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1
Content available Evaluation of the Cause and Consequences of Defects in Cast Metal-Ceramic Composite Foams
Popielarski P., Sika R., Czarnecka-Komorowska D., Szymański P., Rogalewicz M., Gawdzińska K.
Archives of Foundry Engineering
|
2021
|
Vol. 21, iss. 1
81--88
EN
In this research, the quality of manufactured cast metal-ceramic foams (manufactured using blowing gas) was tested. The causes responsible for defect formation in the composite foams and their consequences were analyzed using the FMEA (Failure Mode and Effects Analysis) method, which is a useful tool for minimizing losses caused by low product quality. This method involves analytically determining correlations between the cause and consequences of potential product defects, and it takes into account the criticality factor (risk). The FMEA analysis showed that pore breaks were the most "critical defect" (with the highest number of effects on the product, the Risk Priority Number, affecting the quality of the composite foam). The second most critical defect was discontinuities in the foam frame structure. Destruction or damage to the foam structure (although very rare) deprived the composite foam of its primary function, which is to reinforce the product. The third most critical defect was non-uniform foam pore size.
2
Content available Identification of Substitute Thermophysical Properties of Gypsum Mould
Bernat Ł., Popielarski P.
Archives of Foundry Engineering
|
2020
|
Vol. 20, iss. 1
5--8
EN
Simplifications used in simulation program codes require the use of substitute parameters in the material databases (also called apparent or substitutive). On the one hand, they formally fit into the records used in the heat flow model, porosity, properties etc. and on the other hand they should be determined in conditions most similar to the real casting-mould system. The article presents results of a research on thermophysical parameters of gypsum mould used for precision casting moulds. Experiments were carried out on a cylindrical mould made of Plasticast gypsum, in which the heat source was a cylinder filled with liquid aluminium alloy of the temperature of 655°C. Energetic validation was carried out by using the NovaFlow&Solid ver. 6.3 simulation code. As a result of validation tests, substitute thermophysical parameters of gypsum were determined. For determined parameters, best-fit of solidification time from the experiment and simulation was obtained and the curves of gypsum mass heating were satisfactorily recreate.
3
Content available Computer Simulation of Cast Iron Flow in Castability Trials
Popielarski P., Hajkowski J., Sika R., Ignaszak Z.
Archives of Metallurgy and Materials
|
2019
|
Vol. 64, iss. 4
1433--1439
EN
The paper includes validation studies of the flow module of the NovaFlow&Solid simulation code. Experiments of ductile iron and gray iron casting in a spiral test of castability were carried out. Casting experiments were then carried out in industrial conditions in the Ferrex Foundry in Poznań and the results are the castability spiral length and local cast iron rate during mould cavity pouring. Simulation tests using NovaFlow&Solid Control Volume code were made. The technological castability test was used to determine thermal-physical data through simplified inversion problem. Influence of physical parameters in the database of simulation code on the spiral length obtained as the result of simulation was analyzed. It was found that critical fraction of capillary flow CLF down has the biggest impact on cast iron castability in the simulation code. The simulations resulted in defining parameters of gray iron GJL 250 and ductile iron GJS-400-15. For the parameters set, the length of castability spiral in simulations was in accordance with casting experiments.
4
Content available Cellular Automaton Finite Element Method Applied for Microstructure Prediction of Aluminium Casting Treated by Laser Beam
Hajkowski J., Popielarski P., Ignaszak Z.
Archives of Foundry Engineering
|
2019
|
iss. 3
111--118
EN
What is the limit of improvement the structure obtained directly from the liquid state, with possible heat treatment (supersaturation and aging)? This question was posed by casting engineers who put arbitrary requirements on reducing the DAS (Dendrite Arm Spacing) length to less than a dozen microns. The results of tests related to modification of the surface microstructure of AlSi7Mg alloy casting treated by laser beam and the rapid remelting and solidification of the superficial casting zone, were presented in the paper. The local properties of the surface treated with a laser beam concerns only a thickness ranging from a fraction to a single mm. These local properties should be considered in the aspect of application on surfaces of non-machined castings. Then the excellent surface layer properties can be used. The tests were carried out on the surface of the casting, the surface layer obtained in contact with the metal mould, after the initial machining (several mm), was treated by the laser beam. It turned out that the refinement of the microstructure measured with the DAS value is not available in a different way, i.e. directly by casting. The experimental-simulation validation using the Calcosoft CAFE (Cellular Automaton Finite Element) code was applied.
5
Content available remote Effect of annealing temperature on optical and electrical properties of metallophthalocyanine thin films deposited on silicon substrate
Skonieczny R., Popielarski P., Bała W., Fabisiak K., Paprocki K., Jancelewicz M., Kowalska M., Szybowicz M.
Materials Science Poland
|
2016
|
Vol. 34, No. 3
676--683
EN
The cobalt phthalocyanine (CoPc) thin films (300 nm thick) deposited on n-type silicon substrate have been studied using micro-Raman spectroscopy, atomic force spectroscopy (AFM) and I-V measurement. The CoPc thin layers have been deposited at room temperature by the quasi-molecular beam evaporation technique. The micro-Raman spectra of CoPc thin films have been recorded in the spectral range of 1000 cm-1 to 1900 cm-1 using 488 nm excitation wavelength. Moreover, using surface Raman mapping it was possible to obtain information about polymorphic forms distribution (before and after annealing) of metallophthalocyanine (α and β form) from polarized Raman spectra. The I-V characteristics of the Au/CoPc/n-Si/Al Schottky barrier were also investigated. The obtained results showed that influence of the annealing process plays a crucial role in the ordering and electrical conductivity of the molecular structure of CoPc thin films deposited on n-type silicon substrate.
6
Content available remote Wpływ składu gazu roboczego na proces wzrostu warstw diamentowych otrzymywanych przez chemiczne osadzanie metodą gorącego włókna
Banaszak-Piechowska A., Popielarski P., Franków W.
Przemysł Chemiczny
|
2015
|
T. 94, nr 2
201-204
PL
Badano proces syntezy warstw diamentowych prowadzony metodą HF CVD. Zwrócono uwagę, że zmiana nawet jednego z parametrów procesu wpływa istotnie na zmianę jakości warstwy oraz jej strukturę. W tym celu posłużono się takimi nieinwazyjnymi metodami badawczymi, jak skaningowa mikroskopia elektronowa, spektroskopia Ramana i analiza EDS. Zastosowane metody wzajemnie uzupełniały się i potwierdziły istotny wpływ zawartości metanu w gazie roboczym na jakość oraz wielkość ziaren otrzymanej warstwy diamentowej.
EN
Diamond layers were deposited on a Si substrate by hot-filament chemical vapor deposition from a MeH-H₂ mixt. at 2200°C (W wire) and studied by Raman spectroscopy, scanning electron microscopy and electron dispersive spectroscopy for mol. structure and chem. compn. The grain size in the diamond layer increased with the increasing content of MeH in the gas mixt. (1–3% by vol.).
7
Content available remote Study of CVD diamond layers with amorphous carbon admixture by Raman scattering spectroscopy
Dychalska A., Popielarski P., Franków W., Fabisiak K., Paprocki K., Szybowicz M.
Materials Science Poland
|
2015
|
Vol. 33, No. 4
799--805
EN
Raman spectroscopy is a most often used standard technique for characterization of different carbon materials. In this work we present the Raman spectra of polycrystalline diamond layers of different quality, synthesized by Hot Filament Chemical Vapor Deposition method (HF CVD). We show how to use Raman spectroscopy for the analysis of the Raman bands to determine the structure of diamond films as well as the structure of amorphous carbon admixture. Raman spectroscopy has become an important technique for the analysis of CVD diamond films. The first-order diamond Raman peak at ca. 1332 cm−1 is an unambiguous evidence for the presence of diamond phase in the deposited layer. However, the existence of non-diamond carbon components in a CVD diamond layer produces several overlapping peaks in the same wavenumber region as the first order diamond peak. The intensities, wavenumber, full width at half maximum (FWHM) of these bands are dependent on quality of diamond layer which is dependent on the deposition conditions. The aim of the present work is to relate the features of diamond Raman spectra to the features of Raman spectra of non-diamond phase admixture and occurrence of other carbon structures in the obtained diamond thin films.
8
Content available Methodology of Comparative Validation of Selected Foundry Simulation Codes
Ignaszak Z., Popielarski P., Hajkowski J., Codina E.
Archives of Foundry Engineering
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2015
|
Vol. 15, iss. 4
37--44
EN
The validation of each simulation code used in foundry domain requires individual approach due to its specificity. This validation can by elaborated on the basis of experimental results or in particular cases by comparison the simulation results from different codes. The article concerns the influence of grey cast iron density curve and different forms of solid fraction curve Fs=f(T) on the formation of shrinkage discontinuities. Solid fraction curves applying Newtonian Thermal Analysis (NTA) were estimated. The experimental and numerical simulation tests were performed on the castings, which were made with Derivative Thermal Analysis (DerTA) standard cups. The numerical tests were realized using NovaFlow&Solid (NF&S), ProCast and Vulcan codes. In this work, the coupled influence of both curves on the dynamics of the shrinkage-expansion phenomena and on shrinkage defects prognosis in grey cast iron castings has been revealed. The final evaluation of the simulation systems usefulness should be based on validation experiment, preceded by comparing the simulation results of available systems which are proposed in given technology.
9
Content available remote Wpływ zawartości fazy sp2 na hydrofobowość warstwy diamentowej
Mosińska L., Popielarski P., Popielarski P., Franków W., Banaszak-Piechowska A.
Przemysł Chemiczny
|
2014
|
T. 93, nr 9
1587-1590
PL
Właściwości hydrofobowe warstw diamentowych uzyskanych metodą HF CVD zależą od parametrów syntezy i są ważnym parametrem charakteryzującym stan powierzchni diamentu. W przeprowadzonych badaniach pokazano wpływ jakości struktury krystalicznej na właściwości hydrofobowe. W zależności od parametrów syntezy wielkość krystalitów w warstwach diamentowych zmieniała się w zakresie 0,72–1,04 μm, jak określono za pomocą programu Semafore. Różnice w morfologii potwierdzają również badania ramanowskie – próbki o mniejszych krystalitach charakteryzowały się większą zawartością fazy sp2. Próbka, w której zawartość tej fazy była mniejsza wykazywała silniejsze właściwości hydrofobowe. Pomiar hydrofobowości próbek przeprowadzony został przy użyciu metody kąta zwilżania (contact angle).
EN
Diamond layers were deposited on Si substrate by hotfilament chem. vapour deposition from MeOH/H2 mixt. and studied for crystal structure, hydrophobic properties (contact angle) and crystallite size (0,72–1,04 μm). The morphol. was confirmed by Raman spectroscopy (content of sp2 phase).
10
Content available remote Diament jako materiał przetwornikowy do produkcji biosensorów
Mosińska L., Fabisiak K., Paprocki K., Kowalska M., Popielarski P., Szybowicz M., Stasiak A.
Przemysł Chemiczny
|
2013
|
T. 92, nr 6
919--923
11
Content available remote Cyclic voltammetry and impedance studies of undoped diamond films
Mosińska L., Kowalska M., Popielarski P., Fabisiak K., Paprocki K., Szybowicz M., Wrzyszczynski A., Zhusupkalieva G. K.
Materials Science Poland
|
2013
|
Vol. 31, No. 1
146-150
EN
The undoped, polycrystalline diamond films were deposited on tungsten wire substrates by hot filament chemical vapor deposition (HF CVD), using a precursor gas mixture of methanol with excess of hydrogen. The morphology and quality of the as-deposited films were monitored by scanning electron microscopy (SEM) and Raman spectroscopy. The surface morphology analyzed by SEM resembles a continuous and well faceted diamond film. Raman results showed essential differences in qualities of diamond films grown at different hydrocarbon concentrations. The electrochemical properties of diamond electrodes were examined with cyclic voltammetry (CV) and the electrochemical impedance spectroscopy (EIS). The CV experiments revealed a large chemical window (>~4.3 V) of undoped diamond. Analysis of the ferrocyanide-ferricyanide couple at a diamond electrode suggests some extent of electrochemical quasi-reversibility, but the rates of charge transfer across the diamond substrate interface vary with diamond quality.
12
Content available Examples of new models applied in selected simulation systems with respect to database
Ignaszak Z., Hajkowski J., Popielarski P.
Archives of Foundry Engineering
|
2013
|
Vol. 13, iss. 1
45--50
EN
The tolerance of damage rule progressively meets the approval in the design casting parts procedures. Therefore, there were appeared the new challenges and expectations for permanent development of process virtualization in the mechanical engineering industry. Virtualization is increasingly developed on the stage of product design and materials technologies optimization. Increasing expectations of design and process engineers regarding the practical effectiveness of applied simulation systems with new proposed up-grades modules is observed. The purpose is to obtain simulation tools allowing the most possible realistic prognosis of the casting structure, including indication, with the highest possible probability, places in the casting that are endangered with the possibility of shrinkage– and gas porosity formation. This 3D map of discontinuities and structure transformed in local mechanical characteristics are used to calculate the local stresses and safety factors. The needs of tolerance of damage and new approach to evaluate the quality of such prognosis must be defined. These problems of validation of new models/modules used to predict the shrinkage– and gas porosity including the chosen structure parameters in the example of AlSi7 alloy are discussed in the paper.
13
Content available remote Contribute to quantitative identification of casting defects based on computer analysis of X-ray images
Ignaszak Z., Popielarski P., Krawiec K.
Archives of Foundry Engineering
|
2007
|
Vol. 7, iss. 4
89-94
EN
The forecast of structure and properties of casting is based on results of computer simulation of physical processes which are carried out during the casting processes. For the effective using of simulation system it is necessary to validate mathematica-physical models describing process of casting formation and the creation of local discontinues, witch determinate the casting properties. In the paper the proposition for quantitative validation of VP system using solidification casting defects by information sources of II group (methods of NDT) was introduced. It was named the VP/RT validation (virtual prototyping/radiographic testing validation). Nowadays identification of casting defects noticeable on X-ray images bases on comparison of X-ray image of casting with relates to the ASTM. The results of this comparison are often not conclusive because based on operator's subjective assessment. In the paper the system of quantitative identification of iron casting defects on X-ray images and classification this defects to ASTM class is presented. The methods of pattern recognition and machine learning were applied.
14
Content available remote Identyfikacja podstawowych zastępczych współczynników termofizycznych masy formierskiej w zależności od grubości ścianki odlewu
Ignaszak Z., Popielarski P.
Archiwum Odlewnictwa
|
2006
|
R. 6, nr 22
224-231
PL
W artykule podjęto problem zmienności parametrów termofizycznych masy formierskiej kwarcowej wiązanej żywicą furanową w zależności od czasu i temperatury w powiązaniu z grubością ścianki odlewu. Wykonano eksperyment odlewania żeliwa do formy wielownękowej, a następnie wyznaczono średnie wartości zastępczych [...] tej samej masy, stosując metodę energetycznej walidacji modelu symulacyjnego połączoną z rozwiązaniem zagadnienia odwrotnego. Wykorzystano system symulacyjny Calcosoft.
EN
In the paper a problem of the changeability of parameters of mould quartz sand with furane resin in dependence on the time and the temperature connected with the thickness of the casting wall was undertaken. An experiment of pouring cast iron in the multi-cavity mould was performed and next, averages substitute values of [...] for the same furane sand were set, using method of energy validation of the simulation model. This method was combined with solving of inverse problem. A simulation Calcosoft system was used.
15
Content available remote Eksperymentalno-symulacyjny sposób identyfikacji strefy przewilżonej w formie
Ignaszak Z., Graczyk L., Popielarski P.
Archiwum Odlewnictwa
|
2006
|
R. 6, nr 22
216-223
PL
Badania opisane w artykule dotyczą identyfikacji obecności strefy przewilżonej w masie formierskiej z dodatkiem szkła wodnego, po zalaniu takiej formy ciekłym stopem. Wykonano badania eksperymentalne, a ponadto symulacyjne za pomocą systemu Calcosoft 2D. Przeprowadzono analizę wyników oraz pierwszą próbę walidacji modelu z uwzględnieniem zmienności parametrów termofizycznych masy.
EN
The study described in paper concerns the identification of the over moist zone presence in mould sand with the addition of the water glass after pouring of this mould with liquid alloy. Experimental and simulation examinations were made with the use of the system of Calcosoft 2D. Analysis of results and the first trial of the validation of the model were carried with taking into consideration the changeability of mould sand parameters.
16
Content available remote The problems of testing and validation of the cellular automaton-finite element method applied to forecasting a microstructure of hypoeutectic Al-Si alloys
Ignaszak Z., Hajkowski M., Hajkowski J., Popielarski P.
Archiwum Odlewnictwa
|
2005
|
R. 5, nr 15
139--147
EN
The work provides description of odeling with the use of the Cellular Automation-Finite Element Method and its testing, connected with an attempt of validation of the Calcosoft System (CS-CAFE). Results of identification of selected parameters used in stochastic and thermal models are provided, inclusive of determining their effect on the results of forecasting geometric parameters of hypoeutectic Al-Si microstructure alloys. Validation has been carried out with a simulation-experiment method under various conditions of thermal interaction with the casting mould. The results of metallographic studies of structure of specially made castings have been used.
PL
W pracy przedstawiono opis modelowania metodą Cellular Automaton - Finite Element oraz jego testowanie, połączone z próbą walidacji systemu Calcosoft (CS-CAFE). Podano wyniki identyfikacji wybranych parametrów; użytych w modelach stochastycznym i cieplnym; wraz z określeniem ich wpływu na wyniki prognozowania geometrycznych parametrów mikrostruktury podeutektycznego stopu Al-Si. Walidacja została przeprowadzona metodą symulacyjno-eksperymentalną w zróżnicowanych warunkach cieplnych oddziaływania formy odlewniczej. Wykorzystano wyniki metalograficznych badań struktur specjalnie wykonanych odlewów.
17
Content available remote Heat source description of ISO–exothermic sleeves with the use of continuous function
Ignaszak Z., Popielarski P., Ciura J.
Archiwum Odlewnictwa
|
2005
|
R. 5, nr 15
157--163
EN
The present study was aimed at investigating identification of real thermophysical parameters of insulating–exothermic materials used as riser sleeves. The experiments with steel poured into the moulds containing various insulating and exothermic sleeves were carried out using thermocouples measurement systems (thermal analysis). Then thermal coefficients of these materials were calculated using inverse problem solution. A time–dependent formula of exothermic reaction heat (in W/m3) was called a heat source function. The paper presents a proposed form of the heat source function, providing its justification and the results of tests obtained with its application. For purposes of the study the Calcosoft Inverse Solution system was used.
PL
Celem badań była identyfikacja rzeczywistych parametrów termofizycznych materiałów izolacyjno-egzotermicznych występujących w postaci otulin do nadlewów. Przeprowadzono eksperymenty odlewania staliwa do formy, w której zastosowano otuliny wykonane z różnych materiałów izolacyjno–egzotermicznych i umieszczono system termoelementów w celu przeprowadzenia analizy termicznej. Następnie wyznaczono współczynniki termofizyczne tych materiałów stosując metodę obliczeń odwrotnych. Wyznaczaną zależność wydzielającego się ciepła reakcji egzotermicznej (w W/m3) od czasu nazwano funkcją źródła ciepła. Artykuł przedstawia zaproponowaną postać funkcji źródła ciepła oraz jej uzasadnienie, a także uzyskane wyniki badan z jej zastosowaniem. Do obliczeń wykorzystano system symulacyjny Calcosoft.
18
Content available remote Identyfikacja termofizycznych właściwości mas formierskich z dodatkiem mikro-ochładzalników
Drotlew A., Ignaszak Z., Bieńko G., Popielarski P.
Archiwum Odlewnictwa
|
2004
|
R. 4, nr 14
132-137
PL
Możliwość prognozowania właściwości materiałów jest coraz częściej związana z komputerową symulacją procesów fizycznych zachodzących podczas ich wytwarzania. Aby było to możliwe, niezbędna jest znajomość szeregu parametrów charakteryzujących środowisko wytwórcze. W artykule podano metodykę wyznaczania i równania regresji, w funkcji grubości ścianek odlewu, podstawowych parametrów termofizycznych wiązanych szkłem wodnym kwarcowych mas formierskich, zawierających mikro-ochładzalniki.
EN
Possibility of material properties forecasting is connected with the simulation of physical processes which proceed during manufacture. To this aim the knowledge of many parameters characterizing the manufacture environment in necessary. In this paper the methodology and the relationship between basic thermo-physical parameters of quartz sand with silicate binder and with different quantity of micro-coolers for wall thickness of casting was described by regression equations.
19
Content available remote Wpływ wybranych parametrów symulacji krzepnięcia na obliczany gradient temperatury
Hajkowski M., Ignaszak Z., Popielarski P.
Archiwum Odlewnictwa
|
2003
|
R. 3, nr 9
174--182
PL
W pracy przedstawiono wyniki badań wpływu wybranych parametrów użytych do obliczeń symulacyjnych procesu krzepnięcia odlewu ze stopu AlSi9, takich jak gęstość siatki dyskretyzacyjnej, współczynniki przewodności cieplnej: masy formierskiej, stopu w stanie ciekłym i stałym oraz zmienność ułamka fazy stałej w przedziale likwidus–solidus, na gradient temperatury w kierunku osiowym i promieniowym odlewu walca. Stosowano system symulacyjny Calcosoft–2D. Odpowiedni dobór w.w parametrów pozwolił na uzyskanie średnio 10 % zgodności gradientu temperatury z symulacji i z doświadczenia, co jest zadowalającym wynikiem.
EN
The work presents the results of studies carried out by means of the Calcosoft 2D program including the effects of simulation conditions, mesh size, thermal conductivity of moulding sand, liquid phase of the alloy, solid state of the alloy, and solid solution contribution to the AlSi9 alloy on temperature gradients in axial and radial directions of cylindrical casting. The simulation conditions are provided, for which 10-percent of temperature gradient relative conformity between simulation and experiment may be achieved.
20
Content available remote Właściwości termofizyczne otulin izolacyjno-egzotermicznych oznaczane metodą zagadnień odwrotnych
Ignaszak Z., Popielarski P.
Archiwum Odlewnictwa
|
2003
|
R. 3, nr 9
209--220
PL
Celem badań była identyfikacja rzeczywistych parametrów termofizycznych materiałów izolacyjno-egzotermicznych występujących w postaci otulin do nadlewów. Przeprowadzono eksperymenty odlewania staliwa do formy, w której zastosowano otuliny wykonane z różnych materiałów izolacyjnych i egzotermicznych, a następnie wyznaczono współczynniki termofizyczne tych materiałów stosując metody: energetycznej walidacji modelu symulacyjnego oraz rozwiązanie zagadnienia odwrotnego. Pierwsza metoda polega na wyznaczeniu średnich wartości zastępczych współczynników termofizycznych (λ, c, ρ ). Druga metoda z równoległym zastosowaniem dynamicznej walidacji temperaturowej, umożliwia odtworzenie tych współczynników skorygowanych z uwagi na jednoczesne uwzględnienie źródeł ciepła w materiale egzotermicznym. Wykorzystano w tym celu system symulacyjny Calcosoft.
EN
The aim of this investigation was the identification of real thermophysical parameters of insulating–exothermic materials used in the form of riser sleeves. The experiments of steel pouring in the mould containing different insulating and exothermic sleeve materials was carried out. Then the thermophysic coefficients of these materials was calculated using energetic validation method and inverse problem solution. First method consist in calculating of average apparent values of λ, c and ρ. Second method; with parallel using of dynamic temperature validation; makes possible the identification of these coefficients corrected owing to respect of heat source function in the exothermical material. The tests of Calcosoft system used in order to realize these calculations are described.
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