CN115896513A - Rare earth adding method for rare earth-containing magnesium alloy - Google Patents

Abstract

The invention relates to the technical field of nonferrous metal production, in particular to a method for adding rare earths to magnesium alloys containing rare earths. The method for adding rare earths to magnesium alloys containing rare earths is characterized in that the rare earths are added in the form of rare earth ternary alloys, the rare earth ternary alloys are RE1-RE2-RE3, and the RE1, RE2, and RE3 are each independently La, Ce, and Pr , Nd, Sm, Y, Sc, Gd, Dy, Ho, Er in one. The rare earth addition method of the present invention reduces the melting point of the rare earth ternary alloy to 680-740°C by rationally proportioning the contents of the rare earth elements, which is basically the same as the melting temperature of the magnesium alloy; and cancels the preparation of the magnesium-rare earth master alloy, which can Add directly according to the ratio of demand, reducing the cost of materials.

Description

A kind of rare earth addition method of magnesium alloy containing rare earth

technical field

The invention relates to the technical field of nonferrous metal production, in particular to a method for adding rare earths to magnesium alloys containing rare earths.

Background technique

Rare earth elements have the functions of removing hydrogen, oxygen, iron and slag in magnesium alloys, and can purify the melt. The rare earth has high activity and can form a dense oxide film on the surface of the magnesium alloy melt to isolate the atmosphere and protect the melt. In addition, adding rare earths as alloying and microalloying elements to magnesium alloys can play the role of fine grain strengthening, solid solution strengthening, precipitation strengthening and aging strengthening, and improve the mechanical properties and heat resistance of magnesium alloys. However, the melting point of rare earth elements is relatively high, which is quite different from that of magnesium, so it is difficult to add them directly. For industrial applications, they are generally added in the form of low melting point magnesium-based rare earth master alloys. This method of addition requires the preparation of master alloys in advance, and the cost is high. The invention aims at this problem, and provides a novel rare earth addition method for reducing the cost of the rare earth magnesium alloy, which can greatly reduce the material cost.

Therefore, how to provide a rare earth addition method to reduce the cost of rare earth magnesium alloys, so as to reduce the production cost of magnesium alloy materials, is a technical problem to be solved urgently by those skilled in the art.

Contents of the invention

The object of the present invention is to provide a method for adding rare earths to magnesium alloys containing rare earths, so as to solve the defects in the prior art.

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

The invention provides a method for adding rare earth to a magnesium alloy containing rare earth. The rare earth is added in the form of a rare earth ternary alloy.

Preferably, the rare earth ternary alloy is RE1-RE2-RE3, and the RE1, RE2, RE3 are each independently one of La, Ce, Pr, Nd, Sm, Y, Sc, Gd, Dy, Ho, Er kind.

Preferably, the RE1 mass percentage is 40-65%.

Preferably, the RE2 mass percentage is 10-40%.

Preferably, the RE3 mass percentage is 5-30%.

It can be seen from the above technical solutions that, compared with the prior art, the present invention has the following beneficial effects:

1. The rare earth addition method of the present invention reduces the melting point of the rare earth ternary alloy to 680-740°C by rationally proportioning the content of each rare earth element, which is basically the same as the melting temperature of the magnesium alloy;

2. The rare earth addition method of the present invention cancels the preparation of the magnesium-rare earth master alloy, and can be directly added according to the required ratio, reducing the material cost.

Detailed ways

The present invention provides a method for adding rare earths to magnesium alloys containing rare earths. The rare earths are added in the form of rare earth ternary alloys.

In the present invention, the rare earth ternary alloy is RE1-RE2-RE3, and the RE1, RE2, RE3 are each independently La, Ce, Pr, Nd, Sm, Y, Sc, Gd, Dy, Ho, Er One of, preferably one of La, Ce, Pr, Nd, Sm, Y, Sc, Gd, Ho, Er.

In the present invention, the RE1 mass percentage is 40-65%, preferably 41-63%.

In the present invention, the RE2 mass percentage is 10-40%, preferably 12-38%.

In the present invention, the RE3 mass percentage is 5-30%, preferably 6-28%.

The technical solutions provided by the present invention will be described in detail below in conjunction with the examples, but they should not be interpreted as limiting the protection scope of the present invention.

The refining agent used in the examples and comparative examples of the present invention is No. RJ-6 flux.

Example 1

Prepare a Mg-6Zn-3La-Sm-Y-Mn alloy, wherein the Zn content is 5.0% to 6.0% by mass percentage, the La content is 2.8% to 3.5% by mass percentage, and the Sm content is 0.5% to 1.2% by mass percentage , the Y content is 0.5%-1.2% by mass percentage, the Mn content is 0.3%-1.0% by mass percentage, and the balance is Mg.

Preparation of Mg-6Zn-3La-Sm-Y-Mn Alloy by Adding Rare Earth in La ₆₀ Sm ₂₀ Y ₂₀ Ternary Alloy

(1) According to the mass percentage of each element, Mg is added in the form of pure magnesium ingot, Zn is added in the form of pure zinc ingot, La, Sm, and Y are added in the form of La ₆₀ Sm ₂₀ Y ₂₀ , and Mn is added in the form of Mg-20Mn master alloy join in.

(2) Preheat the crucible to 200°C, add the configured pure magnesium ingots, pure zinc ingots and Mg-20Mn master alloy, and pass in protective gas when the temperature rises to 400°C, the composition of the protective gas is CO ₂ +SF ₆ .

(3) After melting, raise the temperature to 700°C and add the prepared La ₆₀ Sm ₂₀ Y ₂₀ alloy, and fully stir the melt for 8 minutes after melting.

(4) Raise the temperature to 720° C. and add 1.5% of the refining agent accounting for the mass percentage of the melt in batches, and continuously stir the melt for refining treatment, and the refining time is 13 minutes.

(5) After refining, remove the scum on the surface, keep it warm at 720°C, and let it stand for 40 minutes.

(6) The alloy liquid is poured into a metal mold for forming.

Comparative example 1

Prepare a Mg-6Zn-3La-Sm-Y-Mn alloy, wherein the Zn content is 5.0% to 6.0% by mass percentage, the La content is 2.8% to 3.5% by mass percentage, and the Sm content is 0.5% to 1.2% by mass percentage , the Y content is 0.5%-1.2% by mass percentage, the Mn content is 0.3%-1.0% by mass percentage, and the balance is Mg.

Mg-6Zn-3La-Sm-Y-Mn alloys are prepared by adding rare earths to conventional Mg-30La, Mg-30Sm, and Mg-30Y master alloys.

(1) According to the mass percentage of each element, Mg is added in the form of pure magnesium ingot, Zn is added in the form of pure zinc ingot, La is added in the form of Mg-30La master alloy, Sm is added in the form of Mg-30Sm master alloy, and Y is added in the form of Mg -30Y master alloy is added, and Mn is added as Mg-20Mn master alloy.

(2) Preheat the crucible to 200°C, add the configured pure magnesium ingots, pure zinc ingots and Mg-20Mn master alloy, and pass in protective gas when the temperature rises to 400°C, the composition of the protective gas is CO ₂ +SF ₆ .

(3) After melting, raise the temperature to 740°C and add the prepared Mg-30La, Mg-30Sm, and Mg-30Y master alloys in batches. After melting, fully stir the melt for 4 minutes to remove the surface scum.

(4) Cool down to 720° C. and add 1.5% refining agent in batches based on the mass percentage of the melt, and continuously stir the melt for refining treatment, and the refining time is 13 minutes.

(5) After refining, remove the scum on the surface, keep it warm at 720°C, and let it stand for 40 minutes.

(6) The alloy liquid is poured into a metal mold for forming.

See Table 1 for the addition method, temperature and cost comparison of Example 1 and Comparative Example 1.

Table 1 Embodiment 1 and the temperature and cost added by the addition mode of comparative example 1

Note: Rare earth addition cost ratio is the ratio of the cost of rare earth addition to the total material cost.

Example 2

Prepare Mg-8Gd-4Y-Nd-Zn-Zr alloy, wherein the Gd content is 7.5%-8.2% by mass percentage, the Y content is 3.8%-4.5% by mass percentage, and the Nd content is 0.5%-1.0% by mass percentage , the Zn content is 0.8%-1.5% by mass percentage, the Zr content is 0.3%-0.8% by mass percentage, and the balance is Mg.

Mg-8Gd-4Y-Nd-Zn-Zr alloy was prepared by adding rare earth in the form of Gd ₆₂ Y ₃₀ Nd ₈ ternary alloy.

(1) According to the mass percentage of each element, Mg is added in the form of pure magnesium ingot, Zn is added in the form of pure zinc ingot, Gd, Y, and Nd are added in the form of Gd ₆₂ Y ₃₀ Nd ₈ , and Zr is added in the form of Mg-30Zr master alloy join in.

(2) Preheat the crucible to 200°C, add the configured pure magnesium ingots and pure zinc ingots, and pass in protective gas when the temperature rises to 400°C, the composition of the protective gas is CO ₂ +SF ₆ .

(3) After melting, heat up to 720°C and add the prepared Gd ₆₂ Y ₃₀ Nd ₈ alloy. After melting, stir the melt for 8 minutes. Raise the temperature to 740°C and add the prepared Mg-30Zr intermediate alloy. After melting, stir the melt for 4 minutes. .

(4) Cool down to 720° C. and add 1.5% refining agent in batches based on the mass percentage of the melt, and continuously stir the melt for refining treatment, and the refining time is 13 minutes.

(5) After refining, remove the scum on the surface, keep it warm at 720°C, and let it stand for 40 minutes.

(6) The alloy liquid is poured into a metal mold for molding.

Comparative example 2

Prepare Mg-8Gd-4Y-Nd-Zn-Zr alloy, wherein the Gd content is 7.5%-8.2% by mass percentage, the Y content is 3.8%-4.5% by mass percentage, and the Nd content is 0.5%-1.0% by mass percentage , the Zn content is 0.8%-1.5% by mass percentage, the Zr content is 0.3%-0.8% by mass percentage, and the balance is Mg.

Mg-8Gd-4Y-Nd-Zn-Zr alloys are prepared by adding rare earths to conventional Mg-30Gd, Mg-30Y, and Mg-30Nd master alloys.

(1) According to the mass percentage of each element, Mg is added in the form of pure magnesium ingot, Zn is added in the form of pure zinc ingot, Gd is added in the form of Mg-30Gd master alloy, Y is added in the form of Mg-30Y master alloy, and Nd is added in the form of Mg -30Nd master alloy is added, and Zr is added as Mg-30Zr master alloy.

(2) Preheat the crucible to 200°C, add the configured pure magnesium ingots and pure zinc ingots, and pass in protective gas when the temperature rises to 400°C, the composition of the protective gas is CO ₂ +SF ₆ .

(3) After melting, heat up to 740°C and add the configured Mg-30Gd, Mg-30Y, Mg-30Nd master alloys in batches, stir the melt for 4 minutes after melting, then add the configured Mg-30Zr master alloy, and melt Finally, fully stir the melt for 4 minutes, and remove the scum on the surface.

(4) Cool down to 720° C. and add 1.5% refining agent in batches based on the mass percentage of the melt, and continuously stir the melt for refining treatment, and the refining time is 13 minutes.

(5) After refining, remove the scum on the surface, keep it warm at 720°C, and let it stand for 40 minutes.

(6) The alloy liquid is poured into a metal mold for forming.

See Table 2 for the addition method of Example 2 and Comparative Example 2, the temperature and cost of addition.

Table 2 Embodiment 2 and the temperature and cost added by the addition mode of comparative example 2

name Rare earth addition method Rare earth addition temperature/℃ Rare earth addition cost ratio/% Comparative example 2 master alloy 740°C 80% Example 2 Ternary alloy 720°C 50%

Note: Rare earth addition cost ratio is the ratio of the cost of rare earth addition to the total material cost.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (5)

1. A method for adding rare earths to magnesium alloys containing rare earths, characterized in that the rare earths are added in the form of rare earth ternary alloys. 2. The rare earth addition method of a rare earth-containing magnesium alloy according to claim 1, wherein the rare earth ternary alloy is RE1-RE2-RE3, and the RE1, RE2, and RE3 are each independently La, Ce , Pr, Nd, Sm, Y, Sc, Gd, Dy, Ho, Er in one. 3 . The rare earth addition method of a rare earth-containing magnesium alloy according to claim 1 or 2 , characterized in that the RE1 mass percentage is 40-65%. 4 . 4 . The method for adding rare earths to rare earth-containing magnesium alloys according to claim 3 , wherein the RE2 mass percentage is 10-40%. 5 . The method for adding rare earth to a rare earth-containing magnesium alloy according to claim 4 , wherein the mass percentage of RE3 is 5-30%. 6 .