Heat treatment processes, due to qualitative requirements for the cast machinery components and restrictions on energy consumption resulting on the one hand from environmental concerns, and on the other hand from a requirements coming from minimization of manufacturing costs, are resulting in searching after a technologies enabling obtainment of satisfactory results, in form of improved mechanical properties mainly, while minimizing (limiting) parameters of successive operations of the heat treatment. Heat treatment of the T6 type presented in this paper consists in operations of heating of investigated alloys to suitably selected temperature (range of this temperature was evaluated on the base of the ATD method), holding at such temperature for a short time, and next rapid cooling in water (20 oC) followed by artificial ageing, could be such technology in term s of above mentioned understanding of this issue. Performed T6 heat treatment with limited parameters of solutioning operation resulted in visible increase in tensile strength Rm of AlSi7Mg, AlSi7Cu3Mg and AlSi9Cu3(Fe) alloys.

Using methods of physical material studies (scanning electron microscopy and micro X-ray spectral analysis), a study was carried out with focus on alteration of structure and phase composition in surface layers of Al-Si alloy (silumin АК10М2N) treated in electroexplosive alloying with a multiphase plasma jet formed in the process of aluminum foil explosion and carrying particles of Y2O3 weighted powder portion. It was revealed that a porous surface layer with non-homogeneously distributed alloying elements (silicon, yttrium) in it is formed in any conditions of electroexplosive alloying of silumin. Thickness of the modified layer is different, varying 50 to 160 µm, depending on the zone to be examined. The modified surface consists basically of Al, Si and Y. Yttrium in the modified layer is thought to be an indirect evidence of better physical and mechanical properties of the surface layer in comparison with the base material.

The work presents the research results of the silumin coat structure applied on the carbidic alloy ductile iron with the metal matrix: pearlitic, bainitic and martensitic. The coats were made in the AlSi5 silumin bath at the temperature tk = 750±5°C. The holding time of cast iron element in the bath was τ = 180s. Irrespective of the kind of tested ductile iron the obtained coat consisted of three layers with a different phase composition. The first layer from the cast iron ground “g1`” is built from Fe4CSi carbide which contains selected alloy additives of the cast iron. On it the second layer “g1``” crystallizes. It consists of the AlFeSi inter-metallic phase which can appear in its pure form or contain a small quantity of the alloy additives of the cast iron. The last external part of the layer “g2” mainly consists of the hypo-eutectic phases of silumin. The AlFeSi inter-metallic phases in the form of free precipitations with a lamellar or faceted morphology can also appear there. These phases also can contain a small quantity of the alloy additives of the cast iron. More than that, in all the layers of the coat there are graphite precipitations. The phenomenon of graphite movement to the coat is caused by intensive dissolving of the cast iron element surface by the aluminum of the silumin bath.

The paper presents the results of the crystallization process of silumin by the TDA thermographic method and the results of the cast

microstructure obtained in the sampler TDA-10, that was cooling down in ambient air. The study was conducted for silumin AlSi11

unmodified. The work demonstrated that the use of thermal imaging camera allows for the measurement and recording the solidification

process of silumin. Thermal curve was registered with the infrared camera and derivative curve that was calculated on the base of thermal

curve have both a very similar shape to adequate them TDA curves obtained from measurements using a thermocouple. Test results by

TDA thermographic method enable quantitative analysis of the kinetics of the cooling and solidification process of neareutectic silumin.

By the method of modern physical material science (optic microscopy scanning and transmission electron microscopy) the analysis of structural phase states, the morphology of the second phase inclusions and defect substructure of Al-Si alloy (silumin) of hypoeutectic composition, subjected to electron beam processing was done with the following parameters: energy density 25-35 J/cm2, beam length 150 μs, pulse number – 3, pulse repetition rate – 0.3 Hz, pressure of residual gas (argon) 0.02 Pa. The surface irradiation results in the melting of the surface layer, the dissolution of boundary inclusions, the stricture formation of high speed cellular crystallization of submicron sizes, the repeated precipitation of the second phase nanodimentional particles. With the increased distance from the irradiation surface the layer containing the second phase inclusions of quasi-equilibrium shape along with the crystallization cells was revealed. It is indicative of the processes of Al-Si alloy structure globalization on electron beam processing.

The work presents the analysis results of the structure of the coat obtained by dipping in silumin AlSi5 of two grades of alloy cast steel: GX6CrNiTi18-10 (LH18N9T) and GX39Cr13 (LH14). The temperature of the silumin bath was 750±5°C, and the hold-up time of the cast steel element τ = 180 s. The absolute thickness of the coat obtained in the given conditions was g = 104 μm on cast steel GX6CrNiTi18-10 and g = 132 μm on GX39Cr13. The obtained coat consisted of three layers of different phase structure. The first layer from the base “g1`” was constructed of the phase AlFe including Si and alloy additives of the tested cast steel grades: Cr and Ni (GX6CrNiTi18-10) and Cr (GX39Cr13). The second layer “g1``” of intermetallic phases AlFe which also contains Si and Cr crystallizes on it. The last, external layer “g2” of the coat consists of the silumin containing the intermetallic phases AlFeSi which additionally can contain alloy additives of the cast steel. It was shown that there were no carbides on the coat of the tested cast steels which are the component of their microstructure, as it took place in the case of the coat on the high speed steels.

This paper presents the results of measurements of liquid metal fluidity and linear shrinkage of nickel alloy IN-713C in vacuum induction

melting furnace Balzers VSG-2. Because of limited volume of the furnace chamber special models for technological trials were designed

and constructed to fit in the mould of dimensions 170x95x100mm. Two different designs of test models were proposed: horizontal round

rods and modified spiral. Preliminary studies were carried out for alloys Al-Si. Horizontal round rods test was useful for evaluation of

fluidity of hypoeutectic silumin, however in case of nickel superalloy the mould cavity was completely filled in each test because of high

required pouring temperature. Positive results were obtained from the modified spiral test for all alloys used in the research. Relationship

between the linear shrinkage for the test rod and a specific indicator of contraction defined on a spiral was observed.

The work is a continuation of research concerning the influence of intensive cooling of permanent mold in order to increase the casting

efficiency of aluminium alloys using the multipoint water mist cooling system. The paper presents results of investigation of crystallization

process and microstructure of multicomponent synthetic hypereutectic alloy AlSi20CuNiCoMg. The study was conducted for unmodified

silumin on the research station allowing the cooling of the special permanent sampler using a program of computer control. Furthermore,

the study used a thermal imaging camera to analyze the solidification process of multicomponent alloy. The study demonstrated that the

use of mold cooled with water mist stream allows in wide range to form the microstructure of hypereutectic multicomponent silumin. It

leads to higher homogeneity of microstructure and refinement of crystallizing phases of casting.

The work is a continuation of research on the use water mist cooling in order to increase efficiency of die-casting aluminum alloys using

multipoint water mist cooling system. The paper presents results of investigation of crystallization process and microstructure of synthetic

hypereutectic AlSi20 alloy. Casts were made in permanent mold cooled with water mist stream. The study was conducted for unmodified

AlSi20 alloy and modified with phosphorus, titanium and boron on the research station allowing sequential multipoint cooling using a

dedicated program of computer control. The study demonstrated that the use of mold cooled with water mist stream allows the formation

of the microstructure of hypereutectic silumins. A wide range of solidification temperature of hypereutectic silumins increases the

potential impact of changes in the cooling rate on a size, a number and a morphology of preeutectic silicon and eutectic α+β (Al+Si).

The work is a continuation of research on the use of water mist cooling in order to increase efficiency of die-casting aluminum alloys using

multipoint water mist cooling system. The paper presents results of investigation on crystallization process and microstructure of synthetic

hypereutectic AlSi20 alloy. Casts were made in permanent mold cooled a with water mist stream. The study was conducted for unmodified

AlSi20 alloy and a modified one with phosphorus, titanium and boron on the research station allowing sequential multipoint cooling using

a dedicated program of computer control. The study demonstrated that the use of mold cooled with water mist stream and solution heat

treatment allows in wide range for the formation of the microstructure of hypereutectic silumins. It leads to the growth of microstructure

refinement and spheroidizing of phases in the casting.

The work is a continuation of research concerning the influence of intensive cooling of permanent mold in order to increase the casting

efficiency of aluminium alloys using the multipoint water mist cooling system. The paper presents results of investigation of crystallization

process and microstructure of synthetic hypereutectic alloys: AlSi15 and AlSi19. Casts were made in permanent mold cooled with water

mist stream. The study was conducted for unmodified silumins on the research station allowing the cooling of the special permanent probe

using a program of computer control. Furthermore the study used a thermal imaging camera to analyze the solidification process of

hypereutectic silumins. The study demonstrated that the use of mold cooled with water mist stream allows in wide range the formation of

the microstructure of hypereutectic silumins. It leads to higher homogeneity of microstructure and refinement of crystallizing phases and

also it increases subsequently the mechanical properties of casting.

The object of the experimental studies was to determine the mechanical properties of a hypoeutectic EN AC - 42100 (EN ACAlSi7Mg0,3)

silumin alloy, where the said properties are changing as a result of subjecting the samples of different types to solution

treatment. An important aspect of the studies was the use type of device for the heat treatment. As a basic parameter representing the

mechanical properties, the tensile strength of the metal (Rm) was adopted.