Founded on September 26, 1958.
Its basic research trend is studying hydro dynamical, heat-and-mass transfer and crystallization processes during alloy preparation, treatment and solidification under physical and chemical influences; developing technological fundamentals for producing novel materials and high-grade metals.
Principal R&D activities of the Institute address the following subjects:
Studying the liquid state of multi-component alloys, interaction of melts with soluble and Insoluble solid , liquid and gas reagents; improving the existing foundry alloys and developing new ones, using integrated and sparling alloying, modifying, dispersion hardening; producing functional layers of alloys of different compositions;
Investigating physico-chemical, heat-and-mass transfer processes and their effect on metalware characteristics resulting from melt treatment with concentrated power sources;
Studying the effect of the intensity of controlled action of thermal and electromagnetic fields on hydrodynamic, heat-and-mass transfer and crystallization processes during alloy formation and solidification in molds and crystallizing pans;
Working out scientific principles of high-efficiency devices to monitor and control processes
Of high-grade metal production; this ensures a significant rise in productivity, reduction in material input and power consumption, better environment safety and work conditions.
Generally recognized are Institute’s achievements in the theory of graphite formation in modified cast irons; studies of the thermodynamics of forming iron-based metal systems; use of external influences on liquid and solidifying metal; studies of physico-chemical phenomena during alloy modifying and alloying; development of novel processes of steel pouring and producing high-grade ingots and castings; production of advanced cast materials; studies of physico-chemical processes kinetics in metals under the action of high-concentration power sources; mechanics of liquid and solidifying alloys and melt
New grades of high-strength and special cast irons for various purposes, cast wear-resistant and composite materials, steels with carbonitride strengthening , developed by the Institute, have been widely commercialized. Technological processes of centrifugal casting under flux for critical parts, cast iron smelting in electric furnaces, lost-foam and lost-wax methods, two-layer casting, melt treatment with immersed plasma jet, electron-beam melting of complex alloys, casting under low regulated pressure are efficiently used in many industries. Institute’s specialists were the first to produce magneto dynamic units for dosed alloy pouring and systems of continuous temperature control for liquid metal in metallurgical facilities. Researchers of the Institute have secured over 3 thousand patents and author’s certificates for inventions, issued dozens of science monographs. The Institute is the publisher of three R&D journals. The developments of its scientists and engineers were awarded with five Soviet State Prizes and five Ukraine State Prizes in Science and Engineering, four Prizes of USSR Council of Ministers, six NAS commemorative prizes.
and concomitant technologies
for preparationand pouring
of metals and alloys
In the Physico-Technological Institute of Metals and Alloys of the National Academy of Sciences of Ukraine (PTIMA NASU), there are created the scientific bases and new multifunction electrotechnological installations of magnetodynamic type for melting, out-of-furnace treatment, electromagnetic pouring of metal, and for action on crystallization of cast ingots.
It was developed MHD-devices of the casting and metallurgical purposes. These devices have been applied for industry. Also, the wholesale manufacture of such equipment was organized.
The novelty of the engineering solutions stopped in construction of magnetodynamic equipment is confirmed by many copyright patents in Ukraine and foreign countries. Developed magnetodynamic devices were marked by diplomas and awards of domestic and international exhibitions. For enterprises (including abroad Ukraine), there will be deliveredmore than 600 magnetodynamic installations.
Recently, the competitiveness of such equipment increased substantially due to advance of its technical descriptions, decreases of energy consumption, development of effective concomitant technologies for improvement of casting and reduction of dosage error at pouring.
Operational principle and functional possibilities of magnetodynamic devices
Magnetodynamic installations (MDI) are new class of the MHD equipment. They have no direct analogues in Ukraine and abroad.
Physically, magnetodynamic installation is induction channel furnace combined with electromagnetic pump.
The regulated heating of melt in the magnetodynamic device realizes at alternating electric current flow in liquid metal in the channels. This current is provoked by induction way at energizing of inductors which are transformer systems.
At energizing of inductors and electromagnet (which one creates the external magnetic field), the electromagnetic force is generated in working area of the MDI. This force provides motion of liquid metal. Mode, intensity and direction of melt motion depend on switching-on scheme and parameters of inductors and electromagnet of the MDI.
In practice, it is realized the wide range of melt motion, including both different circulation modes between MDI’s channel and crucible and electromagnetic pouring of liquid metal with prescribed temperature and mass flow rate.
The separate control of electromagnetic systems allows regulating independently main parameters of process – temperature of liquid metal and mass flow rate at stirring and pouring.
Magnetodynamic installations can be used at all known technological casting methods for ferrous and non-ferrous metals and alloys, namely casting into sand molds, shell molds and chill molds, die casting, casting under low electromagnetic pressure, on casting conveyers and rotating machines, in continuous casting processes etc.
Main functional possibilities of magnetodynamic devices in contrast to other casting electrotechnological aggregates are following:
- contactless and low-inertia energy transfer to liquid metal by variable electromagnetic fields. It simplifies the control of thermal and hydraulic processes and heat & mass transfer in the magnetodynamic aggregates. Also, it excludes application of inert gas and mechanical devices for melt stirring;
- thermal & forced processing of melt in the magnetodynamic aggregate due to repeated action of heating and crossed variable electromagnetic fields, MHD and hydrodynamic effects in induction channel, working area and liquid metal bath. At that, there is destruction in melt of microinhomogeneities, caused by metallurgical heredity. As result, it is providing improvement of structure and increasing of properties of alloys in solid state;
- control of electromagnetic pressure generated in the MDI. It enables to regulate the electromagnetic dosed pouring of metal on leak-free metal ducts. Also, it is possible to create overpressure in the hydraulically closed systems and to realize casting under low electromagnetic pressure;
- independent adjusting of induction heating and electromagnetic stirring of melt allows to control heat & mass transfer in liquid metal in wide range. It provides to accelerate up to 3 times heating of metal, melting of charge, dissolution of alloying additions, homogenization of temperature and chemical composition of alloys, to intensify interphase interactions between liquid metal and reagent, to make power electromagnetic and MHD actions on melt and inclusions;
- possibility to realize different operations, for example, refining and modifying, and also other types of treatment and pouring of liquid metals and alloys, in one aggregate;
- creation of electrodynamic vibrations in melt, including modulated and pinch-effect, that allows to intensify additionally interphase interactions in liquid and solidifying alloy.
Such МГД-equipment and concomitant technologies allow making alloys, in particular, on aluminium base, and manufacturing cast ingots for Hi-Tech industries, producing functional materials with combination of high level of properties (both traditional and special ones), preparing high-quality solder alloys, including multicomponent ones, and other unique materials.
proposals for cooperation
at fundamental & applied researches
and practical application
of magnetodynamic devices
in casting and metallurgy
1. Multifunction casting & metallurgical complex on base of MDN-6A magnetodynamic installation for production of high-quality aluminium casting.
The complex can be “incorporated” into different technologies and equipment of casting (sand mold casting, chill mold casting, die casting etc.). It allows making both reagent and physical modification of melt, providing high homogeneity of chemical composition of alloys. At using of complex and concomitant technologies, there are provided high indexes of refining of aluminium alloys due to their synchronous degassing from hydrogen by argon blowing (hydrogen content is decreased to 0.10-0.05 cm3/100 g of metal at the economy of 50% argon and time of treatment is reduced on 30% in comparison with conventional degassing processes) and filtration from nonmetallics (their removal makes to 80%). Also, dosage error at electromagnetic pouring of metal into molds and crystallizers is no more than 1-2% from mass of portion. All of these indexes correspond to level of the best world standards.
The multifunction magnetodynamic installation of MDN-6A type can be equipped by crucible of capacity 150, 250, 400, and 600 kg of liquid aluminium alloy. This installation is the base part of complex. It allows: - to heat up melt to required temperature; - to correct chemical composition of alloy by acceleration of dissolution of alloying and modifying additions; - to homogenize temperature and chemical composition of alloy due to electromagnetic stirring; - to make thermal & forced processing of liquid metal for destruction of the microinhomogeneities caused by metallurgical heredity; - to produce degassing of alloy from hydrogen at argon blowing as dispersion bubbles; - to remove nonmetallics from liquid metal by frequent melt motion under action of electromagnetic forces through foam-ceramic filters; - to provide either short-term or long-term holding of melt at prescribed temperature and rational intensity of electromagnetic stirring; - to realize controlled electromagnetic pouring (either dosing or continuous) of prepared alloy into sand molds, chill molds, compression box of die casting machines, crystallizers of aggregates for semicontinuous casting of ingots from aluminium and its alloys.
2. Complex of equipment for casting of aluminium alloys under low controlled electromagnetic pressure (so-called LEMD-process), including casting with use of dispersed non-solidifying gating system (so-called RASLIT-LEMD-process).
The equipment realizes controlled low-inertia pouring (under low electromagnetic pressure) of aluminium alloys, including with low castability, into mold and holding of metal at crystallization under overpressure and additional vibration actions. As result, there is provided high value of liquid metal recovery (ca. 90-98%), decreasing of rejects on gas & shrink defects and non-metal inclusions in 3-5 times, reduction of efforts at fettling (chipping of castings) in 2-3 times, and economy of specific electric power (per unit of products) on 20-50% in comparison to conventional casting methods.
Such process does not require airproofing of crucible with liquid metal and casting metal duct. At realization of technology, it is possible to use molds, mold cores, and models from different materials (sand, metal, ceramic, lost-wax, lost-foam etc.).
As basic equipment, there are used magnetodynamic installations with capacity of crucible to 600 kg of liquid aluminium alloy.
3. Magnetodynamic equipment for heating and pouring of cast iron and steel.
Magnetodynamic mixers-batchers are intended for regulated induction heating of liquid cast iron and steel to required temperature and controlled electromagnetic pouring of melt at casting conveyors of flask & snap-flask molding, into chill molds and centrifugal machines. Such devices provide realization of refining treatment, alloying and modifying of alloys and are used in casting workshops at mass & serial production. Capacity of standard magnetodynamic mixers-batchers makes 3 and 6 tons of iron-carbon melt.
New development is magnetodynamic installation for steel. It has increased both capacity (up to 10 tons of melt) and electric power (up to 600 kW). This aggregate is applied as mixer-batcher in technology of electroslag hard-facing (surfacing) of rental rollers forming rolls (mass to 50 tons) by alloyed steel.
Such unique equipment is prototype of magnetodynamic tundish (MD-T) for continuous casting of steel. The most prospective applications of the MD-T are: 1) semicontinuous casting of on high quality ingots steel at metallurgical micro-works (jointly with Donetsk National Technical University, there is developed the technical project of equipments for realization of this process); 2) continuous casting of thin slabs (the MD-T is integrated into united part with mold of continuous casting machine (CCM) and systems of electromagnetic stirring of melt on different stages of solidification of cast ingots); 3) direct manufacturing of steel sheets & strips at twin-roll continuous casting.
4. New technologies for manufacturing of heat-resistant monotectic alloys on copper base with region of phases’ immiscibility in liquid state with using of MHD-actions.
Alloy “Copper – Chromic cast iron” is monotectic one, i. e. it has region of phases’ immiscibility in liquid state. Complex MHD-actions are used both at stage of alloy preparation (for forming the dispersed drops of other component in matrix melt) and at pouring and crystallization (for fixing the “frozen emulsion” state). At that, such MHD-actions allow: - to suppress the undesirable phenomena of coalescence and sedimentation of phases; - to control the process of forming of reinforcing phase’s inclusions, their sizes and distribution in metal matrix.
It allows getting new alloys with the promoted special properties (heat-resistance threshold makes 800 °C, wear-resistance, electroconductivity etc.) on comparison with existing materials.
Main industries are the fields of application of developed alloys and manufacturing technology (for example, building industry, railway transport).
5. Study of influence of MHD & plasma actions on homogeneity of liquid aluminium alloys and their property in the solid state (fundamental researches).
Conception of researches is based on combination of the homogenizing influence on heat & mass transfer in macrovolume of liquid-metal system of electromagnetic and high-energy plasma actions on the local volume of melt.
It is provided, that liquid aluminium alloy in bath of specialized magnetodynamic aggregate. At that there is realized heating of melt by induction currents and thermostating at prescribed temperature. This temperature is substantially under the temperature of transition of melt from metastable microinhomogeneous state to balanced microhomogeneous one. Thus in the liquid-metal system are formed two regions of actions: 1) area of submerged plasmatron (inside the volume of liquid metal); 2) area of crossed electromagnetic fields in the zone of direct MHD action on melt. In addition, electromagnetic forces are used for continuous and frequent motion of melt through the local zone of maximal temperatures, provided by plasmatron.