According to results of the research, it is determined that the most acceptable technological process with the possibility of obtaining high-quality castings with specified functional properties is the lost-foam casting process.
Mechanism of heat exchange in new systems «metal–model–macroreinforcing element–mold» is established and, on this basis, mathematical models of heat-mass transfer in the mold with the reinforcing phase oriented in it are developed, which can be used for practical application at a choice of thermotemporal parameters of casting and quantity of macroreinforcing phase geometry to obtain reinforced castings from iron-carbon and non-ferrous alloys.
We created physical and hydrogasdynamic models of matrix alloy flow in casting cavity saturated with macroreinforcing phase, based on the peculiarities of interaction of thermodegradation products of polystyrene foam model (solid, liquid and vapor-gas) and their influence on hydrogasdynamic of process with reinforcing phase, which forms pore channels around each of the elements of the macroreinforcing phase by heat transfer at the point of «macroreinforcing phase – matrix alloy», that increases the field of filtration and mass transfer of vapor and liquid products, causing changing of the gas dynamics of the process and conditions of casting quality.
The study of regularity of heat and mass transfer in the new theory of foundry processes system «metal – reinforced phase – shape» using a macro-reinforcing phase, oriented in the form of rods, revealed that the presence of macro-reinforcing phase creates conditions for increasing the solidification velocity of the alloy directly proportional to its mass and increasing it relative to the volume of metal in the mold. While a significant effect of the macro-reinforcing phase has on the removal of overheating of alloys to a temperature Tl, which exceeds the similar during casting solidification in a hollow mold in 2 - 10 times and these velocity reach values of 100 - 400 ° C/s (for copper alloys), that will clearly affect the hydrodynamics of casting and the formation of properties of cast reinforced structures.
The main schemes of obtaining of casting with functional properties during reinforcement of the mold cavity are examined, technological preconditions for liquid-phase combination of system components are determined and it is defined that the formation of microstructure and size of transition zone is influenced by chemical composition of matrix alloy and macroreinforcing phase, temperature of the liquid matrix alloy and cooling rate of the casting, which is also associated with the amount of introduced reinforcing phase.
Classifier of qualitative and quantitative characteristics of cast mono- and reinforced structures made of iron-carbon and non-ferrous alloys has been developed and on this basis we established the quality control parameters of castings during lost-foam casting providing specified quality characteristics of foundry products.
Methodology elaborated of calculating the volume of emissions of harmful substances in the production of cast iron varieties in electric induction furnaces with a metal capacity of 0,5 - 10 tons depending on the metal content of cast products and technological parameters of smelting using the obtained regression equations describing the dependence of the formed harmful gases, including inorganic dust with a SiO2 content of 20-70%; nitrogen dioxide (NO2); sulfur dioxide (SO2); carbon monoxide (CO) from the temperature-time melting parameters and the mass of the charge in the smelting units.
Methodology for calculating the qualitative and quantitative characteristics of harmful substances during manufacture of castings by lost-foam was worked out together with methodology for operational ecomonitoring of facilities and technological processes of foundry production using wireless networks as well as collection, processing and transmission of controlled environmental indicators and developed information system, that provides control of foundries, technological parameters of the processes of obtaining castings by lost-foam, the ecological condition of biological objects in the operation area and environmental monitoring.
As a result of the work was creation of environmentally friendly processes for the manufacture of castings with functional properties by the technology of lost-foam casting, using mono- and reinforced models.
