Unmodified AlSi20 alloy were casted at the research station, allowing for sequential multipoint cooling using a dedicated computer- controlled program. This method allows for the formation of the microstructure of hypereutectic AlSi20 alloy and also increases hardness. Primary silicon dendrites were found in the microstructure of cooled samples. Based on these dendrites, the formation of primary silicon particles is explained. Cooling of casting die with a water mist stream causes changes in solidification, which leads to expansion of the boundary layer with columnar crystals and shrinkage of the core zone with equiaxed crystals. It also causes more regular hardness distribution around pre-eutectic Si crystals, which can lead to tensile strength and machinability improvement.
The paper presents the technology and organization of the artistic cast production. On the basis of the actual cast production system, the manufacturing process was shown, in particular sand–piece moulding, which is a very important process and a time-consuming part of the entire manufacture of the casts. The current state of the production process as well as the organization of the work and production technology were analysed with the use of methods and techniques of production improvement, the Lean Manufacturing concept and computer systems. The results of the analysis and studies were shown with use of schemes and graphs of the layout of the production resources, a flow chart of the production process, value stream mapping, and a costs table for the production and modernization of the moulding stage. The work has shown that there are possibilities to improve the artistic cast production system. This improvement leads to increased productivity, lower production costs of artistic casts and increased competitiveness of the foundry.
The work is a continuation of research concerning the influence of intensive cooling of permanent mold in order to increase the casting efficiency of aluminium alloys using the multipoint water mist cooling system. The paper presents results of investigation of crystallization process and microstructure of multicomponent synthetic hypereutectic alloy AlSi20CuNiCoMg. The study was conducted for unmodified silumin on the research station allowing the cooling of the special permanent sampler using a program of computer control. Furthermore the study used a thermal imaging camera to analyze the solidification process of multicomponent alloy. The study demonstrated that the use of mold cooled with water mist stream allows in wide range to form the microstructure of hypereutectic multicomponent silumin. It leads to higher homogeneity of microstructure and refinement of crystallizing phases of casting.
The paper presents the results of the crystallization process of silumin by the TDA thermographic method and the results of the cast microstructure obtained in the sampler ATD-10, that was cooling down in ambient air. The study was conducted for silumins AlSi8 and AlSi11 unmodified. The work demonstrated that the use of thermal imaging camera allows for the measurement and recording the solidification process of silumin. Thermal curve was registered with the infrared camera and derivative curve that was calculated on the base of thermal curve have both a very similar shape to adequate them TDA curves obtained from measurements using a thermocouple. Test results by TDA thermographic method enable quantitative analysis of the kinetics of the cooling and solidification process of hypo- and neareutectic silumins.
The work is a continuation of research concerning the influence of intensive cooling of permanent mold in order to increase the casting efficiency of aluminium alloys using the multipoint water mist cooling system. The paper presents results of investigation of crystallization process and microstructure of synthetic hypereutectic alloys: AlSi15 and AlSi19. Casts were made in permanent mold cooled with water mist stream. The study was conducted for unmodified silumins on the research station allowing the cooling of the special permanent probe using a program of computer control. Furthermore the study used a thermal imaging camera to analyze the solidification process of hypereutectic silumins. The study demonstrated that the use of mold cooled with water mist stream allows in wide range the formation of the microstructure of hypereutectic silumins. It leads to higher homogeneity of microstructure and refinement of crystallizing phases and also it increases subsequently the mechanical properties of casting.
The work is a continuation of research on the use of water mist cooling in order to increase efficiency of die-casting aluminum alloys using multipoint water mist cooling system. The paper presents results of investigation on crystallization process and microstructure of synthetic hypereutectic AlSi20 alloy. Casts were made in permanent mold cooled a with water mist stream. The study was conducted for unmodified AlSi20 alloy and a modified one with phosphorus, titanium and boron on the research station allowing sequential multipoint cooling using a dedicated program of computer control. The study demonstrated that the use of mold cooled with water mist stream and solution heat treatment allows in wide range for the formation of the microstructure of hypereutectic silumins. It leads to the growth of microstructure refinement and spheroidizing of phases in the casting.
The paper presents the results of the crystallization process of silumin by the TDA thermographic method and the results of the cast microstructure obtained in the sampler TDA-10, that was cooling down in ambient air. The study was conducted for silumin AlSi11 unmodified. The work demonstrated that the use of thermal imaging camera allows for the measurement and recording the solidification process of silumin. Thermal curve was registered with the infrared camera and derivative curve that was calculated on the base of thermal curve have both a very similar shape to adequate them TDA curves obtained from measurements using a thermocouple. Test results by TDA thermographic method enable quantitative analysis of the kinetics of the cooling and solidification process of neareutectic silumin.
W pracy przedstawiono możliwości otrzymywania wysokojakościowych odlewów siluminowych o podwyższonych właściwościach mechanicznych. Zapewnia je zastosowany system wielopunktowego chłodzenia formy mgłą wodną, zarządzany za pomocą dedykowanego komputerowego programu sterującego.
EN
The paper presents the possibility of obtaining highquality silumin castings with enhanced mechanical properties. It ensures the effective use of the multipoint water mist cooling system which is managed by a dedicated computer program.
The work is a continuation of research on the use water mist cooling in order to increase efficiency of die-casting aluminum alloys using multipoint water mist cooling system. The paper presents results of investigation of crystallization process and microstructure of synthetic hypereutectic AlSi20 alloy. Casts were made in permanent mold cooled with water mist stream. The study was conducted for unmodified AlSi20 alloy and modified with phosphorus, titanium and boron on the research station allowing sequential multipoint cooling using a dedicated program of computer control. The study demonstrated that the use of mold cooled with water mist stream allows the formation of the microstructure of hypereutectic silumins. A wide range of solidification temperature of hypereutectic silumins increases the potential impact of changes in the cooling rate on a size, a number and a morphology of preeutectic silicon and eutectic α+β (Al+Si).
W pracy przedstawiono wybrane aspekty teorii i technologii otrzymywania wysokojakościowych odlewów siluminowych w kokilach chłodzonych mgłą wodną. Przedstawione wyniki badań dotyczą poprawy właściwości odlewów siluminowych poprzez oddziaływane na proces stygnięcia ciekłego siluminu odlewanego grawitacyjnie w metalowej formie oraz możliwości sterowania przebiegiem krzepnięcia i krystalizacji odlewu. Wymagana w procesie wysoka efektywność otwartego punktowego systemu chłodzenia wynika z doboru optymalnych parametrów generowanej mgły wodnej i maksymalnego wykorzystania zjawiska odparowywania kropel wody na chłodzonej powierzchni kokili. Opracowana technologia jest wspomagana komputerowym system sterowania umożliwiającym optymalizację dozowania ilości i struktury wytwarzanej mgły wodnej do aktualnego zapotrzebowania wybranych stref kokili i odlewu na efektywność chłodzenia oraz zapewniającym bezpieczeństwo procesu odlewania przez niedopuszczenie do występowania strug wody na powierzchni kokili. W pracy przedstawiono badania efektywności generowania mgły wodnej, wpływu parametrów przepływu powietrza i wody na wytwarzany strumień mgły wodnej, wykonane z zastosowaniem kamery szybkiej rejestracji obrazów w świetle widzialnym. Na ich podstawie zanalizowano proces rozpylania wody, strukturę mgły wodnej i opracowano statystyczne zależności parametrów struktury generowanego strumienia od parametrów przepływu wody i powietrza oraz geometrii zastosowanych rozpylaczy i dyszy emitujących. W badaniach efektywności chłodzenia kokili mgłą wodną wykorzystano kamerę termowizyjną. Przeprowadzono badania występowania zjawiska Leidenfrosta oraz zanalizowano i obliczono wartości strumienia ciepła przejmowanego od kokili oraz zakres zmian wartości współczynnika przejmowania ciepła a. Wyniki te umożliwiły opracowanie równań regresji korelujących wartość odbieranego strumienia ciepła z parametrami strumienia mgły wodnej. Badania termograficzne umożliwiły również zanalizowanie zmian pola temperatury chłodzonej powierzchni kokili oraz strefy wymiany ciepła pomiędzy dyszą emitującą mgłę wodną i kokilą w czasie chłodzenia. Na podstawie badań procesu przejmowania ciepła od kokili i odlewu opracowano model matematyczny wymiany ciepła dla kokili chłodzonej mgłą wodną. Przedstawiono procedurę interfejsu sterowania parametrami procesu chłodzenia i wizualizacji zmian temperatury na grubości ścianki kokili w systemie Mathematica. Przeprowadzono symulacje w układzie jednowymiarowym w systemie Mathematica oraz 3D w systemie Ansys, które wykazały możliwość zastosowania opracowanego modelu do badania metodą symulacji procesu krzepnięcia i stygnięcia odlewu i kokili oraz prognozowania parametrów technologii odlewania w kokilach chłodzonych mgłą wodną prostych odlewów płytowych, jak również o złożonej konstrukcji. Przedstawiono opracowany program sterujący sekwencyjnym wielopunktowym chłodzeniem kokili mgłą wodną w sprzężeniu z ciągłym pomiarem temperatury kokili, który zastosowano w badaniach wpływu chłodzenia mgłą wodną na: przebieg stygnięcia odlewu i kokili, zmianę mikrostruktury i właściwości: Rm, Rp0,2 HB, A5 odlewów z siluminów AlSi11, AlSi9Mg i AlSi7Mg. W pracy wykazano, że sekwencyjne punktowe chłodzenie kokil mgłą wodną, charakteryzujące się szerokim zakresem regulacji i wysoką maksymalną efektywnością przejmowania ciepła, umożliwia sterowanie strumieniem ciepła pomiędzy odlewem i kokilą oraz krzepnięcie warstwowe prowadzące do realizacji w całym odlewie zakładanego rodzaju krzepnięcia kierunkowego lub jednoczesnego. W konsekwencji powoduje to: poprawę jakości odlewów w wyniku eliminowania wad skurczowych i wyraźnego zmniejszenia porowatości w odlewie, zwiększenie jednorodności mikrostruktury i jej rozdrobnienie oraz około 25% podwyższenie właściwości mechanicznych i wzrost wydajności procesu na skutek skrócenia cyklu odlewania kokilowego. Wobec powyższego opracowana technologia może stanowić alternatywę dla znacznie droższych technik odlewniczych w wytwarzaniu wysokojakościowych odlewów siluminowych.
EN
The paper presents some aspects of the theory and technology of high quality silumin castings in metal molds cooled with water mist spray. The results of the work relate to improvement of the properties of silumin casts by affecting the cooling of the liquid silumin in gravity cast in metal form and the possibility of controlling the solidification and crystallization of the casting. The high efficiency required from the cooling system is a consequence of an optimal selection of parameters of the generated mist and the maximum use of the phenomenon of water droplets evaporation on the surface of the cooled mold. The technology is assisted by a computer control system that allows the optimization of the volume and structure of the produced water mist as well as provides a process control to a multipoint sequential mold cooling of selected zones as well as the system prevents creating of water streams on the surface of the cast. To examinate the effectiveness of mold cooling with a water spray there was a thermal camera used. The Leidenfrost phenomenon has been observed and there have been the heat flow values analyzed and calculated from the mold with the extent of changes in the heat transfer coefficient a. These results have enabled the development of regression equations correlating the heat flow values to the water mist flow parameters. Thermographic study also allowed to analyze the changes of the temperature field of the cooled mold’s surface and the heat exchange zone between the nozzle emitting water mist and the mold. On the basis of the observed heat transfer from the mold to the casting a mathematical model of heat transfer was developed. A procedure to the control interface with the parameters of the cooling process and visualization of temperature changes on the mold wall thickness was showed in the program Mathematica. Simulations have been run in a one-dimensional system in the Mathematica and 3D Ansys programs, which showed the applicability of the simulation model to the study on the solidification process and cooling of a casting and a permanent mold as well as forecasting of the parameters in metal molds cooled with water spray of a simple as well as complex construction. Presenting a developed program that controls the sequential multi-mold cooling water spray with a continuous measurement of the mold temperature, which is used in the studies on water mist cooling impact in a cooling process of the casting and mold and the changes in the microstructure and the Rm, Rp0,2 HB, A5 properties of the casting silumins AlSi11, AlSi9Mg and AlSi7Mg. The study showed that sequential spot cooling with use of water mist, characterized by a wide range of control means and a high maximum heat transfer efficiency, enables to control the flow of heat between the casting and the mold and it allows for a layered solidification leading to the realization of the entire cast solidification in the expected way: directional or simultaneous. Consequently, the results are: improvement of the quality of the castings as a result of the elimination of defects and significant reduction in shrinkage porosity in the casting, an increase of the homogeneity and fineness of the microstructure, about 25% increase in the mechanical properties and a process efficiency improvement by a reduced die-casting cycle. Therefore, the developed technology can be an alternative to more expensive casting techniques in the production of high quality silumin castings.
The paper presents the test results of a computerized control system the sequential cooling process of permanent mold with use of water mist in the gravity die casting process. It describes the process for preparing high-quality casts made of AlSi7Mg alloy that achieves enhanced mechanical properties. A scheme of developed device and drivers for selected methods of sequence cooling for manufacturing of castings made in permanent steel mold was presented here. Also the microstructure and mechanical properties of received aluminium casts were described. It was shown that the use of a computer system to control the water mist cooling point of the mold not only accelerates the cooling of the cast and the gravity die casting cycle shortens, but also it has a positive effect on the microstructure and mechanical properties of castings made of unmodified AlSi7Mg alloy in a raw state.
PL
W pracy przedstawiono wyniki badań komputerowego systemu sterowania sekwencyjnym chłodzeniem kokili mgła wodna w odlewaniu grawitacyjnym. Opisano proces otrzymywania wysokojakościowych odlewów z siluminu AlSi7Mg o podwyższonych właściwościach mechanicznych. Przedstawiono opracowane urządzenie, programy sterujące dla zadanych metod wytwarzania odlewów kokilowych i sekwencji chłodzenia. Przedstawiono mikrostrukturę i własności mechaniczne otrzymanych odlewów siluminowych. W pracy wykazano, że zastosowanie systemu komputerowego do sterowania chłodzeniem punktowego mgła wodna nie tylko przyspiesza stygnięcie odlewu i skraca cykl odlewania kokilowego, ale również korzystnie wpływa na mikrostrukturę i własności mechaniczne odlewów z niemodyfikowanego siluminu AlSi7Mg w stanie surowym.
The paper presents some aspects of the theory and technology of high quality silumin castings in metal molds cooled pointed with water mist stream. The results of the work relate to improvement of the properties of silumin casts by affecting the cooling of the liquid silumin in gravity cast in metal mold and the possibility of controlling the solidification and crystallization of the casting. The high efficiency required from the cooling system is a consequence of an optimal selection of parameters of the generated mist and the maximum use of the phenomenon of water droplets evaporation on the surface of the cooled mold. The study showed that sequential spot cooling with use of water mist, characterized by a wide range of control means and a high maximum heat transfer efficiency, enables to control the flow of heat between the casting and the mold and it allows for a layered solidification leading to the realization of the entire cast solidification in the expected way: directional or simultaneous. Consequently, the results are: improvement of the quality of the castings as a result of the elimination of defects and significant reduction in shrinkage porosity in the casting, an increase of the homogeneity and fineness of the microstructure, about 25% increase in the mechanical properties.
The work is a part of research into the reduction of energy consumption in the production of EPS through the modernization of technological equipment used. This paper presents the results of research and analysis of heat transfer process between the water vapor that was provided to machine, the mold, the product and the environment. The paper shows the calculation of the heat balance of the production cycle for two types of mold: standard and modernized. The performance tests used an infrared imaging camera. The results were used to develop a computer image analysis and statistical analysis. This paper presents the main stages of the production process and the construction of technological equipment used, changing the mold surface temperature field during the production cycle and the structure of the heat balance for the mold and its instrumentation. It has been shown that the modernization of construction of technological equipment has reduced the temperature field and as a consequence of decreased of demand for process steam production cycle.
The work is a continuation of research on the use water mist cooling in order to increase efficiency of die-casting aluminum alloys. The paper presents results of research and analysis process, spraying water and generated a stream of water mist, the effect of the type of nozzle, the nozzle size and shape of the emitting of the water mist on the wall surface of casting die on the microstructure and geometry of water mist stream and cooling efficiency. Tests were used to perform high-speed camera to record video in the visible and infrared camera. Results were used to develop a computerized image analysis and statistical analysis. The study showed that there are statistical relationships between water and air flow and geometry of the nozzle and nozzle emitting a stream of microstructure parameters of water mist and heat the incoming stream. These relationships are described mathematical models that allow you to control the generating of adequate stream of water mist and a further consequence, the cooling efficiency of casting die.
The work is a continuation of research on the use of water mist cooling in order to increase efficiency of the die-casting process for aluminum alloys. The paper describes the multipoint sequential cooling system of the casting die and its computer control and monitoring. It also includes results of the tests and analysis of cooling methods during making of the casting. These methods differ from each other in the sequence of casting die cooling and cause effective changes in microstructure and mechanical properties of castings made of AlSi11 alloy. The study demonstrated that the use of multipoint sequential cooling with water mist affects the microstructure refinement and reduces the segregation in the cast as well as more than by 20% increases the mechanical properties of castings in the rough state. The study also demonstrates that the sequential cooling of casting die accelerates the cooling of the casting and shortens die-casting cycle.
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The paper presents the influence of the type of furnace charging melting, refining and modification silumins 226 and 231 on the porosity and microstructure of castings. It was shown that in order to reduce or eliminate the porosity of the castings is necessary to the refining ECOSAL-AL113 of liquid silumin both in the melting furnace, and in the ladle and an additional nitrogen, in the heat furnace modified and refining with nitrogen. To control the effects of refining and modifying the TDA method was used. It was found that based on crystallization curve can be qualitatively assess the gas porosity of the castings. In order to control and quality control silumins author developed a computer program using the method of TDA, which sets out: Rm, A5, HB and casting porosity P and the concentration of hydrogen in them. The program also informs the technological procedures to be performed for liquid silumin improper preparation.
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The paper presents manufacturing technology of pressure castings made of Al-Si alloy without porosity or with low microporosity of castings. It has been shown that the greatest impact on the porosity of the castings and the concentration of hydrogen has had the charge to the melting furnace. Liquidation or occurrence of a small microporosity of castings provides refining with solid ref iners, nitrogen and modification of liquid alloy after various operations of preparing process. The liquid alloy stored in holding furnace should be refined once every 2 h with nitrogen. Authors developed a computer program of Al-Si alloys inspection with using of TDA method. The developed technology was verified under production conditions.
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The paper presents the results of the heat transfer area during the cooling process of steel test die with water mist which consist the flow of air in the range 150-350 l/min and 0.05 0.24 l/min of water. Temperature change in the thickness of die by means showing with the thermal curves and the temperature gradient and temperature distribution in the space between the nozzle and the cooled surface of the metal mold using a thermal imaging camera and thermocouples measurement. The course of changes in the temperature gradient and the received heat flux from the die while cooling its with the flow of air and water mist stream. It has been shown that the use of water mist with a variable flow of air and water controls the process of heat transfer process between the permanent molds, and a stream of water mist.
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The paper presents the results of crystallization and cooling process of research casting die with use of water mist compressed under 0.200.45 MPa. It’s shown the nature of changes of the temperature in AlSi11 casting and in casting die wall using the thermal and derivative curves and regression models. It’s presented the change of the temperature in the crystallization and cooling down process of research areas of casting which wall thickness change in range 5-15mm and solidification modulus 0.16-0.3 cm. It’s shown the equipment used for making of water mist cooling the casting die and special designed rotational jet cooling for spraying of water. It has been shown that the using of water mist and the changing wall thickness of the casting cooled pointwise lets you control the crystallization process, microstructure and quality of the silumin casting.
PL
W pracy przedstawiono wyniki badań procesu chłodzenia kokili badawczej mgła wodna o ciśnieniu w zakresie 0,20-0,45 MPa. Zmianę temperatury w odlewie z siluminu AlSi11 i w ściance kokili pokazano za pomocą krzywych termicznych i derywacyjnych. Przedstawiono przebieg zmian temperatury w procesie krystalizacji i stygnięcia badanych obszarów odlewu o grubości ścianki w zakresie 5-15 mm i module krzepnięcia w zakresie od 0,16-0,3 cm. Pokazano urządzenie do wytwarzania mgły wodnej chłodzącej kokile oraz efekt rozpylania wody za pomocą zaprojektowanego rozpylacza wirowego. Pokazano mikrostrukturę siluminu okołoeutektycznego uzyskana w kokili chłodzonej mgłą wodna. Wykazano, że zastosowanie mgły wodnej oraz zmiana grubości ścianki odlewu chłodzonego punktowo pozwala sterować procesem krystalizacji, mikrostruktura i jakością odlewu siluminowego.
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The paper presents the results of crystallization and cooling process of silumin AlSi9 and temperature distribution in the wall of research casting dies made of cast iron and steel in the temperature range 650÷100 oC during casting of silumin using water mist cooling consisting with air compressed (0,3÷0,4 MPa) and water (0,35÷0,45 MPa). It’s shown the nature and rate of change of casting die temperature and the formation of the temperature gradient at the wall thickness in the axis of the nozzle cooling the outer surface of the wall of casting die. Using derivative curves and regression models were compared to the temporary and average speed of crystallization and cooling of the casting in the 75÷200 oC temperature range. The differences of microstructure resulting from a change in the type of casting die, wall thickness of casting and the use of cooling water mist. It has been shown that the use of water mist and the changing wall thickness of die and the casting cooled pointwise lets you control the crystallization process, microstructure and quality of the silumin casting.
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