US20190271061A1

US20190271061A1 - High-strength magnesium alloy which can rapidly react with a medium and a production process thereof

Info

Publication number: US20190271061A1
Application number: US16/290,933
Authority: US
Inventors: Tingji Tang; Yi Hu
Original assignee: Five Star Downhole Service Inc
Current assignee: Five Star Downhole Service Inc
Priority date: 2018-03-05
Filing date: 2019-03-03
Publication date: 2019-09-05
Also published as: CN108441658B; CN108441658A

Abstract

The present invention provides a high-strength magnesium alloy which can react rapidly with a medium and production processes thereof. In one embodiment, the magnesium alloy comprises gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, gallium, indium, beryllium, calcium and magnesium. In another embodiment, the magnesium alloy comprises gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, lanthanum, cerium, manganese, gallium, indium, beryllium, calcium and magnesium.

Description

FIELD OF THE INVENTION

The invention relates to the field of metal materials. In one embodiment, there is provided a high-strength magnesium alloy which can rapidly react with a medium and a production process thereof

BACKGROUND OF THE INVENTION

Magnesium alloy is an alloy based on magnesium and some other additional elements. It has the following characteristics: low density (about 1.8 g/cm³), high specific strength, high specific elastic modulus, good heat dissipation, good shock absorption, better impact load resistance than aluminum alloy, and good resistance to organic and alkali corrosion. Magnesium alloy has a wide range of applications in various industrial fields, mainly used in aviation, aerospace, transportation, chemical, rocket, oil and gas industries and other industrial sectors. Magnesium is the lightest metal in the practical applications. The specific gravity of magnesium is about ⅔ that of aluminum and ¼ that of iron. Magnesium alloy has high strength and high rigidity. On the other hand, magnesium alloy is chemically active among existing materials and can be used in industrial fields where structural materials are required to be degradable.
Although the chemical properties of magnesium alloys are relatively active, the reaction rate of magnesium with a medium such as water, aqueous solutions and water-oil mixtures is extremely slow at normal temperature. The main reason is that the magnesium hydroxide formed by the reaction can prevent further reaction between magnesium and the medium. Even if the magnesium alloys are heated to the boiling temperature of water, only a very slow reaction can be observed. Because the reaction rate of conventional magnesium alloy with medium is low within a certain temperature range and the controllable range is narrow, it cannot meet the demands of industrial applications. Thus, for the manufacture of structural and functional integrated components in industries such as oil and gas sector, there is a great need for an improved alloying process that would enhance the rate of chemical reaction between magnesium alloy and the medium, while maintaining the high strength of the magnesium alloy.

SUMMARY OF THE INVENTION

To solve the problems in the prior art, it is an object of the present invention to provide a high-strength magnesium alloy which can rapidly react with a medium and a production process thereof.
In one embodiment, the object of the present invention is achieved by the following technical solutions: a high-strength magnesium alloy which can rapidly react with a medium, the magnesium alloys comprises gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, gallium, indium, beryllium, calcium and magnesium.
In one embodiment, the alloy comprises by mass parts 1.0-8.0 parts of gadolinium, 1.0-3.0 parts of yttrium, 0.6-1.5 parts of aluminum, 0.5-6.5 parts of zinc, 0.1-0.5 part of zirconium, 0-2.0 parts of rhenium, a total of 0.05-2.0 parts of silicon, copper, iron, nickel, gallium and indium, 0.1-0.5 part of beryllium and calcium, and 83-97 parts of magnesium.
In another embodiment, the alloy comprises by mass parts 3.0-6.0 parts of gadolinium, 1.5-2.5 parts of yttrium, 0.8-1.2 parts of aluminum, 2.0-5.0 parts of zinc, 0.2-0.4 part of zirconium, 1.0-1.5 parts of rhenium, a total of 0.1-1.5 parts of silicon, copper, iron, nickel, gallium and indium, 0.2-0.4 part of beryllium and calcium, and 85-95 parts of magnesium.
In another embodiment, the alloy comprises by mass parts 5.0 parts of gadolinium, 2.0 parts of yttrium, 1.0 part of aluminum, 4.0 parts of zinc, 0.3 part of zirconium, 1.3 parts of rhenium, a total of 1.0 part of silicon, copper, iron, nickel, gallium and indium, 0.3 part of beryllium and calcium, and 85.1 parts of magnesium.
The present invention also provides a process for producing a high-strength magnesium alloy which can rapidly react with a medium, comprising the steps of: weighing magnesium, aluminum, zinc, nickel, gallium, indium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum-silicon intermediate alloy, and aluminum-iron intermediate alloy; preheating the magnesium, aluminum, zinc, nickel, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum-silicon intermediate alloy, and aluminum-iron intermediate alloy; mixing the above metal materials, followed by smelting, covering and refining treatments to obtain a mixture comprising gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, gallium, indium, beryllium, calcium and magnesium; then an ingot is obtained by casting; subjecting the ingot to a thermal insulation treatment; then subjecting the ingot to a thermal deformation processing so as to obtain a forged piece; subjecting the forged piece to a thermal insulation treatment so as to obtain the high-strength magnesium alloy which can rapidly react with a medium.
In one embodiment, the preheating is carried out at 100-300° C. for 5-10 h.
In one embodiment, a covering agent is used for the covering, a refining agent 1 or a refining agent 2 is used for the refining, and the casting temperature is 670-750° C.
In one embodiment, the covering agent comprises 35-41% MgCl₂, 25-29% KCl, 24-28% NaCl, 6-10% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤2%. Refining agent 1 comprises 24-30% MgCl₂, 20-26% KCl, 28-31% BaCl₂, 13-15% CaF₂, 1-7% NaCl, 1-7% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤2%. Refining agent 2 comprises 54-56% KCl, 14-16% BaCl2, 3-5% CaF₂, 27-29% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤1.5%.
In one embodiment, the thermal insulation treatment on the ingot is at 450-540° C. for 8-48 h; and the thermal deformation processing temperature is 350-450° C.
In one embodiment, the thermal insulation treatment on the forged piece is at room temperature to 250° C. for 20-600 h.
In another embodiment, the present invention provides a high-strength magnesium alloy having high elongation property and can rapidly react with a medium, the magnesium alloy comprises gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, lanthanum, cerium, manganese, gallium, indium, beryllium, calcium and magnesium.
In one embodiment, the alloy comprises by mass parts 0.01-0.1 parts of gadolinium, 0.6-9 parts of aluminum, 0.5-5 parts of zinc, 0.2-4 parts of lanthanum and cerium, a total of 0.1-6.0 parts of silicon, copper, iron, nickel, manganese, gallium and indium, 0.1-0.5 part of beryllium and calcium, 77-98 parts of magnesium.
In one embodiment, the alloy comprises by mass parts 1.0-11.0 parts of gadolinium, 0.6-2 parts of aluminum, 0.5-5 parts of zinc, 0.2-4 parts of lanthanum and cerium, a total of 0.1-6.0 parts of silicon, copper, iron, nickel, manganese, gallium and indium, 0.1-0.5 part of beryllium and calcium, 71-97 parts of magnesium.
The present invention also provides a process for producing the above high-strength magnesium alloy, comprising the steps of: weighing magnesium, aluminum, zinc, nickel, gallium, indium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, magnesium-lanthanum-cerium intermediate alloy, magnesium-manganese intermediate alloy, aluminum-silicon intermediate alloy, and aluminum-iron intermediate alloy; preheating the magnesium, aluminum, zinc, nickel, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum-silicon intermediate alloy, magnesium-lanthanum-cerium intermediate alloy, magnesium-manganese intermediate alloy, and aluminum-iron intermediate alloy; mixing or co-mixing the above metal materials, followed by smelting, covering and refining treatments to obtain a mixture comprising gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, lanthanum, cerium, manganese, gallium, indium, beryllium, calcium and magnesium; then an ingot is obtained by casting; subjecting the ingot to a thermal insulation treatment; then subjecting the ingot to a thermal deformation processing so as to obtain a forged piece; subjecting the forged piece to a thermal insulation treatment so as to obtain the high-strength magnesium alloy which can rapidly react with a medium.
In one embodiment, the preheating is carried out at 100-300° C. for 5-12 h.
In one embodiment, a covering agent is used for the covering, and a refining agent 1 or a refining agent 2 is used for the refining, and the casting temperature is 670-750° C.
In one embodiment, the covering agent comprises 35-41% MgCl₂, 25-29% KCl, 24-28% NaCl, 6-10% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤2%; the refining agent 1 comprises 24-30% MgCl₂, 20-26% KCl, 28-31% BaCl₂, 13-15% CaF₂, 1-7% NaCl, 1-7% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤2%; the refining agent 2 comprises 54-56% KCl, 14-16% BaCl₂, 3-5% CaF₂, 27-29% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤1.5%.
In one embodiment, the thermal insulation treatment on the ingot is at 370-540° C. for 8-48 h; and the thermal deformation processing temperature is 330-450° C.
In one embodiment, the thermal insulation treatment on the forged piece is at room temperature to 250° C. for 20-1500 h.

DETAILED DESCRIPTION OF THE INVENTION

Compared with the prior art, the present invention has the following advantages:
A mixed reaction accelerating element (MRAE) such as Si, Ni, Ga, In is added to the magnesium alloy. The phase formed by these MRAEs and magnesium would destroy the continuity of magnesium hydroxide formed during the reaction between magnesium and a medium, thereby accelerating the reaction between magnesium and the medium. The medium could be aqueous solutions such as fresh water, pond water, lake water, salt water, brine water, produced water or flow back water and their mixture with crude oil etc. In one embodiment, the chemical reaction can be: Mg+2H₂O—→Mg(OH)₂+H₂(gas)
By adjusting the proportion of each element in the magnesium alloy, the reaction rate of the magnesium alloy with the medium can be regulated, resulting in a relatively wider controllable range, and the magnesium alloy material is flexible, so that the magnesium alloy meets the application requirements of the industrial sector such as oil and gas industry.
The mechanical properties such as tensile strength and yield strength of magnesium alloy are improved by adding gadolinium and yttrium to the magnesium alloy. Tensile strength is the resistance of a material to breakage under tension and it is usually obtained by the stress-strain curve. The unit is usually in MPa or kSi etc. Elongation is the amount of extension of an object under stress upon breakage, usually expressed as a percentage of the original length. In the application in oil and gas industries, such as frac balls, frac plugs or frac seats, not only has the magnesium alloys to be dissolved in a medium, but also the alloys need to have higher mechanical strength to withstand the high pressure and high temperature scenario.
The technical solutions of the present invention will be described clearly and sufficiently hereinafter with reference to the examples. It is apparent that the described examples are a part of the present invention, and does not exclude other examples. All other embodiments obtained by a person of ordinary skill in the art based on the examples of the present invention without inventive efforts are within the protection scope of the present invention. For example, those skilled in the art will understand that the technical solutions described in the examples disclosed herein may be modified, and some or all of the technical features may be equivalently replaced. Such modifications or equivalents are within the spirit and scope of the present invention.
In one embodiment, the present invention provides a high-strength magnesium alloy which can rapidly react with a medium, comprising gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, gallium, indium, beryllium, calcium and magnesium.
Rhenium, copper, beryllium and calcium in magnesium alloys are impurity elements.
In one embodiment, gadolinium and yttrium in magnesium alloys are used to improve the mechanical properties (tensile strength and yield strength) of magnesium alloys. Elements of copper, nickel, gallium and indium are used to improve the solubility of various other metal elements. Moreover, copper, nickel, gallium, indium and silicon in magnesium alloys increase the reaction rate of magnesium alloys with a medium. Other elements in magnesium alloys, such as aluminum, zinc, zirconium, rhenium, iron, beryllium and calcium, serve to catalyze the improvement of the mechanical properties of magnesium alloys.
In one embodiment, the high-strength magnesium alloy which can rapidly react with a medium comprises by mass parts 1.0-8.0 parts of gadolinium, 1.0-3.0 parts of yttrium, 0.6-1.5 parts of aluminum, 0.5-6.5 parts of zinc, 0.1-0.5 part of zirconium, 0-2.0 parts of rhenium, a total of 0.05-2.0 parts of silicon, copper, iron, nickel, gallium and indium, 0.1-0.5 part of beryllium and calcium, 83-97 parts of magnesium.
In one embodiment, the high-strength magnesium alloy which can rapidly react with a medium comprises by mass parts 3.0-6.0 parts of gadolinium, 1.5-2.5 parts of yttrium, 0.8-1.2 parts of aluminum, 2.0-5.0 parts of zinc, 0.2-0.4 part of zirconium, 1.0-1.5 parts of rhenium, a total of 0.1-1.5 parts of silicon, copper, iron, nickel, gallium and indium, 0.2-0.4 part of beryllium and calcium, 85-95 parts of magnesium.
In one embodiment, the high-strength magnesium alloy which can rapidly react with a medium comprises by mass parts 5.0 parts of gadolinium, 2.0 parts of yttrium, 1.0 part of aluminum, 4.0 parts of zinc, 0.3 part of zirconium, 1.3 parts of rhenium, a total of 1.0 part of silicon, copper, iron, nickel, gallium and indium, 0.3 part of beryllium and calcium, 85.1 parts of magnesium.
A mixed reaction accelerating element (MRAE) such as Si, Ni, Ga, In is added to the magnesium alloy. The phase formed by these elements with magnesium would destroy the continuity of magnesium hydroxide formed during the reaction between magnesium and a medium, thereby accelerating the reaction between magnesium and the medium. The mechanical properties such as tensile strength and yield strength of magnesium alloy are improved by adding gadolinium and yttrium to the magnesium alloy.
In one embodiment, the production process for the high-strength magnesium alloy of the present invention which can rapidly react with a medium comprises the steps of:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 100-300° C. for 5-10 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with a refining agent 1 or 2, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 670-750° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 450-540° C. for a treatment time of 8-48 h;
subjecting the ingot to a forging processing at 350-450° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at room temperature to 250° C. for a treatment time of 20-600 h.
By adjusting the proportion of each element in the magnesium alloy, the reaction rate of the magnesium alloy with the medium can be regulated, resulting in a relatively wider controllable range, and the magnesium alloy material is flexible, so that the magnesium alloy meets the application requirements of the industrial sector.
In one embodiment, the present invention uses magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy as raw materials because metals gadolinium, yttrium, zirconium, silicon and iron are not easily dissolved to produce magnesium alloys.
In another embodiment, the present invention provides a high-strength and high elongation magnesium alloy which can rapidly react with a medium, comprising gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, lanthanum, cerium, manganese, gallium, indium, beryllium, calcium and magnesium. In one embodiment, the high-strength magnesium alloy comprises by mass parts 0.01-0.1 parts of gadolinium, 0.6-9 parts of aluminum, 0.5-5 parts of zinc, 0.2-4 parts of lanthanum and cerium, a total of 0.1-6.0 parts of silicon, copper, iron, nickel, manganese, gallium and indium, 0.1-0.5 part of beryllium and calcium, and 77-98 parts of magnesium. In another embodiment, the high-strength magnesium alloy comprises by mass parts 1.0-11.0 parts of gadolinium, 0.6-2 parts of aluminum, 0.5-5 parts of zinc, 0.2-4 parts of lanthanum and cerium, a total of 0.1-6.0 parts of silicon, copper, iron, nickel, manganese, gallium and indium, 0.1-0.5 part of beryllium and calcium, and 71-97 parts of magnesium.
The present invention also provides a production process for the high-strength and high elongation magnesium alloy of the present invention, comprising the steps of:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-manganese intermediate alloy, magnesium-lanthanum-cerium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 100-300° C. for 5-12 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with a refining agent 1 or 2, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 670-750° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 370-540° C. for a treatment time of 8-48 h;
subjecting the ingot to a forging processing at 330-450° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at room temperature to 250° C. for a treatment time of 20-1500 h.
By adjusting the proportion of each element in the magnesium alloy, the reaction rate of the magnesium alloy with the medium can be regulated, resulting in a relatively wider controllable range, and the magnesium alloy material is flexible, so that the magnesium alloy meets the application requirements of the industrial sector.
The present invention uses magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum-silicon intermediate alloy, magnesium-lanthanum-cerium intermediate alloy, magnesium-manganese intermediate alloy, and aluminum-iron intermediate alloy as raw materials because metals gadolinium, yttrium, zirconium, silicon, lanthanum, cerium, manganese and iron are not easily dissolved to produce magnesium alloys.
The covering agent, the refining agent 1 and the refining agent 2 are those as described above.
Thus, in one embodiment, the present invention provides a high-strength magnesium alloy which can rapidly react with a medium, the magnesium alloy comprises gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, gallium, indium, beryllium, calcium and magnesium.
In one embodiment, the magnesium alloy comprises by mass parts 1.0-8.0 parts of gadolinium, 1.0-3.0 parts of yttrium, 0.6-1.5 parts of aluminum, 0.5-6.5 parts of zinc, 0.1-0.5 part of zirconium, 0-2.0 parts of rhenium, a total of 0.05-2.0 parts of silicon, copper, iron, nickel, gallium and indium, 0.1-0.5 part of beryllium and calcium, and 83-97 parts of magnesium.
In one embodiment, the magnesium alloy comprises by mass parts 3.0-6.0 parts of gadolinium, 1.5-2.5 parts of yttrium, 0.8-1.2 parts of aluminum, 2.0-5.0 parts of zinc, 0.2-0.4 part of zirconium, 1.0-1.5 parts of rhenium, a total of 0.1-1.5 parts of silicon, copper, iron, nickel, gallium and indium, 0.2-0.4 part of beryllium and calcium, and 85-95 parts of magnesium.
In one embodiment, the magnesium alloy comprises by mass parts 5.0 parts of gadolinium, 2.0 parts of yttrium, 1.0 part of aluminum, 4.0 parts of zinc, 0.3 part of zirconium, 1.3 parts of rhenium, a total of 1.0 part of silicon, copper, iron, nickel, gallium and indium, 0.3 part of beryllium and calcium, and 85.1 parts of magnesium.
In one embodiment, the magnesium alloy of the present invention has increased tensile strength and elongation as compared to the results from the control experiments (see e.g. Table 1).
The present invention also provides a process for producing the above high-strength magnesium alloy which can rapidly react with a medium, the process comprises the steps of:

weighing magnesium, aluminum, zinc, nickel, gallium, indium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy,
preheating magnesium, aluminum, zinc, nickel, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy; mixing or co-mixing the above metal materials by smelting, covering treatment and refining treatment to obtain a mixture comprising gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, gallium, indium, beryllium, calcium and magnesium;
casting an ingot and subjecting the ingot to a thermal insulation treatment;
subjecting the ingot to a thermal deformation processing to obtain a forged piece; and
subjecting the forged piece to a thermal insulation treatment to obtain the high-strength magnesium alloy which can rapidly react with a medium.

In one embodiment, the preheating is carried out at 100-300° C. for 5-10 hours.
In one embodiment, a covering agent is used for the covering treatment, a refining agent 1 or a refining agent 2 is used for the refining treatment, and the casting temperature is 670-750° C., wherein

the covering agent comprises 35-41% MgCl₂, 25-29% KCl, 24-28% NaCl, 6-10% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤2%;
the refining agent 1 comprises 24-30% MgCl₂, 20-26% KCl, 28-31% BaCl₂, 13-15% CaF₂, 1-7% NaCl, 1-7% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤2%;
the refining agent 2 comprises 54-56% KCl, 14-16% BaCl₂, 3-5% CaF₂, 27-29% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤1.5%.

In one embodiment, the thermal insulation treatment on the ingot is at 450-540° C. for 8-48 hours; and the thermal deformation processing is carried out at 350-450° C. In one embodiment, the thermal insulation treatment on the forged piece is at room temperature to 250° C. for 20-600 hours.
In one embodiment, the above magnesium alloy further comprises lanthanum, cerium, and manganese. In one embodiment, such magnesium alloy comprises by mass parts 0.01-0.1 parts of gadolinium, 0.6-9 parts of aluminum, 0.5-5 parts of zinc, 0.2-4 parts of lanthanum and cerium, a total of 0.1-6.0 parts of silicon, copper, iron, nickel, manganese, gallium and indium, 0.1-0.5 part of beryllium and calcium, 77-98 parts of magnesium. In another embodiment, such magnesium alloy comprises by mass parts 1.0-11.0 parts of gadolinium, 0.6-2 parts of aluminum, 0.5-5 parts of zinc, 0.2-4 parts of lanthanum and cerium, a total of 0.1-6.0 parts of silicon, copper, iron, nickel, manganese, gallium and indium, 0.1-0.5 part of beryllium and calcium, 71-97 parts of magnesium.
In one embodiment, the above magnesium alloy of the present invention has increased tensile strength and elongation as compared to the results from the control experiments (see e.g. Table 2).
The present invention also provides a process for producing the above high-strength, high elongation magnesium alloy which can rapidly react with a medium, the process comprises the steps of:

weighing magnesium, aluminum, zinc, nickel, gallium, indium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, magnesium-lanthanum-cerium intermediate alloy, magnesium-manganese intermediate alloy, aluminum-silicon intermediate alloy, and aluminum-iron intermediate alloy;
preheating magnesium, aluminum, zinc, nickel, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum-silicon intermediate alloy, and aluminum-iron intermediate alloy;
mixing or co-mixing the metal materials by smelting, covering treatment and refining treatment to obtain a mixture comprising gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, lanthanum, cerium, manganese, gallium, indium, beryllium, calcium and magnesium;
casting an ingot and subjecting the ingot to a thermal insulation treatment;
subjecting the ingot to a thermal deformation processing to obtain a forged piece; and
subjecting the forged piece to a thermal insulation treatment to obtain the high-strength magnesium alloy which can rapidly react with a medium.

In one embodiment, the preheating in the above process is carried out at 100-300° C. for 5-12 hours.
In one embodiment, a covering agent is used for the covering treatment, a refining agent 1 or a refining agent 2 is used for the refining treatment, and the casting temperature is 670-750° C., wherein

the covering agent comprises 35-41% MgCl₂, 25-29% KCl, 24-28% NaCl, 6-10% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤2%,
the refining agent 1 comprises 24-30% MgCl₂, 20-26% KCl, 28-31% BaCl₂, 13-15% CaF₂, 1-7% NaCl, 1-7% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤2%,
the refining agent 2 comprises 54-56% KCl, 14-16% BaCl₂, 3-5% CaF₂, 27-29% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤1.5%.

In one embodiment, the thermal insulation treatment on the ingot in the above process is carried out at 370-540° C. for 8-48 hours; and the thermal deformation processing is carried out at 330-450° C.
In one embodiment, the thermal insulation treatment on the forged piece in the above process is carried out at room temperature to 250° C. for 20-1500 hours.
In one embodiment, the present invention also provides a method of making a high-strength magnesium alloy which can rapidly react with a medium, the method comprises the step of using a starting material comprising silicon, copper, iron, nickel, gallium and indium. In another embodiment, the starting material further comprises lanthanum, cerium, and manganese.

EXAMPLE 1

In one embodiment, the high-strength magnesium alloy of the present invention comprises 5.0 parts of gadolinium, 2.0 parts of yttrium, 1.0 part of aluminum, 4.0 parts of zinc, 0.3 part of zirconium, 1.3 parts of rhenium, a total of 1.0 part of silicon, copper, iron, nickel, gallium and indium, 0.1 part of beryllium and calcium, and 85.3 parts of magnesium.
In one embodiment, the production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 100° C. for 5 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 1, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 670° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 450° C. for a treatment time of 8 h;
subjecting the ingot to a forging processing at 350° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at room temperature for a treatment time of 20 h.

EXAMPLE 2

In one embodiment, the high-strength magnesium alloy of the present invention comprises 1.0 part of gadolinium, 3.0 parts of yttrium, 0.6 part of aluminum, 6.5 parts of zinc, 0.1 part of zirconium, 2.0 parts of rhenium, a total of 0.05 part of silicon, copper, iron, nickel, gallium and indium, 0.2 part of beryllium and calcium, and 86.6 parts of magnesium.
In one embodiment, the production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 300° C. for 10 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 2, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 750° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 540° C. for a treatment time of 48 h;
subjecting the ingot to a forging processing at 450° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at 250° C. for a treatment time of 600 h.

EXAMPLE 3

In one embodiment, the high-strength magnesium alloy of the present invention comprises 8.0 parts of gadolinium, 1.0 part of yttrium, 1.5 parts of aluminum, 0.5 part of zinc, 0.5 part of zirconium, a total of 2.0 part of silicon, copper, iron, nickel, gallium and indium, 0.3 part of beryllium and calcium, and 86.2 parts of magnesium.
In one embodiment, the production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 200° C. for 6 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 1, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 700° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 500° C. for a treatment time of 20 h;
subjecting the ingot to a forging processing at 400° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at 100° C. for a treatment time of 100 h.

EXAMPLE 4

In one embodiment, the high-strength magnesium alloy of the present invention comprises 3.0 parts of gadolinium, 2.5 parts of yttrium, 0.8 part of aluminum, 5.0 parts of zinc, 0.2 part of zirconium, 1.5 parts of rhenium, a total of 0.1 part of silicon, copper, iron, nickel, gallium and indium, 0.4 part of beryllium and calcium, and 86.5 parts of magnesium.
In one embodiment, the production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 150° C. for 7 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 2, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 680° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 480° C. for a treatment time of 15 h;
subjecting the ingot to a forging processing at 370° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at 150° C. for a treatment time of 200 h.

EXAMPLE 5

In one embodiment, the high-strength magnesium alloy of the present invention comprises 6.0 parts of gadolinium, 1.5 parts of yttrium, 1.2 part of aluminum, 2.0 parts of zinc, 0.4 part of zirconium, 1.0 part of rhenium, a total of 1.5 parts of silicon, copper, iron, nickel, gallium and indium, 0.5 part of beryllium and calcium, and 86.9 parts of magnesium.
In one embodiment, the production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 210° C. for 8 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 1, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 720° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 510° C. for a treatment time of 23 h;
subjecting the ingot to a forging processing at 410° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at 170° C. for a treatment time of 300 h.

EXAMPLE 6

In one embodiment, the high-strength magnesium alloy of the present invention comprises 2.0 parts of gadolinium, 2.8 parts of yttrium, 0.7 part of aluminum, 6.0 parts of zinc, 0.15 part of zirconium, 1.8 parts of rhenium, a total of 0.08 part of silicon, copper, iron, nickel, gallium and indium, 0.15 part of beryllium and calcium, and 86.4 parts of magnesium.
In one embodiment, the production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 230° C. for 8 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 2, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 730° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 530° C. for a treatment time of 33 h;
subjecting the ingot to a forging processing at 440° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at 220° C. for a treatment time of 400 h.

EXAMPLE 7

In one embodiment, the high-strength magnesium alloy of the present invention comprises 7.0 parts of gadolinium, 1.3 parts of yttrium, 1.4 part of aluminum, 1.0 part of zinc, 0.45 part of zirconium, 0.5 part of rhenium, a total of 1.8 part of silicon, copper, iron, nickel, gallium and indium, 0.45 part of beryllium and calcium, and 86.1 parts of magnesium.
In one embodiment, the production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 290° C. for 9 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 1, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 740° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 530° C. for a treatment time of 40 h;
subjecting the ingot to a forging processing at 420° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at 240° C. for a treatment time of 500 h.

CONTROL EXAMPLE 1

This example presents a magnesium alloy comprising 5.0 parts of gadolinium, 2.0 parts of yttrium, 1.0 part of aluminum, 4.0 parts of zinc, 0.3 part of zirconium, 1.3 parts of rhenium, 0.3 part of beryllium and calcium, and 86.1 parts of magnesium. This magnesium alloy does not contain silicon, copper, iron, nickel, gallium and indium.
In one embodiment, the production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 200° C. for 8 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 1, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 700° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 500° C. for a treatment time of 30 h;
subjecting the ingot to a forging processing at 400° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at 100° C. for a treatment time of 300 h.
Results: The magnesium alloy obtained by this example did not react with the medium at room temperature. Thus, this control example demonstrates the importance and advantages of having a magnesium alloy comprising silicon, copper, iron, nickel, gallium and indium to produce a magnesium alloy that would have fast reaction rate with a medium.

CONTROL EXAMPLE 2

This example presents a magnesium alloy comprising 5.0 parts of gadolinium, 2.0 parts of yttrium, 1.0 part of aluminum, 4.0 parts of zinc, 0.3 part of zirconium, 1.3 parts of rhenium, a total of 1.0 part of silicon, copper, iron, nickel, gallium and indium, 0.3 part of beryllium and calcium, 85.1 parts of magnesium. In this example, certain homogenization heat treatment conditions were employed in the production process.
The production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 200° C. for 8 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 2, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 700° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 550° C. for a treatment time of 30 h;
subjecting the ingot to a forging processing at 400° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at 100° C. for a treatment time of 300 h.

CONTROL EXAMPLE 3

This example presents a magnesium alloy comprising 5.0 parts of gadolinium, 2.0 parts of yttrium, 1.0 part of aluminum, 4.0 parts of zinc, 0.3 part of zirconium, 1.3 parts of rhenium, a total of 1.0 part of silicon, copper, iron, nickel, gallium and indium, 0.3 part of beryllium and calcium, 85.1 parts of magnesium. In this example, the production process did not include the thermal deformation processing.
The production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 200° C. for 8 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 2, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 700° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 500° C. for a treatment time of 30 h;
subjecting the forged piece to an aging heat treatment at 100° C. for a treatment time of 300 h.
Results: The magnesium alloy was severely embrittled, and the elongation was only 1-3%.
The mechanical properties of the magnesium alloys of Examples 1-7 and Control Examples 1-3 were determined according to GB/T 228.1-2010, and the results are shown in Table 1. Examples 1-7 are various embodiments of the present invention. In Control Example 1, silicon, copper, iron, nickel, gallium and indium were omitted from the magnesium alloy. In Control Examples 2-3, certain conditions in the production process were employed. The results as shown in Table 1 indicate that the magnesium alloys of Examples 1-7 have significantly enhanced mechanical properties as compared to those of Control Examples 1-3 (see e.g. elongation A %).

TABLE 1

Mechanical properties of magnesium alloys
of Examples 1-7 and Control Examples 1-3

Mechanical	Tensile strength	Yield strength	Elongation
properties	Rm (MPa)	Rp0.2(MPa)	A %

Example 1	343	241	5.5
Example 2	325	224	6.2
Example 3	404	295	5.5
Example 4	322	237	5.2
Example 5	346	239	6.5
Example 6	315	218	9.6
Example 7	375	245	7.2
Control Example 1	330	220	2.1
Control Example 2	335	221	1.7
Control Example 3	220	170	1.6

EXAMPLE 8

This example presents a production process as follows:
weighing 4 parts of aluminum, 2 parts of zinc, 1 part of lanthanum and cerium, a total of 2 parts of silicon, copper, iron, nickel, manganese, gallium and indium, 0.3 part of beryllium and calcium, and 90.7 parts of magnesium;
weighing raw materials such as magnesium alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, magnesium-lanthanum-cerium intermediate alloy, magnesium-manganese intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 100° C. for 5 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 1, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 670° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 420° C. for a treatment time of 8 h;
subjecting the ingot to a forging processing at 370° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at room temperature for a treatment time of 20 h.

EXAMPLE 9

This example presents a magnesium alloy comprising 1.0 part of gadolinium, 1.0 part of aluminum, 6.5 parts of zinc, 0.1 part of zirconium, a total of 0.5 part of silicon, copper, iron, nickel, lanthanum, cerium, manganese, gallium and indium, 0.2 part of beryllium and calcium, and 90.7 parts of magnesium.
In one embodiment, the production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, magnesium-lanthanum-cerium intermediate alloy, magnesium-manganese intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 300° C. for 10 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 2, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 750° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 520° C. for a treatment time of 48 h;
subjecting the ingot to a forging processing at 430° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at 250° C. for a treatment time of 300 h.

CONTROL EXAMPLE 4

This example presents a magnesium alloy comprising 5.0 parts of gadolinium, 3.0 parts of yttrium, 1.0 part of aluminum, 0.7 part of zinc, 1.3 parts of rhenium, 0.3 part of zirconium, 0.3 part of beryllium and calcium, and 88.4 parts of magnesium. This magnesium alloy does not contain silicon, copper, iron, nickel, lanthanum, cerium, manganese, gallium and indium.
In one embodiment, the production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 200° C. for 8 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 1, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 700° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 520° C. for a treatment time of 30 h;
subjecting the ingot to a forging processing at 400° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at 150° C. for a treatment time of 100 h.
Results: The magnesium alloy obtained by this example did not react with the medium at room temperature. Thus, this example demonstrates the importance and advantages of having a magnesium alloy comprising silicon, copper, iron, nickel, lanthanum, cerium, manganese, gallium and indium to produce a magnesium alloy that would have fast reaction rate with a medium.

CONTROL EXAMPLE 5

This example presents a magnesium alloy comprising 5.0 parts of gadolinium, 3.0 parts of yttrium, 1.0 part of aluminum, 0.7 part of zinc, 0.3 part of zirconium, 1.3 parts of rhenium, a total of 2.0 parts of silicon, copper, iron, nickel, gallium and indium, 0.3 part of beryllium and calcium, 86.4 parts of magnesium. In this example, certain homogenization heat treatment conditions were employed in the production process.
The production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 200° C. for 8 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 2, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 700° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 520° C. for a treatment time of 30 h;
subjecting the ingot to a forging processing at 400° C. so as to obtain a forged piece;
subjecting the forged piece to an aging heat treatment at 150° C. for a treatment time of 100 h.

CONTROL EXAMPLE 6

This example presents a magnesium alloy comprising 5.0 parts of gadolinium, 3.0 parts of yttrium, 1.0 part of aluminum, 0.7 parts of zinc, 0.3 part of zirconium, 1.3 parts of rhenium, a total of 2.0 parts of silicon, copper, iron, nickel, gallium and indium, 0.3 part of beryllium and calcium, 86.4 parts of magnesium. In this example, the production process did not include the thermal deformation processing.
The production process is as follows:
weighing raw materials such as magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, nickel, gallium, indium, and pretreating magnesium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum, zinc, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy and nickel at 200° C. for 8 h;
mixing the raw materials, and then smelting them in a crucible electric resistance furnace, covering them with a covering agent, and refining them with the refining agent 2, thus the components are uniformly mixed, removing the inclusions, and casting the materials at 700° C. to form an ingot;
subjecting the ingot to a homogenization heat treatment at 520° C. for a treatment time of 30 h;
subjecting the forged piece to an aging heat treatment at 150° C. for a treatment time of 100 h.
Results: The magnesium alloy was severely embrittled, and the elongation was only 1-3%.
The mechanical properties of the magnesium alloys of Examples 8-9 were determined according to GB/T 228.1-2010, and the results are shown in Table 2. Examples 8-9 are various embodiments of the present invention. In Control Example 4, silicon, copper, iron, nickel, lanthanum, cerium, manganese, gallium and indium were omitted from the magnesium alloy. In Control Examples 5-6, certain conditions in the production process were employed. The results as shown in Table 2 indicate that the magnesium alloys of Examples 8-9 have significantly enhanced mechanical properties of elongation as compared to those of Control Examples 4-6 (see elongation A %).

TABLE 2

Mechanical properties of magnesium alloys
of Examples 8-9 and Control Examples 4-6-

Mechanical	Tensile strength	Yield strength	Elongation
properties	Rm (MPa)	Rp0.2(MPa)	A %

Example 8	280	200	12
Example 9	300	280	10
Control Example 4	300	220	2.1
Control Example 5	280	200	1.9
Control Example 6	220	170	1.8

Claims

What is claimed is:

1. A high-strength magnesium alloy which can rapidly react with a medium, said magnesium alloy comprises gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, gallium, indium, beryllium, calcium and magnesium.

2. The magnesium alloy of claim 1, comprising by mass parts 1.0-8.0 parts of gadolinium, 1.0-3.0 parts of yttrium, 0.6-1.5 parts of aluminum, 0.5-6.5 parts of zinc, 0.1-0.5 part of zirconium, 0-2.0 parts of rhenium, a total of 0.05-2.0 parts of silicon, copper, iron, nickel, gallium and indium, 0.1-0.5 part of beryllium and calcium, and 83-97 parts of magnesium.

3. The magnesium alloy of claim 2, comprising by mass parts 3.0-6.0 parts of gadolinium, 1.5-2.5 parts of yttrium, 0.8-1.2 parts of aluminum, 2.0-5.0 parts of zinc, 0.2-0.4 part of zirconium, 1.0-1.5 parts of rhenium, a total of 0.1-1.5 parts of silicon, copper, iron, nickel, gallium and indium, 0.2-0.4 part of beryllium and calcium, and 85-95 parts of magnesium.

4. The magnesium alloy of claim 1, wherein said alloy has increased tensile strength and elongation as compared to those from control examples.

5. A process for producing a high-strength magnesium alloy of claim 1 which can rapidly react with a medium, the process comprises the steps of:

weighing magnesium, aluminum, zinc, nickel, gallium, indium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy,

preheating magnesium, aluminum, zinc, nickel, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy;

mixing or co-mixing the above metal materials by smelting, covering treatment and refining treatment to obtain a mixture comprising gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, gallium, indium, beryllium, calcium and magnesium;

casting an ingot and subjecting the ingot to a thermal insulation treatment;

subjecting the ingot to a thermal deformation processing to obtain a forged piece; and

subjecting the forged piece to a thermal insulation treatment to obtain the high-strength magnesium alloy which can rapidly react with a medium.

6. The process of claim 5, wherein the preheating is carried out at 100-300° C. for 5-10 hours.

7. The process of claim 5, wherein a covering agent is used for the covering treatment, a refining agent 1 or a refining agent 2 is used for the refining treatment, and the casting temperature is 670-750° C., wherein

the covering agent comprises 35-41% MgCl₂, 25-29% KCl, 24-28% NaCl, 6-10% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤2%;

the refining agent 1 comprises 24-30% MgCl₂, 20-26% KCl, 28-31% BaCl₂, 13-15% CaF2, 1-7% NaCl, 1-7% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤2%;

the refining agent 2 comprises 54-56% KCl, 14-16% BaCl₂, 3-5% CaF₂, 27-29% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤1.5%.

8. The process of claim 5, wherein the thermal insulation treatment on the ingot is at 450-540° C. for 8-48 hours; and the thermal deformation processing is carried out at 350-450° C.

9. The process of claim 5, wherein the thermal insulation treatment on the forged piece is at room temperature to 250° C. for 20-600 hours.

10. The magnesium alloy of claim 1, further comprising lanthanum, cerium, and manganese.

11. The magnesium alloy of claim 10, comprising by mass parts 0.01-0.1 parts of gadolinium, 0.6-9 parts of aluminum, 0.5-5 parts of zinc, 0.2-4 parts of lanthanum and cerium, a total of 0.1-6.0 parts of silicon, copper, iron, nickel, manganese, gallium and indium, 0.1-0.5 part of beryllium and calcium, 77-98 parts of magnesium.

12. The magnesium alloy of claim 10, comprising by mass parts 1.0-11.0 parts of gadolinium, 0.6-2 parts of aluminum, 0.5-5 parts of zinc, 0.2-4 parts of lanthanum and cerium, a total of 0.1-6.0 parts of silicon, copper, iron, nickel, manganese, gallium and indium, 0.1-0.5 part of beryllium and calcium, 71-97 parts of magnesium.

13. The magnesium alloy of claim 10, wherein said alloy has increased tensile strength and elongation as compared to those from control examples.

14. A process for producing a high-strength magnesium alloy of claim 11 which can rapidly react with a medium, the process comprises the steps of:

weighing magnesium, aluminum, zinc, nickel, gallium, indium, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-zirconium intermediate alloy, magnesium-lanthanum-cerium intermediate alloy, magnesium-manganese intermediate alloy, aluminum-silicon intermediate alloy, and aluminum-iron intermediate alloy;

preheating magnesium, aluminum, zinc, nickel, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, aluminum-silicon intermediate alloy, and aluminum-iron intermediate alloy;

mixing or co-mixing the above metal materials by smelting, covering treatment and refining treatment to obtain a mixture comprising gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, lanthanum, cerium, manganese, gallium, indium, beryllium, calcium and magnesium;

casting an ingot and subjecting the ingot to a thermal insulation treatment;

15. The process of claim 14, wherein the preheating is carried out at 100-300° C. for 5-12 hours.

16. The process of claim 14, wherein a covering agent is used for the covering treatment, a refining agent 1 or a refining agent 2 is used for the refining treatment, and the casting temperature is 670-750° C., wherein

the covering agent comprises 35-41% MgCl₂, 25-29% KCl, 24-28% NaCl, 6-10% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤2%,

the refining agent 1 comprises 24-30% MgCl₂, 20-26% KCl, 28-31% BaCl₂, 13-15% CaF₂, 1-7% NaCl, 1-7% CaCl₂, insoluble matter≤1.5%, MgO≤1.5%, moisture content≤2%,

17. The process of claim 14, wherein the thermal insulation treatment on the ingot is at 370-540° C. for 8-48 hours; and the thermal deformation processing is carried out at 330-450° C.

18. The process of claim 14, wherein the thermal insulation treatment on the forged piece is at room temperature to 250° C. for 20-1500 hours.

19. A method of making a high-strength magnesium alloy which can rapidly react with a medium, said method comprises the step of using a starting material comprising silicon, copper, iron, nickel, gallium and indium.

20. The method of claim 19, wherein said starting material further comprises lanthanum, cerium, and manganese.