Nanoparticle reinforced zn-mg binary alloy and method of making same

Abstract

The application discloses a kind of nano-particle reinforced Zn-Mg binary alloy and its preparation method, and the preparation method steps are as follows: A, according to the mass percentage content of each component element, prepare as-cast Zn-Mg binary alloy;The mass percentage content of each component element is: 0.05-3.0% Mg, unavoidable impurity element content≤0.1%, the rest is Zn;B, the as-cast Zn-Mg binary alloy is annealed;C, after Zn-Mg binary alloy is kept at 200-300 DEG C for 2-4h, heat extrusion is carried out, and the extrusion temperature is 200-300 DEG C, the extrusion speed is 0.1-5mm / s, and the extrusion ratio is 9-30:1;D, after Zn-Mg binary alloy after heat extrusion is processed is placed in heat treatment furnace, with furnace temperature rises to 350-430 DEG C and carries out semi-solid isothermal treatment, and keeps for 0.1-4h, then water quenching;E, after Zn-Mg binary alloy is kept at 180-250 DEG C for 2-4h, secondary extrusion is carried out, namely, the extrusion temperature of secondary extrusion is 180-250 DEG C, the extrusion speed is 0.1-5mm / s, and extrusion ratio is 9-60:1.The Zn-Mg binary alloy prepared by the above preparation method has excellent yield strength, tensile strength and elongation.

Description

Technical Field

[0001] This invention relates to a nanoparticle-reinforced Zn-Mg binary alloy and its preparation method, belonging to the field of metal material preparation technology. Background Technology

[0002] Zn-Mg alloys are considered a new generation of biodegradable metallic materials. From a biomedical perspective, although Zn-Mg alloys have good biocompatibility, their strength and ductility are insufficient to meet the standards for biodegradable metals. Therefore, improving the mechanical properties of Zn-Mg alloys is of great significance for their application in biodegradable materials.

[0003] Non-precipitated Mg2Zn 11 The particle size and distribution state have a significant impact on the mechanical properties of Zn-Mg binary alloys. Currently, in modified Zn-Mg alloys, Mg2Zn... 11 The particles are mostly in the micrometer range, and existing deformation techniques make it difficult to further refine Mg2Zn. 11 Particle size. To obtain particle-reinforced Zn-Mg alloys with excellent mechanical properties, existing methods increase the volume fraction of the eutectic phase in the Zn-Mg alloy by increasing the Mg content. However, this leads to a decrease in the alloy's elongation and significantly increases the alloy's cost. In practical applications, Zn-Mg alloys are required to not only possess good biocompatibility and biodegradability but also excellent comprehensive mechanical properties. Therefore, developing high-performance Zn-Mg alloys with excellent yield strength, tensile strength, and elongation is an urgent problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a nanoparticle-reinforced Zn-Mg binary alloy. This method combines semi-solid isothermal treatment and two hot extrusion treatments, and the prepared nanoparticle-reinforced Zn-Mg binary alloy has excellent yield strength, tensile strength and elongation.

[0005] The technical solution adopted by this invention to achieve its objective is: a nanoparticle-reinforced Zn-Mg binary alloy and its preparation method, the preparation method steps are as follows:

[0006] A. Prepare a cast Zn-Mg binary alloy according to the set mass percentage of each component element; the set mass percentage of each component element is: 0.05-3.0%Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn;

[0007] B. Anneal the as-cast Zn-Mg binary alloy prepared in step A;

[0008] C. After holding the annealed Zn-Mg binary alloy obtained in step B at 200-300℃ for 2-4 hours, hot extrusion is carried out at an extrusion temperature of 200-300℃, an extrusion speed of 0.1-5mm / s, and an extrusion ratio of 9-30:1.

[0009] D. Place the hot-extruded Zn-Mg binary alloy obtained in step C into a heat treatment furnace, heat it to 350-430℃ with the furnace for semi-solid isothermal treatment, hold it for 0.1-4 hours, and then water-quench it.

[0010] E. After holding the Zn-Mg binary alloy obtained in step D at 180-250℃ for 2-4 hours, it is then subjected to secondary extrusion to obtain nanoparticle-reinforced Zn-Mg binary alloy; the extrusion temperature of the secondary extrusion is 180-250℃, the extrusion speed is 0.1-5mm / s, and the extrusion ratio is 9-60:1.

[0011] The reaction principle of this invention is as follows: the as-cast Zn-Mg binary alloy eutectic phase morphology obtained in step A is a eutectic with micron-level lamellar spacing (α-Zn + Mg2Zn). 11 The microstructure, after annealing in step B and hot extrusion in step C, breaks down the micron-sized eutectic structure into micron-sized Mg2Zn. 11 Particles; then processed in step D to produce micron-sized Mg2Zn. 11 The particles transform into a eutectic (α-Zn + Mg2Zn) with a lamellar spacing on the nanometer scale. 11 The structure is then subjected to a second extrusion in step E, which breaks down the nanoscale eutectic structure into nanoscale Mg2Zn. 11 Particles are dispersed on the α-Zn matrix to prepare a high-performance Zn-Mg binary alloy with excellent yield strength, tensile strength and elongation.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] I. The mass percentage content of the constituent elements set in step A ensures that the eutectic (α-Zn + Mg2Zn) can be obtained through subsequent processing steps B, C, and D. 11 A Zn-Mg binary alloy with a lamellar spacing of nanometers.

[0014] Second, step B, annealing, removes stress from the alloy, giving it better workability; then, step C, hot extrusion, yields micron-sized Mg2Zn alloy. 11 Particle-reinforced Zn-Mg binary composite.

[0015] III. Step D yields micron-sized Mg2Zn from step C. 11Particle-reinforced Zn-Mg binary alloys were subjected to semi-solid treatment. By controlling the semi-solid treatment temperature and time, as well as the post-semi-solid water quenching temperature, a eutectic (α-Zn + Mg2Zn) was obtained in a short time. 11 A Zn-Mg binary alloy with a lamellar spacing of nanometers.

[0016] IV. This invention achieves the eutectic (α-Zn + Mg2Zn) 11 After forming a Zn-Mg binary alloy with a lamellar spacing on the nanometer scale, a secondary extrusion method is selected to fragment the nano-eutectic phase into nano-sized Mg2Zn. 11 The particles, dispersedly distributed on the α-Zn matrix, yielded nano-sized Mg2Zn. 11 Particle-reinforced Zn-Mg binary alloy.

[0017] In summary, this invention, based on the traditionally cast Zn-Mg binary alloy, combines primary extrusion, semi-solid treatment, and secondary extrusion processes to achieve the transformation of the second phase in the alloy from micron-scale lamellar to micron-scale particles, then to nano-scale lamellar, and finally to nano-scale particles, thus obtaining nano-scale Mg2Zn alloy. 11 Particle-reinforced Zn-Mg binary alloy, Mg2Zn in this invention 11 The particles are all non-precipitated, fragmented second phases in the deformed Zn-Mg binary alloy. Refining the dispersed particle phases on the α-Zn matrix can improve the strengthening effect of the second phase, significantly improve the comprehensive mechanical properties of the Zn-Mg binary alloy, and greatly expand the application range of Zn-Mg binary alloys.

[0018] Furthermore, in step A of the preparation method of the present invention, the mass percentage content of each constituent element in the preparation of the as-cast Zn-Mg binary alloy is set as follows: 0.1-1.1%Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn.

[0019] Experiments have verified that the mass percentage of the above elements can prepare a stable eutectic (α-Zn + Mg2Zn). 11 The Zn-Mg binary alloy with a lamellar spacing of less than 100 nm, without the addition of other strengthening alloying elements, greatly simplifies the preparation of the alloy and reduces the preparation cost.

[0020] Furthermore, the specific operation of step A in the preparation method of the present invention for preparing the as-cast Zn-Mg binary alloy is as follows: according to the set mass percentage ratio of each component element, pure Zn is placed in a crucible and heated to 300-400℃, and CO2 protective gas is introduced. After the pure Zn has completely melted, a mixed protective gas of CO2+SF6 is introduced. Pure Mg is placed in the pure Zn melt using a bell jar, and the temperature is continued to be heated to 450-540℃. After stirring for 2-5 minutes, slag is removed, and the mixture is allowed to stand for 5-15 minutes. When the temperature drops to 430-470℃, the mixture is poured to obtain the as-cast Zn-Mg binary alloy.

[0021] Furthermore, in the preparation method of the present invention, the annealing temperature of step B, annealing treatment, is 270-350℃, and the annealing time is 10-24h.

[0022] Furthermore, in step C of the preparation method of the present invention, the extrusion ratio for hot extrusion of the annealed Zn-Mg binary alloy obtained in step B is 9-15:1.

[0023] Experiments have verified that the above extrusion ratio can make the thickness of the semi-solid Zn-Mg binary alloy more uniform, which is beneficial for preparing Zn-Mg binary alloys with stable nanoscale layer thickness. This, in turn, is conducive to preparing nanoscale Mg2Zn alloys with excellent properties in all aspects. 11 Particle-reinforced Zn-Mg binary alloy.

[0024] Furthermore, in step D of the preparation method of the present invention, the hot-extruded Zn-Mg binary alloy obtained in step C is placed in a heat treatment furnace and heated to 370-410℃ for semi-solid isothermal treatment, held for 0.1-1h, and then water-cooled and quenched.

[0025] Experiments have verified that the above temperature range and holding time are more conducive to the preparation of Zn-Mg binary alloys with stable nanoscale interlamellar spacing, thus facilitating the preparation of nanoscale Mg2Zn alloys with excellent properties in all aspects. 11 Particle-reinforced Zn-Mg binary alloy.

[0026] Furthermore, in step D of the preparation method of the present invention, the quenching medium for water-cooled quenching is water at 20-80°C.

[0027] Experiments have verified that quenching with water within the aforementioned temperature range results in a more uniform layer thickness in the semi-solid Zn-Mg binary alloy. This is beneficial for preparing Zn-Mg binary alloys with stable nanoscale layer thickness, and consequently, for preparing nanoscale Mg2Zn alloys with excellent properties in all aspects. 11 Particle-reinforced Zn-Mg binary alloy.

[0028] Furthermore, the extrusion ratio of the secondary extrusion in step E of the preparation method of the present invention is 9-30:1.

[0029] Experiments have verified that the Zn-Mg binary alloy prepared by the above-mentioned secondary extrusion ratio has better comprehensive mechanical properties and can produce high-performance Zn alloys with excellent yield strength, tensile strength and elongation. Attached Figure Description

[0030] Figure 1 The image shows the tensile curve of the nanoparticle-reinforced Zn-Mg binary alloy prepared in Example 5 of this invention.

[0031] Figure 2 The image shows the OM image of the nanoparticle-reinforced Zn-Mg binary alloy semi-solid structure prepared in step D of embodiment five of the present invention.

[0032] Figure 3 This is a SEM image of the nanoparticle-reinforced Zn-Mg binary alloy semi-solid structure prepared in step D of embodiment five of the present invention.

[0033] Figure 4 This is a SEM image of the extruded microstructure of the nanoparticle-reinforced Zn-Mg binary alloy prepared in step E of Example 5 of the present invention. Detailed Implementation

[0034] Example 1

[0035] A nanoparticle-reinforced Zn-Mg binary alloy and its preparation method are described below:

[0036] A. Prepare a cast Zn-Mg binary alloy according to the set mass percentage ratio of each component element; the set mass percentage of each component element is as follows: 0.1% Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn; the specific operation for preparing the cast Zn-Mg binary alloy is as follows: pure Zn is placed in a crucible and heated to 300°C, and CO2 protective gas is introduced. After the pure Zn is completely melted, a CO2+SF6 mixed protective gas is introduced. Pure Mg is placed in the pure Zn melt using a bell jar, and the temperature is continued to rise to 450°C. After stirring for 5 minutes, the slag is removed, and the mixture is allowed to stand for 10 minutes. When the temperature drops to 450°C, the mixture is poured to obtain the cast Zn-Mg binary alloy.

[0037] B. Anneal the as-cast Zn-Mg binary alloy prepared in step A at 300℃ for 10 hours, and then cool it in the furnace.

[0038] C. After the annealed Zn-Mg binary alloy obtained in step B is kept at 250℃ for 4 hours, it is hot extruded. The extrusion temperature is 250℃, the extrusion speed is 2mm / s, and the extrusion ratio is 9:1.

[0039] D. Place the hot-extruded Zn-Mg binary alloy obtained in step C into a heat treatment furnace, heat it to 380℃ with the furnace for semi-solid isothermal treatment, hold it for 60 minutes, and then water-quench it. The quenching medium for water-quenching is water at 80℃.

[0040] E. After holding the Zn-Mg binary alloy obtained in step D at 200℃ for 2 hours, it is then subjected to a second extrusion to obtain a nanoparticle-reinforced Zn-Mg binary alloy. The extrusion temperature of the second extrusion is 200℃, the extrusion speed is 2 mm / s, and the extrusion ratio is 10:1.

[0041] The Zn-Mg binary alloy prepared in this example has a tensile strength of 299 MPa, a yield strength of 263 MPa, and an elongation of 10.41%.

[0042] Example 2

[0043] A nanoparticle-reinforced Zn-Mg binary alloy and its preparation method are described below:

[0044] A. Prepare a cast Zn-Mg binary alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 0.2% Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn; the specific operation for preparing the cast Zn-Mg binary alloy is as follows: according to the set mass percentage ratio of each component element, place pure Zn in a crucible and heat it to 350°C, then introduce CO2 protective gas. After the pure Zn has completely melted, introduce a CO2+SF6 mixed protective gas. Use a bell jar to place pure Mg in the pure Zn melt, continue heating to 470°C, stir for 4 minutes, remove slag, let stand for 12 minutes, and when the temperature drops to 440°C, pour it to obtain the cast Zn-Mg binary alloy.

[0045] B. Anneal the as-cast Zn-Mg binary alloy prepared in step A at 320℃ for 12 hours and then cool it in the furnace.

[0046] C. After the annealed Zn-Mg binary alloy obtained in step B is kept at 240℃ for 4 hours, it is hot extruded. The extrusion temperature is 240℃, the extrusion speed is 1.8mm / s, and the extrusion ratio is 10:1.

[0047] D. Place the hot-extruded Zn-Mg binary alloy obtained in step C into a heat treatment furnace, heat it to 410℃ with the furnace for semi-solid isothermal treatment, hold it for 10 minutes, and then water-quench it. The quenching medium for water-quenching is water at 50℃.

[0048] E. After holding the Zn-Mg binary alloy obtained in step D at 190℃ for 2.5h, it is then subjected to secondary extrusion to obtain nanoparticle-reinforced Zn-Mg binary alloy; the extrusion temperature of the secondary extrusion is 190℃, the extrusion speed is 1.7mm / s, and the extrusion ratio is 10:1.

[0049] The Zn-Mg binary alloy prepared in this example has a tensile strength of 329 MPa, a yield strength of 284 MPa, and an elongation of 8.65%.

[0050] Example 3

[0051] A nanoparticle-reinforced Zn-Mg binary alloy and its preparation method are described below:

[0052] A. Prepare a cast Zn-Mg binary alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 0.5% Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn; the specific operation for preparing the cast Zn-Mg binary alloy is as follows: according to the set mass percentage ratio of each component element, place pure Zn in a crucible and heat it to 380°C, then introduce CO2 protective gas. After the pure Zn has completely melted, introduce a mixed protective gas of CO2 + SF6. Use a bell jar to place pure Mg in the pure Zn melt, continue heating to 510°C, stir for 4 minutes, remove slag, let stand for 8 minutes, and when the temperature drops to 455°C, pour it to obtain the cast Zn-Mg binary alloy.

[0053] B. Anneal the as-cast Zn-Mg binary alloy prepared in step A at 330℃ for 23h, and then cool it in the furnace.

[0054] C. After the annealed Zn-Mg binary alloy obtained in step B is kept at 225℃ for 3 hours, it is hot extruded. The extrusion temperature is 225℃, the extrusion speed is 1mm / s, and the extrusion ratio is 20:1.

[0055] D. Place the hot-extruded Zn-Mg binary alloy obtained in step C into a heat treatment furnace, heat it to 400℃ with the furnace for semi-solid isothermal treatment, hold it for 20 minutes, and then water-quench it. The quenching medium for water-quenching is water at 40℃.

[0056] E. After holding the Zn-Mg binary alloy obtained in step D at 205℃ for 3 hours, it is then subjected to a second extrusion to obtain a nanoparticle-reinforced Zn-Mg binary alloy. The extrusion temperature of the second extrusion is 205℃, the extrusion speed is 0.95mm / s, and the extrusion ratio is 10:1.

[0057] The Zn-Mg binary alloy prepared in this example has a tensile strength of 366 MPa, a yield strength of 318 MPa, and an elongation of 6.85%.

[0058] Example 4

[0059] A nanoparticle-reinforced Zn-Mg binary alloy and its preparation method are described below:

[0060] A. Prepare a cast Zn-Mg binary alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 1% Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn; the specific operation for preparing the cast Zn-Mg binary alloy is as follows: according to the set mass percentage ratio of each component element, place pure Zn in a crucible and heat it to 400°C, then introduce CO2 protective gas. After the pure Zn has completely melted, introduce a CO2+SF6 mixed protective gas. Use a bell jar to place pure Mg in the pure Zn melt, continue heating to 530°C, stir for 4 minutes, remove slag, let stand for 12 minutes, and when the temperature drops to 468°C, pour it to obtain the cast Zn-Mg binary alloy.

[0061] B. Anneal the as-cast Zn-Mg binary alloy prepared in step A at 308℃ for 18h and then cool it in the furnace.

[0062] C. After the annealed Zn-Mg binary alloy obtained in step B is kept at 260℃ for 4 hours, it is hot extruded. The extrusion temperature is 260℃, the extrusion speed is 3mm / s, and the extrusion ratio is 25:1.

[0063] D. Place the hot-extruded Zn-Mg binary alloy obtained in step C into a heat treatment furnace, heat it to 380℃ with the furnace for semi-solid isothermal treatment, hold it for 30 minutes, and then water-quench it. The quenching medium for water-quenching is water at 25℃.

[0064] E. After holding the Zn-Mg binary alloy obtained in step D at 205℃ for 2.5h, it is then subjected to secondary extrusion to obtain nanoparticle-reinforced Zn-Mg binary alloy; the extrusion temperature of the secondary extrusion is 205℃, the extrusion speed is 2.5mm / s, and the extrusion ratio is 15:1.

[0065] The Zn-Mg binary alloy prepared in this example has a tensile strength of 462 MPa, a yield strength of 362 MPa, and an elongation of 6.4%.

[0066] Example 5

[0067] A nanoparticle-reinforced Zn-Mg binary alloy and its preparation method are described below:

[0068] A. Prepare a cast Zn-Mg binary alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 1.5% Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn; the specific operation for preparing the cast Zn-Mg binary alloy is as follows: according to the set mass percentage ratio of each component element, place pure Zn in a crucible and heat it to 390°C, then introduce CO2 protective gas. After the pure Zn has completely melted, introduce a CO2+SF6 mixed protective gas. Use a bell jar to place pure Mg in the pure Zn melt, continue heating to 519°C, stir for 4 minutes, remove slag, let stand for 12 minutes, and when the temperature drops to 448°C, pour it to obtain the cast Zn-Mg binary alloy.

[0069] B. Anneal the as-cast Zn-Mg binary alloy prepared in step A at 335℃ for 15h and then cool it in the furnace.

[0070] C. After the annealed Zn-Mg binary alloy obtained in step B is held at 261℃ for 4 hours, it is hot extruded. The extrusion temperature is 261℃, the extrusion speed is 2.4 mm / s, and the extrusion ratio is 20:1.

[0071] D. Place the hot-extruded Zn-Mg binary alloy obtained in step C into a heat treatment furnace, heat it to 385℃ with the furnace for semi-solid isothermal treatment, hold it for 45 minutes, and then water-quench it. The quenching medium for water-quenching is water at 20℃.

[0072] E. After holding the Zn-Mg binary alloy obtained in step D at 185℃ for 3.5h, it is then subjected to secondary extrusion to obtain nanoparticle-reinforced Zn-Mg binary alloy; the extrusion temperature of the secondary extrusion is 185℃, the extrusion speed is 2mm / s, and the extrusion ratio is 15:1.

[0073] The Zn-Mg binary alloy prepared in this example has a tensile strength of 478 MPa, a yield strength of 377 MPa, and an elongation of 5.95%.

[0074] Figure 1 The tensile curve of the nanoparticle-reinforced Zn-Mg binary alloy prepared in Example 5 above. Figure 2 This is an OM image of the semi-solid structure of the Zn-Mg binary alloy after semi-solid isothermal treatment in this embodiment. After semi-solid isothermal treatment, the grains gradually become equiaxed, solute atoms are enriched at the grain boundaries and remelted, and after rapid quenching, a eutectic structure with a continuous network structure is formed. Figure 3 This is a SEM image of the semi-solid microstructure of the Zn-Mg binary alloy after semi-solid isothermal treatment in this embodiment. It can be seen that under high solute diffusion rate and short diffusion distance, Mg2Zn 11 The eutectic phase is refined to the nanoscale. Figure 4 This is a SEM image of the extruded microstructure of the nanoparticle-reinforced Zn-Mg binary alloy prepared in step E of Example 5 of this invention. Figure 4 Image (a) shows a SEM image of the hot-extruded nanoparticle-reinforced Zn-Mg binary alloy, with nano-Mg2Zn at the grain boundaries. 11 The layers were completely broken into nano-Mg2Zn 11 The particles are distributed in a band-like pattern along the extrusion direction. Figure 4 Image (b) is a magnified view of a portion of image (a), showing the broken Mg2Zn. 11 The particles are dispersed in the matrix, while some submicron-sized Mg2Zn particles that have not been fully refined still exist. 11 Particles.

[0075] Example 6

[0076] A nanoparticle-reinforced Zn-Mg binary alloy and its preparation method are described below:

[0077] A. Prepare a cast Zn-Mg binary alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 0.05% Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn; the specific operation for preparing the cast Zn-Mg binary alloy is as follows: according to the set mass percentage ratio of each component element, place pure Zn in a crucible and heat it to 350°C, then introduce CO2 protective gas. After the pure Zn has completely melted, introduce a CO2+SF6 mixed protective gas. Use a bell jar to place pure Mg in the pure Zn melt, continue heating to 540°C, stir for 2 minutes, remove slag, let stand for 15 minutes, and when the temperature drops to 470°C, pour it to obtain the cast Zn-Mg binary alloy.

[0078] B. Anneal the as-cast Zn-Mg binary alloy prepared in step A at 270℃ for 24 hours, and then cool it in the furnace.

[0079] C. After the annealed Zn-Mg binary alloy obtained in step B is kept at 200℃ for 4 hours, it is hot extruded. The extrusion temperature is 200℃, the extrusion speed is 0.1mm / s, and the extrusion ratio is 15:1.

[0080] D. Place the hot-extruded Zn-Mg binary alloy obtained in step C into a heat treatment furnace, heat it to 350℃ with the furnace for semi-solid isothermal treatment, hold it for 4 hours, and then water-quench it. The quenching medium for water-quenching is water at 20℃.

[0081] E. After holding the Zn-Mg binary alloy obtained in step D at 180℃ for 4 hours, it is then subjected to secondary extrusion to obtain nanoparticle-reinforced Zn-Mg binary alloy; the extrusion temperature of the secondary extrusion is 180℃, the extrusion speed is 0.1mm / s, and the extrusion ratio is 9:1.

[0082] Example 7

[0083] A nanoparticle-reinforced Zn-Mg binary alloy and its preparation method are described below:

[0084] A. Prepare a cast Zn-Mg binary alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 1.1% Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn; the specific operation for preparing the cast Zn-Mg binary alloy is as follows: according to the set mass percentage ratio of each component element, place pure Zn in a crucible and heat it to 400°C, then introduce CO2 protective gas. After the pure Zn has completely melted, introduce a mixed protective gas of CO2 + SF6. Use a bell jar to place pure Mg in the pure Zn melt, continue heating to 530°C, stir for 4 minutes, remove slag, let stand for 5 minutes, and when the temperature drops to 430°C, pour it to obtain the cast Zn-Mg binary alloy.

[0085] B. Anneal the as-cast Zn-Mg binary alloy prepared in step A at 350℃ for 15 hours, and then cool it in the furnace.

[0086] C. After the annealed Zn-Mg binary alloy obtained in step B is kept at 300℃ for 2 hours, it is hot extruded. The extrusion temperature is 300℃, the extrusion speed is 5mm / s, and the extrusion ratio is 30:1.

[0087] D. Place the hot-extruded Zn-Mg binary alloy obtained in step C into a heat treatment furnace, heat it to 430℃ with the furnace for semi-solid isothermal treatment, hold it for 6 minutes, and then water-quench it. The quenching medium for water-quenching is water at 80℃.

[0088] E. After holding the Zn-Mg binary alloy obtained in step D at 250℃ for 2 hours, it is then subjected to secondary extrusion to obtain nanoparticle-reinforced Zn-Mg binary alloy; the extrusion temperature of the secondary extrusion is 250℃, the extrusion speed is 5mm / s, and the extrusion ratio is 60:1.

[0089] Example 8

[0090] A nanoparticle-reinforced Zn-Mg binary alloy and its preparation method are described below:

[0091] A. Prepare a cast Zn-Mg binary alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 3.0% Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn; the specific operation for preparing the cast Zn-Mg binary alloy is as follows: according to the set mass percentage ratio of each component element, place pure Zn in a crucible and heat it to 400°C, then introduce CO2 protective gas. After the pure Zn has completely melted, introduce a CO2+SF6 mixed protective gas. Use a bell jar to place pure Mg in the pure Zn melt, continue heating to 519°C, stir for 4 minutes, remove slag, let stand for 12 minutes, and when the temperature drops to 448°C, pour it to obtain the cast Zn-Mg binary alloy.

[0092] B. Anneal the as-cast Zn-Mg binary alloy prepared in step A at 335℃ for 15h and then cool it in the furnace.

[0093] C. After the annealed Zn-Mg binary alloy obtained in step B is held at 261℃ for 4 hours, it is hot extruded. The extrusion temperature is 261℃, the extrusion speed is 2.4 mm / s, and the extrusion ratio is 20:1.

[0094] D. Place the hot-extruded Zn-Mg binary alloy obtained in step C into a heat treatment furnace, heat it to 370℃ with the furnace for semi-solid isothermal treatment, hold it for 45 minutes, and then water-quench it. The quenching medium for water-quenching is water at 30℃.

[0095] E. After holding the Zn-Mg binary alloy obtained in step D at 250℃ for 2 hours, it is then subjected to secondary extrusion to obtain nanoparticle-reinforced Zn-Mg binary alloy; the extrusion temperature of the secondary extrusion is 250℃, the extrusion speed is 5mm / s, and the extrusion ratio is 30:1.

[0096] Example 9

[0097] A nanoparticle-reinforced Zn-Mg binary alloy and its preparation method are described below:

[0098] A. Prepare a cast Zn-Mg binary alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 3.0% Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn; the specific operation for preparing the cast Zn-Mg binary alloy is as follows: according to the set mass percentage ratio of each component element, place pure Zn in a crucible and heat it to 400°C, then introduce CO2 protective gas. After the pure Zn has completely melted, introduce a CO2+SF6 mixed protective gas. Use a bell jar to place pure Mg in the pure Zn melt, continue heating to 519°C, stir for 4 minutes, remove slag, let stand for 12 minutes, and when the temperature drops to 448°C, pour it to obtain the cast Zn-Mg binary alloy.

[0099] B. Anneal the as-cast Zn-Mg binary alloy prepared in step A at 335℃ for 15h and then cool it in the furnace.

[0100] C. After the annealed Zn-Mg binary alloy obtained in step B is held at 261℃ for 4 hours, it is hot extruded. The extrusion temperature is 261℃, the extrusion speed is 2.4 mm / s, and the extrusion ratio is 20:1.

[0101] D. Place the hot-extruded Zn-Mg binary alloy obtained in step C into a heat treatment furnace, heat it to 410℃ with the furnace for semi-solid isothermal treatment, hold it for 30 minutes, and then quench it with water at 40℃.

[0102] E. After holding the Zn-Mg binary alloy obtained in step D at 185℃ for 3.5h, it is then subjected to secondary extrusion to obtain nanoparticle-reinforced Zn-Mg binary alloy; the extrusion temperature of the secondary extrusion is 185℃, the extrusion speed is 2mm / s, and the extrusion ratio is 15:1.

Claims

1. A method for preparing a nanoparticle-reinforced Zn-Mg binary alloy, comprising the following steps: A. Prepare a cast Zn-Mg binary alloy according to the set mass percentage of each component element; the set mass percentage of each component element is: 0.05-3.0%Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn; B. Anneal the as-cast Zn-Mg binary alloy prepared in step A; C. After holding the annealed Zn-Mg binary alloy obtained in step B at 200-300℃ for 2-4 hours, hot extrusion is performed to break the eutectic structure with micron-level interlamellar spacing into micron-level Mg2Zn. 11 The granules are extruded at a temperature of 200-300℃, an extrusion speed of 0.1-5mm / s, and an extrusion ratio of 9-30:

1. D. Place the hot-extruded Zn-Mg binary alloy obtained in step C into a heat treatment furnace and heat it to 370-410℃ for semi-solid isothermal treatment, holding it at that temperature for 0.1-1h to obtain eutectic α-Zn+Mg2Zn with nanometer-scale interlaminar spacing. 11 The Zn-Mg binary alloy was then water-quenched. E. After holding the Zn-Mg binary alloy obtained in step D at 180-250℃ for 2-4 hours, perform a second extrusion to make the interlamellar spacing of the Zn-Mg binary alloy a nanometer-scale eutectic α-Zn+Mg2Zn. 11 The tissue was broken into Mg2Zn 11 Nanoparticles are dispersed in the α-Zn matrix to obtain a nanoparticle-reinforced Zn-Mg binary alloy; the extrusion temperature of the secondary extrusion is 180-250℃, the extrusion speed is 0.1-5mm / s, and the extrusion ratio is 9-60:

1.

2. The method for preparing a nanoparticle-reinforced Zn-Mg binary alloy according to claim 1, characterized in that: The mass percentage of each component element in step A for preparing the as-cast Zn-Mg binary alloy is set as follows: 0.1-1.1% Mg, unavoidable impurity element content ≤0.1%, and the remainder is Zn.

3. The method for preparing a nanoparticle-reinforced Zn-Mg binary alloy according to claim 1, characterized in that: The specific operation for preparing the as-cast Zn-Mg binary alloy in step A is as follows: According to the set mass percentage ratio of each component element, pure Zn is placed in a crucible and heated to 300-400℃. CO2 protective gas is introduced. After the pure Zn has completely melted, a mixed protective gas of CO2 and SF6 is introduced. Pure Mg is placed in the pure Zn melt using a bell jar. The mixture is heated to 450-540℃, stirred for 2-5 minutes, and then slag is removed. The mixture is allowed to stand for 5-15 minutes. When the temperature drops to 430-470℃, it is poured to obtain the as-cast Zn-Mg binary alloy.

4. The method for preparing a nanoparticle-reinforced Zn-Mg binary alloy according to claim 1, characterized in that: The annealing temperature for the annealing process is 270-350℃, and the annealing time is 10-24h.

5. The method for preparing a nanoparticle-reinforced Zn-Mg binary alloy according to claim 1, characterized in that: In step C, the hot extrusion ratio of the annealed Zn-Mg binary alloy obtained in step B is 9-15:

1.

6. The method for preparing a nanoparticle-reinforced Zn-Mg binary alloy according to claim 1, characterized in that: In step D, the quenching medium for water-cooled quenching is water at 20-80℃.

7. The method for preparing a nanoparticle-reinforced Zn-Mg binary alloy according to claim 1, characterized in that: The extrusion ratio for the secondary extrusion in step E is 9-30:

1.

8. A nanoparticle-reinforced Zn-Mg binary alloy, characterized in that: The nanoparticle-reinforced Zn-Mg binary alloy is prepared by any one of the preparation methods according to claims 1-7.

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