The paper presents results of assessment of the unit pressure force within the refractory material volume in the course press-moulding of

stampings for refractory precast shapes. The force was evaluated with the use of physical simulation of deformation undergone by lead

balls placed in the raw refractory mass subjected to pressing in a metal die. To determine the value of unit pressure force applied to the

aggregate grains in the course of stamping press-moulding, physical model of deformation of a sphere induced by the uniaxial stress state

was used.

The paper presents results of an analysis of material density distribution in stampings press-moulded in metal dies from raw refractory

materials based on alumina-magnesia-carbon aggregate. The stampings, fabricated on LAEIS HPF 1250 pressing machine, are blanks from

which refractory precast shapes are manufactured by means of drying and firing. Samples for material density evaluation were cut out

from test stampings with the use of diamond-reinforced disc. Density of the material was determined in thirteen layers of stampings

denoted with letters A through M.

The paper presents the method of preparing a composite slurry composed of AlSi11 alloy matrix and 10 vol.% of SiC particles, as well as

the method of its high-pressure die casting and the measurement results concerning the castability of the obtained composite. Composite

castings were produced at various values of the piston velocity in the second stage of injection, diverse intensification pressure values, and

various injection gate width values. There were found the regression equations describing the change of castability of the examined

composite as a function of pressure die casting process parameters. The conclusion gives the analysis and the interpretation of the obtained

results.

The paper discusses a theoretical and an experimental analyses of steel wire drawing in conical drawing dies with a varying length of the die sizing portion. The theoretical analysis was performed in the Drawing 2D, where the wire temperature and drawing stress were determined. The theoretical study was verified by the measurement of drawing force under laboratory conditions and by industrial multi-stage drawing tests carried out under commercial conditions. A relationship has been shown to exist between die sizing portion length and wire temperature and drawing stress.

coin hoard discovered in an unknown locality east of Saint Petersburg in Russia in 2019 ( tpq 1008/9), contained three Polish coins issued by Bolesław I the Brave of hitherto unknown types (Mikhel’son 2023). One of them bears the inscription: +POZZNANI, the oldest record of Poznań’s name, the then-capital center (Fig. 1). The reverse of this coin, like the two others, was struck from a die that contains the inscription: AЯЄAHLAT (Figs 1–3). This die was already known from the first die-chain of Bolesław the Brave’s coinage. This makes it possible to include the newly discovered coins in the die-chain. As a consequence, die-chain no. 1 can be expanded, its chronology can be made more precise (ca. 998–1010), and can help establish that the linked die-chains were used in the Poznań mint.

The measurement results concerning the abrasive wear of AlSi11-SiC particles composites are presented in paper. The method of

preparing a composite slurry composed of AlSi11 alloy matrix and 10, 20% vol.% of SiC particles, as well as the method of its highpressure

die casting was described. Composite slurry was injected into metal mould of cold chamber pressure die cast machine and

castings were produced at various values of the piston velocity in the second stage of injection, diverse intensification pressure values, and

various injection gate width values. Very good uniform arrangement of SiC particles in volume composite matrix was observed and these

results were publicated early in this journal. The kinetics of abrasive wear and correlation with SiC particles arrangement in composite

matrix were presented. Better wear resistance of composite was observed in comparison with aluminium alloy. Very strong linear

correlation between abrasive wear and particle arrangement was observed. The conclusion gives the analysis and the interpretation of the

obtained results.

NC11 steel, in view of the specificity of its manufacturing process, is characterised with band-like orientation of carbides. Depending

on the direction of cutting the material for the inserts out of commercially available steel products, carbide bands can be oriented

in parallel or perpendicularly to the direction in which aggregate grains move in the process of pressing stampings. It has been found that

in case of scratches made in direction perpendicular to carbide bands, depth of the scratches is less than this observed when scratches are

made in direction coinciding with prevailing orientation of carbide precipitates.

The method of pressure die casting of composites with AlSi11 alloy matrix reinforced with 10 vol. % of SiC particles and the analysis of the distribution of particles within the matrix is presented. The composite castings were produced at various values of the piston velocity in the second stage of injection, at diverse intensification pressure values, and various injection gate width values. The distribution of particles over the entire cross-section of the tensile specimen is shown. The index of distribution was determined on the basis of particle count in elementary measuring fields. The regression equation describing the change of the considered index was found as a function of the pressure die casting parameters. The conclusion presents an analysis of the obtained results and their interpretation.

The paper presents the method of preparing a composite slurry composed of AlSi11 alloy matrix and 10 vol.% of SiC particles, as well as

the method of its high-pressure die casting and the measurement results concerning the tensile strength, the yield point, the elongation and

hardness of the obtained composite. Composite castings were produced at various values of the piston velocity in the second stage of

injection, diverse intensification pressure values, and various injection gate width values. There were found the regression equations

describing the change of mechanical properties of the examined composite as a function of pressure die casting process parameters. The

conclusion gives the analysis and the interpretation of the obtained results.

In the paper an analysis of the influence of two parameters on the die wear, i.e. the shape of the die and the backpull with the specified force values has been presented. The conical and curve-profile tools have been selected to determine an influence of the die geometry on its wear, and the backpull force has been tested with the use of conical dies. The research was conducted for the drawing of copper wire by sintered carbide die with a mesh diameter of 3 mm. A fixed draw value of 30% relative gap loss was assumed. The axisymmetric numerical model of the drawing process was built and modeled in the MARC/Mentat commercial program for nonlinear and contact issues. As a result of the tests, wear of the dies according to their shape was determined. In addition, for the conical die the drawing force and the force of the metal pressure on the die using different values of the force of the contraction were calculated, as well as wear of the conical die according to the value of the applied backpull force. It has been shown that in the case of the arc die, the distribution of pressure and stress is more uniform over the entire length of the contact zone compared to the conical die. The highest stress gradients occurred in the area of the transition of the crushing part into the drawing part of the die, which caused that the use of the conical die in this area was more than twice as large as the arc die. In addition, on the example of a conical die, it was shown to what extent the depth of its wear decreases with an increase of the test pull force in the range (0-400) of Newtons.

Final quality of casts produced in a die casting process represents a correlation of setting of technological parameters of die casting cycle, properties of alloy, construction of a die and structure of gating and of bleeding systems. Suitable structure of a gating system with an appertaining bleeding system of the die can significantly influence mechanical and structural properties of a cast. The submitted paper focuses on influence of position of outfall of an gate into the cast on its selected quality properties. Layout of the test casts in the die was designed to provide filling of a shaping cavity by the melt with diverse character of flowing. Setting of input technological parameters during experiment remained on a constant level. The only variable was the position of the gate. Homogeneity represented by porosity f and ultimate strength Rm were selected to be the assessed representative quality properties of the cast. The tests of the influence upon monitored parameters were realized in two stages. The test gating system was primarily subjected to numerical tests with the utilization of a simulation program NovaFlow&Solid. Consequently, the results were verified by the experimental tests carried out with the physical casts produced during operation. It was proved that diverse placement of the gate in relation to the cast influences the mode of the melt flowing through the shaping cavity which is reflected in the porosity of the casts. The experimental test proved correlation of porosity f of the cast with its ultimate strength Rm. At the end of the paper, the interaction dependencies between the gate position, the mode of filling the die cavity, porosity f and ultimate strength Rm.

The objective of the present research is to develop new admixed lubricants which can be used for high-density sintered iron when processed using warm die and warm compaction. Depending on various lubricants, the effect of compaction temperature on the ejection behavior and sintered properties was studied. Lubricants were prepared by mixing of Zn-stearate and ethylene bis stearamide (EBS) in various compositions. The iron powders blended with lubricants were compacted under the pressure of 700 MPa at various temperatures. The green compacts were sintered at 1120°C for 30 min. Microstructure, density, hardness, and transverse rupture strength of sintered materials with different lubricants were investigated in detail.

The paper discusses experimental studies to determine the effect of the die working portion angle on the lubrication conditions, zinc coating thickness and the mechanical properties of medium-carbon steel wires. The test material was 5.5 mm-diameter wire rod which was drawn into 2.2 mm-diameter wire in seven draws at a drawing speed of v = 10 m/s. Conventional drawing dies of a working portion angle of α = 3, 4, 5, 6, 7°, respectively, were used for the drawing process. After the drawing process, the quantity of the lubricant on the wire surface and the thickness of the zinc coating were determined in individual draws. Testing the finished 2.2 mm-diameter wires for mechanical properties, on the other hand, determined the effect of the die working portion on the yield point, tensile strength, uniform and total elongation, reduction in area, the number of twists and the number of bends.

In this article, the authors focused on the widely used aluminium extrusion technology, where the die quality and durability are the essential factors. In this study, detailed solutions in the three-key area have been presented. First is applying marking technology, where a laser technique was proposed as a consistent light source of high power in a selected, narrow spectral range. In the second, an automated and reliable identification method of alphanumeric characters was investigated using an advanced machine vision system and digital image processing adopted to the industrial conditions. Third, a proposed concept of online tool management was introduced as an efficient process for properly planning the production process, cost estimation and risk assessment. In this research, the authors pay attention to the designed vision system’s speed, reliability, and mobility. This leads to the practical, industrial application of the proposed solutions, where the influence of external factors is not negligible.

Wear of the working surfaces of the forging dies in the process of manufacturing products with the die forging technique leads to deterioration of their operational properties as well as their technological quality. A characteristic feature of production in small and medium-sized enterprises is the high variability of the product range and short production series, which can be repeated in the case of re-orders by customers. In this type of production conditions, a technological criterion in form of – a change in the characteristic and selected dimension of forging is usually used to assess the quality of products. An important problem is, whether by taking up another order for a series of the same type of product, it will be possible to implement it with the existing die, or should a new die be made? As a result of the research carried out in the company implementing this type of contract, a procedure was proposed for forecasting the abrasive wear of die working surfaces on the basis of a technological criterion, easy to determine in the conditions of small and medium-sized enterprises. The paper presents the results of the wear assessment of a die made out of hot-work tool steel X37CrMoV5-1 (WCL) and dies made of 42CrMo4 alloy structural steel with hardfacing working surfaces by F-818 wire. To determine and forecast the process of die wear, a mathematical model in the form of neural networks was used. Their task was to forecast the ratio of the increment in introduced wear intensity indicator to the number of forgings made during the process. Taking into account

This paper offers a postcolonial analysis of Ivan Franko’s attack on the Polish national poet Adam Mickiewicz, published as Ein Dichter des Verrathes (A Poet of Treason) in May 1897. Using Gayatri Spivak’s postcolonial notion of subalternity, Ivan Franko’s essay is interpreted as an opportunity for Ukrainian (subaltern) culture in Galicia to gain its own voice in opposition to Polish cultural dominance. As a result of this strategy, Franko deliberately wrote his essay in German and published it in Vienna, the political centre of the Habsburg Monarchy.

The paper reports the results of a physical modelling study of the production of a hypereutectic aluminium alloy to be used for making an alloy vapour source for operation in the magnetron. Within the study, targets from a hypereutectic aluminium-silicon alloy were made in laboratory conditions. Thus obtained material was subjected to heat treatment, porosity analysis, and the assessment of the microstructure and fitness for being used in the magnetron. The process of melting the hypereutectic Al-Si alloy was carried out at the Department of Foundry of the Czestochowa University of Technology. The investigation into the production of the alloy vapour source for the synthesis of the dielectric material from the hypereutectic aluminium alloy has confirmed.

The paper presents analysis of influence of change of physical parameters such as: temperature, friction coefficient and load, during the process of die forging. Optimization of the process effects in achieving high quality products, decreasing shaping resistance, and what follows – lower energy consumption. Temperature is the basic factor affecting the process of plastic working. Analyzing that influence in individual die fragments, allows to engineer the flow of shaped material. The QForm3D commercial program for finite element method calculations was used for numerical simulations. The paper presents multi-variant analysis of forging process with the usage of numerical simulation, which provided many valuable information concerning changes of key parameters, such as: temperature, stress and strain distribution and variations of technological parameters, as well as their mutual influence, difficult to obtain in analysis of industrial process.

The impulse noise is agent harmful to health not only in the case of shots from firearms and the explosions of explosive materials. This kind of noise is also present in many workplaces in the industry. The paper presents the results of noise parameters measurements in workplaces where four different die forging hammers were used. The measured values of the C-weighted peak sound pressure level, the A-weighted maximum sound pressure level and A-weighted noise exposure level normalized to an 8 h working day (daily noise exposure level) exceeded the exposure limit values. For example, the highest measured value of the C-weighted peak sound pressure level was 148.9 dB. In this study possibility of the protection of hearing with the use of earplugs or earmuffs was assessed. The measurement method for the measurements of noise parameters under hearing protection devices using an acoustical test fixture instead of testing with the participation of subjects was used. The results of these measurements allows for assessment which of two tested earplugs and two tested earmuffs sufficiently protect hearing of workers in workplaces where forging hammers are used.

In contemporary high-pressure die casting foundries, the mastery of each sequence in the production cycle is more and more important. In the paper, an example of virtual analysis of gearbox casting from Al alloy will be presented. It includes a large variety of parameters, as follows: choosing of appropriate foundry technology, calculation of computer simulation of casting process which takes into account the filling process of cold chamber and filling of cavity, model description of three phases in high-pressure die casting, flow of molten metal, solidification, formation of stress and deformations. Additionally, the optimization of cooling and heating systems will be compared with calculated volume defects, dimensions of castings and their deformations with experimentally obtained values.

In earlier works were described trends in the production of tools for die casting (hot work). Almost the entire set of issues dealt with may seem insignificant when incompletely assembled acceptance of the material and the associated risks of processing a material with an inappropriate structure, leading to a very early defect of the die. Therefore, further work will focus particularly on identifying the causes of thermal cracks and preventing a suitable choice of acceptance criteria conditions and heat treatment.

Magnesium alloys are one of the lightest of all the structural materials. Because of their excellent physical and mechanical properties the

alloys have been used more and more often in various branches of industry. They are cast mainly (over 90%) on cold and hot chamber die

casting machines. One of the byproducts of casting processes is process scrap which amounts to about 40 to 60% of the total weight of a

casting. The process scrap incorporates all the elements of gating systems and fault castings. Proper management of the process scrap is

one of the necessities in term of economic and environmental aspects.

Most foundries use the process scrap, which involves adding it to a melting furnace, in a haphazard way, without any control of its content

in the melt. It can lead to many disadvantageous effects, e.g. the formation of a hard buildup at the bottom of the crucible, which in time

makes casting impossible due to the loss of the alloy rheological properties. The research was undertaken to determine the effect of an

addition of the process scrap on the mechanical properties of AZ91 and AM50 alloys. It has been ascertained that the addition of a specific

amount of process scrap to the melt increases the mechanical properties of the elements cast from AZ91 and AM50 alloys.

The increase in the mechanical properties is caused mainly by compounds which can work as nuclei of crystallization and are introduced

into the scrap from lubricants and anti-adhesive agents. Furthermore carbon, which was detected in the process scrap by means of SEM

examination, is a potent grain modifier in Mg alloys [1-3].

The optimal addition of the process scrap to the melt was determined based on the statistical analysis of the results of studies of the effect

of different process scrap additions on the mean grain size and mechanical properties of the cast parts.

Experimental Mg-Al-RE type magnesium alloys for high-pressure die-casting are presented. Alloys based on the commercial AM50

magnesium alloy with 1, 3 and 5 mass % of rare earth elements were fabricated in a foundry and cast in cold chamber die-casting

machines. The obtained experimental casts have good quality surfaces and microstructure consisting of an α(Mg)-phase, Al11RE3,

Al10RE2Mn7 intermetallic compound and small amount of α+γ eutectic and Al2RE phases.

This paper presents the effect of the temperature and hold time in the holding furnace of 226 silumin on the characteristic quantities of

TDA curves. The temperature of phase transformations and the cooling rate were tested.It has been shown that increasing both the hold

time and the temperature in the holdingfurnace cause the decreasethe end ofα+Al9Fe3Si2+β and α+Al2Cu+βternary eutectics

crystallizationtemperature in the tested silumin. This is due to the fact an increase in amounts of impurities as a result of reacting theliquid

alloy with the gases contained in the air.It has been shown, however, that examined technological factors ofthe metal preparation do not

cause systematic changes in the cooling rate.