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1
Content available Defects analysis of seat belt tensioner cast body
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.
PL
W artykule przedstawiono podstawowe informacje o założeniach projektu dotyczącego opracowania i wykonania kompleksowej linii produkcyjnej odlewy ciśnieniowe o znacząco obniżonej porowatości.
EN
The basie information concerning the assumptions of the project of designing and development the complex production line of die castings of a significantly decreased porosity, are presented in the hereby paper.
EN
This article is the effect of industrial work and many surveys in the one of the Polish foundries that specialize in aluminum alloys. The main goal of our explorations is to evaluate the influence of manganese on Al-Si alloy properties. In die-cast alloys, it is recommended to use larger amounts of iron to reduce the impact on the pressure chamber and mold. Manganese neutralizes the harmful effect of iron by changing the morphology of the separated brittle ferrous phases. The unfavorable form of the iron-containing phases in the form of long needles changes into the forms of fine compact crystals, which are less harmful to the mechanical properties. Nowadays, the main client requirement is to obtain the right parameters at the best price. Specifically, the customer is in the automotive industry, where new technologies provide a connection between the high quality and low weight of car parts [1–3].
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.
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%.
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%.
EN
There is an increasing interest in casting pressure elements in the automotive and household industry. Mechanical properties, implementation precision and quality play major role here. Unfortunately, this manufacturing technology is accompanied with disadvantageous features of the material structure as porosity, which must be controlled during production. On the basis of comparative studies of three selected research methods the most optimal research method for this group of products and materials was selected. It is a technique based on acoustic microscopy which, allows for the research of large components in the X and Y axes and a relatively high Z-axis. The research enables an analysis of all components without necessity of cutting a product into smaller elements subjected to separate analysis.
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.
PL
W artykule zaprezentowano wyniki badań wpływu wybranych parametrów odlewania na strukturę odlewów, wykonanych pod wysokim ciśnieniem na maszynie odlewniczej firmy BÜHLER typ H630-B, ze stopu AlSi9Cu3 z grupy EN AB-46000 przy zmiennych parametrach pracy tłoka. Badania przeprowadzono na odpowiednio przygotowanych próbkach pobranych z odlewów wspornika oparcia foteli. Do oceny struktury odlewów zastosowano skaningowy mikroskop elektronowy, którego oprogramowanie EDS pozwala na określenie składu stopu wraz z uwzględnieniem rozmieszczenia pierwiastków oraz przeprowadzono pomiary twardości odlewów i mikrotwardości składników struktury. Po przeprowadzeniu serii badań dokonano oceny struktury na zgładach metalograficznych próbek odlewów wykonanych przy zmiennych parametrach zalewania, w trakcie II i III fazy odlewania ciśnieniowego. Stwierdzono, że przy małych prędkościach tłoka krystalizują większe wydzielenia charakteryzujące się bardzo dużą twardością. Zwiększanie prędkości tłoka powoduje rozdrobnienie struktury wyrobu, jednakże zmniejszenie ciśnienia intensyfikacji III fazy wpływa na spadek twardości odlewu.
EN
The article presents the results of investigations of the effect of selected casting parameters on the structure of casts made under high pressure by means of the casting machine produced by BÜHLER, type H630-B, out of the AlSi9Cu3 alloy from the EN AB-46000 group, with varying parameters of the piston operation. The investigations were performed on appropriately prepared specimen sampled from casts of an armchair back bracket. For the evaluation of the cast structure a scanning electron microscope was used, whose EDS software allows for determining the composition of the alloy with the consideration of the distribution of the elements. Also, measurements of the cast hardness and the structure component microhardness were performed. After a series of tests, evaluation of the structure of the microsections of the samples of casts made with varying casting parameters, during phase II and III of the pressure casting process, was performed. It was established that, at low piston rates, larger precipitations crystallize, which were characterized by very high hardness. Increasing the piston rate causes refinement of the product structure; however, decreasing the pressure of intensification of phase III leads to a drop of the cast hardness.
10
Content available remote Characteristics of titanium Grade 2 and evaluation of corrosion resistance
EN
Purpose: The paper attempts to improve the properties of titanium Grade 2 by the use of the injection casting method with rapid cooling. Design/methodology/approach: Microstructural observations by using an optical microscope, microhardness studies, X-ray qualitative analysis as well as corrosion resistance tests were carried out. Corrosion resistance tests were conducted by measuring the open circuit potential and measuring the resistance to corrosion by the method of anodic polarization curves in a potential range close to the corrosion potential. Findings: Studies have shown that the application of the abovementioned preparation method affect the microstructure of the finished item. There has been a fragmentation of the structure and the formation of dendrites. Those changes have improved corrosion resistance and increase microhardness. There were no changes in the phase composition. Research limitations/implications: Studies were performed only in the Ringer's solution indicating a potential use of this material as a biomaterial. Further research should be conducted in more aggressive environments especially for the energy industry and chemical industry. Practical implications: The application of injection casting carries some complications, which mainly relate to quartz capillary where ingot is melted. Titanium as a reactive element strongly absorbs silicon out of the capillary causing changes in the chemical composition in the surface layer of the final element. The addition of silicon in the surface layer may affect on obtained results. Originality/value: Using the production method indicates its use in future in many industries.
EN
The paper presents the use of rapid prototyping technology of three dimensional printing (3DP) to make a prototype shell casting mold. In the first step, for identification purposes, a mold was prepared to enable different alloys to be cast. All molds being cast were designed in a universal CAD environment and printed with the zp151 composite material (Calcium sulfate hemihydrate) with a zb63 binder (2-pyrrolidone). It is designated to be used to prepare colourful models presenting prototypes or casting models and molds. The usefulness of 3DP technology for use with copper alloys, aluminum and zinc was analyzed. The strength of the mold during casting was assumed as a characteristic comparative feature in the material resistance to high temperature, the quality of the resulting casting and its surface roughness. Casting tests were carried out in vacuum – pressure casting. The casting programs applied, significantly increased the quality of castings and enabled precise mold submergence. Significant improvement was noted in the quality compared to the same castings obtained by gravity casting.
PL
W opracowaniu przedstawiono opis przebiegu uruchomienia produkcji odlewu ciśnieniowego ze stopu aluminium (ALSi), stanowiącego element konstrukcyjny bocznego lusterka wstecznego do nowej wersji samochodu Volkswagen Passat.
EN
The work presents the results of the examinations of silumin 226 as well as a silumin produced on its basis containing a W and Mo addition introduced in the amount of 0.1; 0.2; 0.3 and 0.4% of both elements simultaneously. Investigations of the crystallization process of the silumins by the TDA method were conducted. Also, a microscopic analysis of their microstructure was performed and their basic mechanical properties were determined. Microstructure tests were made on casts produced in an TDA sampler as well as by the pressure method. The investigations exhibited a change in the course of crystallization of the silumin containing 0.3 and 0.4% W and Mo with respect to silumin 226 and the silumin with the addition of 0.1 and 0.2%. The presence of additional phases which did not occur in the case of lower addition contents was established in the silumin containing 0.3-0.4% W and Mo, regardless of the applied casting technology. The tests showed the possibility of increasing the tensile strength Rm, the proof stress Rp0,2 and the unit elongation A of the silumin as a result of a simultaneous introduction of the W and Mo addition. The highest values of Rm, Rp0,2 and A were obtained in the silumins with the additions of these elements within the range of 0.1-0.2% each.
EN
The work presents the effect of strontium and antimony modification on the microstructure and mechanical properties of 226 silumin casts. The performed research demonstrated that strontium causes high refinement of silicon precipitations in the eutectic present in the microstructure of the examined silumin and it significantly affects the morphology of eutectic silicon from the lamellar to the fibrous one. Sr modification also causes an increase of: the tensile strength „Rm” by 12%; the proof stress „Rp0,2” by 5%; the unit elongation „A” by 36% and the hardness HB by 13%. Antimony did not cause a change in the microstructure of the silumin, yet it caused an increase in Rm and HB by 5%, in Rp0,2 by 7% and in A by 4%.
15
EN
The work presents the results of the investigations of the effect of the nitrogen (N2) refining time „traf” and the gas output on the course of the crystallization process, the microstructure and the gassing degree of silumin 226 used for pressure casting. The refinement of the examined silumin was performed with the use of a device with a rotating head. The crystallization process was examined by way of thermal analysis and derivative analysis TDA. The performed examinations showed that the prolongation of the N2 refining time causes a significant rise of the temperature of the crystallization end of the silumin, „tL”, as well as a decrease of its gassing degree, „Z”. An increase of the nitrogen output initially causes an increase of the temperature „tL” and a drop of the gassing degree „Z”, which reach their maximal values with the output of 20 dm3/min. Further increase of the output causes a decrease of the value „tL” and an increase of „Z”. The examined technological factors of the refining process did not cause any significant changes in the microstructure of silumin 226.
EN
There is a continuous demand for high performance composite propellant formulations to meet future requirements. The performance of composite propellant formulations can be enhanced by the addition of energetic oxidizers, like ADN/HNF as well as an energetic binder & a plasticizer. However, on incorporation of energetic ingredients, the composition becomes sensitive, and thus processing, handling and transportation pose a greater threat. Therefore, a moderately high burn rate composition having a burn rate ~ 13-14 mmźs -1 at 7000 kPa was tailored by increasing the solid loading of the propellant from 85.15% to 87.27% with the help of ammonium perchlorate and process aids without affecting the burn rate and mechanical properties. The tailored composition was studied for different properties such as end of mix viscosity, density, mechanical & ballistic properties. The evaluated data reveal that the end of mix viscosity of the tailored composition is higher than the base composition, i.e., 672 Paźs and 2340 Paźs at the same temperature; however, this viscosity was castable using a pressure casting technique. The properties of the cured propellant reveal that there is an enhancement of density from 1.74 gźcm -3 to 1.79 gźcm -3 with no other changes in mechanical properties. The performance index of the tailored composition has been increased from 416 to 437, well supported by results of ballistic evaluation motors of 2 kg.
PL
Celem pracy była ocena szczelności odlewów ciśnieniowych wykonanych ze stopu Z41 po obróbce mechanicznej oraz po zabiegu impregnacji odlewów nieszczelnych. Ocenę prowadzono za pomocą specjalistycznego oprzyrządowania do badania szczelności oraz na podstawie zdjęć mikroskopowych elementów pracujących w eksploatacji pod ciśnieniem sprężonego powietrza. Badane odlewy produkowane są technologią odlewania ciśnieniowego na pionowej maszynie zimnokomorowej. Zakres badań obejmował wytworzenie odlewów w jednej z krajowych odlewni, badanie szczelności, zabiegi impregnacji nieszczelnych odlewów oraz ocenę struktury na podstawie badań mikroskopowych.
EN
Evaluation of pressuretightness of pressure castings made of a Z41 alloy after mechanical processing and impregnation treatment of leaky castings was the purpose of the work. Evaluation was conducted using specialized equipment for leak testing and basing on microscopic images of elements working under the operating air pressure. Tested castings were produced by pressure casting technology in cold chamber vertical machine. The domain of study included manufacturing of castings in one of the national foundries, pressuretightness test, impregnation treatment and evaluation of the structure on the basis of microscopic examination.
EN
The results of investigation of structure stability of the AlSi6Cu4 matrix alloy and composites with graphite particles at elevated temperatures were presented. Composites and matrix alloy were prepared by squeeze casting method and then they were annealed at 573 K and 673 K during 1, 20, 100, 500, and 1000 hours. The structures of composites and matrix alloy were observed and compared after annealing. Changes in the structure both in matrix alloy and composite were stated at both temperatures. These changes are characterised by the change in morphology of eutectic silicon, which needle-like grains turn into spheroids. The spheroidization starts in the pure alloy after 500 hours of annealing at 573 K and after 300 hours of annealing at 673 K. The changes occur sooner in the composite than in matrix alloy: they can be stated after 100 hours of annealing at 573 K, while at 673 K they started between 50 and 100 hours. The change in the morphology of eutectic silicon takes place faster along and among the graphite particles than in particle-free regions of composite. The matrix/graphite interface was found to be free of reaction products (Al4C3 and others).
EN
Results of examination of the AlSil2Cu2 alloy mechanical properties achieved by pressure casting with use of horizontal cold chamber machine employing the “full sleeve” construction at various process parameters have been presented. Both the piston velocity during injection and the intensification pressure have been changed according to the factor experiment design. Regression relationships between mechanical properties of alloy and the variable parameters of casting have been found both for the conventional method and for the “full sleeve” construction. The analysis of results points to an increase in strength and plastic properties of the investigated alloy cast by the “full sleeve” method as compared with these properties for the alloy cast by conventional method. A strong influence of plunger velocity and pressure on the examined properties of castings produced by the two methods has been stated.
PL
W pracy omówiono wpływ warstewki powierzchniowej tworzącej się podczas drążenia elektroiskrowego form wtryskowych na ich skłonność do uszkodzeń. Przeanalizowano również rolę mikrostruktury stali stosowanej na formy wtryskowe w ich mechanizmie zużywania się ze szczególnym uwzględnieniem morfologii wąglików pierwotnych i wtórnych. Badania wykonano na zużytych częściach form wtryskowych stosowanych przy produkcji elementów zamków błyskawicznych ze stopu ZnAl4Cu1. Zaproponowano sposoby modyfikacji tworzywa na elementy form wtryskowych oraz technologii produkcji takich form, które powinny umożliwić zwiększenie wydajności produkcji.
EN
In the presented work the effect of subsurface (white) layer formed upon spark machining, on wear susceptibility to damage of injection moulds is discussed. The role of microstructure in wear mechanism of steel applied for injection moulds was additionally analysed with special attention paid to the morphology of carbides. The investigations were performed on the worn out parts of injection moulds applied for production of zip-fastener elements made of ZnAl4Cu1 alloy. Methods for modification of production technology and material applied for elements of injection moulds are proposed.
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