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P. Just and T. Pacyniak

The Influence of the Shape of the Reaction Chamber on Spheroidisation of Cast Iron Produced in the Lost Foam Casting Process with Use of the Inmold Method

The article presents the results of the research on the influence of the shape of reaction chamber on spheroidisation of cast iron produced with use of the inmold method. The amounts of nodular graphite precipitates in castings produced with the use of different reaction chambers have been compared.

Open access

T. Pacyniak and R. Kaczorowski

The Influence of Ingate Size on the Lost Foam Casting Process

The article presents analysis of the influence of ingate size on the Lost Foam casting process. In particular, analysis of simulation tests has been carried out to determine the ingate size influence on the rate of filling of the mould cavity, pressure in the gas gap and size of the gas gap. A specially prepared mathematical model of the process and an original calculation algorithm were used in simulation tests of full-mould casting. The tests have indicated that the increase of the ingate size results in the increase of filling rate and increase of pressure of gases in the gas gap. However, significant influence on mould cavity filling occurs only when the ingate size is less than ~1 cm2.

Open access

K. Buczkowska and T. Pacyniak

Abstract

The aging granulate is to activate the blowing agent during the manufacturing process to granulate models can re-expand and shape the model of well-sintered granules, smooth surface and a suitable mechanical strength. The article presents the results of studies which aim was to determine the optimum time for aging pre-foamed granules for pre-selected raw materials.

The testing samples were shaped in an autoclave, with constant parameters sintering time and temperature. Samples were made at 30 minute intervals. Models have been subjected to flexural strength and hardness.

Open access

T. Pacyniak and K. Buczkowska

Abstract

This work presents the analysis of the final shaping process of the patterns aimed at determining the influence of the pressure and the time of sintering on the resistance to bending. The analysis of the research results proved that when the pressure of the sintering rises and reaches Ps=2.1 bar the resistance to bending increases, above this level of the pressure the resistance value starts decreasing. The time of styrofoam sintering at which the highest bending resistance values were obtained is ts=90s. When the sintering pressure is less than 2 bar prolongation of the time of sintering over 90 s causes a slight increase in the resistance, however, at higher pressures prolongation of the time of sintering causes submelting of the styrofoam pattern.

Open access

T. Pacyniak, K. Buczkowska and W. Bogus

The Analysis of the Influence of the Polystyrene Patterns Shaping Parameters on the Resistance Properties

This work presents the technology of making foam plastics patterns used in casting as well as the final shaping stand. The analysis of the sintering process was carried out aiming at determining the influence of the pressure and the time of sintering on the flexural strength properties. The analysis of the research results confirmed that when the sintering pressure grows to the value of Pa =1,7 bar the flexural strength also increases, when the pressure value is higher than that, the degradation of the material takes place and the strength properties decrease.

Open access

C. Rapiejko, B. Pisarek and T. Pacyniak

Abstract

The paper presents the results of the investigation of the effect of Cr and/or V alloy additions on the microstructure and mechanical properties of the magnesium AM60 alloy. The examinations are performed within the frames of a project aiming at the elaboration of an experimental and industrial technology of producing constructively complex elements of machines and devices made of magnesium alloys with the method of investment casting. It has been proven that small numbers of Cr and V alloy additions improve the strength properties: Rm, A%, and the hardness HB of the obtained casts. The experimental casts were made in ceramic molds.

Open access

R. Kaczorowski, P. Just and T. Pacyniak

Abstract

This paper presents a technology of ductile cast iron obtain by lost foam process with use of inmold method. Spheroidization was carried out using master alloy in an amount of 1.5% by mass on casting iron. Research the influence of the gating system configuration and the shape of the reaction chamber, the degree of spheroidization cast iron, which estimated based on the shape of the graphite. Research have shown that the greatest impact on the degree of spheroidization has cast the infusion position relative to the casting inlet and the reaction chamber, and the shape of the reaction chamber.

Open access

R. Władysiak, A. Kozuń and T. Pacyniak

Abstract

Unmodified AlSi20 alloy were casted at the research station, allowing for sequential multipoint cooling using a dedicated computer- controlled program. This method allows for the formation of the microstructure of hypereutectic AlSi20 alloy and also increases hardness. Primary silicon dendrites were found in the microstructure of cooled samples. Based on these dendrites, the formation of primary silicon particles is explained. Cooling of casting die with a water mist stream causes changes in solidification, which leads to expansion of the boundary layer with columnar crystals and shrinkage of the core zone with equiaxed crystals. It also causes more regular hardness distribution around pre-eutectic Si crystals, which can lead to tensile strength and machinability improvement.

Open access

C. Rapiejko, B. Pisarek, E. Czekaj and T. Pacyniak

Abstract

The work presents the test results of the crystallisation and cooling of magnesium alloys: AM60 and AZ91, with the use of the TDA method. The tested alloys were cast into ceramic shells heated up to 180°C, produced according to the technology of the shell production in the investment casting method. The TDA method was applied to record and characterize the thermal effect resulting from the phase transformations occurring during the crystallisation of magnesium alloys. The kinetics and dynamics of the thermal processes of the crystallisation of AM60 and AZ91 in the ceramic shells were determined. Metallographic tests were performed with the use of an optical microscope as well as scanning microscopy, together with the EDS chemical analysis of the phases present in the tested casts. A comparison of these test results with the thermal effect recorded by way of the TDA method was made.

Open access

T. Szymczak, G. Gumienny and T. Pacyniak

Abstract

This article presents the results of studies in the hypoeutectic silumin destined for pressure die casting with the simultaneous addition of chromium and tungsten. The study involved the derivative and thermal analysis of the crystallization process, metallographic analysis and mechanical properties testing. Silumin 226 grade was destined for studies. It is a typical silumin to pressure die casting. AlCr15 and AlW8 preliminary alloys were added to silumin. Its quantity allowed to obtain 0.1, 0.2, 0.3 and 0.4% of Cr and W in the tested alloy. Studies of the crystallization process as well as the microstructure of the silumin poured into DTA sampler allowed to state the presence of additional phase containing 0.2% or more Cr and W. It has not occurred in silumin without the addition of above mentioned elements. It is probably the intermetallic phase containing Cr and W. DTA studies have shown this phase crystallizes at a higher temperature range than α (Al) solid solution. In the microstructure of each pressure die casting containing Cr and W the new phases formed. Mechanical properties tests have shown Cr and W additives in silumin in an appropriate amount may increase its tensile strength Rm (about 11%), the yield strength Rp0.2 (about 21%) and to a small extent elongation A.