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Kinetics of the Binding Process of Furan Moulding Sands, Under Conditions of Forced Air Flow, Monitored by the Ultrasonic Technique

Matonis Natalia, Zych Jerzy

Archives of Foundry Engineering

2023

Vol. 23, iss. 4

93--98

The paper presents the results of research on the kinetics of the binding process of self-hardening moulding sands with an organic binder under conditions of forced air flow at various pressure values. Three moulding sands made using urea-furfuryl resin Furanol FR75A technology were studied. The moulding sands were prepared on a base of quartz sand with an average grain size of dL = 0.25, 0.29 and 0.37 mm, with permeability values of 306, 391 and 476 m2108Pa x s (for ρo = 1.60, 1.60 and 1.61 g/cm3 , respectively). The research was conducted for a resin content of 1% with a constant proportion of hardener to resin, which was equal to 50%. Samples of the tested moulding sands were blown with air at pressures of 0.1, 0.2, 0.4, 0.6, 0.8, and 1.0 bar. The kinetics of the hardening process was monitored using ultrasound technology, according to a previously developed methodology [1]. The research was carried out on an ultrasound testing station equipped with a temperature chamber and an airflow reducer. The tests were conducted at a temperature of 20°C, and of the air flow pressure on the changes in ultrasonic wave velocity in the hardening mouldins sand as a function of time, the kinetics of the hardening process, and the degree of moulding sand hardening were determined. Additionally, the influence of the moulding sand permeability on the course of the hardening process at a constant air flow pressure was determined.

The thermal deformation of core and moulding sands according to the hot distortion parameter investigations

Jakubski J., Dobosz S. M.

Archives of Metallurgy and Materials

2007

Vol. 52, iss. 3

421-427

Effects which proceed in moulds during casting determinate quality of casts. Dimension accuracy, smoothness of surface and frequency of defetecs appearance are depended on thermal and mechanical deformation rate. The high test instrumentation used to analyze effects like this, affords us to know, how this effects influence on change in core and moulding sands. The results of dilatation and distortion in high temperatures investigation for moulds prepared with cold box and self-hardening moulding sands technology are shown in this article. In second part of this article, the influence of coating type and thickness on sample behavior in high temperature was qualified.

Zjawiska zachodzące w formie w czasie zalewania ciekłym metalem decydują o jakości odlewów. Od stopnia odkształcenia i deformacji cieplnej i mechanicznej form i rdzeni zależy dokładność wymiarowa i gładkość powierzchni odlewu oraz częstotliwość występowania wad. Stosowanie nowoczesnej aparatury badawczej umożliwiającej analizę tego rodzaju zjawisk pozwoli na dokładne poznanie ich wpływu na charakter zmian zachodzących w masach formierskich i rdzeniowych. W artykule przedstawiono wyniki badań własnych dylatacji i odkształceń w podwyższonych temperaturach mas wykonanych w technologii cold box oraz sypkich mas samoutwardzalnych. W drugiej części przedstawiono badania dotyczące wpływu rodzaju i grubości powłoki ochronnej na zachowanie rdzeni w czasie deformacji cieplnej.