This article deals with the effect of manganese that is the most applied element to eliminate the negative effect of iron in the investigated alloy AlSi7Mg0.3. In this time are several methods that are used for elimination harmful effect of iron. The most used method is elimination by applying the additive elements, so-called iron correctors. The influence of manganese on the morphology of excluded ironbased intermetallic phases was analysed at various iron contents (0.4; 0.8 and 1.2 wt. %). The effect of manganese was assessed in additions of 0.1; 0.2; 0.4 and 0.6 wt. % Mn. The morphology of iron intermetallic phases was assessed using electron microscopy (SEM) and EDX analysis. The increase of iron content in investigated alloys caused the formation of more intermetallic phases and this effect has been more significant with higher concentrations of manganese. The measurements carried out also showed that alloys with the same Mn/Fe ratio can manifest different structures and characteristics of excluded iron-based intermetallic phases, which might, at the same time, be related to different resulting mechanical properties.
Manganese is an effective element used for the modification of needle intermetallic phases in Al-Si alloy. These particles seriously
degrade mechanical characteristics of the alloy and promote the formation of porosity. By adding manganese the particles are being
excluded in more compact shape of “Chinese script” or skeletal form, which are less initiative to cracks as Al5FeSi phase. In the present
article, AlSi7Mg0.3 aluminium foundry alloy with several manganese content were studied. The alloy was controlled pollution for achieve
higher iron content (about 0.7 wt. % Fe). The manganese were added in amount of 0.2 wt. %, 0.6 wt. %, 1.0 wt. % and 1.4 wt. %. The
influence of the alloying element on the process of crystallization of intermetallic phases were compared to microstructural observations.
The results indicate that increasing manganese content (> 0.2 wt. % Mn) lead to increase the temperature of solidification iron rich phase
(TAl5FeSi) and reduction this particles. The temperature of nucleation Al-Si eutectic increase with higher manganese content also. At
adding 1.4 wt. % Mn grain refinement and skeleton particles were observed.
This paper deals with influence on segregation of iron based phases on the secondary alloy AlSi7Mg0.3 microstructure by nickel. Iron is
the most common and harmful impurity in aluminum casting alloys and has long been associated with an increase of casting defects. In
generally, iron is associated with the formation of Fe-rich intermetallic phases. It is impossible to remove iron from melt by standard
operations. Some elements eliminates iron by changing iron intermetallic phase morphology, decreasing its extent and by improving alloy
properties. Realization of experiments and results of analysis show new view on solubility of iron based phases during melt preparation
with higher iron content and influence of nickel as iron corrector of iron based phases.
This paper deals with influence on segregation of iron based phases on the secondary alloy AlSi7Mg0.3 microstructure by chrome. Iron is
the most common and harmful impurity in aluminum casting alloys and has long been associated with an increase of casting defects. In
generally, iron is associated with the formation of Fe-rich phases. It is impossible to remove iron from melt by standard operations, but it is
possible to eliminate its negative influence by addition some other elements that affect the segregation of intermetallics in less harmful
type. Realization of experiments and results of analysis show new view on solubility of iron based phases during melt preparation with
higher iron content and influence of chrome as iron corrector of iron based phases. By experimental work were used three different
amounts of AlCr20 master alloy a three different temperature of chill mold. Our experimental work confirmed that chrome can be used as
an iron corrector in Al-Si alloy, due to the change of intermetallic phases and shortening their length.
In Al-Si alloy the iron is the most common impurity and with presence of other elements in alloy creates the intermetallic compounds,
which decreases mechanical properties and increases of porosity. The cause of the negative effect of intermetallic particles on the
mechanical properties is that it is more easily break off the tension load as the aluminium matrix or small particles of silicon. By adding
suitable alloying elements, also known as iron correctors, is possible to reduce this harmful effect.
In the article is evaluated influence of manganese on microstructure with performed EDX analysis selected intermetallic phases and tensile
test and measurement of length of Al5FeSi phase. For realization experiments was used AlSi7Mg0.3 alloy with increased iron content.
Manganese was added in the amount 0.3 wt. %, 0.6 wt. %, 0.8 wt.% and 1,2 wt. %. From performed measurements it has been concluded,
that increased amount of manganese, i.e. Mn/Fe ratio, does not have significant influence on mechanical properties AlSi7Mg0.3 alloy in
the melted state.
The paper deals with the effect of microstructure diversified by means of variable cooling rate on service properties of AlSi7Mg cast alloy
refined traditionally with Dursalit EG 281, grain refining with titanium-boron and modified with sodium and a variant of the same alloy
barbotage-refined with argon and simultaneously grain refining with titanium-boron and modified with strontium. For both alloy variants,
the castings were subject to T6 thermal treatment (solution heat treatment and artificial aging). It turned out that AlSi7Mg alloy after
simultaneous barbotage refining with argon and grain refining with titanium-boron and modified with strontium was characterised with
lower values of representative microstructure parameters (SDAS – secondary dendrite arm spacing, λE, lmax) and lower value of the
porosity ratio compared to the alloy refined traditionally with Dursalit EG 281 and grain refining with titanium-boron and modified with
sodium. The higher values of mechanical properties and fatigue strength parameters were obtained for the alloy simultaneously barbotagerefined
with argon and grain refining with titanium-boron and modified with strontium.
The paper deals with the influence of manganese in AlSi7Mg0.3 alloy with higher iron content. Main aim is to eliminate harmful effect of intermetallic – iron based phases. Manganese in an alloy having an iron content of about 0.7 wt. % was graded at levels from 0.3 to 1.4 wt. %. In the paper, the effect of manganese is evaluated with respect to the resulting mechanical properties, also after the heat treatment (T6). Morphology of the excluded intermetallic phases and the character of the crystallisation of the alloy was also evaluated. From the obtained results it can be concluded that the increasing level of manganese in the alloy leads to an increase in the temperature of the β-Al5FeSi phase formation and therefore its elimination. Reducing the amount of β-Al5FeSi phase in the structure results in an improvement of the mechanical properties (observed at levels of 0.3 to 0.8 wt. % Mn). The highest addition of Mn (1.4 wt.%) leads to a decrease in the temperature corresponding to the formation of eutectic silicon, which has a positive influence on the structure, but at the same time the negative sludge particles were also present
The paper deals with squeeze casting technology. For this research a direct squeeze casting method has been chosen. The influence of process parameters variation (casting temperature, mold temperature, pressure) on mechanical properties and structure will be observed. The thicknesses of the individual walls were selected based on the use of preferred numbers and series of preferred numbers (STN ISO 17) with the sequence of 3.15, 4.00, 5.00, 6.00 and 8.00 mm. The width of each wall was 22 mm with a length of 100 mm. As an experimental material was chosen the AlSi12 and AlSi7Mg0.3 alloys. The mechanical properties (UTS, E) for individual casting parameters and their individual areas of different thicknesses were evaluated. In the structure the influence of pressure on the change of the eutectic morphology, the change of the volume of eutectic and the primary alpha phase, the effect of the pressure on the more fine-grain and the regularization of the structure were evaluated.
The paper deals with the effect of heating of various prepared batch materials into semisolid state with subsequent solidification of the cast under pressure. The investigated material was a subeutectic aluminium alloy AlSi7Mg0.3. The heating temperature to the semisolid was chosen at 50% liquid phase. The used material was prepared in a variety of ways: heat treatment, inoculation and by squeeze casting. Also the influence of the initial state of material on inheritance of mechanical properties and microstructure was observed. The pressure was 100 MPa. Effect on the resulting casting structure, alpha phase distribution and eutectic silicon was observed. By using semisolid squeeze casting process the mechanical properties and microstructures of the casts has changed. The final microstructure of the casts is very similar to the microstructure that can be reached by technology of thixocasting. The mechanical properties by using semisolid squeeze casting has been increased except the heat treated material.
This paper deals with influence of chrome addition and heat treatment on segregation of iron based phases in the secondary alloy
AlSi7Mg0.3 microstructure by chrome and heat treatment. Iron is the most common and harmful impurity in aluminum casting alloys and
has long been associated with an increase of casting defects. In generally, iron is associated with the formation of Fe-rich intermetallic
phases. It is impossible to remove iron from melt by standard operations, but it is possible to eliminate its negative influence by addition
some other elements that affect the segregation of intermetallics in less harmful type or by heat treatment. Realization of experiments and
results of analysis show new view on solubility of iron based phases during melt preparation with higher iron content and influence of
chrome as iron corrector of iron based phases.
This article deals with the fatigue properties of newly used AlZn10Si8Mg aluminium alloy where the main aim was to determine the
fatigue strength and compare it with the fatigue strength of AlSi7Mg0.3 secondary aluminium alloys which is used in the automotive
industry for cyclically loaded components. AlZn10Si8Mg aluminium alloy, also called UNIFONT 90, is self-hardening (without heat
treatments), which contributes to economic efficiency. This is one of the main reasons why is compared, and may be an alternative
replacement for AlSi7Mg0.3 alloy which is heat treated to achieve required mechanical properties. The experiment results show that the
fatigue properties of AlZn10Si8Mg alloy are comparable, if not better, than AlSi7Mg0.3 alloy. Fatigue properties of AlZn10Si8Mg alloy
are achieved after seven days of natural ageing, immediately after casting and achieving value of fatigue strength is caused by structural
components formed during solidification of the melt.
The fluidity is the term to determine the materials ability to fill the mold cavity properly. Fluidity is complex property with many variables. Up to this date, there is no methodology for defining the fluidity in a semisolid material state. Submitted paper deals with the proposal of a new method designed for aluminium alloy fluidity evaluation in semi-solid state trough the design of the layered construction die. Die will be primary used for fluidity tests of semi-solid squeeze casted aluminium alloy and to observe the pressing force flow by mentioned casting technology. The modularity consists of possibility to change each die segment. In the experiment the die design was evaluated by simulation in ProCAST 11.5 and by production of experimental castings. The die was made by laser cutting technology from construction steel S355JR. Experimental material was aluminium alloy AlSi7Mg0.3. The temperature of the semisolid state was chosen to achieve 35% of solid phase. The result of next study should be a selected parameters observation and their effect on the fluidity of aluminium alloy in semi-solid state. This will be very important step to determine the optimal conditions to achieve a castings with certain wall thickness produced by the method of semi-solid squeeze casting.
The article is focused on the synergic effect of constant content of Zr and higher content of Ti on mechanical properties Al-Si alloy. The Ti additions were in proportions of 0.1, 0.2 and 0.3 wt.% Ti. The casting process was carried out in ceramic molds, created for the investment casting technology. Half of the experimental samples were processed by precipitation curing T6. The measured results were compared with primary alloy AlSi7Mg0,3 and experimental alloy AlSi7Mg0.3Cu0.5Zr0.15. In variant with addition 0.1 wt. %, the tensile strength Rm increased by 1,5% but the elongation AM decreased to 40%. Variants with 0.2 and 0.3 wt. % addition of Ti achieved similar Rm but approximately 40% decrease in AM. However, it is interesting that yield strength Rp0.2 increased for all variants by approximately 14 to 20%. The results point out the possibility of developing a more sophisticated alloy for automotive industry.