Experimental and Simulation Research on the Influence of Stirring Parameters on the Distribution of Particles in Cast SiCp/A356 Composites

Abstract

Achieving the uniform distribution of reinforcement particles in MMCs is very important for the effect of stirring parameters and the flow action of the melt, which should be known. The effect of stirring parameters on the distribution of SiC particles in SiCp/A356 composites was studied by the experimental and numerical methods in this paper. The experimental results show the SiC distribution with different stirring parameters. In addition, the effects of the fluid velocity and volume fraction of SiC particle at different position of crucible on the SiC distribution were analyzed by numerical simulation. The velocity magnitude, axial velocity, and radial velocity were analyzed to explain theoretically the particle distribution. The shearing force, moments, and stirring power of the stirring rod were simulated based on CFD code. The numerical results show that the stirring temperature is lower, the shearing force is greater, the stirring time is longer, and particle dispersion gets better. On the other hand, the higher the stirring speed is, the more uniform the radial and axial flow are, and the better the particles were dispersed. The numerical results were in good agreement with the experimental data.

A Comparative Study of the Impact of the Stirrer Design in the Stir Casting Route to Produce Metal Matrix Composites

“…e different positions of the volume fraction of SiC were controlled at different stirring temperatures, stirring speeds, and stirring times. ey concluded that according to the simulation of the shearing force, moments, and stirring power of the stirring rod the SiC is unwell dispersed at the position closer to the stirring rod without analyzing it [11]. Figure 14 shows the stirring rod and its position when the stirring rod and its blades dimensions are unclear but from the figure it seems it has two stages.…”

“…e proper design of experiments was not used by many researchers, so there is no clarification and analysis of the interactions between the various inputs [8][9][10]. Authors investigated that the stirring casting process is not obvious enough, and the reason behind the particle distribution is not comprehended for the aluminum ceramic powder composite [11]. In addition, the researchers analyzed the complexity and difficulty of understanding the SiC particles distribution process in the aluminum alloy, including the interaction between particles themselves and with the matrix alloy [11].…”

“…Authors investigated that the stirring casting process is not obvious enough, and the reason behind the particle distribution is not comprehended for the aluminum ceramic powder composite [11]. In addition, the researchers analyzed the complexity and difficulty of understanding the SiC particles distribution process in the aluminum alloy, including the interaction between particles themselves and with the matrix alloy [11]. Others criticized the lack of clarity about the effects of the blade angle, the impeller diameter, the stirrer geometry, and the interaction of these parameters on the flowing characteristics in the stirred crucible during stir casting [12].…”

“…An increase in stirring time in the AAMC stir casting manufacturing might lead to good dispersion of microceramics powder into the aluminum alloy matrix, but it is the energy consumption and cost. Yang et al stated that, with the extension of the stirring time, the particle dispersion in the composite is more uniform when they investigated the effect of stirring parameters on the distribution of SiC particles in AMCs by using experimental and computational methods [11]. Over the past decades, much energy and attention have gone to optimize the mechanical properties of MMCs, but unfortunately, the flow pattern during stirring cannot be observed as they are done in closed furnaces, which are nontransparent; direct measurements also are dangerous, time-consuming, and not effective.…”

Structure and phase composition formation of cast aluminum matrix composites during multiple remelting

“…Сообщается, что агломерации частиц в некоторых случаях удается избежать путем увеличения длительности перемешивания до 20 мин и более [22], однако при этом одновременно возрастает риск коробления, частичного растворения и эрозионного разрушения материала импеллера, а также усиления химических реакций между частицами и расплавом. На стадии приготовления композиционного расплава распределение частиц в матричном сплаве определяется такими факторами, как вязкость композиционной суспензии, эффективность перемешивания с позиций разрушения агломератов, а также захват газов при замешивании частиц и характеристики частиц, влияющие на скорость их седиментации [23]. Проведенные эксперименты показывают, что в ходе повторных переплавов происходят процессы перераспределения армирующих частиц, приводящие к разрушению агломератов даже в отсутствие интенсивного перемешивания импеллером.…”