<p>Because of its unique structure, graded porous materials are widely utilized in filtration, separation, energy and catalysis. However, there are many defects in the traditional manufacturing methods, and the manufacturing process is much complicated. It is of great significance to realize the orderly separation and arrangement of different size particles quickly and conveniently, so as to realize the construction of graded porous materials. In this paper, the discrete element method (DEM) was employed to simulate the vibration process of fine particles with continuous size distribution, and the influences of vibration amplitude (<i>A</i>) and frequency (<i>f</i>) on the segregation behavior and related properties of packing structure were systematically investigated. The dynamics and mechanism of vibration segregation were analyzed through packing morphology, particle trajectory and velocity information. Finally, the graded pore structure could be obtained by appropriate vibration. The results show that for the 316L stainless steel powder used in this paper, the graded particle structure is prone to be gained within a range of large vibration intensities (e.g., <i>A</i> = 13.5&#xa0;μm and <i>f</i> = 600&#xa0;Hz). Simultaneously, the overall porosity (<i>ε</i>) is also higher (<i>ε</i> = 0.44). The difference in size between large and small particles causes the difference in motion behavior during movement, which makes it easier for small particles to drill into the pores formed by large particles, and directly leads to particle segregation. In the typical graded porous structure (e.g., <i>A</i> = 13.5&#xa0;μm and <i>f</i> = 600&#xa0;Hz), the pore volume distribution of the bottom particles is narrow, and its volume is only 0–0.2 × 10<sup>–13</sup>&#xa0;m<sup>3</sup>. Along the + Z direction, the size distribution width of the pores increases, the peak position moves to the right, and the average pore volume becomes larger. The exploration results of this paper will provide a novel idea and theoretical basis for the construction of graded porous materials.</p>

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The essential role of vibration segregation in the construction of graded porous materials

  • Dengzhi Yao,
  • Chenyang Xu,
  • Xizhong An,
  • Qingchuan Zou,
  • Dazhao Gou

摘要

Because of its unique structure, graded porous materials are widely utilized in filtration, separation, energy and catalysis. However, there are many defects in the traditional manufacturing methods, and the manufacturing process is much complicated. It is of great significance to realize the orderly separation and arrangement of different size particles quickly and conveniently, so as to realize the construction of graded porous materials. In this paper, the discrete element method (DEM) was employed to simulate the vibration process of fine particles with continuous size distribution, and the influences of vibration amplitude (A) and frequency (f) on the segregation behavior and related properties of packing structure were systematically investigated. The dynamics and mechanism of vibration segregation were analyzed through packing morphology, particle trajectory and velocity information. Finally, the graded pore structure could be obtained by appropriate vibration. The results show that for the 316L stainless steel powder used in this paper, the graded particle structure is prone to be gained within a range of large vibration intensities (e.g., A = 13.5 μm and f = 600 Hz). Simultaneously, the overall porosity (ε) is also higher (ε = 0.44). The difference in size between large and small particles causes the difference in motion behavior during movement, which makes it easier for small particles to drill into the pores formed by large particles, and directly leads to particle segregation. In the typical graded porous structure (e.g., A = 13.5 μm and f = 600 Hz), the pore volume distribution of the bottom particles is narrow, and its volume is only 0–0.2 × 10–13 m3. Along the + Z direction, the size distribution width of the pores increases, the peak position moves to the right, and the average pore volume becomes larger. The exploration results of this paper will provide a novel idea and theoretical basis for the construction of graded porous materials.