In the present work, different Cu-alloyed model ductile irons with ferritic (0%Cu-0.09%Mn), mixed ferritic-pearlitic (0.38%Cu-0.40%Mn) and pearlitic (0.69%Cu-0.63%Mn) microstructure were produced and analyzed in terms of their electrochemical corrosion behavior in a 3.5wt.%NaCl aqueous solution containing naturally dissolved oxygen at room temperature (25°C). The remaining elements such as Si and Mg were kept at balanced levels in an attempt to minimize variations in graphite size and distribution among different samples. The corrosion resistance was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization. Microstructure analysis of the cast alloys confirmed similarity in the graphite morphology among the different cast samples and the expected variations in the metallic matrix. In the absence of passivation, it was found that the addition of copper led to an increase in corrosion resistance, which could be attested by higher values polarization resistance and corrosion potential.

For quality grey cast iron production, the challenging issues are to avoid cementite structure and obtain the desired graphite morphology with proper matrix as well as hardness. The objective of the present research is to find out the right combination of preconditioner and inoculant that may help to overcome the challenges. In this work, sulphur content is kept low (0.01%). Two preconditioners namely metallurgical SiC and zirconium bearing FeSi with two types of inoculant are individually used to make four combinations of sample and for each case metal is poured into the green sand mould. Finally Brinell hardness and graphite morphology is observed in the thickest and thinnest portions of the castings. Metallurgical SiC with barium bearing inoculant gives better graphite morphology and hardness than strontium bearing inoculant, on the other hand zirconium bearing FeSi gives more satisfying result than SiC with every type of inoculant. Among all of the combinations Zr bearing preconditioner with Ba bearing inoculant gives good graphite morphology with best mechanical properties in both thickest and thinnest portions of the casting.

In this paper results of microstructural observations for series of CuZn39Pb2 alloys produced from qualified scraps are presented. The individual alloy melts were differentiated in terms of thermal parameters of continuous casting as well as refining methods and modifications. Structural observations performed by SEM and TEM revealed formation of different types of intermetallic phases including “hard particles”. EDS results show that “hard particles” are enrich in silicon, phosphorus, iron, chromium and nickel elements. Additionally, formation of Al-Fe-Si and Al-Cr in alloy melts was observed as well. It was found that quantity and morphology of intermetallic phases strongly depends upon the chemical composition of raw materials, process parameters, modifiers and refining procedure applied during casting. It was observed that refining process results in very effective refinement of intermetallic phases, whereas modifiers, particularly carbon-based, results in formation of large particles in the microstructure.

The surfacing technologies are used for constitution of protection layer against wear and is destined for obtaining coating with high

hardness. Among many weldings methods currently used to obtain the hard surface layer one of the most effective way of hardfacing is

using flux cored arc welding. This additional material gives more possibilities to make expected hard surface layer.

Chemical composition, property and economic factors obtained in flux cored wire are much richer in comparison to these obtained with

other additional materials. This is the reason why flux cored wires give possibilities of application this kind of material for improving

surface in different sectors of industry.

In the present paper the imperfection in the layers was used for hardfacing process in different situations to show the possible application

in the surface layer. The work presents studies of imperfection of the welds, contains the picture of microstructures, macrostructures and

shows the results of checking by visual and penetrant testing methods.

Trial series of cast alloy MO59 obtained from qualified scrap was investigated. SEM and TEM of resulting precipitates were conducted.

The SEM analysis demonstrated the dependence of silicon, phosphorus, iron, chromium and nickel in the composition of the so-called

hard precipitates. TEM analysis showed the formation of phase AlFeSi and AlCr. Made studies have shown the important role of the

composition of the batch melts brass CuZn39Pb2 type. The analysis of SEM and TEM resulting precipitates pointed to the formation of

various forms of divisions, only one of which was described in the literature character of the so-called hard inclusions. The SEM studies

demonstrated the dependence of the occurrence of inclusions rich in silicon, phosphorus, iron, chromium and nickel. In contrast, additional

TEM analysis indicated the formation of AlFeSi phase type and AlCr. The results of the analyses referred to the structure of the batch. Due

to the difficulty of obtaining recycled materials that do not contain these elements necessary to carry out further analyzes in the direction

of defining the role of phosphorus in the formation of the so-called hard inclusions.

In this paper is discussed the effect of the inoculant mischmetal addition on the microstructure of the magnesium alloy AZ91. The concentration of the inoculant was increased in the samples within the range from 0.1% up to 0.6%. The thermal process was performed with the use of Derivative and Thermal Analysis (DTA). A particular attention was paid to finding the optimal amount of the inoculant, which causes fragmentation of the microstructure. The concentration of each element was verified with use of a spark spectrometer. In addition, the microstructures of every samples were examined with the use of an optical microscope and also was performed an image analysis with a statistical analysis using the NIS–Elements program. The point of those analyses was to examine the differences in the grain diameters of phase αMg and eutectic αMg+γ(Mg17Al12) in the prepared samples as well as the average size of each type of grain by way of measuring their perimeters. This paper is the second part of the introduction into a bigger research on grain refinement of magnesium alloys, especially AZ91. Another purpose of this research is to achieve better microstructure fragmentation of magnesium alloys without the relevant changes of the chemical composition, which should improve the mechanical properties.

The presented work discusses the influence of material of foundry mould on the effect of modification of AlSi11 alloy. For this purpose castings were produced in moulds made of four various materials. Castings of the first type were cast in a metal die, the second ones in the conventional mould of bentonite-bound sand, those of the third type in the sand mould with oil binder, the last ones in a shell mould where phenol-formaldehyde resin was applied as a binder. All the castings were made of AlSi11 alloy modified with strontium. For a purpose of comparison also castings made of the non-modified alloy were produced. The castings were examined with regard to their microstructures. The performed investigations point out that the addition of strontium master alloy results in refining of the alloy structure, particularly of the α-phase, causes some morphological changes in the alloy and the refinement of eutectics. The advantageous influence of modifier on the structure of the examined silumin was observed particularly in the case of alloy cast either in the conventional oil-bound sand mould or in the shell mould. The non-modified alloy cast into a metal die exhibits a structure similar to those of modified alloy solidifying in the other moulds. The improvement in both tensile strength and unit elongation suggests that the modification was carried out correctly. The best mechanical properties were found for the alloy cast in a metal die, both with and without modification treatment.

Magnesium alloys thanks to their high specific strength have an extensive potential of the use in a number of industrial applications. The most important of them is the automobile industry in particular. Here it is possible to use this group of materials for great numbers of parts from elements in the car interior (steering wheels, seats, etc.), through exterior parts (wheels particularly of sporting models), up to driving (engine blocks) and gearbox mechanisms themselves. But the use of these alloys in the engine structure has its limitations as these parts are highly thermally stressed. But the commonly used magnesium alloys show rather fast decrease of strength properties with growing temperature of stressing them. This work is aimed at studying this properties both of alloys commonly used (of the Mg-Al-Zn, Mn type), and of that ones used in industrial manufacture in a limited extent (Mg-Al-Sr). These thermomechanical properties are further on complemented with the microstructure analysis with the aim of checking the metallurgical interventions (an effect of inoculation). From the studied materials the test castings were made from which the test bars for the tensile test were subsequently prepared. This test took place within the temperature range of 20°C – 300°C. Achieved results are summarized in the concluding part of the contribution.

In Poland, researchers have a very strong interest in archaeometallurgy, which, as presented in classical works, focuses on dating artefacts

from the prehistoric and early medieval periods in the form of cast iron and copper castings. This study, extending the current knowledge,

presents the results of a microstructure investigation into the findings from the Modern era dating back to the late Middle Ages. The

investigated material was an object in the form of a heavy solid copper block weighing several kilograms that was excavated by a team of

Polish archaeologists working under the direction of Ms Iwona Młodkowska-Przepiórowska during works on the marketplace in the city of

Czestochowa during the summer of 2009. Pre-dating of the material indicates the period of the seventeenth century AD.

The solid copper block was delivered in the form of a part shaped like a bell, named later in this work as a “kettlebell”. To determine the

microstructure, the structural components, chemical composition, and homogeneity, as well as additives and impurities, investigations

were carried out using light microscopy, scanning electron microscopy including analysis of the chemical composition performed in

micro-areas, and qualitative X-ray phase analysis in order to investigate the phase composition.

Interpretation of the analytical results of the material’s microstructure will also help modify and/or develop new methodological

assumptions to investigate further archaeometallurgical exhibits, throwing new light on and expanding the area of knowledge of the use

and processing of seventeenth-century metallic materials.

Secondary or multiple remelted alloys are common materials used in foundries. For secondary (recycled) Al-Si-Cu alloys, the major problem is the increased iron presence. Iron is the most common impurity and with presence of other elements in alloy creates the intermetallic compounds, which may negatively affect the structure. The paper deals with effect of multiple remelting on the microstructure of the AlS9iCu3 alloy with increased iron content to about 1.4 wt. %. The evaluation of the microstructure is focused on the morphology of iron-base intermetallic phases in caste state, after the heat treatment (T5) and after natural aging. The occurrence of the sludge phases was also observed. From the obtained results can be concluded that the multiple remelting leads to change of chemical composition, changes in the final microstructure and also increases sludge phases formation. The use of heat treatment T5 led to a positive change of microstructure, while the effect of natural aging is beneficial only to the 3rd remelting.

The work determined the influence of aluminium in the amount from about 1% to about 7% on the graphite precipitates in cast iron with

relatively high silicon content (3.4% to 3.90%) and low manganese content (about 0.1%). The cast iron was spheroidized with cerium

mixture and graphitized with ferrosilicon. The performed treatment resulted in occurring of compact graphite precipitates, mainly nodular

and vermicular, of various size. The following parameters were determined: the area percentage occupied by graphite, perimeters of

graphite precipitates per unit area, and the number of graphite precipitates per unit area. The examinations were performed by means of

computer image analyser, taking into account four classes of shape factor. It was found that as the aluminium content in cast iron increases

from about 1.1% to about 3.4%, the number of graphite precipitates rises from about 700 to about 1000 per square mm. For higher

Al content (4.2% to 6.8%) this number falls within the range of 1300 – 1500 precipitates/mm2

. The degree of cast iron spheroidization

increases with an increase in aluminium content within the examined range, though when Al content exceeds about 2.8%, the area

occupied by graphite decreases. The average size of graphite precipitates is equal to 11-15 μm in cast iron containing aluminium in the

quantity from about 1.1% to about 3.4%, and for higher Al content it decreases to about 6 μm.

The influence of aluminium (added in quantity from about 0.6% to about 2.8%) on both the alloy matrix and the shape of graphite precipitates in cast iron treated with a fixed amounts of cerium mischmetal (0.11%) and ferrosilicon (1.29%) is discussed in the paper. The metallographic examinations were carried out for specimens cut out of the separately cast rods of 20 mm diameter. It was found that the addition of aluminium in the amounts from about 0.6% to about 1.1% to the cast iron containing about 3% of carbon, about 3.7% of silicon (after graphitizing modification), and 0.1% of manganese leads to the occurrence of the ferrite-pearlite matrix containing cementite precipitates in the case of the treatment of the alloy with cerium mischmetal . The increase in the quantity of aluminium up to about 1.9% or up to about 2.8% results either in purely ferrite matrix in this first case or in ferrite matrix containing small amounts of pearlite in the latter one. Nodular graphite precipitates occurred only in cast iron containing 1.9% or 2.8% of aluminium, and the greater aluminium content resulted in the higher degree of graphite spheroidization. The noticeable amount of vermicular graphite precipitates accompanied the nodular graphite.

The influence of aluminium added in amounts of about 1.6%, 2.1%, or 2.8% on the effectiveness of cast iron spheroidization

with magnesium was determined. The cast iron was melted and treated with FeSiMg7 master alloy under industrial conditions.

The metallographic examinations were performed for the separately cast rods of 20 mm diameter. They included the assessment of the

shape of graphite precipitates and of the matrix structure. The results allowed to state that the despheroidizing influence of aluminium

(introduced in the above mentioned quantities) is the stronger, the higher is the aluminium content in the alloy. The results of examinations

carried out by means of a computer image analyser enabled the quantitative assessment of the considered aluminium addition influence.

It was found that the despheroidizing influence of aluminium (up to about 2.8%) yields the crystallization of either the deformed nodular

graphite precipitates or vermicular graphite precipitates. None of the examined specimens, however, contained the flake graphite

precipitates. The results of examinations confirmed the already known opinion that aluminium widens the range of ferrite crystallization.