Wyniki wyszukiwania - BazTech

1

Study of Thermal Properties of Cast Metal-Ceramic Composite Foams

Gawdzińska K., Chybowski L., Przetakiewicz W.

Archives of Foundry Engineering

|

2017

|

Vol. 17, iss. 4

47--50

EN

Owing to its properties, metallic foams can be used as insulation material. Thermal properties of cast metal-ceramic composite foams have applications in transport vehicles and can act as fire resistant and acoustic insulators of bulkheads. This paper presents basic thermal properties of cast and foamed aluminum, the values of thermal conductivity coefficient of selected gases used in foaming composites and thermal capabilities of composite foams (AlSi11/SiC). A certificate of non-combustibility test of cast aluminum-ceramic foam for marine applications was included inside the paper. The composite foam was prepared by the gas injection method, consisting in direct injection of gas into liquid metal. Foams with closed and open cells were examined. The foams were foaming with foaming gas consisting of nitrogen or air. This work is one of elements of researches connected with description of properties of composite foams. In author's other works acoustic properties of these materials will be presented.

2

Examination of Electrical Resistance of Carburizers Used for Cast Iron Production

Książek D., Koza M., Bieroński M., Krasa O., Kuś R.

Archives of Foundry Engineering

|

2016

|

Vol. 16, iss. 4

65--68

EN

The publication presents the results of examination of selected carburizers used for cast iron production with respect to their electric resistance. Both the synthetic graphite carburizers and petroleum coke (petcoke) carburizers of various chemical composition were compared. The relationships between electrical resistance of tested carburizers and their quality were found. The graphite carburizers exhibited much better conductivity than the petcoke ones. Resistance characteristics were different for the different types of carburizers. The measurements were performed according to the authors’ own method based on recording the electric current flow through the compressed samples. The samples of the specified diameter were put under pressure of the gradually increased value (10, 20, 50, 60, and finally 70 bar), each time the corresponding value of electric resistance being measured with a gauge of high accuracy, equal to 0.1μΩ. The higher pressure values resulted in the lower values of resistance. The relation between both the thermal conductance and the electrical conductance (or the resistance) is well known and mentioned in the professional literature. The results were analysed and presented both in tabular and, additionally, in graphic form.

3

Materials Used in the Automotive Industry

Orłowicz A. W., Mróz M., Tupaj M., Trytek A.

Archives of Foundry Engineering

|

2015

|

Vol. 15, iss. 2

75--78

EN

Elaborated shapes of many car components are the reason for which the use of casting techniques to fabricate them is a solution wellfounded from the economical point of view. Currently applicable regulatory requirements concerning emissions of exhaust fumes force the carmakers to reduce the overall weight of their products, as this is a basic precondition for reducing fuel consumption. As a result, newly launched car models contain a continuously increasing share of thin-walled castings made of materials which ensure a satisfactory level of service properties. At the same time, developing new technological processes allowing to extend the service life of individual components by means of surface improving becomes more and more important.

4

Nowoczesne materiały kompozytowe zastępujące tradycyjne materiały odlewnicze

Mierzwa P., Olejnik E., Janas A.

Archives of Foundry Engineering

|

2012

|

Vol. 12, iss. 1s

137--142

PL

W pracy przedstawiono możliwość przekształcenia klasycznych materiałów odlewniczych w kompozyty in situ. Materiały te znajdują coraz szersze zastosowanie w różnych gałęziach przemysłu, a szczególnie w przemyśle wydobywczym. Przekształcenie stopu klasycznego w materiał kompozytowy, wpływa wyraźnie na poprawę jego właściwości mechanicznych. W wyniku przeprowadzonych badań uzyskano nowy materiał inżynierski, który wytworzono metodą syntezy objętościowej z wykorzystaniem reakcji SHSB. Zastosowana metoda pozwala umocnić klasyczne materiały odlewnicze zarówno lokalnie, jak również objętościowo. Umocnienie to polega na syntezie cząstek ceramicznych w kąpieli metalowej, bezpośrednio w jednoetapowym procesie odlewniczym. Materiałem wyjściowym do badań było staliwo manganowe, które w wyniku przeprowadzonej reakcji syntezy, przekształcono w kompozyt typu MMCs. Fazą wzmacniającą nowego materiału były ceramiczne cząstki węglika tytanu. Prezentowane w niniejszej pracy wyniki, wskazują na znaczną poprawę zarówno właściwości mechanicznych, jak i użytkowych otrzymanego materiału kompozytowego, dotyczy to takich parametrów, jak twardości i odporności na ścieranie.

EN

The study presents an opportunity to transform the traditional casting materials into in situ composites, the latter ones being currently used on a growing scale in various sectors of the industry, especially in the extractive industries. The transformation of standard alloy into a composite considerably improves the mechanical properties. As a result of the experiment, a new engineering material was produced by the method of bulk synthesis and an SHSB reaction. The method enables hardening of the traditional casting materials, both locally and in the whole volume of the material. The hardening is obtained by the synthesis of ceramic particles in a metal bath, directly in a one-step casting process. The starting material for research was cast manganese steel which, as a result of the reaction of synthesis, was converted into an MMCs type composite. The reinforcing phase in the new material were ceramic particles of titanium carbide. The results presented in this paper show a significant improvement in both mechanical and performance properties of the composite material obtained, this also applying to parameters such as hardness and abrasive wear resistance.

5

The influence of copper on the microstructure and selected parameters of duplex cast steel

Stradomska J., Stachura S., Stradomski Z., Soiński M. S.

Archives of Foundry Engineering

|

2009

|

Vol. 9, iss. 1

87-90

EN

Technological problems related to mastering the production of castings made of ferritic-austenitic cast steel (duplex type), i.e problems related to low carbon content (Cmax 0.03%) and high hot cracking susceptibility due to phenomena taking place during solidification and cooling of castings, cause that this material, although attractive due to its price and improving company prestige, is rarely produced in Poland. The undertaken attempts have mainly dealt with GX2CrNiMoCu25-6-3-3 grade containing copper due to the requirements of power industry which is the main possible customer with respect to the elements made of duplex cast steel. The authors of this paper have thought it reasonable to present selected aspects of microstructural and mechanical properties for the two cast steel grades described in the PN-EN 10283:2002 Standard, which differ only by Cu addition. The examinations concerned mainly the as-cast condition, because it is decisive for the defective production. It has been shown that the weak austenite-forming copper exerts a strong influence on the primary structure of cast steel, resulting in precipitating the [...] austenite within ferrite, where the austenite is crystallographically dependent on the matrix. The GX2CrNiMoCu25-6-3-3 cast steel in supersaturated state is characterised by Charpy V-notch impact energy lower by about 30% than for the cast steel grade without Cu addition.

6

The analysis of solidification process of ferritic-austenitic cast steel

Stradomska J., Stradomski Z., Soiński M. S.

Archives of Foundry Engineering

|

2009

|

Vol. 9, iss. 1

83-86

EN

One of the most common defects leading to the rejection of faulty castings made of duplex cast steel is hot cracking. Hot cracking - differently from cold cracking which occur on cooling, when the material exhibits already distinct elastic properties - proceeds in the semi-solid state, particularly when the temperature of solidifying casting is close to the equilibrium solidus point. There exist a range of temperatures in the vicinity of the solidus point within which the solidifying metal shows very small deformation ability and small strength. Therefore even little stresses occurring at the solidification stage and caused by density difference between ferrite and austenite, or restricted shrinkage, or various temperature gradients, can be the reason of hot cracking. Copper addition, as it is used in cast steel grades implemented in Polish power industry applications, decreases the temperature of the end of solidification, thus affecting beneficially the surface reproduction quality, but on the other hand it can promote, along with several other elements contained in duplex cast steel, the peritectic transformation during the last stage of solidification. The presence of peritectic solidification, i.e. strictly speaking the structural stresses accompanying that process, is the well-known and significant reason of the increased steel defectiveness in the continuous steel casting (CSC) technology if the steel with carbon content promoting the peritectic transformation is processed. The authors have presented the examination results of the solidification phenomenon for two duplex cast steel grades - one without copper addition, and the other with addition of about 3.0% Cu.

7

Effect of additives promoting the formation of lustrous carbon on the knocking out properties of foundry sands with new inorganic binders

Izdebska-Szanda I., Stefański Z., Pezarski F., Szolc M.

Archives of Foundry Engineering

|

2009

|

Vol. 9, iss. 1

17-20

EN

The article presents the results of investigations, which make a fragment of the broad-scale studies carried out as a part of the statutory activity on optimising the foundry sand technology using new, modified, inorganic binders. The results of investigations regarding the effect of lustrous carbon carriers on the technological properties of foundry sands with inorganic binders were presented in a concise manner. The selected additives were introduced to moulding sands prepared with the new, modified, inorganic binders bonded by the chemical reaction or by blowing with gaseous CO2. Attention was focussed on the effect of selected additives promoting the formation of lustrous carbon on the knocking out properties of moulds and cores prepared from sands with the new types of inorganic binders. The quality of the test castings was also evaluated along with the tendency to the formation of lustrous carbon at the metal - mould interface, basing on the results of microscopic examinations and analysis of the chemical composition using an X-ray microanalyser.

8

Determination of application possibilities of microwave heating in the curing process of water glass molding sands with fluid esters. Part 2

Granat K., Nowak D., Pigiel M., Stachowicz M., Wikiera R.

Archives of Foundry Engineering

|

2009

|

Vol. 9, iss. 1

51-56

EN

This article, constituting continuation of the subject discussed in the first part, presents results of the experimental trial of water glass molding sands' curing method modification with application of fluid esters and innovative microwave heating. The research objective was to determine possibilities of microwave application for curing of water glass molding sands prepared with addition of hardening agents sold under the trade name of Mach. After initial chemical curing molding sands, prepared with addition of the above mentioned hardeners, have been heated with microwaves in order to determine their influence on changes of basic technological and strength parameters of the sands, and indirectly on the quality of quartz grains binding. Studies aimed at determination of water content changes in the sands have also been undertaken. As our studies demonstrated, microwave heating allows for quick reduction of water content, thus resulting in improvement of strength parameters such as bending and tensile strength. Application of the combined methods of ester curing and innovative microwave heating facilitates production of high quality foundry moulds and cores, while simultaneously improving mould and core preparation procedures at the foundries and as a result reduces their time to an indispensable minimum.

9

Determination of application possibilities of microwave heating in the curing process of water glass molding sands with fluid esters. Part 1

Granat K., Nowak D., Pigiel M., Stachowicz M., Wikiera R.

Archives of Foundry Engineering

|

2009

|

Vol. 9, iss. 1

45-50

EN

This article presents results of the experimental trial of combination of the chemical method of water glass molding sands' curing, used in foundry industry, with an innovative microwave heating. The research objective was to indicate at new areas of microwave energy application. The sands prepared, according to recommendations for curing technology, with the use of ethylene glycol diacetate, have been subject to microwave influence. The attempt at determination of microwave influence on qualitative changes of the binding bridges created during the curing process concerned such parameters as: bending and tensile strength, permeability as well as wear resistance. Moreover, we also determined the influence of microwave curing on the phenomena accompanying the process as well as bond stability (storage time of the prepared molding and core sands). It has been found, basing on the result analysis, that the innovative microwave heating might constitute a very good supplementation of the ester curing method. The advantages of the combined chemical and microwave gelation process include, among others, improvement of the described resistance and technological parameters as well as significant decrease of preparation time of foundry moulds and cores. The subject discussed in this article will be continued in its second part.

10

Standaryzacja badań pneumatycznej klasyfikacji materiałów ziarnistych

Fedoryszyn A.

Archiwum Odlewnictwa

|

2002

|

R. 2, nr 5

48--55

PL

W referacie przedstawiono problematykę standaryzacji procedur badawczych klasyfikacji ziarnistych materiałów na przykładzie piasków odlewniczych. Omówiono zakres ustaleń dotyczących analizy sitowej. Podano warunki własnych badań rozdziału ziaren w strumieniu powietrza. Omówiono sposób opracowania wyników klasyfikacji pneumatycznej bazujący na procedurach z analizy sitowej.

EN

In the paper some problems of classification research procedure standardization of grain materials have been presented. As example the classification process of foundry quartz sand has been taken into account. The range of determination concerning sieve analysis has been described. The own research conditions of grains classification in air stream as well as the method of results elaboration based on sieve analysis procedures have been described.