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Number of results: 7
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Abstract

The demand for castings of high quality and sound work is nowadays very high. The production of sound castings without foundry errors is the big issue in modern foundries. Foundry simulation software can do a lot to help improve the disposition of castings, gating system and feeder system, and assure good filling and solidification conditions, and also produce sound casting without the need of the old method of "try and error". One can easily change a lot of parameters for filling and solidification, and create the best proposal for production. Connor inlets have two functions. One is that it serves as an ingate, through which molten metal passes and comes into the mould cavity. The second function is that it serves as a feeder and substitutes the metal contracted during solidification and cooling of the castings. It can also save quite a lot of metal in comparison to classic feeders.

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Authors and Affiliations

D. Fecko
I. Vasková
Ľ. Eperješi
M. Závodný
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Abstract

The herein paper contains the results of investigations on a new type of cellulose blend used for the manufacture of profiles applied in the

process of making gating systems in the foundry industry. A standard cellulose profile was subjected to an experiment. During the

experiment the profile was filled with a liquid cast iron and at the same time the temperatures of the liquid metal crystallizing inside the

profile were measured as well as the temperature of the outer layer of the profile was controlled. Further, the microstructure of the cast

iron, which crystallized out inside the cellulose profile, was analysed and the cellulose, thermally degraded after the experiment, was

verified with the use of the chemical analysis method. Moreover, a quality analysis of the original as well as the degraded cellulose profile

was run with the use of the FTIR infrared spectroscopy. The presented results revealed that the cellulose blend is aluminium silicate

enriched and contains organic binder additives. The cast iron, which crystallized out, tended to have an equilibrium pearlitic structure with

the release of graphite and carbides. The generation of disequilibrium ausferrite phases was also observed in the structure.

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Authors and Affiliations

J. Sawicki
G. Gumienny
Z. Zawieja
A. Sobczyk-Guzenda
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Abstract

The objective of the study reported in this paper was to determine the effect of structure on thermal power of cast-iron heat exchangers which in this case were furnace chambers constituting the main component of household fireplace-based heating systems and known commonly as fireplace inserts. For the purpose of relevant tests, plate-shaped castings were prepared of gray iron with flake graphite in pearlitic matrix (the material used to date typically for fireplace inserts) as well as similar castings of gray cast iron with vermicular graphite in pearlitic, ferritic-pearlitic, and ferritic matrix. For all the cast iron variants of different structures (graphite precipitate shapes and matrix type), calorimetric measurements were carried out consisting in determining the heat power which is quantity representing the rate of heat transfer to the ambient environment. It has been found that the value of the observed heat power was affected by both the shape of graphite precipitates and the type of alloy matrix. Higher thermal power values characterize plate castings of gray iron with vermicular graphite compared to plates cast of the flake graphite gray iron. In case of plates made of gray cast iron with vermicular graphite, the highest values of thermal power were observed for castings made of iron with ferritic matrix.

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Authors and Affiliations

Marek Mróz
ORCID: ORCID
A.W. Orłowicz
ORCID: ORCID
M. Tupaj
ORCID: ORCID
M. Jacek-Burek
M. Radoń
M. Kawiński
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Abstract

The paper presents the results of investigations concerning the influence of gray cast iron modification on free vibration frequency of the disc casting. Three different chemical composition melts of gray cast iron were prepared in induction furnace. During gravity casting 0.05% and 0.3% mass of the Inolate modifier was added on stream of metal for changing graphite flakes in castings. Sound signal vibration of cast iron sample was registered by means on microphone for free vibration frequency measurements. Decreasing of free vibration frequency of modified cast iron in comparison with non modified castings was observed. Higher contents of modifier causes more decreasing of free vibration frequency. Cast iron with smaller contents of carbon and silicon have higher free vibration frequency in comparison with eutectic composition cast iron. Hardness of examined cast iron is lower when the more modifier is added during modification process. Free frequency is smaller with smaller Brinell hardness of disc casting. It was concluded that control of free vibration frequency of disc castings by means of chemical composition and modification process can improved comfort and safety of working parts.

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Authors and Affiliations

Z. Konopka
Małgorzata Łągiewka
ORCID: ORCID
A. Zyska
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Abstract

The article considers the method of obtaining reinforced castings from gray cast iron by lost foam casting. The aim of this study was to determine the microstructure formation of gray cast iron reinforced with inserts of carbon and stainless steel in this casting method. The results of the research have shown that the products of destruction of expanded polystyrene have a positive effect on the bonding formation of cast iron with reinforcing inserts. When steel wire is used as reinforcement, a decarbonized layer of cast iron is being formed around it, in which the inclusions of graphite are smaller and their quantity is less than in the main metal. Due to carburization, the surface structure of the reinforcement changes from ferrite to pearlite with cementite. Steel wire reinforcement can be effective in increasing strength and toughness of gray cast iron. The usage of stainless steel reinforcement leads to the formation of a transition layer on the part of the matrix metal. It contains ledeburite with dissolved chromium, which increase the wear resistance of cast iron.
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Authors and Affiliations

Pavlo Kaliuzhnyi
1
Inna Shalevska
1
ORCID: ORCID
Vadym Sliusarev
1
ORCID: ORCID

  1. Department of Physical Chemistry of Foundry Processes, Physico-Technological Institute of Metals and Alloys of the National Academy of Sciencesof Ukraine, Ukraine
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Abstract

The article presents the influence of the percentage share of pig iron and steel scrap on the chemical composition, physicochemical and mechanical properties. Using an induction furnace, 6 melts were carried out with a variable amount of pig iron in the charge from 0 to 50%. For carburizing, a RANCO 9905 carburizer with a carbon content of 99.2% was used. After melting and introducing FeSi75, temperature measurement was carried out and the metal was superheated to 1500°C. The next step was to pour the samples for chemical analysis, DTA (Derivation Thermal Analysis) and strength and hardness from the melting furnace without inoculation. The last step was to carry out the inoculation by introducing 0.3% barium inoculant into the vat and pouring samplers for DTA analysis. The inoculation was carried out solely to determine changes in DTA parameters, mainly Temin, compared to castings without inoculation.
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Authors and Affiliations

R. Dwulat
1 2
ORCID: ORCID
K. Janerka
2
ORCID: ORCID
K. Grzesiak
1
M. Gałuszka
2

  1. Foundry Lisie Kąty, Lisie Kąty 7, 86-302 Grudziądz
  2. Department of Foundry Engineering, Silesian University of Technology, Towarowa 7, 44-100 Gliwice
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Abstract

The paper presents the results of calculations and measurements of the first natural frequency of castings of solid and ventilated brake discs made of gray cast iron of the EN-GJL-200 class. The tests were carried out for three types of chemical composition, taking into account the permissible minimum and maximum content of alloying elements. Numerical simulations of natural vibrations were carried out on the basis of our own production material databases. To determine the elastic properties of cast iron, the ultrasonic method with the measurement of the propagation velocity of longitudinal and transverse waves was used. Measurements were made directly on casts of raw discs of various thicknesses. The values of Young's modulus and Poisson's number calculated from ultrasonic measurements were used to define the stiffness matrix in the equilibrium equation, which is solved by the solver of the MSC Nastran program. A high compatibility between the results of numerical simulations and the results of experimental FRF frequency analysis was obtained. The differences between the calculated and actual values were at the level of several hertz, while the estimated average error of numerical simulations was 0.76%. It was also found out that cast iron melts for brake discs must be subject to strict control in terms of chemical composition. Slight deviations of the eutectic saturation coefficient from the optimal value cause a significant change in the first natural frequency of the brake discs, regardless of their geometry.
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Bibliography

[1] Zagrajek, T., Krzesiński, G., Marek, P. (2006). Finite element method in structural mechanics. Warszawa: Oficyna Wydawnicza Politechniki Warszawskiej. (in Polish).
[2] Qatu, M.S., Abdelhamid, M.K., Pang J. & Sheng, G. (2009). Overview of automotive noise and vibration. International Journal of Vehicle Noise and Vibration. 5(1-2), 1-35. https://doi.org/10.1504/IJVNV.2009.029187.
[3] Lü, H. & Yu, D. (2014). Brake squeal reduction of vehicle disc brake system with interval parameters by uncertain optimization. Journal of Sound and Vibration. 333(26), 7313-7325. https://doi.org/10.1016/j.jsv.2014.08.027.
[4] Yoon, J., Park, J. & Min, S. (2022). Optimal disc brake design for reducing squeal instability using slip-dependent complex eigenvalue analysis. Mechanical Systems and Signal Processing. 177, 109240. https://doi.org/10.1016/j.ymssp. 2022.109240.
[5] Liu, P., Zheng, H., Cai, C., Wang, Y.Y., Lu, C., Ang, K.H. & Liu G.R. (2007). Analysis of disc brake squeal using the complex eigenvalue method. Applied Acoustics. 68(6), 603-615. https://doi.org/10.1016/j.apacoust.2006.03.012.
[6] Sinou, J.-J. (2010). Transient non-linear dynamic analysis of automotive disc brake squeal – On the need to consider both stability and non-linear analysis. Mechanics Research Communications. 37(1), 96-105. https://doi.org/10.1016/ j.mechrescom.2009.09.002.
[7] Nouby, M., Mathivanan, D. & Srinivasan, K. (2009). A combined approach of complex eigenvalue analysis and design of experiments (DOE) to study disc brake squeal. International Journal of Engineering, Science and Technology. 1(1), 254-271. DOI: 10.4314/ijest.v1i1.58084 .
[8] Armstrong, P.E., in: R.F. Bunshan (Ed.) (1971). Measurement of Mechanical Properties, Techniques of Metals Research. vol. V (Part 2). New York: Wiley.
[9] Radovic, M., Lara-Curzio, E., Riester, L. (2004). Comparison of different experimental techniques for determination of elastic properties of solids. Materials Science and Engineering A. 368(1-2), 56-70. https://doi.org/10.1016/ j.msea.2003.09.080.
[10] Migliori, A., Sarrao, J.L. (1997). Resonant Ultrasound Spectroscopy: Applications to Physics. Materials Measurements and Nondestructive Evaluation. , New York: Wiley.
[11] Wadsworth, H.M. (1990). Handbook of Statistical Methods for Engineers and Scientists. New York: Mc-Graw-Hill.
[12] WT/054/PIMOT/93 (1993). Brake discs of motor vehicles. Security requirements. (in Polish).
[13] Wehr, J. (1972). Measurements of the speed and attenuation of ultrasonic waves. Warszawa: PWN.
[14] Konopka, Z., Łągiewka, M. & Zyska, A. (2020). Influence of cast iron modification on free vibration frequency of casting. Archives of Foundry Engineering. 20(1), 23-26. DOI: 10.24425/afe.2020.131277.
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Authors and Affiliations

Andrzej Zyska
1
ORCID: ORCID
Mariusz Bieroński
2
ORCID: ORCID

  1. Department of Metallurgy and Metal Technology, Czestochowa University of Technology, Al. Armii Krajowej 19, 42-200 Częstochowa, Poland
  2. Brembo Poland Sp. z o.o., ul. Roździeńskiego 13, 41-308 Dąbrowa Górnicza

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