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CN-121976099-A - Mg (magnesium)2Si/AZ91 composite material and preparation method thereof

CN121976099ACN 121976099 ACN121976099 ACN 121976099ACN-121976099-A

Abstract

The application discloses an Mg 2 Si/AZ91 composite material and a preparation method thereof, wherein the method comprises the following steps of cleaning and drying raw materials of Mg-5% Mn, al-30% Si and Mg-30% Ca intermediate alloy, smelting the raw materials of Mg, al, zn, mg-5% Mn intermediate alloy and Al-30% Si intermediate alloy under the combined protection of argon and a covering agent, obtaining an Mg 2 Si/AZ91 alloy melt after the raw materials are completely melted, adding Mg-30% Ca into the melt in the step 2, adding Sb particles into the melt in the step 3, cooling and stirring the melt prepared in the step 4, taking out slag, standing and casting into a mould, and preparing an Mg2Si/AZ91 composite material ingot. The Mg2Si/AZ91 composite material comprises the following components in percentage by mass of 2% of Sb, 1% of Zn, 2% of Al, 3% of Si, 2% of Al, 0.75% of Ca and the balance of Mg, wherein the sum of the mass percentages of the components is 100%. The application solves the problems of poor high-temperature mechanical property and limited strength-plasticity matching of the AZ91 alloy.

Inventors

  • WANG XUDONG
  • SHI HAO
  • Sun Benzhe
  • WANG XIAOXIA
  • WANG DONG
  • JIN GEGE
  • LI JUNJIE
  • LIU JIANXIONG

Assignees

  • 榆林学院
  • 府谷县旭丽机电技术有限公司

Dates

Publication Date
20260505
Application Date
20260210

Claims (7)

  1. 1. The Mg 2 Si/AZ91 composite material is characterized by comprising, by mass, 2% of Sb, 1% of Zn, 2% of Al, 3% of Si, 2% of Al, 0.75% of Ca and the balance of Mg, wherein the sum of the mass percentages of the components is 100%.
  2. 2. A method for preparing the Mg 2 Si/AZ91 composite material according to claim 1, which comprises the following specific steps: Step 1, preparing pure Mg, pure Al, pure Zn, pure Sb, mg-5% Mn, al-30% Si and Mg-30% Ca intermediate alloy, cleaning and drying the raw materials in advance, wherein the drying temperature is 65-100 ℃, cleaning by alcohol and drying by a blower; Step 2, smelting a pure Mg, al, zn, mg-5% Mn intermediate alloy and an Al-30% Si intermediate alloy serving as raw materials under the combined protection of argon and a covering agent, and obtaining an Mg 2 Si/AZ91 alloy melt after the raw materials are completely melted; step3, adding Mg-30% Ca into the melt in the step 2; step 4, pure Sb particles are added into the melt in the step 3 independently; And 5, reducing the temperature of the melt prepared in the step 4 to enable the melt to be semi-solid, mechanically stirring, fishing out slag, standing for a period of time, casting into a preheated mould in advance, and preparing the Mg 2 Si/AZ91 composite material cast ingot.
  3. 3. The method for preparing Mg 2 Si/AZ91 composite material according to claim 2, wherein in step 3, mg is 70% and ca is 30% of the alloy.
  4. 4. The method for preparing Mg 2 Si/AZ91 composite material according to claim 2, wherein the mass percentage of Ca in the alloy melt in step 3 is controlled to be 0.75%.
  5. 5. The method for preparing the Mg 2 Si/AZ91 composite material according to claim 2, wherein the Sb added in the step 4 is 2.0wt% of the total mass of the composite material.
  6. 6. The method for preparing a Mg 2 Si/AZ91 composite according to claim 2, wherein the temperature in step 5 is 740 ℃ to 760 ℃.
  7. 7. The method for preparing the Mg 2 Si/AZ91 composite material according to claim 2, wherein the covering agent is any one of RJ-2 solvent or KCl-MgCl 2 -NaCl mixed solvent.

Description

Mg 2 Si/AZ91 composite material and preparation method thereof Technical Field The invention belongs to the field of metal matrix composite materials, and particularly relates to a Mg 2 Si/AZ91 composite material and a preparation method thereof. Background Currently, among magnesium alloys, AZ91 is most widely used due to its good casting fluidity, excellent specific strength and mature industrialization base. However, the inherent performance shortboards of AZ91 alloy, especially their poor high temperature mechanical properties and limited strength plastic match, make it difficult to meet the severe requirements of power transmission systems under the same high Wen Fuyi working conditions, which greatly limits the further application of magnesium alloys. At present, the development of novel heat-resistant magnesium alloy and composite materials thereof has become a research hotspot in the field. The in-situ authigenic Mg 2 Si particle reinforced AZ91 composite material has great potential due to the advantages of good heat stability of the reinforced phase, strong interfacial bonding force between the reinforced phase and the matrix, and the like. However, the primary Mg 2 Si phase generally presents a coarse Chinese character shape, which can cause the concentration of internal stress and crack initiation of the material, thereby obviously reducing the mechanical property of the composite material. Disclosure of Invention The invention aims to provide a Mg 2 Si/AZ91 composite material and a preparation method thereof, which solve the problems of poor high-temperature mechanical property and limited strength-plasticity matching of an AZ91 alloy in the prior art. The application provides a technical scheme that: The Mg 2 Si/AZ91 composite material comprises, by mass, 2% of Sb, 1% of Zn, 2% of Al, 3% of Si, 2% of Al, 0.75% of Ca and the balance of Mg, wherein the sum of the mass percentages of the components is 100%. The invention also provides another technical scheme that the preparation method of the Mg 2 Si/AZ91 composite material comprises the following specific steps: Step 1, preparing pure Mg, pure Al, pure Zn, pure Sb, mg-5% Mn, al-30% Si and Mg-30% Ca intermediate alloy, cleaning and drying the raw materials in advance, cleaning with alcohol at the drying temperature of 65-100 ℃ and drying with a blower. And 2, smelting the pure Mg, al, zn, mg-5% Mn intermediate alloy and the Al-30% Si intermediate alloy serving as raw materials under the combined protection of argon and a covering agent, and obtaining the Mg 2 Si/AZ91 alloy melt after the raw materials are completely melted. And step 3, adding Mg-30% Ca into the melt in the step 2. And 4, independently adding pure Sb particles into the melt in the step 3. And 5, reducing the temperature of the melt prepared in the step 4 to enable the melt to be semi-solid, mechanically stirring, fishing out slag, standing for a period of time, casting into a preheated mould in advance, and preparing the Mg 2 Si/AZ91 composite material cast ingot. Further, in the step 3, the alloy comprises 70% of Mg and 30% of Ca. Further, the mass percentage of Ca in the alloy melt in the step 3 is controlled to be 0.75%. Further, the added amount of Sb in the step 4 is 2.0wt% of the total mass of the composite material. Further, the temperature in the step 5 is 740-760 ℃. Further, the covering agent is any one of RJ-2 solvent or KCl-MgCl 2 -NaCl mixed solvent. The method has the beneficial effects that the method realizes synergistic optimization modification treatment by combining the Sb and Ca elements in the modification process of the Mg 2 Si/AZ91 composite material and precisely regulating and controlling the addition proportion, modification temperature, heat preservation time and other key process parameters of the two elements, and finally prepares the Mg 2 Si/AZ91 composite material with regular morphology, fine size, uniform distribution and excellent comprehensive mechanical properties of the Mg 2 Si phase. Drawings FIG. 1 is a metallographic photograph of a Mg 2 Si/AZ91+2.0 wt% Sb composite material not modified by Ca in comparative example 1 of the present application, wherein the darker polygonal particles are Mg 2 Si, and the lighter polygonal particles are [ ]) A phase; FIG. 2 is a metallographic photograph of Mg 2 Si/AZ91+2.0 wt% Sb+0.75 wt% Ca composite material of example 1 of the present application, with a significant reduction in the size of the darker Mg 2 Si particles; FIG. 3 is a graph of tensile stress-strain at room temperature for four types of Mg 2 Si/AZ91+2.0 wt% Sb+x wt% Ca (x= 0,0.25,0.75,1.25) composites in example 1 of the present application, where the 0.75 wt% Ca content composites exhibited the best mechanical properties. Detailed Description The following description of the technical solutions in the embodiments of the present application will be clear and complete, and it is obvious that the described embodiments are only some embodiments