Effect of Temperature on Chromite-Based Moulding Sands Bonded with Sodium Silicate

• Autorzy: Stachowicz M. , Kamiński M. , Granat K. , Pałyga Ł.

Identyfikatory

DOI

DOI: 10.1515/afe-2017-0058

• Języki publikacji: EN

Abstrakty

EN

In the paper, a research on effects of baking temperature on chromite sand base of moulding sands bonded with sodium silicate is presented. Pure chromite sand and its chromite-based moulding sand prepared with use of sodium silicate were subjected to heating within 100 to 1200°C. After cooling-down, changes of base grains under thermal action were determined. Chromite moulding sand was prepared with use of 0.5 wt% of domestic made, unmodified sodium silicate (water-glass) grade 145. After baking at elevated temperatures, creation of rough layer was observed on grain surfaces, of both pure chromite sand and that used as base of a moulding sand. Changes of sand grains were evaluated by scanning microscopy and EDS analyses. It was found that changes on grain surfaces are of laminar nature. The observed layer is composed of iron oxide (II) that is one of main structural components of chromite sand. In order to identify changes in internal structure of chromite sand grains, polished sections were prepared of moulding sand hardened with microwaves and baked at elevated temperatures. Microscopic observations revealed changes in grains structure in form of characteristically crystallised acicular particles with limited magnesium content, intersecting at various angles. EDS analysis showed that these particles are composed mostly of chromium oxide (III) and iron oxide (II). The temperature above that the a.m. changes are observed in both chromite-based moulding sand and in pure chromite sand. The observed phenomena were linked with hardness values and mass of this sand.

Słowa kluczowe

EN

foundry engineering; chromite sand; moulding sand; baking temperature; sodium silicate

PL

odlewnictwo; piasek formierski; masa formierska; temperatura zapiekania; krzemian sodu

• Wydawca: Komisja Odlewnictwa Polskiej Akademii Nauk Oddział w Katowicach
• Czasopismo: Archives of Foundry Engineering
• Rocznik: 2017
• Tom: Vol. 17, iss. 2
• Strony: 95--100
• Opis fizyczny: Bibliogr. 16 poz., il., rys., tab.

Twórcy

autor

Stachowicz M.

• Wroclaw University of Technology, Department of Foundry Engineering, Plastics and Automation, ul. Smoluchowskiego 25, 50-372 Wrocław, Poland

autor

Kamiński M.

• Wroclaw University of Technology, Department of Foundry Engineering, Plastics and Automation, ul. Smoluchowskiego 25, 50-372 Wrocław, Poland

autor

Granat K.

• Wroclaw University of Technology, Department of Foundry Engineering, Plastics and Automation, ul. Smoluchowskiego 25, 50-372 Wrocław, Poland

autor

Pałyga Ł.

• Wroclaw University of Technology, Department of Foundry Engineering, Plastics and Automation, ul. Smoluchowskiego 25, 50-372 Wrocław, Poland

Bibliografia

• [1] Lewandowski, J.L. (1997). Materials for foundry moulds. Publisher Akapit. (in Polish).
• [2] Sakwa, W., Wachelko, T. (1981). Materials for foundry moulds and cores. Publisher Śląsk. (in Polish).
• [3] Janicki, E., Sakwa, W. (1965). Moulding materials – properties and application. Publisher Wydawnictwo Naukowo-Techniczne. (in Polish).
• [4] Polish Norm PN-91/H-11007. Chromite sand. (in Polish).
• [5] Wróbel, J. (2016). Effect of binder content in chromite sand on the formation of gas defects in castings. Przeglad Odlewnictwa. 1-2, 32-35. (in Polish).
• [6] Wróbel, J. (2016). Chromite sand and furan sandmix (that is, what to look for, that helped, rather than harming). Przeglad Odlewnictwa. 9-10, 466-470. (in Polish).
• [7] Dańko, R., Holtzer, M. & Dańko, J. (2015). Investigations of Physicochemical Properties and Thermal Utilisation of Dusts Generated in the Mechanical Reclamation Process of Spent Moulding Sands. Archives of Metallurgy and Materials. 60(1), 313-318.
• [8] Holtzer, M. (1992) A study of the mechanism and degree of interaction between Hadfield liquid cast steel and moulding sand. Publisher Scientific bulletins of University of Mining and Metallurgy in Krakow: Metallurgy and foundry practise Bulletin 142. (in Polish).
• [9] Modrzyński, A. (2000). Production of the Thick-Walled Casts from Hadfield Steel. Solidification of Metals and Alloys. 2(43), 375-382. (in Polish).
• [10] Bengulur, S., Darwada, H.R., Gurram, K.R. & Vundavilli, P.R. (2013). Experimental Studies on Properties of Chromite-based Resin Bonded Sand System. Recent Advances in Robotics, Aeronautical and Mechanical Engineering. 230-238. ISBN: 978-1-61804-185-2.
• [11] Małachowska, A., Stachowicz, M. & Granat, K. (2012). Innovative microwave hardening of water-glass containing sandmixes in technical-economic approach. Archives of Foundry Engineering. 12(1), 75-80.
• [12] Stachowicz, M., Granat, K. & Małachowska, A. (2014). Comparison of traditional method and modern microwave method of manufacturing cores of sandmixes with water-glass. Archives of Foundry Engineering. 14(spec.2), 83-88. (in Polish).
• [13] Stachowicz, M., Mażulis, J., Granat, K. & Janus, A. (2014). Influence of molding and core sands matrix on the effectiveness of the microwaves absorption. Metalurgija. 53(3), 317-319.
• [14] Stachowicz, M. & Granat, K. (2014). Possibilities of reclamation microwave-hardened molding sands with water glass. Archives of Metallurgy and Materials. 59(2), 757-760
• [15] Wiśniewska, K. & Szczerba, J. (2014). Effects of firing conditions on evolution of microstructure of magnesia-chromite materials. Materiały Ceramiczne (Ceramic Materials). 66(3), 341-344. (in Polish).
• [16] Murakami, Y., Sawata, A. & Tsuru, Y. (1999). Crystallization behavior of amorphous solid solutions and phase separation in the Cr2O3-Fe2O3 system. Journal of Materials Science. 34, 951-955.

Uwagi

PL

Opracowanie ze środków MNiSW w ramach umowy 812/P-DUN/2016 na działalność upowszechniającą naukę (zadania 2017)

PL

artykuł ukazał się wcześniej w Archives of Foundry Eng. 2016, Vol. 16, iss. 4