PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 64

Liczba wyników na stronie
first rewind previous Strona / 4 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 4 next fast forward last
1
Content available Physical Modelling of the Production of an Alloy Vapour Source for the Synthesis of Dielectric Material
Nadolski M., Stradomski G., Zdunek K., Okrasa S.
Archives of Metallurgy and Materials
|
2020
|
Vol. 65, iss. 1
201--206
EN
The paper reports the results of a physical modelling study of the production of a hypereutectic aluminium alloy to be used formaking 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.
2
Content available Physical and Numerical Modeling of Duplex Cast Steel Thin-Walled Castings
Stradomski G., Nadolski M., Zyska A., Kania B., Rydz D.
Archives of Metallurgy and Materials
|
2019
|
Vol. 64, iss. 4
1449--1456
EN
The paper, which is a summary and supplement of previous works and research, presents the results of numerical and physical modeling of the GX2CrNiMoCuN25-6-3 duplex cast steel thin-walled castings production. To obtain thin-walled castings with wall in the thinnest place even below 1 mm was used the centrifugal casting technology and gravity casting. The analyzed technology (centrifugal casting) enables making elements with high surface quality with reduced consumption of batch materials and, as a result, reducing the costs of making a unitary casting. The idea behind the production of cast steel with the use of centrifugal technology was to find a remedy for the problems associated with unsatisfactory castability of the tested alloy. The technological evaluation of the cast construction was carried out using the Nova Flow & Solid CV 4.3r8 software. Numerical simulations of crystallization and cooling were carried out for a casting without a gating system and sinkhead located in a mold in accordance with the pouring position. It was assumed that the analyzed cast will be made in the sand form with dimensions 250×250×120 mm.
3
Content available The Assessment of Resistance to Thermal Fatigue and Thermal Shock of Cast Iron Used for Glass Moulds
Stradomski G., Gzik S., Jakubus A., Nadolski M.
Archives of Foundry Engineering
|
2018
|
Vol. 18, iss. 3
173--178
EN
Constantly developing production process and high requirements concerning the quality of glass determine the need for continuous improvement of tools and equipment needed for its production. Such tools like forms, most often made of cast-iron, are characterized by thick wall thickness compared to their overall dimensions and work in difficult conditions such as heating of the surface layer, increase of thermal stresses resulting from the temperature gradient on the wall thickness, occurrence of thermal shock effect, resulting from cyclically changing temperatures during filling and emptying of the mould. There is no best and universal method for assessing how samples subjected to cyclic temperature changes behave. Research on thermal fatigue is a difficult issue, mainly due to the instability of this parameter, which depends on many factors, such as the temperature gradient in which the element works, the type of treatment and the chemical composition of the material. Important parameters for these materials are at high temperature resistance to thermal shock and thermal fatigue what will be presented in this paper.
4
Content available The Evaluation of Mechanical Properties of High-tin Bronzes
Nadolski M.
Archives of Foundry Engineering
|
2017
|
Vol. 17, iss. 1
127--130
EN
High-tin bronzes are used for church bells and concert bells (carillons). Therefore beside their decorative value, they should also offer other functional properties, including their permanence and good quality of sound. The latter is highly influenced by the structure of bell material, i.e. mostly by the presence of internal porosity which interferes with vibration of the bell waist and rim, and therefore should be eliminated. The presented investigations concerning the influence of tin content ranging from 20 to 24 wt% on mechanical properties of high-tin bronzes allowed to prove the increase in hardness of these alloys with simultaneous decrease in the tensile and the impact strengths (Rm and KV, respectively) for the increased tin content. Fractures of examined specimens, their porosity and microstructures were also assessed in order to explain the observed regularities. A reason of the change in the values of mechanical properties was revealed to be the change in the shape of α-phase crystals from dendritic to acicular one, and generation of grain structure related to the increased Sn content in the alloy.
5
Content available remote The method of production of thin-walled castings made of GX2CrNiMoN25-6-3 cast steel
Nadolski M., Stradomski G., Zyska A.
Computer Methods in Materials Science
|
2016
|
Vol. 16, No. 2
104--109
EN
The possibility of production of thin-walled castings made of GX2CrNiMoN25-6-3 cast steel was assessed for the exemplary final casting with variable wall thickness. The assessment both of the solidification process of the GX2CrNiMoN25-6-3 alloy and of the final degree of mould cavity filling was done by means of the NovaFlow&Solid program. The body of the casting with its variable wall thickness, including sections thinner than 1 mm, demanded for the appropriate production technology. There are presented the results of technological tests with respect to the application of the centrifugal casting, which confirm the adopted technology of pattern and mould production. The analyzed technology makes possible the production of casting of high surface quality, while simultaneously the yield is increased, and by the same the unit cost of production is lower as compared with the production method used thus far.
PL
W pracy ocenie poddano możliwość wykonania cienkościennych odlewów ze staliwa GX2CrNiMoCuN25-6-3 na przykładzie docelowego odlewu o zmiennej grubości ścianki. Wykonano ocenę wypełniania i krzepnięcia stopu GX2CrNiMoN25-6-3 na podstawie symulacji komputerowej wykonanej przy użyciu programu NovaFlow&Solid. Bryła odlewu o zmiennej grubości ścianki, w tym nawet poniżej jednego 1 mm, wymogła zastosowanie odpowiedniej technologii wykonania. Przedstawiono wyniki prób technologicznych odlewania odśrodkowego, potwierdzające przyjętą technologię modelu i formy. W porównaniu do dotychczas stosowanej metody wykonania, analizowana technologia umożliwia wykonywanie odlewów o wysokiej jakości powierzchni przy jednoczesnym zwiększeniu uzysku i tym samym obniżając koszty wykonania jednostkowego odlewu.
6
Content available Modelling of the Dendritic Crystallization by the Cellular Automaton Method
Zyska A., Konopka Z., Łągiewka M., Nadolski M.
Archives of Foundry Engineering
|
2016
|
Vol. 16, iss. 1
99--106
EN
A numerical model of binary alloy crystallization, based on the cellular automaton technique, is presented. The model allows to follow the crystallization front movement and to generate the images of evolution of the dendritic structures during the solidification of a binary alloy. The mathematic description of the model takes into account the proceeding thermal, diffusive, and surface phenomena. There are presented the results of numerical simulations concerning the multi-dendritic growth of solid phase along with the accompanying changes in the alloying element concentration field during the solidification of Al + 5% wt. Mg alloy. The model structure of the solidified casting was achieved and compared with the actual structure of a die casting. The dendrite interaction was studied with respect to its influence on the generation and growth of the primary and secondary dendrite arms and on the evolution of solute segregation both in the liquid and in the solid state during the crystallization of the examined alloy. The morphology of a single, free-growing dendritic crystal was also modelled. The performed investigations and analyses allowed to state e.g. that the developed numerical model correctly describes the actual evolution of the dendritic structure under the non-equilibrium conditions and provides for obtaining the qualitatively correct results of simulation of the crystallization process.
7
Azotowanie jarzeniowe staliwa austenitycznego CF3M
Pilarska M., Frączek T., Nadolski M.
Hutnik, Wiadomości Hutnicze
|
2015
|
Vol. 82, nr 11
717--721
PL
Zaprezentowano wstępne wyniki badań właściwości warstw powierzchniowych otrzymanych na podłożu staliwa austenitycznego CF3M wg ASTM, w wyniku klasycznego wyładowania jarzeniowego na katodzie. Proces azotowania został przeprowadzony w atmosferze reaktywnej wodorowo-azotowej, w czasie 10 godzin i temperaturze 650°C. Na podstawie dokonanych obserwacji mikroskopowych, badań topografii powierzchni, twardości powierzchniowej oraz analizy struktur warstw wierzchnich, oceniono wpływ zastosowanego wariantu azotowania na budowę warstw powierzchniowych.
EN
Presented preliminary results of the properties of the surface layers received CF3M austenitic cast steel, resulting in the classic cathode glow discharge. Nitriding process was conducted in an atmosphere of reactive hydrogen - nitrogen, for 10 hours and at 650 °C. Based on its microscopic observation, analysis of surface topography, surface hardness and analysis of surface layer structures evaluated the effect of nitriding variant used for the construction of the surface layers.
8
Content available Microstructure and Functional Properties of Prosthetic Cobalt Alloys CoCrW
Nadolski M., Golański G., Klimas J., Szota M., Szymański J.
Archives of Metallurgy and Materials
|
2015
|
Vol. 60, iss. 3A
1999--2003
EN
The material subject to investigation was two commercial alloys of cobalt CoCrW (No. 27 and 28) used in prosthodontics. The scope of research included performing an analysis of microstructure and functional properties (microhardness, wear resistance and corrosion resistance), as well as dilatometric tests. The examined alloys were characterized by diverse properties, which was considerably influenced by the morphology of precipitates in these materials. Alloy No. 27 has a higher corrosion resistance, whereas alloy No. 28 shows higher microhardness, better wear resistance and higher coefficient of linear expansion. Lower value of the expansion coefficient indicates less probability of initiation of a crack in the facing ceramic material.
PL
Badaniu poddano dwa komercyjne stopy kobaltu CoCrW (nr 27 i 28) stosowane w protetyce stomatologicznej. Zakres badań obejmował przeprowadzenie analizy mikrostrukturalnej, właściwości użytkowych (mikrotwardość, odporność na ścieranie i odporność korozyjna) oraz badania dylatometryczne. Badane stopy charakteryzowały się zróżnicowanymi właściwościami na co zasadniczy wpływ miała morfologia wydzieleń w tych materiałach. Stop nr 27 posiada wyższą odporność korozyjną natomiast stop nr 28 wykazuje: wyższą mikrotwardość, lepszą odporność na ścieranie oraz niższy współczynnik rozszerzalności liniowej. Niższa wartość współczynnika rozszerzalności liniowej wskazuje na mniejsze prawdopodobieństwo inicjacji pęknięcia licującego materiału ceramicznego.
9
Content available The Microstructure of Thin-walled GX2CrNiMoN25-6-3 Cast Steel Made by Centrifugal Casting
Stradomski G., Nadolski M., Stradomski Z.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 3 spec.
77--82
EN
The paper presents the results of investigation into the technological possibility of making light-section castings of GX2CrNiMoN25-6-3 cast steel. Due the fact that the GX2CrNiMoN25-6-3 duplex cast steel has a complex microstructure authors of this paper took on its analysis. For making castings with a wall thickness in the thinnest place as small as below 1 mm, the centrifugal casting technology, as it was presented in the paper [1], is one of the most effective technology. In the paper was made the analysis of four different parameters of the casting process and different parameters of heat treatment.
10
Content available The Influence of Remelting on the Quality of Prosthetic Cobalt Alloys
Nadolski M., Łągiewka M., Konopka Z., Zyska A., Golański G.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 3 spec.
53--58
EN
A commercial cobalt alloy applied in dental prosthetics was investigated. The scope of the work included the microstructure analysis, performance examination (tensile strength, microhardness, corrosion resistance), and dilatometric examination. The investigated alloy after a single remelting was characterised by higher tensile strength and hardness. There were not found the definite results with regard to the corrosion resistance of the examined materials. No significant change occurred in the coefficient of thermal expansion.
11
Content available The Influence of Pressure Die Casting Parameters on the Castability of AlSi11-SiCp Composites
Konopka Z., Zyska A., Łągiewka M., Nadolski M.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 1
29--34
EN
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.
12
Content available The Influence of Graphite Type on the Abrasive Wear of AlMg10 Matrix Composites
Łągiewka M., Konopka Z., Zyska A., Nadolski M.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 1 spec.
65--68
EN
The presented work discuss the influence of various types of graphite additions on the abrasive wear of AlMg10 matrix alloy composites. Flake graphite, electrographite, and short graphite fibre were used as a composite reinforcement. Composites containing 10 vol. % of graphite particles were produced by mechanical mixing of the liquid alloy with simultaneous introduction of the reinforcement. Composite suspensions were gravity cast into metal moulds. The achieved castings were tested for the abrasive wear. Also the pure matrix alloy was examined. Microphotographs of the produced materials were taken, the specimens were also examined after the abrasion test by observing the microsections perpendicular to the abraded surface. The carried out experiments allow to state that even the little addition of graphite influences beneficially the tribological properties of composite under small loads applied to the frictional pair. It was found that under the increased load (30 N) the least abrasive wear is exhibited by the composite reinforced with graphite fibre, the largest one occurring for the composite reinforced with electrographite. The composite reinforced with electrographite, however, exhibited the mass loss less by 25% than the pure matrix alloy.
13
Content available Technological Assessment of the Possibility of Making Light-section Castings of GX2CrNiMoN25-6-3 Cast Steel by the Centrifugal Casting Method
Stradomski G., Nadolski M., Stradomski Z.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 3
57--60
EN
The paper presents the results of investigation into the technological possibility of making light-section castings of GX2CrNiMoN25-6-3 cast steel. For making castings with a wall thickness in the thinnest place as small as below 1 mm, the centrifugal casting technology was employed. The technology under consideration enables items with high surface quality to be obtained, while providing a reduced consumption of the charge materials and, as a result, a reduction in the costs of unit casting production.
14
Content available Porosity of Castings Produced by the Vacuum Assisted Pressure Die Casting Method
Zyska A., Konopka Z., Łągiewka M., Nadolski M.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 1
125--130
EN
The paper presents the results of investigations concerning the influence of negative (relative) pressure in the die cavity of high pressure die casting machine on the porosity of castings made of AlSi9Cu3 alloy. Examinations were carried out for the VertaCast cold chamber vertical pressure die casting machine equipped with a vacuum system. Experiments were performed for three values of the applied gauge pressure: -0.3 bar, -0.5 bar, and -0.7 bar, at constant values of other technological parameters, selected during the formerly carried initial experiments. Porosity of castings was assessed on the basis of microstructure observation and the density measurements performed by the method of hydrostatic weighing. The performed investigation allowed to find out that – for the examined pressure range – the porosity of castings decreases linearly with an increase in the absolute value of negative pressure applied to the die cavity. The negative pressure value of -0.7 bar allows to produce castings exhibiting porosity value less than 1%. Large blowholes arisen probably by occlusion of gaseous phase during the injection of metal into the die cavity, were found in castings produced at the negative pressure value of -0.3 bar. These blowholes are placed mostly in regions of local thermal centres and often accompanied by the discontinuities in the form of interdendritic shrinkage micro-porosity. It was concluded that the high quality AlSi9Cu3 alloy castings able to work in elevated temperatures can be achieved for the absolute value of the negative pressure applied to the die cavity greater than 0.5 bar at the applied set of other parameters of pressure die casting machine work.
15
Content available The Influence of the Mould Filling Conditions on the Quality of Castings Made of EN AC-44000 Alloy
Nadolski M., Konopka Z., Łągiewka M., Zyska A.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 2
19--22
EN
The work deals with the influence of change in the filling conditions of the ceramic moulds with plaster binder on the presence of gaseous porosity and the microstructure of the achieved test castings with graded wall thickness. Castings made of EN AC-44000 alloy, produced either by gravity casting, or by gravity casting with negative pressure generated around the mould (according to the Vacumetal technology), or by counter-gravity casting were compared. The results of examinations concerning the density of the produced castings indicate that no significant change in porosity was found. The increased size of silicon crystals was found for the increased wall thicknesses due to the slower cooling and solidification of castings.
16
Content available The Influence of the Method of Mould Filling on the Quality of Castings Made of EN AC-44000 or EN AC-46200 Alloy
Nadolski M., Konopka Z., Łągiewka M., Zyska A.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 4
73--76
EN
The performed examinations concerning the process of filling the plaster ceramic moulds with aluminium alloys allowed to assess the influence of various methods of introducing the metal into the mould cavity on the macro- and microstructure of the obtained experimental castings. The comparison was performed for castings with graded wall thickness made either of EN AC-44000 alloy or of EN AC-46000 alloy, produced either by gravity casting, or by gravity casting with negative pressure generated around the mould (according to the Vacumetal technology), or by counter-gravity casting. It was found that the silicon crystals grow in size with an increase in wall thickness due to the slower cooling and solidification of castings.
17
Content available The Effect of Vacuum Assistance on the Quality of Castings Produced by High Pressure Die Casting Method
Łągiewka M., Konopka Z., Nadolski M., Zyska A.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 2
23--26
EN
The presented work is aimed to deal with the influence of changes in the value of negative (relative) pressure maintained in the die cavity of pressure die casting machine on the surface quality of pressure castings. The examinations were held by means of the modified Vertacast pressure die casting machine equipped with a vacuum system. Castings were produced for the parameters selected on the basis of previous experiments, i.e. for the plunger velocity in the second stage of injection at the level of 4 m/s, the pouring temperature of the alloy equal to 640°C, and the die temperature of 150°C. The examinations were carried on for three selected values of negative gauge pressure: - 0.03, - 0.05, and - 0.07 MPa. The quality of casting was evaluated by comparing the results of the surface roughness measurements performed for randomly selected castings. The surface roughness was measured by means of Hommel Tester T1000. After a series of measurements it was found that the smoothest surface is exhibited by castings produced at negative gauge pressure value of - 0.07 MPa.
18
Content available The Assessment of Modification of High-Zinc Aluminium Alloy
Zyska A., Konopka Z., Łągiewka M., Nadolski M.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 2
53--56
EN
The results of examinations of the influence of titanium-boron inoculant on the solidification, the microstructure, and the mechanical properties of AlZn20 alloy are presented. The examinations were carried out for specimens cast both of the non-modified and the inoculated alloy. There were assessed changes in the alloy overcooling during the first stage of solidification due to the nuclei-forming influence of the inoculant. The results of quantitative metallographic measurements concerning the refinement of the grain structure of casting produced in sand moulds are presented. The cooling rate sensitivity of the alloy was proved by revealing changes in morphology of the α-phase primary crystals. Differences in mechanical properties resulting from the applied casting method and optional inoculation were evaluated.
19
Content available Correlations Between Arrangement of Reinforcing Particles and Mechanical Properties in Pressure Die Cast AlSi11-SiC Composites
Konopka Z., Pasieka A., Łągiewka M., Nadolski M., Zyska A.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 2
31--36
EN
The work presents the investigation results concerning the structure of composite pressure die castings with AlSi11 alloy matrix reinforced with SiC particles. Examination has been held for composites containing 10 and 20 volume percent of SiC particles. The arrangement of the reinforcing particles within the matrix has been qualitatively assessed in specimens cut out of the castings. The index of distribution was determined on the basis of particle count in elementary measuring fields. The tensile strength, the yield point and elongation of the obtained composite were measured. 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. The regression equation describing the change of the considered arrangement particles index and mechanical properties were found as a function of the pressure die casting parameters. The infuence of particle arrangement in composite matrix on mechanical properties these material was examined and the functions of correlations between values were obtained. The conclusion gives the analysis and the interpretation of the obtained results.
20
Content available Determination of the strengthening coefficient of pressure cast AlSi13Cu2/chopped carbon fibre composite
Konopka Z., Łągiewka M., Nadolski M., Zyska A.
Archives of Metallurgy and Materials
|
2013
|
Vol. 58, iss. 3
957--960
EN
The purpose of the work is the determination of the strengthening coefficient for the AlSi13Cu2 alloy matrix composite reinforced with chopped carbon fibre and produced by high-pressure casting method. This coefficient was determined during the static tensile test using the Ramberg-Osgood equation. The regression relationships between strain and stress were established, serving as a basis for finding the strengthening coefficient values. The measurements and calculations were performed also for the matrix alloy itself, for the purpose of comparison. The examined coefficient decreased with an increase of fibre fraction in the composite. Its value for composite containing 15 vol. % of chopped fibre was found to be lower by 30% than the value determined for matrix alloy, what means the strengthening of the alloy to such a degree.
PL
Celem pracy jest wyznaczenie współczynnika umocnienia kompozytu na osnowie stopu AlSi13Cu2 zbrojonego ciętymi włóknami węglowymi wytworzonego metodą ciśnieniowego odlewania. Współczynnik ten wyznaczono w statycznej próbie rozciągania korzystając z równania Ramberga-Osgooda. Opracowano regresyjne zależności odkształcenia i naprężenia, na podstawie których wyznaczono współczynnik umocnienia. Dla porównania wykonano pomiary dla stopu osnowy bez włókien. Stwierdzono zmniejszenie się tego współczynnika ze wzrostem udziału włókien w kompozycie. Jego wartość dla kompozytu zawierającego 15% obj. ciętych włókien jest o około 30% niższa od wartości wyznaczonej dla stopu osnowy, co oznacza, że materiał został w takim stopniu umocniony.
first rewind previous Strona / 4 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.