CN109371302B

CN109371302B - Corrosion-resistant high-performance magnesium alloy and preparation process thereof

Info

Publication number: CN109371302B
Application number: CN201811487585.9A
Authority: CN
Inventors: 陈寅; 敖四海; 于丹
Original assignee: Guizhou Aerospace Fenghua Precision Equipment Co Ltd
Current assignee: Guizhou Aerospace Fenghua Precision Equipment Co Ltd
Priority date: 2018-12-06
Filing date: 2018-12-06
Publication date: 2021-02-12
Anticipated expiration: 2038-12-06
Also published as: CN109371302A

Abstract

The invention discloses a corrosion-resistant high-performance magnesium alloy which comprises the following components in percentage by weight: 0.8-1.2 wt.% Ge, 0.3-0.8 wt.% Zr, 0.2-0.7 wt.% Mo, 0.1-0.3 wt.% Na, 0.9-1.3 wt.% Ru, 22-30 wt.% Al, 0.4-0.9 wt.% Ca, 0.5-2.3 wt.% Zn, 0.4-1.2 wt.% Hf, 1.1-1.6 wt.% Ti, 0.1-0.4 wt.% Cu, 0.6-1.3 wt.% Mn, 0.5-1.2 wt.% Cr, 0.8-2.0 wt.% Si, 0.1-0.3 wt.% Y, 0.8-1.4 wt.% C, 1.0-1.6 wt.% W, and the balance magnesium. The steel plate has the advantages of high strength, good toughness, high temperature resistance, corrosion resistance, wear resistance and the like.

Description

Corrosion-resistant high-performance magnesium alloy and preparation process thereof

Technical Field

The invention belongs to the technical field of alloy processing technology, and particularly relates to a corrosion-resistant high-performance magnesium alloy and a preparation process thereof.

Background

The magnesium alloy is an alloy formed by adding other elements on the basis of magnesium. The method is characterized in that: the density is small (the density is 1.8 g/cm)³Left and right), high strength, large elastic modulus, good heat dissipation, good shock absorption, larger impact load bearing capacity than aluminum alloy, and good organic matter and alkali corrosion resistance. The main alloy elements comprise aluminum, zinc, manganese, cerium, thorium, a small amount of zirconium or cadmium and the like. Currently, the most widely used are magnesium-aluminum alloys, followed by magnesium-manganese alloys and magnesium-zinc-zirconium alloys. The method is mainly used in aviation, aerospace, transportation, chemical engineering, rocket and other industrial departments. The lightest of the practical metals, magnesium has a specific gravity of about 2/3 for aluminum and 1/4 for iron. It is the lightest metal of practical metals, and has high strength and high rigidity.

The high-performance magnesium alloy is widely applied to the fields of transportation, Electronic industry, medical treatment, military industry and the like due to excellent comprehensive performance, is prominently used in 3C products, and 3C respectively represents Computer, Consumer Electronic Product and Communication Electronic Product, and the fields of light rail, automobile, aerospace, medical health and the like, has wide prospect, and has become one of the development directions of future novel materials.

In the military industry, the mass reduction of weapons and equipment is one of the main development targets, the selection of light-weight materials is the key, and magnesium alloy is an ideal metal structural material and is used in airplane casings, wing ribs, shelter supports, generator shells, pressing plates, mortar bases and the like. In recent years, domestic high-performance magnesium alloy materials are gradually and successfully applied to weapons and ammunition, and the development is very rapid.

High performance magnesium alloys are most widely used in the automotive industry. The lightweight automobile is one of the most concerned problems at home and abroad, mainly realized by two ways of structural optimization and lightweight material use, and the high-performance magnesium alloy is taken as the material, so that the manufactured automobile parts have the outstanding characteristics, namely the weight of the automobile is obviously reduced, the oil consumption is greatly reduced, the emission of tail gas is correspondingly reduced, the integration level of the parts can be improved, the flexibility of automobile design is promoted, and the like. Therefore, high-performance magnesium alloys are widely used in the automotive industry as parts such as seat brackets, engine blocks, transmission housings, vehicle doors, and the like.

Because the density of magnesium metal is only 1.74g/cm³Two thirds of aluminum metal and one quarter of steel, the lightest metal structural material. The magnesium alloy also has high specific strength, specific rigidity, shock absorption, recyclability, good heat conductivity and electrical conductivity and the like, is beneficial to industrial processing and forming, and is called as '21 st century green engineering metal'. Therefore, as one of engineering materials with excellent performance, the material is widely applied to the fields of military weapons, transportation, electronic communication, medical health and the like.

With the continuous development and progress of science and technology, the requirements of industrial application on the material performance are higher and higher, and although magnesium alloy materials are widely applied, the magnesium alloy materials still have defects. The method mainly comprises the following aspects:

(1) the strength is low, and the strength and the creep resistance are obviously reduced when the temperature is increased;

(2) the room temperature plasticity is poor, and the processability is poor;

(3) flammability, leading to difficulties in smelting processes;

(4) the corrosion resistance is poor.

With the rapid progress of the digitalization technology, electronic and communication products gradually develop towards high integration, lightness, thinness, miniaturization and environmental protection, while the application of magnesium alloy in the electronic field is rapidly increased due to the characteristics of lightness, good high temperature resistance, corrosion resistance, wear resistance and the like, at present, electronic products using magnesium alloy to make parts are countless, and 3C products (notebook computers, mobile phones and digital cameras) are mainly used, so that the application of the magnesium alloy is continuously increased. Therefore, it is important to develop a corrosion-resistant magnesium alloy.

Disclosure of Invention

The invention provides a corrosion-resistant high-performance magnesium alloy and a preparation process thereof for solving the technical problems. The raw materials used in the method are cheap, the magnesium alloy with high strength, good toughness, high temperature resistance, corrosion resistance and wear resistance is obtained by adopting the process steps of heating and smelting, vacuum treatment, thermoforming, cooling and the like, the mechanical property of the magnesium alloy is improved, the process method is simple to operate, the process parameters are easy to control, and the method is suitable for industrial mass production.

In order to achieve the above purpose, the invention adopts the following technical scheme:

the corrosion-resistant high-performance magnesium alloy comprises the following components in percentage by weight: 0.8-1.2 wt.% Ge, 0.3-0.8 wt.% Zr, 0.2-0.7 wt.% Mo, 0.1-0.3 wt.% Na, 0.9-1.3 wt.% Ru, 22-30 wt.% Al, 0.4-0.9 wt.% Ca, 0.5-2.3 wt.% Zn, 0.4-1.2 wt.% Hf, 1.1-1.6 wt.% Ti, 0.1-0.4 wt.% Cu, 0.6-1.3 wt.% Mn, 0.5-1.2 wt.% Cr, 0.8-2.0 wt.% Si, 0.1-0.3 wt.% Y, 0.8-1.4 wt.% C, 1.0-1.6 wt.% W, and the balance magnesium and unavoidable impurities.

Further, the corrosion-resistant high-performance magnesium alloy comprises the following components in percentage by weight: 0.9-1.1 wt.% Ge, 0.4-0.7 wt.% Zr, 0.3-0.6 wt.% Mo, 0.15-0.25 wt.% Na, 1.0-1.2 wt.% Ru, 23-29 wt.% Al, 0.5-0.8 wt.% Ca, 0.6-2.2 wt.% Zn, 0.5-1.1 wt.% Hf, 1.2-1.5 wt.% Ti, 0.2-0.3 wt.% Cu, 0.7-1.2 wt.% Mn, 0.6-1.1 wt.% Cr, 0.9-1.9 wt.% Si, 0.15-0.25 wt.% Y, 0.9-1.3 wt.% C, 1.1-1.5 wt.% W, and the balance magnesium and unavoidable impurities.

Further, the corrosion-resistant high-performance magnesium alloy comprises the following components in percentage by weight: 1.0 wt.% Ge, 0.5 wt.% Zr, 0.5 wt.% Mo, 0.2 wt.% Na, 1.1 wt.% Ru, 26 wt.% Al, 0.6 wt.% Ca, 1.4 wt.% Zn, 0.8 wt.% Hf, 1.3 wt.% Ti, 0.25 wt.% Cu, 0.9 wt.% Mn, 0.9 wt.% Cr, 1.4 wt.% Si, 0.2 wt.% Y, 1.1 wt.% C, 1.3 wt.% W, the balance being magnesium and unavoidable impurities.

Further, the preparation process of the corrosion-resistant high-performance magnesium alloy comprises the following steps:

(1) putting the components of the magnesium alloy into a vacuum heat treatment furnace according to the weight percentage, heating and smelting the components into alloy liquid, electromagnetically stirring the alloy liquid to fully react the raw materials, and then controlling the temperature to 550-600 ℃ along with the furnace temperature in a mode of firstly heating and then cooling;

(2) after the vacuum heat treatment is finished, naturally cooling and preserving heat;

(3) and (3) feeding the material obtained in the step (2) into a forming die, heating to the temperature of magnesium alloy thermoforming, then preserving heat, introducing cooling water for cooling, naturally cooling to 80 ℃, taking out from the die, and naturally cooling to room temperature to obtain the corrosion-resistant high-performance magnesium alloy.

Further, in the step (1), the temperature control and heat preservation time is 2-3 h; the working pressure of the vacuum heat treatment is 0.35-0.55 Pa.

Further, in the step (1), the electromagnetic stirring time is 9-13 min.

Further, in the step (2), the temperature is reduced to 400-450 ℃, the cooling speed is-8 to-13 ℃/min, and the heat preservation time is 80-100 min.

Further, in the step (3), the thermoforming temperature is 480-520 ℃, and the heat preservation time is 3-10 min.

Further, in the step (3), the cooling water is cooled by introducing cold water to reduce the temperature to 230-260 ℃, and the cooling speed of the cooling water is-20 to-40 ℃/min.

The components of the magnesium alloy prepared by the method have the following functions:

ge is the chemical symbol of germanium, with an atomic number of 32, and an atomic weight of 72.64. In the 4 th cycle, group IVA of the periodic Table of the elements. The simple substance of germanium is a grey-white metal, has luster and hardness, belongs to the carbon family, has chemical properties similar to those of tin and silicon in the same family, and is insoluble in water, hydrochloric acid and dilute caustic solutionIt is soluble in aqua regia, concentrated nitric acid or sulfuric acid, has amphipathy, so that it is soluble in molten alkali, peroxide alkali, alkali metal nitrate or carbonate, and is stable in air, and in nature, germanium has five isotopes: 70, 72, 73, 74, 76, reacting with oxygen at a temperature above 700 ℃ to form GeO₂When reacting with hydrogen at 1000 deg.C or higher, germanium can be burnt in chlorine or bromine, and germanium is an excellent semiconductor, and can be used for detection of high-frequency current and rectification of alternating current, and can be used for infrared light material, precision instruments, and catalysts. Germanium compounds are useful in the manufacture of fluorescent panels and various glasses having high refractive indices.

Zr is the chemical symbol of zirconium, has an atomic number of 40, is a silver-white, high-melting metal, and is light gray in color. Widely found in zircon and baddeleyite. Is widely applied to the alloy and jewelry manufacturing industry. In 1789, Clapurode, Germany, when analyzing zirconium stannum, zircon was found. One of the high melting point metals, in light gray. Density 6.49g/cm³. Melting point 1852. + -. 2 ℃ and boiling point 4377 ℃. Valency +2, +3, and + 4. The first ionization energy is 6.84 electron volts. The surface of zirconium is easy to form a layer of oxide film, and has luster, so the appearance is similar to that of steel. Corrosion resistance, and is soluble in hydrofluoric acid and aqua regia; at high temperatures, it can react with non-metallic elements and many metallic elements to form solid solution compounds. The powder iron is mixed with zirconium nitrate to be used as flash powder. Zirconium metal is almost exclusively used as cladding for uranium fuel elements in nuclear reactors. Also used for making photographic flashlamps, and corrosion resistant vessels and pipes, especially resistant to hydrochloric acid and sulfuric acid. Zirconium chemicals can be used as cross-linking agents for polymers. Can also be used as degasser for some vacuum instruments.

Mo is the chemical symbol of Molybdenum (Molybdenum), is a chemical element of group VIB in the fifth period of the periodic table of elements, has an atomic number of 42 and an atomic weight of 95.94, and is a gray transition metal. The metal is silver gray and has a body-centered cubic crystal structure, a melting point of 2617 ℃, a boiling point of 4612 ℃ and a density of 10.22g/cm³The first ionizing energy 7.099 electron volts. The properties of molybdenum and tungsten are very similar, and the high-temperature-strength high-hardness high-density high-corrosion-resistance high-power high-voltage power cable has the advantages of good high-temperature strength, high hardness, high density, strong corrosion resistance, small thermal expansion coefficient, good electric conductivity and good electric conductivityHeat conduction and the like. The pure metal of molybdenum is silvery white and very hard. The steel may be hardened by adding a small amount of molybdenum to the steel. Molybdenum is an important nutrient for plants and is also found in some enzymes. Is not corroded by air at normal temperature. Is unreactive with hydrochloric acid or hydrofluoric acid. Valency +2, +4 and +6, with the most stable compound being + 6. The high-valence oxidation state compound of the molybdenum is acidic, the low-valence oxidation state compound is alkaline, and + 6-valence ions have strong tendency to form complexes. The compact molybdenum is stable in the air at normal temperature, slightly oxidized at 400 ℃ and quickly oxidized at 500 ℃. Molybdenum can absorb a large amount of hydrogen at 1000 ℃ to form a solid solution. Reacting molybdenum with nitrogen at 1500 deg.C to obtain molybdenum nitride, and reacting with carbon to obtain Mo₂C, reaction with sulfur to form MoS₂Important molybdenum compounds are molybdenum trioxide, amine paramolybdate, sodium molybdate, calcium molybdate, barium molybdate, molybdenum hexafluoride and various molybdenum polymers.

Na is a chemical symbol of sodium, is located in the 3 rd period and the IA group in the periodic table, is a representative of alkali metal elements, is soft in texture, can react with water to generate sodium hydroxide and hydrogen, reacts violently with water, and explodes when the amount is large. Sodium element is widely distributed in land and sea in the form of salt, sodium is also one of important components in human muscle tissue and nerve tissue, the chemical property of sodium is very active, sodium is combined with oxygen respectively at normal temperature and heating, sodium can react with a large amount of inorganic substances, most nonmetal simple substances and most organic substances, sodium is used as a reducing agent when the sodium reacts with other substances through oxidation-reduction reaction, the sodium is usually combined in the form of ionic bond and covalent bond, and the valence is increased from 0 to +1 (due to ns1 electron pair). Sodium can also be combusted in carbon dioxide and reacted with lower alcohols to produce hydrogen gas and liquid ammonia with very weak ionization capacity. The outermost layer of sodium atoms has only 1 electron and is easily lost, so that it has strong reducibility. Metallic is strong, while ionic oxidizing is weak.

Ru is the chemical symbol of ruthenium, a hard, brittle, light gray polyvalent rare metal element, a member of the platinum group of metals. The content in the earth's crust is only parts per billion, which is one of the rarest metals, but ruthenium is indeed the least expensive of the platinum group metals, although other metals such as platinum, palladium, etc. are more abundant than ruthenium. The ruthenium has stable property and strong corrosion resistance, can resist the corrosion of hydrochloric acid, sulfuric acid, nitric acid and aqua regia at normal temperature,

al is the chemical symbol of aluminum, has an atomic number of 13, and is ductile. The commodity is usually made into rod, sheet, foil, powder, strip and thread. An oxide film that prevents corrosion of the metal can be formed in humid air. The aluminum powder is heated in the air to burn violently and emit dazzling white flame. Is easy to dissolve in dilute sulfuric acid, nitric acid, hydrochloric acid, sodium hydroxide and potassium hydroxide solution, and is difficult to dissolve in water. The relative density is 2.70, the melting point is 660 ℃, and the boiling point is 2327 ℃. The content of the aluminum element in the earth crust is second to that of oxygen and silicon, and is the third most abundant metal element in the earth crust, and the content of the aluminum element is 8.3 percent. The corundum existing in nature belongs to alpha-Al₂O₃Its hardness is second only to diamond, melting point is high, and it is acid and alkali resistant. The development of three important industries, namely aviation, building and automobile, requires the material characteristics to have the unique properties of aluminum and its alloy, which greatly facilitates the production and application of the new metal aluminum.

Ca is the chemical symbol of calcium, has an atomic number of 20 and an atomic weight of 40.078, and is the most active element in alkaline earth metals. Melting point 839 deg.C, boiling point 1484 deg.C, 1.54g/cm³Density. The oxidation state of calcium is +2, and the calcium can slowly react with oxygen and nitrogen in the air to generate a layer of oxide and nitride protective film; the calcium and cold water have slow action and react violently in hot water to release hydrogen; calcium can directly react with halogen elements and react with sulfur and carbon under heating; calcium forms hexaammine calcium with concentrated ammonia, a highly conductive solid with metallic luster. Calcium in the animal body participates not only in the composition of bones and teeth but also in metabolism.

Zn is a chemical symbol of zinc, has an atomic number of 30, is located in the 4 th period and IIB group of the periodic table of chemical elements, has a non-wear-out status for battery manufacturing in modern industry, and is a very important metal. In the air at normal temperature, a thin and compact basic zinc carbonate film is formed on the surface, and further oxidation can be prevented. When the temperature reaches 225 ℃, zinc is oxidized violently, the melting point of an oxide film of the zinc is high, but the melting point of metal zinc is very low. The galvanization has excellent atmospheric corrosion resistance, and a layer of protective film is easily generated on the surface at normal temperature, so the zinc is used for the galvanization industry to the greatest extent; zinc has suitable mechanical properties. The strength and hardness of zinc are not high, but after alloy elements such as aluminum, copper and the like are added, the strength and hardness are greatly improved, namely the zinc-copper-titanium alloy appears, the comprehensive mechanical property of the zinc-copper-titanium alloy is close to or reaches the level of aluminum alloy, brass and gray cast iron, and the creep resistance of the zinc-copper-titanium alloy is also greatly improved.

Hf is the chemical symbol for hafnium, atomic number 72, atomic number 178.49, a lustrous silver-gray transition metal. Hafnium has 6 naturally stable isotopes: hafnium 174, 176, 177, 178, 179, 180. Hafnium does not react with dilute hydrochloric acid, dilute sulfuric acid and strong alkaline solutions, but is soluble in hydrofluoric acid and aqua regia. Hafnium, which is present in the earth's crust in an amount of 0.00045%, is associated in nature with zirconium, and has allotropic modifications at high temperatures. Hafnium metal has a high neutron absorption cross section and can be used as a control material for a reactor. Hafnium has a plastic metal that becomes hard and brittle when impurities are present. Stable in air and only dull on the surface when burned. The filaments may be ignited by the flame of a match. Does not react with water, dilute acid or strong base, but is easily dissolved in aqua regia and hydrofluoric acid. Hafnium has good corrosion resistance and is not easy to be corroded by common acid-base aqueous solution. Hafnium can also be directly combined with gases such as oxygen and nitrogen at high temperatures to form oxides and nitrides.

Ti is a chemical symbol of titanium, and is a silvery-white transition metal characterized by light weight, high strength, metallic luster, and resistance to wet chlorine corrosion. However, titanium cannot be used in dry chlorine gas, and even dry chlorine gas at a temperature of 0 ℃ or below can undergo a violent chemical reaction to produce titanium tetrachloride, which is then decomposed to produce titanium dichloride, and even burned. Only when the water content in chlorine is above 0.5% is the titanium retained therein with reliable stability. Titanium can react with many elements and compounds at higher temperatures.

Cu is a chemical symbol of copper, is insoluble in non-oxidizing acids, is a soft metal, has good ductility, and has high thermal and electrical conductivity, and thus is the most commonly used material in cables and electrical and electronic components, and can be used as a building material to form a variety of alloys. Copper alloys have excellent mechanical properties and very low electrical resistivity, the most important of which are bronze and brass. In addition, copper is also a durable metal that can be recycled many times without compromising its mechanical properties. The activity of copper is weak, and the simple substance of copper can be replaced by the reaction of the simple substance of iron and copper sulfate.

Mn is a chemical symbol of manganese and is a transition metal. The manganese simple substance is gray black, is brittle and hard, can be oxidized in a wet position, and is used for manufacturing special steel in the metallurgical industry; ferro-manganese alloy as desulfurizing and deoxidizing agent for iron and steel production, manganese oxide (MnO)₂) Can be used as a catalyst. In the steel-making process, manganese is a good deoxidizer and desulfurizer, the content of manganese in general steel is 0.30-0.50%, and when more than 0.70% of manganese steel is added into carbon steel, the steel is called manganese steel. The steel added with the common manganese content has enough toughness, higher strength and hardness, improves the quenching property of the steel and improves the hot workability of the steel, for example, the 16Mn steel has 40 percent higher yield point than A3(Q235), and the steel containing 11-14 percent of manganese has extremely high wear resistance and is used for excavator buckets, wear-resisting machine lining plates and the like. However, the higher the amount of manganese, the lower the corrosion resistance of the steel and the lower the weldability.

Cr is the chemical symbol of chromium, and the simple substance is steel gray metal. The element names are from greek and are originally intended as "color" because chromium compounds are all colored. The content of chromium in the earth crust is 0.01%, which is located at the 17 th position. Free chromium does not exist in nature, mainly exists in chrome lead ore, and is the metal with the highest hardness.

Si is the chemical symbol of silicon, which is known as silicon, and has two allotropes, amorphous silicon and crystalline silicon. High purity single crystal silicon is an important semiconductor material; cermet, important materials for space navigation; fiber optic communications, the latest modern means of communication; silicon organic compounds with excellent performance; silicon can improve the hardness of plant stems and increase the difficulty of feeding and digesting by pests; the organic silicon has unique structure, has the performances of inorganic materials and organic materials, has the basic properties of low surface tension, small viscosity-temperature coefficient, high compressibility, high gas permeability and the like, has the excellent characteristics of high and low temperature resistance, electrical insulation, oxidation resistance stability, weather resistance, flame retardancy, hydrophobicity, corrosion resistance, no toxicity, no odor, physiological inertia and the like, is widely applied to the industries of aerospace, electronics and electricity, construction, transportation, chemical industry, textile, food, light industry, medical treatment and the like, and is mainly applied to sealing, adhesion, lubrication, coating, surface activity, demolding, defoaming, foam inhibition, water prevention, moisture prevention, inert filling and the like.

Y (yttrium) is a metal element. It is one of rare earth metal elements, grey metal. Density 4.4689 g/cc, melting point 1522 ℃, boiling point 3338 ℃, valence + 3. The first ionization energy is 6.38 electron volts. Can react with hot water and is easily dissolved in dilute acid. Mixing with europium to obtain red fluorescent powder for color TV set. Yttrium oxide is mixed with iron oxide to form a deep red crystal for use in radar. The rare earth metal and the alloy thereof play roles of deoxidation and desulfurization in steel making, can reduce the content of the rare earth metal and the alloy to be less than 0.001 percent, change the form of inclusions, and refine grains, thereby improving the processing property of steel, improving the strength, the toughness, the corrosion resistance, the oxidation resistance and the like. The rare earth metal and its alloy are used to make nodular cast iron, high-strength grey cast iron and vermicular cast iron, and can change the form of graphite in cast iron, improve casting technology and raise the mechanical performance of cast iron. The strength, elongation, heat resistance and electrical conductivity of the alloy can be improved by adding a small amount of rare earth metal in the bronze and brass smelting. 1 to 1.5 percent of rare earth metal is added into the cast aluminum-silicon alloy, so that the high-temperature strength can be improved. The addition of rare earth metal in the aluminum alloy wire can improve the tensile strength and the corrosion resistance. 0.3% of rare earth metal is added into the Fe-Cr-Al electrothermal alloy, so that the oxidation resistance can be improved, and the resistivity and the high-temperature strength can be increased. The addition of rare earth metal in titanium and its alloy can refine crystal grains, reduce creep rate and improve high-temperature corrosion resistance.

C is a chemical symbol of carbon and is a non-metallic element, and the Latin is Carbonium, which means 'coal, charcoal'. Carbon is a very common element that is widely found in the atmosphere and in the earth's crust and organisms in a variety of forms. The simple substance of carbon has long been recognized and utilized, and a series of compounds of carbon, namely organic substances, are the basis of life. Carbon is one of the components of pig iron, wrought iron and steel. Carbon is chemically capable of self-association to form a large number of compounds, and is a biologically and commercially important molecule. Most molecules in living organisms contain carbon.

W is the chemical symbol for tungsten, atomic number 74, atomic weight 183.84, atomic radius 137 picometers, density 19.35 grams per cubic centimeter, and belongs to group VIB of the sixth period (the second long period) of the periodic Table of elements. Tungsten is a hexavalent cation in nature, and its ionic radius is 0.68X 10-10 m. Due to W⁶⁺Small ion radius, high electrovalence, strong polarizability and easy formation of complex anion, so tungsten is mainly in the form of complex anion [ WO₄]^2-With Fe in solution²⁺、Mn²⁺、Ca²⁺The cations are combined to form wolframite or scheelite precipitate. The smelted tungsten is silvery white and glossy metal, has extremely high melting point, very high hardness, very low vapor pressure, small evaporation speed and relatively stable chemical property, and is not corroded by air at normal temperature; the main application is to manufacture filament, high-speed cutting alloy steel and superhard die, and also to optical instruments and chemical instruments. China is the largest tungsten reservoir in the world.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

(1) the magnesium alloy has good high temperature resistance, corrosion resistance, wear resistance and other properties, the product stability is high, and the prepared magnesium alloy can be used in the fields of automobiles, aviation and the like.

(2) The raw materials used in the method are cheap, the magnesium alloy with high strength, good toughness, high temperature resistance, corrosion resistance and wear resistance is obtained by adopting the process steps of heating and smelting, vacuum treatment, thermoforming, cooling and the like, the mechanical property of the magnesium alloy is improved, the process method is simple to operate, the process parameters are easy to control, and the method is suitable for industrial mass production.

(3) According to the method, metal Zn and Zr are added into the raw materials, so that the castability, high-temperature type, strength and toughness of the magnesium alloy are improved; after the raw materials are heated and smelted, an Mg-Zn-Zr high-temperature resistant phase is formed, and the addition of the rare earth element Y improves the tensile strength, the yield strength, the flame retardance, the corrosion resistance, the high-temperature resistance and the heat-resistant temperature of the magnesium alloy; the raw material contains trace surface active element Ca, and the Ca has lower potential than magnesium to form cathode protection, so that the corrosion rate of the magnesium alloy is reduced, and the rare earth element Y is added to uniformly wrap the surface of the magnesium alloy in a vacuum and thermal forming treatment mode, so that the corrosion resistance of the magnesium alloy is further improved.

Detailed Description

The following is a detailed description of the embodiments of the present invention, but the present invention is not limited to these embodiments, and any modifications or substitutions in the basic spirit of the embodiments are included in the scope of the present invention as claimed in the claims.

Example 1

The corrosion-resistant high-performance magnesium alloy comprises the following components in percentage by weight: 0.8 wt.% Ge, 0.3 wt.% Zr, 0.2 wt.% Mo, 0.1 wt.% Na, 0.9 wt.% Ru, 22 wt.% Al, 0.4 wt.% Ca, 0.5 wt.% Zn, 0.4 wt.% Hf, 1.1 wt.% Ti, 0.1 wt.% Cu, 0.6 wt.% Mn, 0.5 wt.% Cr, 0.8 wt.% Si, 0.1 wt.% Y, 0.8 wt.% C, 1.0 wt.% W, the balance being magnesium and unavoidable impurities.

A preparation process of the corrosion-resistant high-performance magnesium alloy comprises the following steps:

(1) putting the components of the magnesium alloy into a vacuum heat treatment furnace according to the weight percentage, heating and smelting the components into alloy liquid, electromagnetically stirring the alloy liquid to fully react the raw materials, and then controlling the temperature to 550 ℃ along with the furnace temperature in a mode of firstly heating and then cooling; the temperature control and heat preservation time is 2 hours; the working pressure of the vacuum heat treatment is 0.35 Pa; the electromagnetic stirring time is 9 min;

(2) after the vacuum heat treatment is finished, naturally cooling and preserving heat; the cooling is to reduce the temperature to 400 ℃, the cooling speed is-8 ℃/min, and the heat preservation time is 80 min;

(3) feeding the material obtained in the step (2) into a forming die, heating to the temperature of magnesium alloy thermoforming, then preserving heat, introducing cooling water for cooling, naturally cooling to 80 ℃, taking out from the die, and naturally cooling to room temperature to obtain the corrosion-resistant high-performance magnesium alloy; the thermal forming temperature is 480 ℃, and the heat preservation time is 3 min; the cooling water is cooled to 230 ℃ by introducing cold water, and the cooling speed of the cooling water is-20 ℃/min.

Example 2

The corrosion-resistant high-performance magnesium alloy comprises the following components in percentage by weight: 1.2 wt.% Ge, 0.8 wt.% Zr, 0.7 wt.% Mo, 0.3 wt.% Na, 1.3 wt.% Ru, 30 wt.% Al, 0.9 wt.% Ca, 2.3 wt.% Zn, 1.2 wt.% Hf, 1.6 wt.% Ti, 0.4 wt.% Cu, 1.3 wt.% Mn, 1.2 wt.% Cr, 2.0 wt.% Si, 0.3 wt.% Y, 1.4 wt.% C, 1.6 wt.% W, the balance being magnesium and unavoidable impurities.

(1) putting the components of the magnesium alloy into a vacuum heat treatment furnace according to the weight percentage, heating and smelting the components into alloy liquid, electromagnetically stirring the alloy liquid to fully react the raw materials, and then controlling the temperature to 600 ℃ along with the furnace temperature in a mode of firstly heating and then cooling; the temperature control and heat preservation time is 3 hours; the working pressure of the vacuum heat treatment is 0.55 Pa; the electromagnetic stirring time is 13 min;

(2) after the vacuum heat treatment is finished, naturally cooling and preserving heat; the cooling is to reduce the temperature to 450 ℃, the cooling speed is-13 ℃/min, and the heat preservation time is 100 min;

(3) feeding the material obtained in the step (2) into a forming die, heating to the temperature of magnesium alloy thermoforming, then preserving heat, introducing cooling water for cooling, naturally cooling to 80 ℃, taking out from the die, and naturally cooling to room temperature to obtain the corrosion-resistant high-performance magnesium alloy; the thermoforming temperature is 520 ℃, and the heat preservation time is 10 min; the cooling water cooling is to introduce cold water to reduce the temperature to 260 ℃, and the cooling water cooling speed is-40 ℃/min.

Example 3

The corrosion-resistant high-performance magnesium alloy comprises the following components in percentage by weight: 0.9 wt.% Ge, 0.4 wt.% Zr, 0.3 wt.% Mo, 0.15 wt.% Na, 1.0 wt.% Ru, 23 wt.% Al, 0.5 wt.% Ca, 0.6 wt.% Zn, 0.5 wt.% Hf, 1.2 wt.% Ti, 0.2 wt.% Cu, 0.7 wt.% Mn, 0.6 wt.% Cr, 0.9 wt.% Si, 0.15 wt.% Y, 0.9 wt.% C, 1.1 wt.% W, the balance being magnesium and unavoidable impurities.

(1) putting the components of the magnesium alloy into a vacuum heat treatment furnace according to the weight percentage, heating and smelting the components into alloy liquid, electromagnetically stirring the alloy liquid to fully react the raw materials, and then controlling the temperature to 560 ℃ along with the furnace temperature in a mode of firstly heating and then cooling; the temperature control and heat preservation time is 2.2 hours; the working pressure of the vacuum heat treatment is 0.40 Pa; the electromagnetic stirring time is 10 min;

(2) after the vacuum heat treatment is finished, naturally cooling and preserving heat; the cooling is to cool the temperature to 410 ℃, the cooling speed is minus 9 ℃/min, and the heat preservation time is 85 min;

(3) feeding the material obtained in the step (2) into a forming die, heating to the temperature of magnesium alloy thermoforming, then preserving heat, introducing cooling water for cooling, naturally cooling to 80 ℃, taking out from the die, and naturally cooling to room temperature to obtain the corrosion-resistant high-performance magnesium alloy; the thermal forming temperature is 490 ℃, and the heat preservation time is 4 min; the cooling water is cooled to 235 ℃ by introducing cold water, and the cooling speed of the cooling water is-22 ℃/min.

Example 4

The corrosion-resistant high-performance magnesium alloy comprises the following components in percentage by weight: 1.1 wt.% Ge, 0.7 wt.% Zr, 0.6 wt.% Mo, 0.25 wt.% Na, 1.2 wt.% Ru, 29 wt.% Al, 0.8 wt.% Ca, 2.2 wt.% Zn, 1.1 wt.% Hf, 1.5 wt.% Ti, 0.3 wt.% Cu, 1.2 wt.% Mn, 1.1 wt.% Cr, 1.9 wt.% Si, 0.25 wt.% Y, 1.3 wt.% C, 1.5 wt.% W, the balance being magnesium and unavoidable impurities.

(1) putting the components of the magnesium alloy into a vacuum heat treatment furnace according to the weight percentage, heating and smelting the components into alloy liquid, electromagnetically stirring the alloy liquid to fully react the raw materials, and then controlling the temperature to 590 ℃ along with the furnace temperature in a mode of firstly heating and then cooling; the temperature control and heat preservation time is 2.9 hours; the working pressure of the vacuum heat treatment is 0.50 Pa; the electromagnetic stirring time is 12 min;

(2) after the vacuum heat treatment is finished, naturally cooling and preserving heat; the cooling is to reduce the temperature to 440 ℃, the cooling speed is-12 ℃/min, and the heat preservation time is 95 min;

(3) feeding the material obtained in the step (2) into a forming die, heating to the temperature of magnesium alloy thermoforming, then preserving heat, introducing cooling water for cooling, naturally cooling to 80 ℃, taking out from the die, and naturally cooling to room temperature to obtain the corrosion-resistant high-performance magnesium alloy; the thermoforming temperature is 510 ℃, and the heat preservation time is 9 min; the cooling water cooling is to introduce cold water to cool to 255 ℃, and the cooling water cooling speed is-37 ℃/min.

Example 5

The corrosion-resistant high-performance magnesium alloy comprises the following components in percentage by weight: 1.0 wt.% Ge, 0.5 wt.% Zr, 0.5 wt.% Mo, 0.2 wt.% Na, 1.1 wt.% Ru, 26 wt.% Al, 0.6 wt.% Ca, 1.4 wt.% Zn, 0.8 wt.% Hf, 1.3 wt.% Ti, 0.25 wt.% Cu, 0.9 wt.% Mn, 0.9 wt.% Cr, 1.4 wt.% Si, 0.2 wt.% Y, 1.1 wt.% C, 1.3 wt.% W, the balance being magnesium and unavoidable impurities.

(1) putting the components of the magnesium alloy into a vacuum heat treatment furnace according to the weight percentage, heating and smelting the components into alloy liquid, electromagnetically stirring the alloy liquid to fully react the raw materials, and then controlling the temperature to 575 ℃ along with the furnace temperature in a mode of firstly heating and then cooling; the temperature control and heat preservation time is 2.5 hours; the working pressure of the vacuum heat treatment is 0.45 Pa; the electromagnetic stirring time is 11 min;

(2) after the vacuum heat treatment is finished, naturally cooling and preserving heat; the cooling is to cool to 425 ℃, the cooling speed is-10 ℃/min, and the heat preservation time is 90 min;

(3) feeding the material obtained in the step (2) into a forming die, heating to the temperature of magnesium alloy thermoforming, then preserving heat, introducing cooling water for cooling, naturally cooling to 80 ℃, taking out from the die, and naturally cooling to room temperature to obtain the corrosion-resistant high-performance magnesium alloy; the thermal forming temperature is 500 ℃, and the heat preservation time is 6 min; the cooling water cooling is to introduce cold water to cool to 245 ℃, and the cooling speed of the cooling water is-30 ℃/min.

Example 6

The corrosion-resistant high-performance magnesium alloy comprises the following components in percentage by weight: 0.85 wt.% Ge, 0.5 wt.% Zr, 0.4 wt.% Mo, 0.12 wt.% Na, 0.95 wt.% Ru, 24 wt.% Al, 0.6 wt.% Ca, 1.0 wt.% Zn, 0.6 wt.% Hf, 1.3 wt.% Ti, 0.15 wt.% Cu, 0.9 wt.% Mn, 0.8 wt.% Cr, 1.1 wt.% Si, 0.12 wt.% Y, 1.0 wt.% C, 1.2 wt.% W, the balance being magnesium and unavoidable impurities.

(1) putting the components of the magnesium alloy into a vacuum heat treatment furnace according to the weight percentage, heating and smelting the components into alloy liquid, electromagnetically stirring the alloy liquid to fully react the raw materials, and then controlling the temperature to 570 ℃ along with the furnace temperature in a mode of firstly heating and then cooling; the temperature control and heat preservation time is 2.3 h; the working pressure of the vacuum heat treatment is 0.33 Pa; the electromagnetic stirring time is 10 min;

(2) after the vacuum heat treatment is finished, naturally cooling and preserving heat; the cooling is to cool the temperature to 420 ℃, the cooling speed is minus 10 ℃/min, and the heat preservation time is 83 min;

(3) feeding the material obtained in the step (2) into a forming die, heating to the temperature of magnesium alloy thermoforming, then preserving heat, introducing cooling water for cooling, naturally cooling to 80 ℃, taking out from the die, and naturally cooling to room temperature to obtain the corrosion-resistant high-performance magnesium alloy; the thermal forming temperature is 485 ℃, and the heat preservation time is 5 min; the cooling water cooling is to introduce cold water to cool to 240 ℃, and the cooling water cooling speed is-25 ℃/min.

Example 7

The corrosion-resistant high-performance magnesium alloy comprises the following components in percentage by weight: 1.15 wt.% Ge, 0.6 wt.% Zr, 0.5 wt.% Mo, 0.28 wt.% Na, 1.25 wt.% Ru, 28 wt.% Al, 0.7 wt.% Ca, 1.8 wt.% Zn, 1.0 wt.% Hf, 1.4 wt.% Ti, 0.35 wt.% Cu, 1.0 wt.% Mn, 0.9 wt.% Cr, 1.8 wt.% Si, 0.28 wt.% Y, 1.2 wt.% C, 1.4 wt.% W, the balance being magnesium and unavoidable impurities.

(1) putting the components of the magnesium alloy into a vacuum heat treatment furnace according to the weight percentage, heating and smelting the components into alloy liquid, electromagnetically stirring the alloy liquid to fully react the raw materials, and then controlling the temperature to 580 ℃ along with the furnace temperature in a mode of firstly heating and then cooling; the temperature control and heat preservation time is 2.7 hours; the working pressure of the vacuum heat treatment is 0.53 Pa; the electromagnetic stirring time is 11 min;

(2) after the vacuum heat treatment is finished, naturally cooling and preserving heat; the cooling is to cool the temperature to 430 ℃, the cooling speed is minus 11 ℃/min, and the heat preservation time is 98 min;

(3) feeding the material obtained in the step (2) into a forming die, heating to the temperature of magnesium alloy thermoforming, then preserving heat, introducing cooling water for cooling, naturally cooling to 80 ℃, taking out from the die, and naturally cooling to room temperature to obtain the corrosion-resistant high-performance magnesium alloy; the thermoforming temperature is 515 ℃, and the heat preservation time is 7 min; the cooling water cooling is to introduce cold water to cool to 250 ℃, and the cooling water cooling speed is-35 ℃/min.

Comparative example 1

A high-performance magnesium alloy comprises the following components in percentage by weight: 28 wt.% Al, 0.7 wt.% Ca, 1.8 wt.% Zn, the balance being magnesium and unavoidable impurities.

A preparation process of the high-performance magnesium alloy comprises the following steps:

(1) putting the components of the magnesium alloy into a vacuum heat treatment furnace according to the weight percentage, heating and smelting the components into alloy liquid, electromagnetically stirring the alloy liquid to fully react the raw materials, and then controlling the temperature to 580 ℃ along with the furnace temperature in a mode of firstly heating and then cooling; the temperature control and heat preservation time is 2.7 hours; the working pressure of the vacuum heat treatment is 0.53 Pa; the electromagnetic stirring time is 13 min;

(2) after the vacuum heat treatment is finished, naturally cooling and preserving heat; the cooling is to reduce the temperature to 450 ℃, the cooling speed is-11 ℃/min, and the heat preservation time is 100 min;

(3) feeding the material obtained in the step (2) into a forming die, heating to the temperature of magnesium alloy thermoforming, then preserving heat, introducing cooling water for cooling, naturally cooling to 85 ℃, taking out from the die, and naturally cooling to room temperature to obtain the high-performance magnesium alloy; the thermal forming temperature is 500 ℃, and the heat preservation time is 7 min; the cooling water cooling is to introduce cold water to cool to 290 ℃, and the cooling water cooling speed is-55 ℃/min.

Effect test

The high-strength corrosion-resistant magnesium alloy prepared in examples 1 to 7 and the magnesium alloy prepared in comparative example 1 were subjected to a tensile test and a corrosion test, and the specific method was as follows:

(1) tensile test method: processing a room-temperature tensile test sample by using a GB/T228.1: 2010 standard, and testing the magnesium alloy prepared by the methods of examples 1-7 and comparative example 1 on a SANSI UTM5000 universal testing machine (the test temperature is 25 ℃ at room temperature and the tensile rate is 3 mm/s);

(2) the corrosion test method comprises the following steps: a room temperature (25 ℃) soaking corrosion test is adopted, and a corrosion medium is 15% NaCl solution. The corrosion sample is a wafer-shaped magnesium alloy sample, and the size of the corrosion sample is phi 15mm multiplied by 3 mm; the corrosion test time was 100 h. The weight loss of the magnesium alloy sample before and after corrosion is measured, and the daily corrosion rate (mg cm) of the magnesium alloy sample is calculated by combining the surface area of the magnesium alloy sample^-2·d^-1)。

The specific test results are shown in table 1.

TABLE 1

Group of	Tensile strength (MPa)	Yield strength (MPa)	Elongation percentage	Corrosion rate (mg. cm)^-2·d^-1)
					Example 1	300	255	28％	0.058
Example 2	290	215	30％	0.053
					Example 3	305	270	29％	0.055
Example 4	315	260	25％	0.057
					Example 5	330	285	31％	0.048
Example 6	305	245	20％	0.050
					Example 7	320	265	26％	0.053
Comparative example 1	255	180	16％	0.143

As shown in the experimental data in Table 1, the tensile strength, the yield strength and the elongation of the high-performance magnesium alloy prepared by the method are respectively greater than 290MPa, 215MPa, 20% and less than 0.06 mg-cm for corrosion rate per day^-2·d^-1. Therefore, the high-performance magnesium alloy prepared by the method has better strength, elongation and corrosion resistance.

In summary, the metal Zn and Zr are added into the raw materials, so that the castability, the high-temperature type, the strength and the toughness of the magnesium alloy are improved; after the raw materials are heated and smelted, an Mg-Zn-Zr high-temperature resistant phase is formed, and the addition of the rare earth element Y improves the tensile strength, the yield strength, the flame retardance, the corrosion resistance, the high-temperature resistance and the heat-resistant temperature of the magnesium alloy; the raw materials contain trace surface active element Ca, and the Ca has lower potential than magnesium to form cathode protection, so that the corrosion rate of the magnesium alloy is reduced, and the rare earth element Y is added to uniformly wrap the surface of the magnesium alloy through vacuum and thermal forming treatment modes, so that the corrosion resistance of the magnesium alloy is further improved.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. The corrosion-resistant high-performance magnesium alloy is characterized by comprising the following components in percentage by weight: 0.8-1.2 wt.% Ge, 0.3-0.8 wt.% Zr, 0.2-0.7 wt.% Mo, 0.1-0.3 wt.% Na, 0.9-1.3 wt.% Ru, 22-30 wt.% Al, 0.4-0.9 wt.% Ca, 0.5-2.3 wt.% Zn, 0.4-1.2 wt.% Hf, 1.1-1.6 wt.% Ti, 0.1-0.4 wt.% Cu, 0.6-1.3 wt.% Mn, 0.5-1.2 wt.% Cr, 0.8-2.0 wt.% Si, 0.1-0.3 wt.% Y, 0.8-1.4 wt.% C, 1.0-1.6 wt.% W, and the balance magnesium and unavoidable impurities;

the preparation process comprises the following steps:

(3) feeding the material obtained in the step (2) into a forming die, heating to the temperature of magnesium alloy thermoforming, then preserving heat, introducing cooling water for cooling, naturally cooling to 80 ℃, taking out from the die, and naturally cooling to room temperature to obtain the corrosion-resistant high-performance magnesium alloy;

in the step (1), the temperature control and heat preservation time is 2-3 h; the working pressure of the vacuum heat treatment is 0.35-0.55 Pa;

in the step (3), the thermoforming temperature is 480-520 ℃, and the heat preservation time is 3-10 min.

2. The corrosion-resistant high-performance magnesium alloy according to claim 1, wherein the magnesium alloy comprises the following components in percentage by weight: 0.9-1.1 wt.% Ge, 0.4-0.7 wt.% Zr, 0.3-0.6 wt.% Mo, 0.15-0.25 wt.% Na, 1.0-1.2 wt.% Ru, 23-29 wt.% Al, 0.5-0.8 wt.% Ca, 0.6-2.2 wt.% Zn, 0.5-1.1 wt.% Hf, 1.2-1.5 wt.% Ti, 0.2-0.3 wt.% Cu, 0.7-1.2 wt.% Mn, 0.6-1.1 wt.% Cr, 0.9-1.9 wt.% Si, 0.15-0.25 wt.% Y, 0.9-1.3 wt.% C, 1.1-1.5 wt.% W, and the balance magnesium and unavoidable impurities.

3. The corrosion-resistant high-performance magnesium alloy according to claim 1, wherein the magnesium alloy comprises the following components in percentage by weight: 1.0 wt.% Ge, 0.5 wt.% Zr, 0.5 wt.% Mo, 0.2 wt.% Na, 1.1 wt.% Ru, 26 wt.% Al, 0.6 wt.% Ca, 1.4 wt.% Zn, 0.8 wt.% Hf, 1.3 wt.% Ti, 0.25 wt.% Cu, 0.9 wt.% Mn, 0.9 wt.% Cr, 1.4 wt.% Si, 0.2 wt.% Y, 1.1 wt.% C, 1.3 wt.% W, the balance being magnesium and unavoidable impurities.

4. The corrosion-resistant high-performance magnesium alloy according to claim 1, wherein: in the step (1), the electromagnetic stirring time is 9-13 min.

5. The corrosion-resistant high-performance magnesium alloy according to claim 1, wherein: in the step (2), the temperature is reduced to 400-450 ℃, the cooling speed is-8 to-13 ℃/min, and the heat preservation time is 80-100 min.

6. The corrosion-resistant high-performance magnesium alloy according to claim 1, wherein: in the step (3), the cooling water is cooled by introducing cold water to be cooled to 230-260 ℃, and the cooling speed of the cooling water is-20 to-40 ℃/min.