Modified Hot Distortion Test to Investigate the Effect of the Inorganic Binder on the High-Temperature Behaviour of Physically Hardened Moulding Sands

• Autorzy: Stachowicz M.

Identyfikatory

DOI

10.24425/122501

• Języki publikacji: EN

Abstrakty

EN

This study is an attempt to determine by Hot Distortion Test (HDT) the impact of physical methods of hardening inorganic binders in the moulding sands on phenomena caused by influence of thermal energy from heating elements with a temperature of 900°C +/- 10°C. Medium silica sand-based moulding mixtures were densified and then hardened using two physical methods: microwave heating at a frequency of 2.45 GHz or classical drying at a temperature of 110°C. Sodium silicate bonded sand (SSBS) with five unmodified kinds of hydrated sodium silicates subjected to two different types of hardening method were assessed in terms of their behaviour in high temperature. Thermal behaviour by means of deformation measurement was carried out with a modified Hot Distortion Test (mHDT). Due to this advanced, but unstable by appropriate standards Hot Distortion Test gives an opportunity to measure thermoplastic deformations (L) in moulding sands in many aspects, such as time of annealing. Research carried out in this way exposed differences between inorganic binders with molar module ranging from 3.4 to 2.0. It was established that deformations under the influence of high temperature last the longest in SSBS containing binders with molar module ranging from 3.4 to 2.9. Similarly, for these types of moulding sands the method of hardening the binder is found to be essential for increasing/decreasing the rate of thermoplastic deformations during the annealing of samples. The samples of SSBS made with binders with molar module from 2.5 to 2.0 are found to be excessively susceptible to thermoplastic deformation as a result of heating them in high environmental temperature presence.

Słowa kluczowe

EN

foundry engineering; sodium silicate; bonded sand; thermal deformation; hot distortion test; microwave heating

PL

odlewnictwo; krzemian sodu; piasek związany; odkształcanie termiczne; nagrzewanie mikrofalowe

• Wydawca: Komisja Odlewnictwa Polskiej Akademii Nauk Oddział w Katowicach
• Czasopismo: Archives of Foundry Engineering
• Rocznik: 2018
• Tom: Vol. 18, iss. 2
• Strony: 45--50
• Opis fizyczny: Bibliogr. 22 poz., rys., tab., wykr.

Twórcy

autor

Stachowicz M.

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

Bibliografia

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• [6] Liu, F., Fan, Z., Liu, X., Wang, H. & He, J. (2014). Research on humidity resistance of sodium silicate sand hardened by twice microwave heating process. Materials and Manufacturing Processes. 29(2), 184-187.
• [7] Stachowicz, M. & Granat, K. (2016). Influence of wet activation of used inorganic binder on cyclically refreshed water glass moulding sands hardened by microwaves. China Foundry. 13(6), 427-432.
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• [15] Mocek, J., Zych, J. & Chojecki, A. (2004). Study of erosion phenomena in sand moulds poured with cast iron. International Journal of Cast Metals Research. 17(1), 47-50.
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• [21] Stachowicz, M., Paduchowicz, P. & Granat, K. (2017). Impact of density degree and grade of inorganic binder on behaviour of moulding sand at high temperature. Journal of Casting and Materials Engineering. 1(3), 64-69.
• [22] Zych J. (2005). Role of compaction in the casting mould technology based on moulding sands containing water-glass or chemical binding agents. Przegląd Odlewnictwa. 55(2), 88-97 (in Polish).

Uwagi

PL

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).