The research described in this contribution is focused on fractographic analysis of the fracture area of newly developed eutectic silumin type AlSi9NiCuMg0.5 (AA 4032), which was developed and patented by a team of staff of the Faculty of Mechanical Engineering. The paper presents determination of the cause of casting cracks in operating conditions. Fractographic analysis of the fracture area, identification of the structure of the casting, identification of structural components on the surface of the fracture surface and chemical analysis of the material in the area of refraction were performed within the experiment. Al-Si alloys with high specific strength, low density, and good castability are widely used in pressure-molded components for the automotive and aerospace industries. The results shown that the inter-media phases Fe-Al and Fe-Si in aluminium alloys lead to breakage across the entire casting section and a crack that crossed the entire cross section, which was confirmed by EDS analysis.

The work presents the results of the investigations of the effect of the nitrogen (N2) refining time „τraf” and the gas output on the course of

the crystallization process, the microstructure and the gassing degree of silumin 226 used for pressure casting. The refinement of the

examined silumin was performed with the use of a device with a rotating head. The crystallization process was examined by way of

thermal analysis and derivative analysis TDA. The performed examinations showed that the prolongation of the N2 refining time causes

a significant rise of the temperature of the crystallization end of the silumin, „tL”, as well as a decrease of its gassing degree, „Z”. An

increase of the nitrogen output initially causes an increase of the temperature „tL” and a drop of the gassing degree „Z”, which reach their

maximal values with the output of 20 dm3

/min. Further increase of the output causes a decrease of the value „tL” and an increase of „Z”.

The examined technological factors of the refining process did not cause any significant changes in the microstructure of silumin 226.

The results of statistical analysis applied in order to evaluate the effect of the high melting point elements to pressure die cast silumin on its tensile strength Rm, unit elongation A and HB were discussed. The base alloy was silumin with the chemical composition similar to ENAC 46000. To this silumin, high melting point elements such as Cr, Mo, V and W were added. All possible combinations of the additives were used. The content of individual high melting point additives ranged from 0.05 to 0.50%. The tests were carried out on silumin with and without above mentioned elements. The values of Rm, A and HB were determined for all the examined chemical compositions of the silumin. The conducted statistical analysis showed that each of the examined high melting point additives added to the silumin in an appropriate amount could raise the values of Rm, A and HB. To obtain the high tensile strength of Rm = 291 MPa in the tested silumin, the best content of each of the additives should be in the range of 0.05-0.10%. To obtain the highest possible elongation A of about 6.0%, the best content of the additives should be as follows: chromium in the range of 0.05-0.15%, molybdenum 0.05% or 0.15%, vanadium 0.05% and tungsten 0.15%. To obtain the silumin with hardness of 117 HB, chromium, molybdenum and vanadium content should be equal to about 0.05%, and tungsten to about 0.5%.

The work presents the effect of strontium and antimony modification on the microstructure and mechanical properties of 226 silumin casts.

The performed research demonstrated that strontium causes high refinement of silicon precipitations in the eutectic present in the microstructure

of the examined silumin and it significantly affects the morphology of eutectic silicon from the lamellar to the fibrous one. Sr

modification also causes an increase of: the tensile strength „Rm” by 12%; the proof stress „Rp0,2” by 5%; the unit elongation „A” by 36%

and the hardness HB by 13%. Antimony did not cause a change in the microstructure of the silumin, yet it caused an increase in Rm and

HB by 5%, in Rp0,2 by 7% and in A by 4%.

To prepare a high-quality asymmetrical bending pipe of aluminum alloy by casting, the parting surfaces of the asymmetrical parts were determined based on the characteristics of the parts. Also, the forming process was designed and calculated. After that, the different types of gating systems were designed and the casting process was calculated by ProCAST, and then the influence of different casting gating systems on asymmetrical bending pipes was analyzed. The simulation results show that in the solidification process, although the filling speed of the single runner was slow, but the filling was stable. The gating system with a single runner-round flange filling system would lead to being more uniform for filling flow field and be sequential solidification of temperature field distribution, and stronger of the feeding ability. During the solidification process, the solid phase ratio of the single runner-round flange casting system is larger, and the shrinkage volume is smaller, which made the quality of castings better. Finally, a metal mold and core were made to cast a perfect asymmetric bending pipe of aluminum alloy product in a die casting machine. So the single runner-round flange filling system is suitable for asymmetrical bending pipe casting.

The work presents the results of the examinations of silumin 226 as well as a silumin produced on its basis containing a W and Mo addition

introduced in the amount of 0.1; 0.2; 0.3 and 0.4% of both elements simultaneously. Investigations of the crystallization process of the

silumins by the TDA method were conducted. Also, a microscopic analysis of their microstructure was performed and their basic mechanical

properties were determined. Microstructure tests were made on casts produced in an TDA sampler as well as by the pressure method.

The investigations exhibited a change in the course of crystallization of the silumin containing 0.3 and 0.4% W and Mo with respect to

silumin 226 and the silumin with the addition of 0.1 and 0.2%. The presence of additional phases which did not occur in the case of lower

addition contents was established in the silumin containing 0.3-0.4% W and Mo, regardless of the applied casting technology. The tests

showed the possibility of increasing the tensile strength Rm, the proof stress Rp0,2 and the unit elongation A of the silumin as a result of a

simultaneous introduction of the W and Mo addition. The highest values of Rm, Rp0,2 and A were obtained in the silumins with the additions

of these elements within the range of 0.1-0.2% each.

The study presents the results of the application of a statistical analysis for the evaluation of the effect of high-melting additions introduced into a pressure cast Al-Si alloy on the obtained level of its proof stress Rp0.2. The base Al-Si alloy used for the tests was a typical alloy used for pressure casting grade EN AC-46000. The base alloy was enriched with high-melting additions, such as: Cr, Mo, V and W. The additions were introduced into the base Al-Si alloy in all the possible combinations. The content of the particular high-melting addition in the Al-Si alloy was within the scope of 0.05 to 0.50%. The investigations were performed on both the base alloy and alloy with the high-melting element additions. Within the implementation of the studies, the values of Rp0.2 were determined for all the considered chemical compositions of the Al-Si alloy. A database was created for the statistical analysis, containing the independent variables (chemical composition data) and dependent variables (examined Rp0.2 values). The performed statistical analysis aimed at determining whether the examined high-melting additions had a significant effect on the level of Rp0.2 of the Al-Si alloy as well as optimizing their contents in order to obtain the highest values of the Al-Si alloy's proof stress Rp0.2. The analyses showed that each considered high-melting addition introduced into the Al-Si alloy in a proper amount can cause an increase of the proof stress Rp0.2 of the alloy, and the optimal content of each examined high-melting addition in respect of the highest obtained value of Rp0.2 equals 0.05%.

The paper presents the use of rapid prototyping technology of three dimensional printing (3DP) to make a prototype shell casting mold. In

the first step, for identification purposes, a mold was prepared to enable different alloys to be cast. All molds being cast were designed in a

universal CAD environment and printed with the zp151 composite material (Calcium sulfate hemihydrate) with a zb63 binder (2-

pyrrolidone). It is designated to be used to prepare colourful models presenting prototypes or casting models and molds. The usefulness of

3DP technology for use with copper alloys, aluminum and zinc was analyzed. The strength of the mold during casting was assumed as a

characteristic comparative feature in the material resistance to high temperature, the quality of the resulting casting and its surface

roughness. Casting tests were carried out in vacuum – pressure casting. The casting programs applied, significantly increased the quality of

castings and enabled precise mold submergence. Significant improvement was noted in the quality compared to the same castings obtained

by gravity casting.

In this study, AZ91 Magnesium alloy is produced by cold chamber high pressure die casting (HPDC) method. Different combinations of the cold chamber HPDC process parameters were selected as; in-mold pressure values of 1000 bar and 1200 bar, the gate speed of 30 m/s and 45 m/s, the casting temperatures of 640°C and 680°C. In addition, the test samples were produced by conventional casting method. Tensile test, hardness test, dry sliding wear test and microstructure analysis of samples were performed. The mechanical properties of the samples produced by the cold chamber HPDC and the conventional casting method were compared. Using these parameters; the casting temperature 680°C, in-mold pressure 1000 bar and the gate speed 30 m/s, the highest tensile strength and the hardness value were obtained. Since the cooling rate in the conventional casting method is slower than that of the cold chamber HPDC method, high mechanical properties are obtained by the formation of a fine-grained structure in the cold chamber HPDC method. In dry sliding wear tests, it was observed that there was a decrease in friction coefficient and less material loss with the increase of hardness values of the sample produced by the cold chamber HPDC method.