest metoda destylacji próżniowej, oparta na zjawiskach parowania lotnych składników z kąpieli metalicznej. W procesie odparowania składników z ciekłych stopów, w warunkach obniżonego ciśnienia, podstawowe znaczenie odgrywają zjawiska transportu masy. Badania procesu parowania w próżni wykazują, że jego szybkość może być zwiększona nie tylko przez obniżenie ciśnienia czy wzrost temperatury procesu, lecz także przez zmianę warunków hydrodynamicznych w układzie. Można także przypuszczać, że w zależności od rodzaju stopu kontrola kinetyczna omawianego procesu jest znacznie zróżnicowana. Wykazanie, który z tych czynników najistotniej wpływa na kinetykę procesu parowania, wymaga określenia etapu kontrolującego proces, a także określenia wpływu tych czynników na zmianę jego kontroli. W ramach pracy przeprowadzono badania próżniowego oddestylowania cynku ze stopów Zn-Ag-Pb w zakresie ciśnień od I do 1000 Pa i temperatur od 823 do 898 K. Badania przeprowadzono dla stopu o składzie chemicznym: 50,0% Ag, 35,0% Pb i 15,0% Zn. Podstawowym urządzeniem wykorzystywanym w badaniach był agregat próżniowy składający się z głowicy roboczej, pieca indukcyjnego PIS O I TR i układu pomp próżniowych SP2000 PA. Po każdym doświadczeniu określano wielkość ubytku masy próbki oraz analizowano skład chemiczny stopu oznaczając zawartość: cynku, srebra i ołowiu metodą atomowej spektrometrii absorpcyjnej (AAS) z zastosowaniem spektrometru firmy Perkin-Elmer model 603. Na podstawie analizy uzyskanych wartości podstawowych parametrów kinetycznych: gęstości strumienia masy oraz współczynnika przenikania masy dla zakresu ciśnień od IO do 20 Pa obserwuje się silną zależność tych wielkości od ciśnienia panującego w układzie pomiarowym. Oznacza to, że w tym zakresie ciśnień następuje zmiana kontroli procesu i opory w fazie gazowej nakładają się na opory w fazie ciekłej. Można więc przyjąć, że w obszarze ciśnień od IO do 20 Pa mamy do czynienia z mieszaną kontrolą procesu. W zakresie ciśnień powyżej 20 Pa można natomiast przyjąć, że proces zachodzi w obszarze dyfuzyjnym i jest kontrolowany oporami w fazie gazowej. Szybkość procesu odcynkowania stopów Zn-Ag-Pb wzrasta silniej w miarę obniżania ciśnienia niż przy wzroście temperatury. W zakresie ciśnień poniżej IO Pa, wartości pozornej energii aktywacji procesu zbliżone są do wartości energii aktywacji dyfuzji cynku w ciekłym srebrze. Stanowi to potwierdzenie faktu, że w tym zakresie ciśnień proces destylacji cynku kontrolowany jest głównie transportem masy w fazie ciekłej.

Brief review on history and development of OTA as thermal analysis method; with special aspect to the application of quantitative thermodynaimc analysis for binary metal systems, are presented in this paper. Importance of the calibration constat determination is pointed out, as well as its changeable value depending on composition of the investigated system. Results obtained using OTA method in termodynamic analysis of some binary systems are also given and compared with data measured by other experimental techniques (calorimetry, EMF measurements) or calculated by thermodynamic predicting methods. Good agreement reached between these results enables to the correctness of application of quantitative OTA.