A thermo-insulating moulding sand with a binder made of aluminosilicate microspheres with organic binder was subjected to testing. The aim of the analysis was to determine selected technological properties of the developed compounds. Compressive strength, friability and gas permeability were determined. The binder content was changed within a range of 5÷20 wt% with a 5% step. The applied matrix is characterized by good thermo-insulating properties and a small size of grains, while synthetic organic binder has favourable functional properties, among which the most noteworthy are the extended life and setting time, good rheological properties as well as high resistance to chemical agents. The intended use of the compound is the casting of 3D CRS (Composite Reinforced Skeletons), which are characterized by a well-developed heat transfer surface area, good absorption of impact energy, low mass and a target thickness of connectors within a range of 1.5÷3 mm. The construction of 3D CRS castings is an original concept developed by the employees of the Department of Foundry Engineering at the Silesian University of Technology.
The production of thin-walled castings with wall thickness in the range of 1.5 to 3 mm and below requires the development of insulation
moulding sands and/or core materials. The test has been taken to develop these kind of materials. The study included a description of their
thermophysical properties. Authors described problems related to the heat flow in the casting-mould system, i.e. mathematically described
the main dependence of heat give-up during crystallization of the casting. The influence of the content of polyglicol on the thermophysical
properties of the mould with gypsum and cement binder was examined. Using the ATD method determined were the increments ΔT1 and
ΔT2 describing the temperature changes in the mould during crystallization of hypoeutectic alloy of AlSi6 and the temperature difference
between casting material and mould during the crystallization. In the considered range of technological parameters a description of the
heat flow kinetics was given.
Until now, the mould sand in general use in the foundry industry are based on bentonite, which resulted from the fact that a good recognition properties and phenomena associated with this material. Come to know and normalized content of montmorillonite and carbonates and their important role in the construction of bentonite, and mass properties of the participation of compressive strength or scatter. Halloysite is widely used in industry and beyond them. However, little is known about its use in the foundry in Poland and abroad. This article presents preliminary research conducted at the Foundry Department of Silesian University of Technology on this material. Will raise the question of the representation of this two materials, which contains information connected with history and formation of materials, their structure and chemical composition. In the research, the results of compressive strength tests in wet masses of quartz matrix, where as a binder is used halloysite and bentonite in different proportions.
Preliminary tests aimed at obtaining a cellular SiC/iron alloy composite with a spatial structure of mutually intersecting skeletons, using a
porous ceramic preform have been conducted. The possibility of obtaining such a composite joint using a SiC material with an oxynitride
bonding and grey cast iron with flake graphite has been confirmed. Porous ceramic preforms were made by pouring the gelling ceramic
suspension over a foamed polymer base which was next fired. The obtained samples of materials were subjected to macroscopic and
microscopic observations as well as investigations into the chemical composition in microareas. It was found that the minimum width of a
channel in the preform, which in the case of pressureless infiltration enables molten cast iron penetration, ranges from 0.10 to 0.17 mm. It
was also found that the ceramic material applied was characterized by good metal wettability. The ceramics/metal contact area always has
a transition zone (when the channel width is big enough), where mixing of the components of both composite elements takes place.
Using the available analytical methods, including the determination of chemical composition using wavelength-dispersive X-ray
fluorescent spectroscopy technique and phase composition determined using X-ray diffraction, microstructural observations in a highresolution
scanning microscope equipped with an X-ray microanalysis system as well as determination of characteristic softening and
sintering temperatures using high-temperature microscope, the properties of particular chromite sands were defined. For the study has been
typed reference sand with chemical properties, physical and thermal, treated as standard, and the sands of the regeneration process and the
grinding process. Using these kinds of sand in foundries resulted in the occurrence of the phenomenon of the molding mass sintering.
Impurities were identified and causes of sintering of a moulding sand based on chromite sand were characterized. Next, research methods
enabling a quick evaluation of chromite sand suitability for use in the preparation of moulding sands were selected.