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1

Options for solutions of the inlet system into the mold

Ružbarský Juraj, Krenický Tibor, Maščeník Jozef, Coranič Tomáš

Systemy Wspomagania w Inżynierii Produkcji

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2023

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Vol. 12, iss. 2

57--70

EN

The presented contribution points out the possibilities of solving the inlet system, as one of the important factors influencing the final quality of the castings. Due to its design and function, the sprue system influences the process of filling the mold cavity. With the correct design of the sprue system, we achieve the continuity of filling the mold cavity and the elimination of qualitative and quantitative errors caused by non-observance of basic principles in the design of sprue systems. When conducting the experiments, we monitored the mold inlet system, modeling the process of filling the mold cavity and the speed of the liquid metal in the notch and the mold cavity. The results of the experiments show that the speed of the liquid metal when filling the mold is approximately half of the calculated theoretical value.

2

Innovative zinc alloy for production of positioners of car window accessories

Pasierb Łukasz, Łakomski Jan, Oblaciński Michał

Polish Technical Review

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2023

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No. 3

2--8

EN

The present paper is related to the problems of production of car window accessories from the modified foundry alloys of zinc. The material includes the results of the conducted industrial tests and developmental work. The range of the requirements for components and the properties of standardized materials were discussed. The innovative method for titanium alloying in the zinc ZnAI4Cu3 alloy was developed and described. The casts made from innovative materials, as produced in the demonstration line were subjected to a series of endurance (fatigue) tests.

PL

Artykuł dotyczy zagadnienia wytwarzania pozycjonerów osprzętu szyb samochodowych ze zmodyfikowanych stopów odlewniczych cynku. Materiał obejmuje wyniki przeprowadzonych badań przemysłowych oraz prac rozwojowych. Przedstawiono zakres wymagań stawianych komponentom oraz właściwości znormalizowanych materiałów. Opracowano oraz opisano nowatorską metodę stopowania tytanu w stopie cynku ZnAl4Cu3. Wytworzone w ramach linii demonstracyjnej odlewy z innowacyjnego materiału podano szeregowi badań oraz testom zmęczeniowym.

3

Influence of manganese content on the microstructure and properties of AlSi10MnMg(Fe) alloy for die castings

Piątkowski Jarosław, Hejne M., Wieszała R.

Archives of Materials Science and Engineering

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2023

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Vol. 123, nr 1

5--12

EN

Purpose: This paper was to determine the effect of different manganese addition contents from 0.2 to 1.0 wt.% on the microstructure, HB hardness and selected mechanical properties (UTS; YS; EL) of AlSi10MnMg alloy with increased iron content (about 1.0 wt.%). The proportion of iron in the studied alloy is so high because approx. 50% of the charge came from secondary materials. Design/methodology/approach: Chemical composition tests were performed using a Foundry Master Compact 8 emission spectrometer. Static tensile testing at ambient temperature was carried out according to PN-EN ISO 6892-1 on an Instron 3382 using a 20:1 ratio and a constant tensile speed of 5 mm/min-1. Tensile strength (UTS), conventional yield strength (YS), and per cent elongation after rupture of a proportional sample (EL) were determined from this test. Brinell hardness measurement was performed on a Zwick ZHF1, with a loading force of 250 N, with a 5 mm diameter ball for 35 s. Ten measurements were taken, discarding the two outliers, and the arithmetic mean was calculated from the remaining measurements. Metallographic studies were conducted on a MeF-2 Reichert light microscope. X-ray microanalysis studies were carried out on a Hitachi S-3400 scanning microscope coupled to an EDS Voyager X-ray spectrometer equipped with an SE secondary and BSE backscattered electron detector. Chemical composition analysis was performed by energy dispersive X-ray microanalysis (EDS) using a Thermo Noran detector. Findings: Increased iron content in aluminium-silicon alloys is a major concern. It causes a significant reduction in the mechanical properties of the materials. This is due, among other things, to the increasing scarcity of primary materials (high cost and environmentally unjustifiable) versus the increasing share of recycled materials. Based on the study, AlSi10MnMg(Fe) alloys obtained under pressure with higher iron content (about 1% wt.), the optimal value of manganese addition is about 0.58% wt. Practical implications: This research has shown that it is possible to use recycled Al-Si materials. The article presents one way to reduce the negative impact of iron addition to aluminium alloys as a result of reusing this type of material. Originality/value: The article presents the effect of manganese addition on the selected aluminium alloy. It was determined that the addition of manganese in the amount of 0.58% wt. causes a significant reduction in the negative effect of iron phases. The article is intended not only for the academic community but also for specialists in the foundry industry.

4

Casting machines and properties of Al-Si castings alloys

Ružbarský Juraj, Krenický Tibor, Maščeník Jozef, Coranič Tomáš

Systemy Wspomagania w Inżynierii Produkcji

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2022

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Vol. 11, iss. 2

8--34

EN

The paper focuses on the research of holding pressure inside the mould cavity and pressing speed as technological parameters of die casting. The experiments conducted within the frame of the practical part examined the plunger and the pressure or the holding pressure in the mould cavity influencing the mechanical properties of a casting which were represented by ultimate tensile strength and percentage share of porosity of Al-Si castings. The results of experiments and analysis of the measured values proved the relation between pressure, or holding pressure, in the mould cavity and the ultimate tensile strength and porosity of castings. Plunger pressing speed is closely related to mould cavity filling mode which affected the final porosity of casting. It can be assumed that die casting is positively influenced by the increase of ultimate tensile strength and reduction of porosity during the increase of pressure or of holding pressure in the mould cavity. Higher values of holding pressure caused the elimination of pores which resulted in a decrease in the percentage share of pores in the casting and an increase in values of ultimate tensile strength.

5

Investigation of non-imaging Fresnel lens prototyping with different manufacturing methods for solar energy application

Sexton Ai Jiang, Qandil Hassan, Abdallah Mohammad, Zhao Weihuan

Journal of Mechanical and Energy Engineering

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2021

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Vol. 5, No 2

113--122

EN

Non-imaging Fresnel lenses have been playing an important role in improving the efficiency of the solar energy systems. Many researchers have been developing novel designs of Fresnel lenses to enhance the concentrator performance. To bring the complex design of a Fresnel lens from a conceptual theory to a real-life application while maintaining its efficiency, it is critical to find the optimum manufacturing method that achieves the best quality fabrication at low cost in the lab scale. This work will systematically investigate four advanced manufacturing methods for their lens-making capabilities, including pressure casting, hot embossing, 3D printing, and CNC machining. Six Fresnel lenses were fabricated by the four methods, which were tested in the lab by a solar simulator and a solar cell to demonstrate their performances. The CNC machining provides the best quality lab-scale Fresnel lens that enhances the solar cell efficiency by 118.3%. 3D printing and hot embossing methods are also promising for the fabrication of good performance lenses – increasing the solar cell efficiency by 40-70%. However, the 3D printed lens has the issue of material degradation on the long term. Although the pressure casting is the easiest manufacturing method, the performance of fabricated lens was the lowest.

6

Role of Metal Quality and Porosity Formation in Low Pressure Die Casting of A356: Experimental Observations

Gursoy O., Nordmak A., Syversten F., Colak M., Tur K., Dispinar D.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 1

5--10

EN

Porosity is one of the major problems in casting operations and there are several discussions in the literature about the porosity formation in aluminum castings. Bifilms are the defects that are introduced into the melt by turbulence. They can be detected with reduced pressure test and presented numerically by measuring bifilm index. The measure of bifilm index is the sum of total oxide length given in millimeters from the cross-section of reduced pressure test sample solidified under 0.01 MPa. In this work, low pressure die casting (LPDC) unit was built in an attempt to enhance the producibility rate. The unit consists of a pump housing that was placed inside the melt in the melting furnace where the pressure was applied instead of the whole melt surface. It was observed that the melt quality of A356 alloy was deteriorated over time which had led to higher porosity. This was attributed to the increased oxide thickness of the bifilm by the consumption of air in between the folded oxides. A relationship was found between bifilm index and pore formation.

7

Methodology for Diagnosing the Causes of Die-Casting Defects, Based on Advanced Big Data Modelling

Okuniewska A., Perzyk M. A., Kozłowski J.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 4

103--109

EN

The purpose of this paper was to develop a methodology for diagnosing the causes of die-casting defects based on advanced modelling, to correctly diagnose and identify process parameters that have a significant impact on product defect generation, optimize the process parameters and rise the products’ quality, thereby improving the manufacturing process efficiency. The industrial data used for modelling came from foundry being a leading manufacturer of the high-pressure die-casting production process of aluminum cylinder blocks for the world's leading automotive brands. The paper presents some aspects related to data analytics in the era of Industry 4.0. and Smart Factory concepts. The methodology includes computation tools for advanced data analysis and modelling, such as ANOVA (analysis of variance), ANN (artificial neural networks) both applied on the Statistica platform, then gradient and evolutionary optimization methods applied in MS Excel program’s Solver add-in. The main features of the presented methodology are explained and presented in tables and illustrated with appropriate graphs. All opportunities and risks of implementing data-driven modelling systems in high-pressure die-casting processes have been considered.

8

Defects analysis of seat belt tensioner cast body

Soroczyński Artur, Czyżewski Piotr, Rechowicz Krzysztof

Welding Technology Review

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2020

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R. 92, nr 2

33--38

EN

The article presents an analysis of the implementation of a selected element of the traveler safety system used in road transport. The results of metallographic tests were presented, and the state of stress introduced to the casting by means of forming the element by means of plastic forming was analyzed. An analysis of the manufacturing process was carried out indicating the risks that may lead to cracks in the material structure. Possible causes of founding defects were pointed out and possible technological solutions were pointed out in order to avoid them.

PL

W artykule przedstawiono analizę wykonania wybranego elementu wyposażenia systemu bezpieczeństwa podróżnych, stosowanego w transporcie samochodowym. Przedstawiono wyniki badań metalograficznych oraz dokonano analizy stanu naprężeń wprowadzanych do odlewu poprzez kształtowanie elementu metodą obróbki plastycznej. Dokonano analizy procesu wytwarzania wskazując na zagrożenia, które mogą prowadzić do powstawania pęknięć w strukturze materiału. Wskazano na możliwe przyczyny powstawania wad odlewniczych oraz wskazano możliwe rozwiązania technologiczne w celu ich uniknięcia.

9

Impact Strength of AE-type Alloys High Pressure Die Castings

Braszczyńska-Malik K., Malik M. A.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 3

5--8

EN

The results of the Charpy impact test of AE-type magnesium alloys produced by the high pressure die casting method are presented. Three alloys with different weight fractions of rare earth elements (RE; e.g. 1, 3 and 5 wt%) and the same mass fraction of aluminium (5 wt%) were prepared. The casts were fabricated using a typical cold chamber high pressure die casting machine with a 3.8 MN locking force. Microstructural analyses were performed by means of a scanning electron microscope (SEM). The impact strength (IS) was determined using a Charpy V hammer with an impact energy equal to 150 J. The microstructure of the experimental alloys consisted of an [alpha]-Mg solid solution and Al11RE3, Al10Ce2Mn7 and Al2RE intermetallic compounds. The obtained results show the significant influence of the rare earth elements to aluminium ratio on the impact strength of the investigated materials. Lower the RE/Al ratio in the chemical composition of the alloy results in a higher impact strength of the material.

10

Fabrication Optimization of Al 7075/Expanded Glass Syntactic Foam by Cold Chamber Die Casting

Bolat C., Goksenli A.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 3

112--118

EN

Recently, aluminum matrix syntactic foams (AMSFs) have become notably attractive for many different industrial areas like automotive, aerospace, construction and defense. Owing to their low density, good compression response and perfect energy absorption capacity, these advanced composite materials are also considered as strong alternatives to traditional particle reinforced composites and metal foams. This paper presents a promising probability of AMSF fabrication by means of industrial cold chamber die casting method. In this investigation, contrary to other literature studies restricted in laboratory scale, fully equipped custom-build cold chamber die casting machine was used first time and all fabrication steps were designed just as carried out in the real industrial high pressure casting applications. Main casting parameters (casting temperature, injection pressure, piston speed, filler pre-temperature and piston waiting time) were optimized in order to obtain flawless AMSF samples. The density alterations of the syntactic foams were analyzed depending upon increasing process values of injection pressure, piston speed and piston waiting time. In addition, macroscopic and microscopic investigations were performed to comprehend physical properties of fabricated foams. All these efforts showed almost perfect infiltration between filler particles at the optimized injection parameters.

11

Application of Modular Die for Fluidity Test and Monitoring of the Pressing Force Flow by Semi-solid Squeeze Casting of AlSi7Mg0.3

Martinec D., Pastirčák R.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 3

69--73

EN

The fluidity is the term to determine the materials ability to fill the mold cavity properly. Fluidity is complex property with many variables. Up to this date, there is no methodology for defining the fluidity in a semisolid material state. Submitted paper deals with the proposal of a new method designed for aluminium alloy fluidity evaluation in semi-solid state trough the design of the layered construction die. Die will be primary used for fluidity tests of semi-solid squeeze casted aluminium alloy and to observe the pressing force flow by mentioned casting technology. The modularity consists of possibility to change each die segment. In the experiment the die design was evaluated by simulation in ProCAST 11.5 and by production of experimental castings. The die was made by laser cutting technology from construction steel S355JR. Experimental material was aluminium alloy AlSi7Mg0.3. The temperature of the semisolid state was chosen to achieve 35% of solid phase. The result of next study should be a selected parameters observation and their effect on the fluidity of aluminium alloy in semi-solid state. This will be very important step to determine the optimal conditions to achieve a castings with certain wall thickness produced by the method of semi-solid squeeze casting.

12

Wpływ chromu na proces krystalizacji, mikrostrukturę i właściwości siluminu podeutektycznego

Szymczak T., Gumienny G., Wilk-Kolodziejczyk D., Pacyniak T.

Prace Instytutu Odlewnictwa

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2018

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Vol. 58, no. 1

55--72

PL

W pracy przedstawiono wyniki badań siluminu podeutektycznego z dodatkiem chromu przeznaczonego do odlewania pod ciśnieniem. W charakterze stopu wyjściowego zastosowano silumin o składzie chemicznym zbliżonym do siluminu gatunku EN AC-46000. W celu wprowadzenia chromu do siluminu wyjściowego zastosowano zaprawę AlCr15. Ilość siluminu wyjściowego oraz zaprawy AlCr15 dobrano w proporcjach pozwalających na uzyskanie w stopie zawartości Cr około 0,1; 0,2; 0,3; 0,4 i 0,5% wag. W ramach realizacji pracy zbadano zarówno silumin wyjściowy, jak również siluminy z dodatkiem chromu. Przedstawiono wyniki analizy termicznej i derywacyjnej ATD (ang. Differential Thermal Analysis – DTA), przeprowadzonej w celu zbadania procesu krystalizacji siluminów. Pokazano mikrostrukturę siluminów odlewanych do próbnika ATD oraz ciśnieniowo. Określono podstawowe właściwości mechaniczne siluminów odlewanych pod ciśnieniem. Przedstawione wyniki analizy ATD wykazały wpływ dodatku chromu na przebieg procesu krystalizacji badanego siluminu. Na krzywych ATD siluminu wyjściowego występują trzy efekty cieplne wywołane odpowiednio krystalizacją roztworu stałego α(Al), oraz dwóch eutektyk α + Al15(Fe,Mn)3Si2 + + β i α + Al2Cu + AlSiCuFeMnMgNi + β. Wprowadzenie chromu w ilości około 0,2% wag. spowodowało wystąpienie na krzywej derywacyjnej dodatkowego efektu cieplnego pochodzącego od krystalizacji fazy międzymetalicznej zawierającej chrom. Krystalizacja tej fazy zachodzi przed wydzielaniem się z cieczy dendrytów fazy α(Al). Analiza mikrostruktury siluminów odlewanych do próbnika ATD wykazała pojawienie się wydzieleń „nowej” fazy w siluminach zawierających 0,2% wag. lub więcej Cr. Wraz z pojawieniem się na krzywych ATD dodatkowego efektu cieplnego oraz „nowej” fazy w mikrostrukturze siluminu zauważono brak fazy Al15(Fe,Mn)3Si2. W siluminach odlewanych ciśnieniowo dodatek chromu również spowodował powstanie „nowej” fazy międzymetalicznej. Faza ta pojawia się przy zawartości około 0,3% wag. lub większej Cr. Ma ona morfologię zbliżoną do ścianowej. Wraz z podwyższaniem ilości chromu rozmiary tej fazy znacząco się zwiększają. Badania podstawowych właściwości mechanicznych siluminów odlewanych pod ciśnieniem wykazały, że dodatek Cr daje możliwość znaczącego podwyższenia głównie wytrzymałości na rozciąganie Rm i wydłużenia względnego A. Pierwiastek ten w mniejszym stopniu wpłynął na podwyższenie twardości HB. Wartości umownej granicy plastyczności Rp0,2 siluminu wyjściowego i siluminów z podwyższoną zawartością chromu nie zmieniają się istotnie. Najwyższe właściwości mechaniczne uzyskano dla siluminów zawierających około 0,2 i 0,3% wag. Cr.

EN

The paper presents the results of studies of hypoeutectic silumin with a chromium addition used for pressure casting. A silumin with the composition similar to that of EN AC-46000 was used as the initial one. In order to introduce chromium into the initial silumin, an AlCr15 master alloy was applied. The amounts of the initial silumin and the AlCr15 master alloy were selected in the proportions making it possible to obtain about 0.1; 0.2; 0.3; 0.4 and 0.5 wt. % of Cr in the alloy. Both the initial silumin and the silumins with the chromium addition were examined. The results of the thermal and derivational analysis performed to investigate the silumins' crystallization process have been presented. The microstructure of the silumins cast into an DTA tester and under pressure has been demonstrated. The basic mechanical properties of the pressure cast silumins have been presented. The results of the DTA analysis showed an effect of the chromium addition on the course of the crystallization process of the examined silumin. Three thermal effects are present on the silumin's DTA curves, caused by the crystallization of the solid solution α(Al), and of two eutectics α + Al15(Fe,Mn)3Si2 + β and α + Al2Cu + AlSiCuFeMnMgNi + + β. The introduction of chromium in the amount of about 0.2 wt. % caused the presence of an additional thermal effect on the derivation curve, originating from the crystallization of the intermetallic phase containing chromium. The crystallization of this phase occurs before the precipitation of the dendrites of phase α(Al) from the liquid. The microstructure analysis of the silumins cast into the DTA tester showed the presence of precipitations of a “new” phase in the silumins containing 0.2% wt. Cr or more. With the occurrence of an additional thermal effect on the DTA curves as well as the “new” phase in the silumin's microstructure, the lack of phase Al15(Fe,Mn)3Si2 was observed. In the pressure cast silumins, the chromium addition also caused the formation of a “new” intermetallic phase, which occurs with the Cr content of about 0.3 wt. % or more. Its morphology is similar to a faceted one. With an increase of the chromium content, the size of this phase significantly increases as well. The investigations of the basic mechanical properties of the pressure cast silumins showed that the Cr addition makes it possible to significantly increase mainly the tensile strength Rm and the unit elongation A. To a lesser extent, this element caused an increase of the hardness HB. The values of the proof stress Rp0.2 of the initial silumin and the silumins with an increased chromium content do not change significantly. The highest mechanical properties were obtained for the silumins containing about 0.2 and 0.3 wt. % Cr.

13

Badanie wpływu podciśnienia w formie na chropowatość powierzchni odlewów

Łągiewka M., Konopka Z., Zyska A.

Prace Instytutu Odlewnictwa

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2018

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Vol. 58, no. 1

3--11

PL

W artykule przedstawiono wyniki badań wpływu podciśnienia w formie i układzie zalewania na chropowatość powierzchni odlewów. Badania chropowatości powierzchni wykonano na odlewach ze stopu EN AB 46000 wykonanych metodą odlewania ciśnieniowego na maszynie Vertacast z zastosowaniem zmiennego podciśnienia w formie. Stwierdzono zmniejszenie chropowatości powierzchni odlewów ze zmniejszeniem ciśnienia w formie na podstawie wartości różnych charakterystycznych parametrów chropowatości. Badania chropowatości odlewów wykonano na urządzeniu Hommel Tester T1000.

EN

The article discusses the results of the studies of the effect of negative pressure in the mould and the casting system on the roughness of the casts' surfaces. Roughness tests were performed on casts made of alloy EN AB 46000, by means of the pressure casting method in the Vertacast machine, and with the use of varying negative pressure in the mould. The surface roughness of the casts decreasing with a decrease in the pressure in the mould was determined based on the values of different characteristic surface roughness parameters. The cast roughness examinations were conducted on the Hommel Tester T1000 device.

14

Statistical Methods Used in the Assessment of the Influence of the Al-Si Alloy's Chemical Composition on its Properties

Szymczak T., Szymszal J., Gumienny G.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 1

203--211

EN

The paper presents the results of the application of a statistical analysis to evaluate the effect of the chemical composition of the die casting Al-Si alloys on its basic mechanical properties. The examinations were performed on the hypoeutectic Al-Si alloy type EN AC-46000 and, created on its basis, a multi-component Al-Si alloy containing high-melting additions Cr, Mo, W and V. The additions were introduced into the base Al-Si alloy in different combinations and amounts (from 0,05% to 0,50%). The tensile strength Rm; the proof stress Rp0,2; the unit elongation A and the hardness HB of the examined Al-Si alloys were determined. The data analysis and the selection of Al-Si alloy samples without the Cr, Mo, W and V additions were presented; a database containing the independent variables (Al-Si alloy's chemical composition) and dependent variables (Rm; Rp0,2; A and HB) for all the considered variants of Al-Si alloy composition was constructed. Additionally, an analysis was made of the effect of the Al-Si alloy's component elements on the obtained mechanical properties, with a special consideration of the high-melting additions Cr, Mo, V and W. For the optimization of the content of these additions in the Al-Si alloy, the dependent variables were standardized and treated jointly. The statistical tools were mainly the multivariate backward stepwise regression and linear correlation analysis and the analysis of variance ANOVA. The statistical analysis showed that the most advantageous effect on the jointly treated mechanical properties is obtained with the amount of the Cr, Mo, V and W additions of 0,05 to 0,10%.

15

Evaluation of the Effect of the Cr, Mo, V and W Content in an Al-Si Alloy Used for Pressure Casting on its Proof Stress

Szymczak T., Szymszal J., Gumienny G.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 2

105--111

EN

The study presents the results of the application of a statistical analysis for the evaluation of the effect of high-melting additions introduced into a pressure cast Al-Si alloy on the obtained level of its proof stress Rp0.2. The base Al-Si alloy used for the tests was a typical alloy used for pressure casting grade EN AC-46000. The base alloy was enriched with high-melting additions, such as: Cr, Mo, V and W. The additions were introduced into the base Al-Si alloy in all the possible combinations. The content of the particular high-melting addition in the Al-Si alloy was within the scope of 0.05 to 0.50%. The investigations were performed on both the base alloy and alloy with the high-melting element additions. Within the implementation of the studies, the values of Rp0.2 were determined for all the considered chemical compositions of the Al-Si alloy. A database was created for the statistical analysis, containing the independent variables (chemical composition data) and dependent variables (examined Rp0.2 values). The performed statistical analysis aimed at determining whether the examined high-melting additions had a significant effect on the level of Rp0.2 of the Al-Si alloy as well as optimizing their contents in order to obtain the highest values of the Al-Si alloy's proof stress Rp0.2. The analyses showed that each considered high-melting addition introduced into the Al-Si alloy in a proper amount can cause an increase of the proof stress Rp0.2 of the alloy, and the optimal content of each examined high-melting addition in respect of the highest obtained value of Rp0.2 equals 0.05%.

16

Evaluation of the Effect of Cr, Mo, V and W on the Selected Properties of Silumins

Szymczak T., Szymszal J., Gumienny G.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 4

77--82

EN

The results of statistical analysis applied in order to evaluate the effect of the high melting point elements to pressure die cast silumin on its tensile strength Rm, unit elongation A and HB were discussed. The base alloy was silumin with the chemical composition similar to EN-AC 46000. To this silumin, high melting point elements such as Cr, Mo, V and W were added. All possible combinations of the additives were used. The content of individual high melting point additives ranged from 0.05 to 0.50%. The tests were carried out on silumin with and without above mentioned elements. The values of Rm, A and HB were determined for all the examined chemical compositions of the silumin. The conducted statistical analysis showed that each of the examined high melting point additives added to the silumin in an appropriate amount could raise the values of Rm, A and HB. To obtain the high tensile strength of Rm = 291 MPa in the tested silumin, the best content of each of the additives should be in the range of 0.05-0.10%. To obtain the highest possible elongation A of about 6.0%, the best content of the additives should be as follows: chromium in the range of 0.05-0.15%, molybdenum 0.05% or 0.15%, vanadium 0.05% and tungsten 0.15%. To obtain the silumin with hardness of 117 HB, chromium, molybdenum and vanadium content should be equal to about 0.05%, and tungsten to about 0.5%.

17

Wpływ wanadu na proces krystalizacji, mikrostrukturę i właściwości siluminu EN AC-46000

Szymczak T., Gumienny G., Pacyniak T.

Prace Instytutu Odlewnictwa

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2017

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Vol. 57, no. 3

187--199

PL

W niniejszej pracy przedstawiono wyniki badań siluminu z dodatkiem wanadu przeznaczonego do odlewania pod ciśnieniem. Jako stop wyjściowy zastosowano silumin podeutektyczny gatunku EN AC-46000. Do siluminu wyjściowego wprowadzano zaprawę AlV10 w ilości pozwalającej na uzyskanie zawartości wanadu w kolejno wytapianych siluminach po około 0,1; 0,2; 0,3; 0,4 i 0,5% wag. Badaniom poddano zarówno silumin wyjściowy, jak i siluminy zawierające wanad. Badania obejmowały analizę termiczną i derywacyjną (ATD) procesu krystalizacji, analizę metalograficzną mikrostruktury odlewów wykonanych w próbniku ATD i ciśnieniowych oraz określenie podstawowych właściwości mechanicznych siluminu odlewanego ciśnieniowo. Badania ATD wykazały wzrost temperatury początku krystalizacji siluminu oraz brak dodatkowych efektów cieplnych. Badania metalograficzne wykazały zmniejszenie średniej wielkości faz w mikrostrukturze stopu odlewanego do próbnika ATD. W siluminach zawierających 0,3; 0,4 i 0,5% wag. V zarówno płytkowe wydzielenia krzemu eutektycznego, jak i faz międzymetalicznych pochodzących z eutektyk charakteryzują się znacząco mniejszymi maksymalnymi wymiarami w porównaniu z siluminami o mniejszej zawartości V. W mikrostrukturze siluminów odlewanych pod ciśnieniem, które zawierają wanad powstają „nowe” fazy niewystępujące w siluminach niezawierających tego pierwiastka. Są to najprawdopodobniej fazy międzymetaliczne zawierające wanad. Wielkość wydzieleń tych faz rośnie wraz ze zwiększeniem zawartości wanadu w siluminie. Przeprowadzone badania podstawowych właściwości mechanicznych siluminów odlewanych pod ciśnieniem wykazały możliwość uzyskania większych wartości wytrzymałości na rozciąganie Rm, umownej granicy plastyczności Rp0,2 oraz twardości HB siluminów zawierających wanad w porównaniu z siluminami bez tego pierwiastka. Największe wartości: Rm = 248 MPa uzyskano w siluminie zawierającym około 0,3% wanadu; Rp0,2 = 113 MPa przy zawartości 0,1 i 0,2% oraz HB = 116 dla dodatku V około 0,2% wag. Względem siluminu bez dodatku V uzyskane wartości powodują podwyższenie Rm o 26%; Rp0,2 o 12% oraz HB o 7%.

EN

The paper presents the results of the study of Al-Si alloys with a vanadium addition used in pressure casting. The hypoeutectic Al-Si alloy grade EN AC-46000 was applied as the initial alloy. The master alloy AlV10 was introduced into the initial alloy in the amount making it possible to obtain the vanadium content in the consecutively melted Al-Si alloys of about 0.1; 0.2; 0.3; 0,4 and 0.5 wt. %. The tests were performed on both the initial Al-Si alloy and alloys containing vanadium. The investigations included a thermal and derivative (DTA) analysis of the crystallization process, a metallographic analysis of the microstructure of casts prepared in DTA tester and pressure casts, as well as the determination of the basic mechanical properties of the pressure cast Al-Si alloy. The DTA tests showed an increase in the temperature at the beginning of the Al-Si alloy crystallization and no additional thermal effects. The metallographic examinations demonstrated a decrease of the average phase size in the microstructure of the alloy cast in the DTA tester. In the Al-Si alloys containing 0.3; 0.4 and 0.5 wt. % V, both the lamellar precipitates of eutectic silicon and of the intermetallic phases originating in the eutectics were characterized by significantly lower maximal dimensions, compared to the Al-Si alloys with lower V contents. In the microstructure of the pressure cast Al-Si alloys, which contain vanadium, “new” phases may form, which did not occur in the Al-Si alloys without V. These are probably intermetallic phases containing vanadium. The size of these precipitates increases with the increase of the vanadium content in the Al-Si alloy. The performed tests of the basic mechanical properties of the pressure cast Al-Si alloys showed the possibility of obtaining higher values of tensile strength Rm, proof stress Rp0.2 and hardness HB of the Al-Si alloys containing vanadium, compared to the Al-Si alloys without this element. The highest values: Rm = 248 MPa were obtained in the Al-Si alloy containing about 0.3% vanadium; Rp0.2 = 113 MPa – with the content of 0.1, and 0.2% and HB = 116 for the V addition of about 0.2 wt. %. As regards the Al-Si alloy without a vanadium addition, the obtained values caused an increase of Rm by 26%; Rp0.2 by 12% and HB by 7%.

18

Hypoeutectic Al-Si Alloy with Cr, V and Mo to Pressure Die Casting

Szymczak T., Gumienny G., Stasiak I., Pacyniak T.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 1

153--156

EN

This paper presents the results of hypoeutectic 226 grade alloy as well as prepared on its basis Al-Si alloy containing Cr, V and Mo. The additives tested were added as AlCr15, AlV10 and AlMo8 master alloys. Alloys tested were poured into DTA sampler as well as using pressure die casting. An amount of Cr, V and Mo additives in alloy poured into DTA sampler comprised within the range approximately 0.05-0.35%. Alloys to pressure die casting contained 0.05-0.20% Cr, V and Mo. The crystallization process was examined using the derivative thermal analysis (DTA). The microstructure of castings made in the DTA sampler as well as castings made with use of pressure die casting were examined. The basic mechanical properties of castings made using pressure die casting were defined too. It has been shown in the DTA curves of Al-Si alloy containing approximately 0.30 and 0.35% Cr, Mo, and V there is an additional thermal effect probably caused by a peritectic crystallization of intermetallic phases containing the aforementioned additives. These phases have a morphology similar to the walled and a relatively large size. The analogous phases also occur in pressure die casting alloys containing 0.10% or more additions of Cr, V and Mo. The appearance of these phases in pressure die casting Al-Si alloys coincides with a decrease in the value of the tensile strength Rm and the elongation A. It has been shown die castings made of Al-Si alloys containing the aforementioned additives have a higher Rm and A than 226 alloy.

19

Wpływ molibdenu na proces krystalizacji, mikrostrukturę i właściwości siluminu 226

Szymczak T., Gumienny G., Pacyniak T.

Prace Instytutu Odlewnictwa

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2016

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Vol. 56, no. 3

193--204

PL

W niniejszym artykule przedstawiono wyniki badań siluminu podeutektycznego z dodatkiem molibdenu przeznaczonego do odlewania ciśnieniowego. Badania obejmowały analizę termiczną i derywacyjną procesu krystalizacji, analizę metalograficzną mikrostruktury odlewów wykonanych w próbniku ATD i ciśnieniowych oraz określenie podstawowych właściwości mechanicznych siluminu. Do badań przeznaczono silumin gatunku 226, który jest typowym siluminem do odlewania pod ciśnieniem. Do tego siluminu wprowadzano zaprawę AlMo8 w ilości pozwalającej na uzyskanie stężenia Mo w stopie po około 0,1; 0,2; 0,3; 0,4 i 0,5%. Badania procesu krystalizacji wykazały analogiczny przebieg krzywych ATD siluminu bez dodatku Mo oraz siluminów zawierających około 0,1; 0,2; 0,3 i 0,4% Mo. Wykazano zmianę w procesie krystalizacji badanego siluminu wywołaną zwiększeniem stężenia Mo do 0,5%. Zmiana ta polegała na wystąpieniu dodatkowego efektu cieplnego na krzywych ATD, który nie występował w siluminie bez dodatku Mo i siluminach o mniejszym jego stężeniu. W mikrostrukturze siluminu odlewanego do próbnika ATD zawierającego 0,3−0,5% Mo wystąpiły fazy, których nie obserwowano w stopach bez badanego dodatku i o mniejszym jego stężeniu. W odlewach ciśnieniowych fazy te wystąpiły we wszystkich badanych siluminach z dodatkiem Mo. Wymiary tych faz zwiększają się wraz ze wzrostem stężenia Mo w siluminie. Przeprowadzone badania podstawowych właściwości mechanicznych siluminów odlewanych pod ciśnieniem wykazały, że największą wartość wytrzymałości na rozciąganie Rm i wydłużenia względnego A uzyskano dla siluminu 226 z dodatkiem 0,4% Mo. Stanowi to wzrost Rm o 7,6% i A o 13,8% w ujęciu względnym w stosunku do siluminu 226 bez dodatku Mo. Największą wartość umownej granicy plastyczności Rp0,2 i twardości HB uzyskano dla siluminu 226 bez dodatku Mo.

EN

The article presents the results of studies of hypoeutectic silumin with a molybdenum addition used for pressure casting. The studies included a thermal-derivative analysis of the crystallization process, a metallographic analysis of the microstructure of casts made in a DTA tester and pressure casts, as well as the determination of the basic mechanical properties of the silumin. For the tests, silumin 226 was selected, which is a typical silumin for pressure casting. The AlMo8 master alloy was introduced into the silumin in an amount allowing the Mo concentration in the alloy to be about 0.1; 0.2; 0.3; 0.4 and 0.5%. The examination of the crystallization process showed an analogous course of the DTA curves of the silumin without the Mo addition and the silumins containing about 0.1; 0.2; 0.3 and 0.4% Mo. A change in the crystallization process of the examined silumin was established, caused by an increase of the Mo concentration to 0.5%. This change consisted in the occurrence of an additional thermal effect on the DTA curves, which did not take place in the silumin without the Mo addition or in the silumins with lower Mo concentrations. The microstructure of the silumin cast into the DTA tester with 0.3−0.5% Mo contained phases which were not observed in the alloys without the examined addition or with its lower concentrations. In the pressure casts, these phases were present in all the examined silumins with the Mo addition. The dimensions of these phases increase with the increase of the Mo concentration in the silumin. The performed studies of the basic mechanical properties of the silumins cast under pressure showed that the highest value of tensile strength Rm and unit elongation A were obtained for silumin 226 with the addition of 0.4% Mo. This constitutes an increase of Rm by 7.6% and of A by 13.8% in relative terms with respect to silumin 226 without the Mo adszczególdition. The highest values of yield strength Rp0.2 and hardness HB were obtained for silumin 226 without the Mo addition.

20

Analiza wtrąceń niemetalicznych w odlewach ze stopu AZ91 wykonanych z udziałem złomu obiegowego w procesie wysokociśnieniowego odlewania

Konopka Z., Chojnacki A.

Prace Instytutu Odlewnictwa

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2016

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Vol. 56, no. 4

321--328

PL

W artykule przedstawiono wyniki badań wpływu udziału złomu obiegowego we wsadzie stopu AZ91 na zmianę struktury odlewów wykonanych metodą wysokociśnieniowego odlewania, ze szczególnym uwzględnieniem tworzenia się wtrąceń niemetalicznych. Na podstawie obserwacji wtrąceń metodą mikroskopii skaningowej określono skład chemiczny tych wtrąceń w wytopach z różnym udziałem złomu obiegowego we wsadzie.

EN

The article presents research results of the process foundry return influence in the AZ91 alloy charge on the change in the structure of castings made by the high-pressure casting method, with special consideration of the formation of non-metallic inclusions. Based on the observations of inclusions by the scanning microscopy method, the chemical composition of the inclusions in melts with different process scrap contents in the charge was determined.