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CN-121976098-A - Preparation method of high-damping nanocrystalline pure magnesium material

CN121976098ACN 121976098 ACN121976098 ACN 121976098ACN-121976098-A

Abstract

The invention discloses a preparation method of a high-damping nanocrystalline pure magnesium material, which belongs to the technical field of high-performance metal material preparation, and comprises the following steps of firstly adopting discharge plasma sintering and solidification to Mg powder subjected to high-energy ball milling treatment to obtain a block material, then obtaining a pure magnesium bar through hot extrusion, then carrying out electric pulse treatment to the pure magnesium bar to induce microstructure reconstruction to obtain an ultrafine nanocrystalline pure magnesium material, and forming uniformly distributed nanocrystalline pure magnesium through high-energy ball milling, discharge plasma sintering, hot extrusion and electric pulse treatment and reconstruction of microstructure.

Inventors

  • FAN JIANFENG
  • SU DI
  • ZHANG QIANG

Assignees

  • 太原理工大学

Dates

Publication Date
20260505
Application Date
20260113

Claims (10)

  1. 1. The preparation method of the high-damping nanocrystalline pure magnesium material is characterized by comprising the following steps of: S1, sintering and solidifying Mg powder subjected to high-energy ball milling by adopting spark plasma to obtain a block material; S2, obtaining a pure magnesium bar through hot extrusion; And S3, performing electric pulse treatment on the pure magnesium bar, and inducing microstructure reconstruction to obtain the superfine nanocrystalline pure magnesium material.
  2. 2. The method for preparing the high-damping nanocrystalline pure magnesium material according to claim 1, wherein the ball milling speed of the high-energy ball milling treatment is 200-300 rpm, and the ball milling time is 180-220 hours.
  3. 3. The method for preparing a high damping nanocrystalline pure magnesium material according to claim 1 or 2, wherein stearic acid with a total Mg mass of 1.0-1.5 wt% is added to Mg powder during the high energy ball milling process.
  4. 4. The method for preparing the high-damping nanocrystalline pure magnesium material according to claim 3, wherein the prepared Mg powder is placed in a stainless steel ball milling tank under the protection of inert atmosphere, and three stainless steel balls with different sizes are filled in the ball milling tank for high-energy ball milling.
  5. 5. The method for preparing the high-damping nanocrystalline pure magnesium material according to claim 4, wherein the diameters of three stainless steel balls with different sizes are phi 5 mm, phi 8 mm and phi 10 mm respectively, and the mass ratio is 5:3:2.
  6. 6. The preparation method of the high damping nanocrystalline pure magnesium material according to claim 1, wherein the spark plasma sintering is carried out in a spark plasma sintering furnace under the protection of inert atmosphere by adopting plasma discharge, the pressure in the furnace reaches 1-1.1 atmosphere, the heating temperature is 560-570 ℃, and the heat preservation time is 15-20 min.
  7. 7. The method for preparing the high-damping nanocrystalline pure magnesium material according to claim 1, wherein the extrusion temperature of the hot extrusion is 370-400 ℃, and the extrusion ratio is 15-20:1.
  8. 8. The method for preparing a high damping nanocrystalline pure magnesium material according to claim 1, wherein the rod material after hot extrusion is processed into pure magnesium sheet along extrusion direction, and then is subjected to electric pulse treatment.
  9. 9. The method for preparing a high damping nanocrystalline pure magnesium material according to claim 1 or 8, wherein the current density of the electric pulse treatment is 0.43×10 8 -1.25×10 8 A/m 2 , and the treatment time is 12-15 min.
  10. 10. The method for preparing high damping nanocrystalline pure magnesium material according to claim 1, wherein the purity of Mg powder adopted in step S1 is not less than 99.9 wt%, and the particle size of Mg powder is 63-75 μm.

Description

Preparation method of high-damping nanocrystalline pure magnesium material Technical Field The invention belongs to the technical field of high-performance metal material preparation, and particularly relates to a preparation method of a high-damping nanocrystalline pure magnesium material. Background Nanocrystalline pure magnesium materials have proven to be an effective strategy for exciting grain boundary damping. The commonly used preparation method of the nanocrystalline metal material mainly comprises the steps of preparing the nanocrystalline material through high-energy ball milling, high-pressure torsion, equal-diameter angular extrusion, accumulated rolling, cold rolling and other serious plastic deformation processes. In recent years, the high-energy ball milling process is simple to operate, is suitable for various powder systems, and can be used for obtaining compact block materials with arbitrary shapes through sintering, so that the application field is wide, and the high-energy ball milling process is widely focused. The high-energy ball milling process is to obtain nanocrystalline pure magnesium material by plastically deforming the powder and increasing dislocation density to achieve grain refinement through recrystallization. At present, the high-energy ball milling process is mainly used for continuously prolonging the ball milling time to increase plastic deformation and dislocation density and refine grains in the recrystallization process. However, as the ball milling time increases, the dislocation density gradually increases, and when the increasing rate of the dislocation density and the dynamic recrystallization rate reach dynamic equilibrium, the grain size reaches a saturation value, and it is difficult to achieve the purpose of grain refinement even if the ball milling time is continuously increased, and the prepared nanocrystals generally stay in a larger nano-size range. Therefore, a new preparation method of nanocrystalline pure magnesium is needed, which can break through the grain size limitation of the traditional ball milling process, realize the preparation of smaller nanocrystalline, fully excite the grain boundary damping mechanism, and remarkably improve the damping performance of pure magnesium. Disclosure of Invention The invention overcomes the defects of the prior art, provides a preparation method of a high-damping nanocrystalline pure magnesium material, and solves the problem that the nanocrystalline pure magnesium cannot break through smaller nano-size under the prior process conditions, so that the magnesium damping performance is improved to a limited extent. The invention is realized by the following technical scheme: S1, sintering and solidifying Mg powder subjected to high-energy ball milling by adopting spark plasma to obtain a block material; S2, obtaining a pure magnesium bar through hot extrusion; And S3, performing electric pulse treatment on the pure magnesium bar, and inducing microstructure reconstruction to obtain the superfine nanocrystalline pure magnesium material. Preferably, the ball milling speed of the high-energy ball milling treatment is 200-300 rpm, and the ball milling time is 180-220 hours. Preferably, stearic acid is added to the Mg powder during the high energy ball milling process in an amount of 1.0 to 1.5 wt% by total Mg mass. Preferably, under the protection of inert atmosphere, the prepared Mg powder is placed in a stainless steel ball grinding tank, and then three stainless steel balls with different sizes are filled in the ball grinding tank for high-energy ball grinding. Preferably, the diameters of three stainless steel balls with different sizes are phi 5mm, phi 8 mm and phi 10 mm respectively, and the mass ratio is 5:3:2. Preferably, the spark plasma sintering is carried out in a spark plasma sintering furnace under the protection of inert atmosphere by adopting plasma discharge, the pressure in the furnace reaches 1-1.1 atmosphere, the heating temperature is 560-570 ℃, and the heat preservation time is 15-20 min. Preferably, the extrusion temperature of the hot extrusion is 370-400 ℃ and the extrusion ratio is 15-20:1. Preferably, the bar after hot extrusion is processed into pure magnesium sheets along the extrusion direction, and then subjected to electric pulse treatment. Preferably, the current density of the electrical pulse treatment is 0.43×10 8-1.25×108A/m2 and the treatment time is 12-15: 15 min. Preferably, the purity of the Mg powder adopted in the step S1 is more than or equal to 99.9 wt percent, and the particle size of the Mg powder is 63-75 mu m. Compared with the prior art, the invention has the following beneficial effects: 1. The preparation method of the invention can prepare the pure magnesium bar by high-energy ball milling, spark plasma sintering and hot extrusion, and then form the uniformly distributed nanocrystalline pure magnesium by electric pulse treatment and reconstruction of microstructure