The ceaseless progress of nanotechnology, observed in the last years, causes that nanomaterials are more and more often applied in several
fields of industry, technique and medicine. E.g. silver nanoparticles are used in biomedicine for disinfection and polymer nanoparticles
allow insulin transportation in pharmacology. New generation materials containing nanoparticles are also used in the chemical industry
(their participation in the commercial market equals app. 53 %). Nanomaterials are used in electronics, among others for semiconductors
production (e.g. for producing nanoink Ag, which conducts electric current).
Nanomaterials, due to their special properties, are also used in the foundry industry in metallurgy (e.g. metal alloys with nanocrystalline
precipitates), as well as in investment casting and in moulding and core sand technologies. Nanoparticles and containing them composites
are applied in several technologies including foundry practice, automotive industry, medicine, dentistry etc. it is expected that their role
and market share will be successively growing.
The nanocomposites based on water glass matrix were attempted in the study. Nanoparticles of ZnO, Al2O3 or MgO in organic solutions
were applied into water glass matrix in the amounts of: 1.5; 3; 4 or 5 mas. %. Wettability of the quartz sad by the nanocomposites based on
water glass matrix was determined by testing changes of the wetting angle θ in time τ for the system: quartz – binder in non-stationary
state, by means of the device for measuring wetting angles. Wettability measurements were carried out under isothermal conditions at an
ambient temperature (20 – 25 oC). The modification improves wettability of quartz matrix by water glass, which is effective in improving
strength properties of hardened moulding sands. Out of the considered modifiers in colloidal solution of propyl alcohol water glass
modified by MgO nanoparticles indicated the smallest values of the equilibrium wetting angle θr. This value was equal app. 11 degrees and
was smaller no less than 40 degrees than θr value determined for not modified water glass. Viscosity η of nanocomposites based on water
glass matrix was determined from the flow curve, it means from the empirically determined dependence of the shearing stress τ on shear
rate γ: τ = f (γ) (1), by means of the rotational rheometer. Measurements were carried out at a constant temperature of 20 oC. The
modification influences the binder viscosity. This influence is conditioned by: amount of the introduced modifier as well as dimensions and
kinds of nanoparticles and organic solvents. The viscosity increase of the modified binder does not negatively influence its functional
properties.
The work is a part of research into the reduction of energy consumption in the production of EPSthrough the modernization
of technological equipment used. This paper presents the results of research and analysis of heat transfer process between the water vapor
that was provided to machine, the mold, the product and the environment. The paper shows the calculation of the heat balance of the
production cycle for two types of mold: standard and modernized. The performance tests used an infrared imaging camera.
The results were used to develop a computer image analysis and statistical analysis. This paper presents the main stages of the production
process and the construction of technological equipment used, changing the mold surface temperature field during the production cycle
and the structure of the heat balance for the mold and its instrumentation. It has been shown that the modernization of construction
of technological equipment has reduced the temperature field and as a consequence of decreased of demand for process steam production
cycle.
The aim of this study is to demonstrate the possibility of using moulding sands based on inorganic binders hardened in a microwave chamber in the technology of ablation casting of aluminium alloys. The essence of the ablation casting technology consists in this that a mould with a water-soluble binder is continuously washed with water immediately after being poured with liquid alloy until its complete erosion takes place. The application of an environmentally friendly inorganic binder improves the ecology of the whole process, while microwave hardening of moulding sands allows moulds to be made from the sand mixture containing only a small amount of binder.
The studies described in this article included microwave-hardened sand mixtures containing the addition of selected inorganic binders available on the market. The strength of the sands with selected binders added in an amount of 1.0; 1.5 and 2.0 parts by mass was tested. As a next step, the sand mixtures with the strength optimal for ablation casting technology, i.e. about 1.5 MPa, were selected and tested for the gas forming tendency. In the four selected sand mixtures, changes occurring in the samples during heating were traced. Tests also included mould response to the destructive effect of ablation medium, which consisted in the measurement of time necessary for moulds to disintegrate while washed with water. Tests have shown the possibility of using environmentally friendly, microwave-hardened moulding sands in ablation casting of aluminium alloys.
The paper presents the results of studies on the development of manufacturing technologies to cast hearth plates operating in chamber
furnaces for heat treatment. Castings made from the heat-resistant G-X40CrNiSi27-4 steel were poured in hand-made green sand molds.
The following operations were performed: computer simulation to predict the distribution of internal defects in castings produced by the
above mentioned technology with risers bare and coated with exothermic and insulating sleeves, analysis of each variant of the technology,
and manufacture of experimental castings. As a result of the conducted studies and analysis it was found that the use of risers with
exothermic sleeves does not affect to a significant degree the quality of the produced castings of hearth plates, but it significantly improves
the metal yield.
The aging granulate is to activate the blowing agent during the manufacturing process to granulate models can re-expand and shape the
model of well-sintered granules, smooth surface and a suitable mechanical strength.
The article presents the results of studies which aim was to determine the optimum time for aging pre-foamed granules for pre-selected
raw materials.
The testing samples were shaped in an autoclave, with constant parameters sintering time and temperature. Samples were made at 30
minute intervals. Models have been subjected to flexural strength and hardness.