阅读说明：本技术 一种高强度镁稀土合金材料及其制备方法 (High-strength magnesium rare earth alloy material and preparation method thereof ) 是由 何文敬 李蕾 高晓山 张德文 于 2019-10-10 设计创作，主要内容包括：本发明公开了一种高强度镁稀土合金材料及其制备方法,包括镁稀土合金本体和镁稀土合金本体表面耐腐蚀膜层,镁合金本体含有的化学元素成分及质量百分比为：镧2.5～3.5％、铈1.5～2.5％、碳0.5～1.0％、锰0.2～0.4％、钒0.10～0.30％、钆0.25～0.50％、钇0.3～0.6％和余量的镁。在电解槽的阴极首先是氯化镁中的镁离子得到电子被还原成金属镁,然后金属镁进一步氧化置换出氯化稀土中的稀土元素,从而形成了均匀致密的镁稀土合金本体,为了调高镁稀土合金本体的抗腐蚀性能,在镁稀土合金本体的表面再涂覆一层耐腐蚀膜层,具有很好的耐盐水腐蚀性能,能够显著提高镁稀土合金本体的实际应用温度。(The invention discloses a high-strength magnesium rare earth alloy material and a preparation method thereof, wherein the high-strength magnesium rare earth alloy material comprises a magnesium rare earth alloy body and a corrosion-resistant film layer on the surface of the magnesium rare earth alloy body, and the magnesium alloy body comprises the following chemical element components in percentage by mass: 2.5-3.5% of lanthanum, 1.5-2.5% of cerium, 0.5-1.0% of carbon, 0.2-0.4% of manganese, 0.10-0.30% of vanadium, 0.25-0.50% of gadolinium, 0.3-0.6% of yttrium and the balance of magnesium. The cathode of the electrolytic cell is characterized in that magnesium ions in magnesium chloride are firstly subjected to electron reduction to form magnesium metal, then the magnesium metal is further oxidized and replaced by rare earth elements in rare earth chloride, so that a uniform and compact magnesium rare earth alloy body is formed, in order to improve the corrosion resistance of the magnesium rare earth alloy body, a corrosion-resistant film layer is further coated on the surface of the magnesium rare earth alloy body, the magnesium rare earth alloy body has good salt water corrosion resistance, and the practical application temperature of the magnesium rare earth alloy body can be obviously improved.)

1. A high-strength magnesium rare earth alloy material is characterized in that: the magnesium rare earth alloy coating comprises a magnesium rare earth alloy body and a corrosion-resistant film layer on the surface of the magnesium rare earth alloy body; the magnesium alloy body comprises the following chemical element components in percentage by mass: 2.5-3.5% of lanthanum, 1.5-2.5% of cerium, 0.5-1.0% of carbon, 0.2-0.4% of manganese, 0.10-0.30% of vanadium, 0.25-0.50% of gadolinium, 0.3-0.6% of yttrium and the balance of magnesium;

the corrosion-resistant film layer is a cerium oxide doped yttrium oxide stabilized zirconia coating.

2. The high-strength magnesium rare earth alloy material as set forth in claim 1, wherein: the magnesium alloy body comprises the following chemical element components in percentage by mass: 3.2% of lanthanum, 1.6% of cerium, 0.6% of carbon, 0.3% of manganese, 0.15% of vanadium, 0.30% of gadolinium, 0.4% of yttrium and the balance of magnesium.

3. The high-strength magnesium rare earth alloy material as set forth in claim 1, wherein: the thickness of the corrosion-resistant film layer is 10-50 mu m.

4. A preparation method of a high-strength magnesium rare earth alloy material is characterized by comprising the following steps: comprises the following steps of (a) carrying out,

(1) preparing anhydrous rare earth chloride: the method comprises the following steps of (1) dehydrating chlorinated lanthanum-cerium mixed rare earth for 2-5 hours at a high temperature of 200-250 ℃ in a vacuum dehydration furnace to obtain dehydrated chlorinated rare earth;

(2) preparing magnesium rare earth alloy by electrolysis: adopting a graphite crucible as an electrolytic cell, simultaneously taking the graphite crucible as an anode, taking molybdenum as a cathode, and using potassium chloride, sodium chloride, calcium chloride, magnesium chloride and the obtained rare earth chloride as electrolyte, wherein the electrolysis temperature is 700-800 ℃, the current is 180-320A, the electrolysis time is 1.5-2.5 h, and obtaining a magnesium rare earth alloy body at the cathode after the electrolysis is finished;

(3) pretreatment: preparing the magnesium rare earth alloy body obtained in the step (2) into a workpiece model, degreasing the workpiece model by using acetone, soaking the workpiece model in 6% sodium hydroxide solution at 70 ℃ for 10-15 min, and finally washing the workpiece model by water and then drying the workpiece model by air;

(4) preparing corrosion-resistant film sol: using n-propanol as a solvent, preparing 0.5mol/L zirconium n-propoxide and 0.5mol/L yttrium nitrate, stirring at 50 ℃ to form sol, and then adding 0.5mol/L cerous nitrate in an equal volume to obtain the composite corrosion-resistant film layer sol.

(5) Coating a corrosion-resistant film layer by using sol: and (3) coating the corrosion-resistant film layer sol obtained in the step (4) on the surface of the magnesium rare earth alloy body obtained in the step (3) by adopting a dip-coating method, and preserving heat for 1.0-1.5 hours at the temperature of 150 ℃ to obtain the magnesium rare earth alloy.

5. The method for preparing the high-strength magnesium rare earth alloy material according to claim 4, wherein the method comprises the following steps: the lanthanum compound content in the lanthanum-cerium mixed rare earth is 25-35%, and the cerium compound content is 10-25%.

6. The method for preparing the high-strength magnesium rare earth alloy material according to claim 4, wherein the method comprises the following steps: the mass ratio of the potassium chloride to the sodium chloride to the calcium chloride to the magnesium chloride to the rare earth chloride is 1:3:4.5:200: 20.

Technical Field

The invention relates to the technical field of high-strength rare earth alloys, in particular to a high-strength magnesium rare earth alloy material and a preparation method thereof.

Background

The magnesium alloy is the lightest metal structure material in engineering application, has the advantages of high specific strength, high specific rigidity, easy processing, easy recovery and the like, and has huge application market in the fields of spaceflight, war industry, electronic communication, transportation and the like. The rare earth element is one of the most effective elements for improving the performance of the magnesium alloy, but because the melting points and the densities of magnesium and the rare earth elements are different, the composition segregation of the rare earth element in the alloy is easy to cause when the magnesium and the rare earth elements are doped, and the adoption of an electrolytic method is a common method for preparing the magnesium-rare earth intermediate alloy.

Therefore, the invention mainly solves the problem that the magnesium rare earth alloy has poor practical application effects in corrosion resistance, hardness, high temperature resistance and the like due to uneven distribution of all components in the magnesium rare earth alloy.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a high-strength magnesium rare earth alloy material and a preparation method thereof, and mainly solves the problem that the magnesium rare earth alloy has poor practical application effects in corrosion resistance, hardness, high temperature resistance and the like due to uneven distribution of components in the magnesium rare earth alloy.

The invention solves the technical problems through the following technical means:

a high-strength magnesium rare earth alloy material comprises a magnesium rare earth alloy body and a corrosion-resistant film layer on the surface of the magnesium rare earth alloy body; the magnesium alloy body comprises the following chemical element components in percentage by mass: 2.5-3.5% of lanthanum, 1.5-2.5% of cerium, 0.5-1.0% of carbon, 0.2-0.4% of manganese, 0.10-0.30% of vanadium, 0.25-0.50% of gadolinium, 0.3-0.6% of yttrium and the balance of magnesium;

the corrosion-resistant film layer is a cerium oxide doped yttrium oxide stabilized zirconia coating.

Preferably, the high-strength magnesium rare earth alloy material comprises the following chemical element components in percentage by mass: 3.2% of lanthanum, 1.6% of cerium, 0.6% of carbon, 0.3% of manganese, 0.15% of vanadium, 0.30% of gadolinium, 0.4% of yttrium and the balance of magnesium;

preferably, the thickness of the corrosion-resistant film layer is 10-50 μm.

A preparation method of a high-strength magnesium rare earth alloy material comprises the following steps,

(1) preparing anhydrous rare earth chloride: the method comprises the following steps of (1) dehydrating chlorinated lanthanum-cerium mixed rare earth for 2-5 hours at a high temperature of 200-250 ℃ in a vacuum dehydration furnace to obtain dehydrated chlorinated rare earth;

(2) preparing magnesium rare earth alloy by electrolysis: adopting a graphite crucible as an electrolytic cell, simultaneously taking the graphite crucible as an anode, taking molybdenum as a cathode, and using potassium chloride, sodium chloride, calcium chloride, magnesium chloride and the obtained rare earth chloride as electrolyte, wherein the electrolysis temperature is 700-800 ℃, the current is 180-320A, the electrolysis time is 1.5-2.5 h, and obtaining a magnesium rare earth alloy body at the cathode after the electrolysis is finished;

(3) pretreatment: preparing the magnesium rare earth alloy body obtained in the step (2) into a workpiece model, degreasing the workpiece model by using acetone, soaking the workpiece model in 6% sodium hydroxide solution at 70 ℃ for 10-15 min, and finally washing the workpiece model by water and then drying the workpiece model by air;

(4) preparing corrosion-resistant film sol: using n-propanol as a solvent, preparing 0.5mol/L zirconium n-propoxide and 0.5mol/L yttrium nitrate, stirring at 50 ℃ to form sol, and then adding 0.5mol/L cerous nitrate in an equal volume to obtain the composite corrosion-resistant film layer sol.

(5) Coating a corrosion-resistant film layer by using sol: and (3) coating the corrosion-resistant film layer sol obtained in the step (4) on the surface of the magnesium rare earth alloy body obtained in the step (3) by adopting a dip-coating method, and preserving heat for 1.0-1.5 hours at the temperature of 150 ℃ to obtain the magnesium rare earth alloy.

Preferably, the preparation method of the high-strength magnesium rare earth alloy material comprises the following steps of 25-35% of lanthanum compound and 10-25% of cerium compound in the lanthanum-cerium mixed rare earth.

Preferably, the preparation method of the high-strength magnesium rare earth alloy material comprises the following steps of mixing potassium chloride, sodium chloride, calcium chloride, magnesium chloride and rare earth chloride in a mass ratio of 1:3:4.5:200: 20.

The invention has the advantages that: magnesium ions in magnesium chloride are firstly obtained at the cathode of the electrolytic cell and are reduced into magnesium metal, and then the magnesium metal is further oxidized and replaced with rare earth elements in rare earth chloride, so that a uniform and compact magnesium rare earth alloy body is formed, and the magnesium rare earth alloy body has better requirements on hardness and toughness; in order to improve the corrosion resistance of the magnesium rare earth alloy body, the surface of the magnesium rare earth alloy body is coated with a corrosion-resistant film layer, so that the magnesium rare earth alloy body has good salt water corrosion resistance, and the actual application temperature of the magnesium rare earth alloy body can be obviously improved.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.