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Simulation codes currently used in the foundry industry are primarily used to predict casting quality, quality tied mainly to the location of defects such as shrinkage (voids of shrinkage origin). The effective use of the simulation system requires identification and knowledge of, adapted to the reality, physical parameters (thermal) of the casting - mould system. The lack of as complete as a possible identification of these values, used in modelling dependencies, is the cause of limitation of the development and scope of models describing casting solidification. The development condition of the simulation code in the foundry practice is the correct model installation and the use of the database corresponding to the model. The following application presents the analysis of the impact of simulation parameters on the prediction of the casting defects.

The article presents results on the decomposition of polylactic acid (PLA)/halloysite nanotube (HNT) biocomposites. Experiments were carried out in laboratory conditions simulating composting in the industrial pile using the so-called short degradation method. In this paper, the effects of the composting process (duration from 30 to 90 days) on the behavior of PLA/HNT composites were studied. In addition, the selected physicochemical properties of PLA/HNTs biocomposites such as the average molecular weight were investigated. The results obtained confirmed the viability of composting PLA with halloysite which contributes to the reduction of plastic waste and the use of this material in technological applications.

Plastics recycling has become a key industry in developed countries, to reduce ecological damage and save non-renewable resources. This paper discusses the concept and the design of electrostatic separator as a test bench for the separation of different plastics in recycling applications. In the automotive recycling process, all these waste materials must be processed further for re-entering the cycle or thermal utilization. The following application presents the possibility of research and technological tests by changing several parameters, such as a position of the electrodes, control of the polarity and voltage, variable speed of feeder and drum, and also tribo-electrification parameters (time, intensity). The impact of process parameters on the efficiency of the plastic separation can be analyzed by the developed a specialized computer vision system. The preliminary results of conducted tests showed that separation is dependent on many variations of parameters. The results of this study indicate that the proposed innovative design of the research stand ensures the high research potential of the proposed equipment.

Aluminum metal matrix composites (Al MMCs) are a class of materials characterized by being light in weight and high hardness. Due to these properties, Al MMCs have various applications in the automobile, aeronautical and marine industries. Ceramic-reinforced Al MMCs in the form of sinters are known for having excellent abrasive properties, which makes them an attractive material in certain fields of technology. The biggest problem in their production process is their low ability to infiltrate ceramics with alloys and consequently the difficulty of filling a ceramic preform. The castability of such composites has not yet been researched in detail. The aim of this study was to create aluminum metal matrix composite castings based on aluminum alloys (AlSi11) reinforced with an Al2O3 sinter preform using a Castability Trials spiral mold, and then to determine the degree of saturation with the liquid metal of the produced ceramic shaped body (Castability Trials spiral). For the selected AlSi11 alloy, the liquidus (Tl) and solidus (Ts) temperatures were determined by performing thermal-derivation analysis during cooling, which is Tl—579.3 °C and Ts—573.9 °C. The resultant pressure necessary for the infiltration process was estimated for the reinforcement capillaries with the following dimensions: 10, 15, 20, 25, 30 and 35 microns. The following values were used to determine the capillary pressure (Pk): surface tension of the alloy—σ = 840 mN/m; the extreme wetting angle of the reinforcement by the metal—θ = 136°. It has been experimentally confirmed that for the vacuum saturation process, the estimated resultant pressure enables saturation of reinforcement with capillaries larger than 25 microns, provided that the alloy temperature does not drop lower than the infiltration temperature. After the experiment, the time and route of the liquid metal flow in the spiral were determined. On the basis of the obtained values, a simulation was developed and initial assumptions such as saturation time, alloy temperature, reinforcement and mold temperature were verified. The energy balance showed that the saturation limit temperature was Tk = 580.7 °C for the reinforcement temperature of 575 °C. In contrast to the above, the assumption that the temperature of the metal after equalizing the temperature of the composite components must be higher than the liquidus temperature (Tliq = 579.3 °C) for the aluminum alloy used must be fulfilled. After the experiment, the time and path of the liquid metal flow in the spiral were determined. Then, on the basis of the obtained values, a simulation was developed, and the initial assumptions (saturation time and temperature) were verified. [ABSTRACT FROM AUTHOR]