DRYING AND HARDENING OF CERAMIC MOULDS APPLIED IN THE INVESTMENT CASTING TECHNOLOGY - INVESTIGATIONS OF THE PROCESS KINETICS
DOI:
https://doi.org/10.7494/mafe.2011.37.1.41Keywords:
investment technology, ceramic moulds, ultrasonic technique, hardening kineticsAbstract
Ceramic moulds applied in the investment casting technology are multilayer structures, built in an alternating process of depositing and drying of successive layers. Each individual layer is formed from a fluid (liquid) ceramic moulding sand and a grain matrix. In the current, environmentally technology fluid ceramic sands based on ethyl silicate are being substituted by ceramic sands containing colloidal silica as a binder. The ability and rates of drying and hardening of these new colloidal (water) ceramic moulding sands are quite different than of the ones which have a binder dissolved in alcohol. The kinetics of the process based on new binders is not well known. The technological principle requires that the successive layer deposition is done only when the one deposited previously is already sufficiently dry. Investigations of the possibility of application of some methods including: ultrasound, resistance and weigh method are presented in the paper. Advantages and disadvantages of each method are indicated as well as the assessment of their practical suitability is perfomed.
Downloads
References
Zych J.: Synthesis of the Ultrasonic Techniąue Applications to Kinetics Analysis of the Selected Processes Occurring on Moulding Materials, AGH University of Science and Technology Press, Cracow 2007, Dis-sertations-Monographs 163, ISSN 0867-6631
Zych J.: Application of the novel ultrasonic method in the on linę research of the setting, and hardening process of ceramic materials, Inżynieria Materiałowa, 27 (2006) 3, pp. 680-683
Zych J. Method of examining the hardening process of core and moulding sand mixes containing ahardenable binder, Akademia Górniczo-Hutnicza: Patent G01N 29/00 (2006.01) Poland
Zych J.: Moulding sands surface layer-kinetics of the changes its property, Archives of Foundry, 6 (2006) 20, pp. 77-84
Zych J.: Effecting of the weather conditions on the surface layer condition of moulds madę with moulding sand whit the chemical bonding, Archives of Foundry, 6 (2006) 22, pp. 576-581
