WO2020052129A1 - Rare-earth aluminum alloy material having high ductility and high strength and preparation method therefor - Google Patents

Abstract

On one hand, provided in the present invention is a rare-earth aluminum alloy material that has high ductility and high strength, that is calculated according to mass percentage, and that comprises the following components: 2.0-3.5% Si, 3.5%-5.0% Cu, 0.5%-0.9% Mn, 0.1%-0.5% Re, 0.1%-0.2% Ti, 0.005%-0.05% Sr, and 80%-92% Al, wherein Re is mixed rare earth containing Ce and La. In the present invention, a rare earth element is introduced into an aluminum alloy to improve the fluidity of the aluminum alloy and reduce shrinkage, contraction cavities and the production of cracks. On the other hand, provided in the present invention is a method for preparing a rare-earth aluminum alloy material that has high ductility and high strength, which uses an indirect extrusion casting process to achieve industrial scale production, and has huge development potential in the fields of automobile lightweighting, intelligent robots, aerospace, etc.

Description

Rare-earth aluminum alloy material with high ductility and high strength and preparation method thereof Technical field

The invention belongs to the technical field of metal alloys, and particularly relates to a rare-earth aluminum alloy material with high ductility and high strength and a preparation method thereof.

Background technique

Aluminum alloy is a kind of non-ferrous metal structural material, which has the advantages of low density, high strength, good plasticity, excellent electrical and thermal conductivity, and corrosion resistance. It is widely used in aerospace, automobile manufacturing, 3C products, ships, and chemical industries. With the development trend of light weight, the demand for aluminum alloy materials is increasing; in the field of automobile manufacturing, the use of aluminum alloy materials for the entire body and accessories is the development direction of lightweight vehicles, so the mechanical properties and casting of aluminum alloy materials Higher performance requirements.

High-toughness aluminum alloy materials are mainly two types of deformed aluminum alloy and cast aluminum alloy. Deformed aluminum alloys reduce casting defects by means of pressure processing. At the same time, during the deformation process, the grains are refined by shear strain and recrystallization, which improves the density of the material, and has the advantages of high strength and good toughness. However, the deformed aluminum alloy has high requirements on equipment and tooling molds, complicated preparation processes, and has the disadvantages of long production cycles and high production costs. Compared with deformed aluminum alloys, cast aluminum alloys have the advantages of short procedures and high production efficiency, especially in the production of complex castings. However, cast aluminum alloys have strict requirements on alloy composition control and alloy properties, such as: cast aluminum The alloy needs to have good flow properties and solidification shrinkage, otherwise the cast product is difficult to form or has defects that are difficult to eliminate. At present, A356 aluminum alloy is a widely used type of cast aluminum alloy. Its disadvantages are: general tensile strength and elongation performance, and limited application scope.

Therefore, there is an urgent need to develop a new type of aluminum alloy material, which has both good ductility and high strength, and is easy to realize industrial production. Compared with the existing aluminum alloy materials, it has obvious competitive advantages.

Summary of the Invention

The present invention addresses the shortcomings of the prior art. On the one hand, it provides a rare-earth aluminum alloy material with high ductility and high strength. The rare-earth element is introduced into the aluminum alloy to improve the fluidity of the aluminum alloy and reduce shrinkage and shrinkage Initiation of holes and cracks; on the other hand, the present invention provides a method for preparing a rare-earth aluminum alloy material with high ductility and high strength, and adopts an indirect extrusion casting process to realize industrial production.

The present invention achieves the objective through the following technical solution: a rare-earth aluminum alloy material with high ductility, calculated in terms of mass percentage, including the following components: 2.0-3.5% Si, 3.5% -5.0% Cu, 0.5% -0.9% Mn, 0.1% to 0.5% Re, 0.1% to 0.2% Ti, 0.005% to 0.05% Sr, and 80% to 92% Al, the Re is a mixed rare earth containing Ce and La.

Further, in the Re, the mass percentage of Ce is 50% to 60%.

Further, calculated in terms of mass percentage, the following components are included: 2.4% Si, 4.6% Cu, 0.70% Mn, 0.30% Re, 0.20% Ti, 0.01% Sr, and 91.63% Al, and the balance is Impurities.

Further, in the Re, the mass ratio of the Ce to the La is 14:11.

The method for preparing a rare earth aluminum alloy material disclosed in the present invention specifically includes the following steps:

S1. Prepare each raw material according to mass percentage;

S2. The prepared Al material, Cu material and Mn material are heated and melted to obtain melt A;

S3. The melt A is heated to 750 ° C, and then the Si material and the Re material are added, and the mixture is allowed to stand still to obtain the melt B;

S4. Degassing and purifying the melt B, and adding a refining agent;

S5. After the refining is completed, slagging is performed, and then Sr material is added, and after stirring, it is left to obtain melt C;

S6. Transfer the melt C to the extrusion casting machine, and add Ti material to the feeding cylinder of the extrusion casting machine in a wire feeding manner to perform extrusion casting molding;

S7. After cutting and extruding the sample, the sample is heat-treated to obtain a rare earth aluminum alloy material.

Further, in the above step, the Cu material is a Cu ingot or an Al-10Cu intermediate alloy, the Mn material is an Al-10Mn intermediate alloy, the Si material is an Al-10Si intermediate alloy, and the Re material is Al-20CeLa intermediate alloy, the Sr material is an Al-20Sr intermediate alloy, and the Ti material is an Al-5Ti-B intermediate alloy.

Further, in the step S5, a graphite rotor gas generator is used for refining and degassing the melt, and the refining agent is argon or nitrogen.

Further, in the step S7, indirect extrusion is used for casting and molding, and the casting temperature is 710-730 ° C.

Further, in the step S8, the heat treatment process includes the following steps:

S8.1. Dissolve the sample at 520 ° C for 9 hours;

S8.2. Water-quench the sample after solution, and then age for 8 h at 180 ° C;

S8.3. The sample of step S8.2 will be air-cooled for 24 hours.

The beneficial effects of the present invention are:

1. The invention discloses a rare-earth aluminum alloy material with high ductility and high strength. The rare-earth elements Ti, Sr, Ce and La are introduced into Al-Cu, which effectively improves the casting performance of the aluminum alloy and reduces the solidification of the alloy. Interval and dendrite spacing, with high strength and plasticity, tensile strength of more than 380MPa, elongation of up to 8%, can be used in automotive manufacturing, intelligent equipment, aerospace and other fields;

2. The aluminum alloy material of the present invention has relatively wide composition requirements. It does not require high-purity Al ingots and the addition of expensive Zr, V, Y and other alloys. The production cost is low, and it has high industrial value. There is huge development potential in intelligent robots, aerospace and other fields;

3. The aluminum alloy material of the present invention is formed by an indirect extrusion casting process, and the defective rate is controlled within 10%. The forming efficiency is better than gravity casting and is close to high pressure casting, which solves the problem of low production efficiency of high-strength Al-Cu alloys. , With the advantages of high production efficiency and industrialized production;

detailed description

In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to specific embodiments. The drawings show the preferred embodiments of the present invention. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough understanding of the present disclosure.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention.

Comparative example

The comparative example is a commercially available A356 aluminum alloy, which belongs to a cast aluminum alloy. The tensile strength of the A356 aluminum alloy is 295 MPa, the elongation is 3%, and the hardness is 80 HBW. A356 aluminum alloy is mainly used in the manufacture of various housings, aircraft pump parts, aircraft joints, automotive transmissions, high heat resistance branch stress parts, machine tool parts and other fields.

The A356 aluminum alloy of the comparative example is calculated in terms of mass percentage and includes the following components: 7.44% Si, 0.33% Mg, the balance is Al and inevitable impurities, and the mass percentage of the impurity element Fe is 0.16%.

Example one

This embodiment discloses a rare-earth aluminum alloy material with high ductility and high strength and a preparation method thereof. The rare-earth aluminum alloy material introduces Ti, Sr, Ce, and La rare earth elements into Al-Cu, which effectively improves the aluminum alloy. The casting performance of the alloy reduces the solidification interval and the dendrite spacing of the alloy, and has high strength and plasticity. The rare-earth aluminum alloy material does not require high-purity Al ingots and the addition of expensive Zr, V, Y and other alloys, and does not require high control of the proportion of certain components, has low production costs, and has high industrial value.

The rare earth aluminum alloy material of this embodiment is calculated in terms of mass percentage and includes the following components: 2.4% Si, 4.6% Cu, 0.70% Mn, 0.30% Re, 0.20% Ti, 0.01% Sr, and 91.63% Al, the balance is impurities; in the Re, the mass ratio of Ce to La is 14:11.

The indirect extrusion casting process is used to prepare the rare earth aluminum alloy material. The raw materials are: Al ingot, Cu ingot, Al-10Mn master alloy, Al-10Si master alloy, Al-20CeLa master alloy, Al-20Sr master alloy, and Al-5Ti. -B intermediate alloy, the above raw materials are all commercially available, and the purity is not specifically limited.

The indirect extrusion casting process is used to prepare the rare earth aluminum alloy material, and the equipment involved is a graphite crucible, a graphite rotor degasser, an extrusion casting machine, and a resistance furnace with air circulation.

The preparation process of the rare earth aluminum alloy material specifically includes the following steps:

S1. Prepare each raw material according to the mass percentage of the formula and dry it;

S2. The prepared Al ingot, Cu ingot, and Al-10Mn intermediate alloy are placed in a graphite crucible for heating and melting to obtain melt A;

S3. The graphite crucible is heated to raise the melt A to 750 ° C, and then the Al-10Si intermediate alloy and the Al-20CeLa intermediate alloy are added to the melt A, and the mixture is stirred for 15 minutes.

S4. The graphite rotor degasser is used to degas the melt B and pass the refining agent Ar;

S5. After the refining is completed, slagging is performed, and then the Al-20Sr intermediate alloy is added, stirred for 5 minutes, and mixed for 20 minutes to obtain melt C;

S6. Transfer the melt C to the extrusion casting machine, and add Al-5Ti-B intermediate alloy to the feeding cylinder of the extrusion casting machine by wire feeding, and perform extrusion casting to obtain a sample;

S7. The sample is cut into a size suitable for the furnace of the resistance furnace, and then the sample is heat-treated to obtain a rare-earth aluminum alloy material with high ductility and high strength.

The above steps need to be explained. The reason that the respective raw materials are added in the above order is: first, Al ingot and Cu ingot are used as matrix raw materials, and the purpose of adding Mn is to reduce the content of Fe as an impurity element in the smelting process; The addition at 750 ° C is to ensure the diffusion and melting efficiency of the elements; again, because Sr is easily lost during melting, Sr needs to be added after the refining process; finally, because of the low melting point of Al-5Ti-B and the short aging time (5 ～ 10min), so AL-Ti-B is added by wire feeding during casting to avoid the problem of deterioration and degradation of the effect.

In step S6, indirect extrusion is used for casting and molding, the casting temperature is 710 ° C to 720 ° C, the boost pressure is 43 MPa, and the dwell time is 5 s. The indirect extrusion casting molding process of this embodiment can control the rate of defective products within 10%, the forming efficiency is better than gravity casting, and is close to high pressure casting.

In step S7, the heat treatment process is as follows: first, the rare-earth aluminum alloy sample is solid-dissolved at 520 ° C for 9 hours; then the solid-dissolved sample is water-quenched, and then aged at 180 ° C for 8 hours; finally, air-cooled for 24 hours the above. Among them, the quenching transfer time is ≤10s.

The rare earth aluminum alloy material obtained by the above preparation method has both high strength and good mechanical properties. As described in Table 1, the tensile strength is 382 MPa, the elongation is 8%, and the hardness is 93 HBW. It has high strength and plasticity. Good advantages can be applied in the fields of automobile manufacturing, intelligent equipment, aerospace and so on.

Example two

This embodiment provides a rare earth aluminum alloy material, which is calculated in terms of mass percentage and includes the following components: including the following components: 3.1% Si, 4.1% Cu, 0.6% Mn, 0.15% Re, 0.13% Ti, 0.04% of Sr and 91.68% of Al, and the balance is impurities; wherein, in the Re, the mass ratio of Ce to La is 1: 1.

The preparation raw materials, equipment and preparation method of the rare earth aluminum alloy material are the same as those of the first embodiment, but the added amount of each raw material is prepared according to the formula of this embodiment. As shown in Table 1, the tensile strength of this rare earth aluminum alloy material is 354 MPa, the elongation is 11%, and the hardness is 89 HBW, which has the advantages of high strength and good plasticity.

Example three

This embodiment provides a rare earth aluminum alloy material, which is calculated in terms of mass percentage and includes the following components: including the following components: 3.5% Si, 4.8% Cu, 0.9% Mn, 0.4% Re, 0.15% Ti, 0.02% of Sr and 90.03% of Al, the balance is impurities; in the Re, the mass ratio of Ce to La is 7: 5.

The preparation raw materials, equipment and preparation method of the rare earth aluminum alloy material are the same as those of the first embodiment, but the added amount of each raw material is prepared according to the formula of this embodiment. As shown in Table 1, the tensile strength of the rare earth aluminum alloy material is 375 MPa, the elongation is 9%, and the hardness is 91 HBW, which has the advantages of high strength and good plasticity.

Embodiment 4

This embodiment provides a rare earth aluminum alloy material, which is calculated in terms of mass percentage and includes the following components: including the following components: 3.5% Si, 5.0% Cu, 0.7% Mn, 0.5% Re, 0.17% Ti, 0.05% Sr and 89.88% Al, the balance is impurities; in the Re, the mass ratio of Ce to La is 3: 2.

The preparation raw materials, equipment and preparation method of the rare earth aluminum alloy material are the same as those of the first embodiment, but the added amount of each raw material is prepared according to the formula of this embodiment. As shown in Table 1, the tensile strength of the rare earth aluminum alloy material is 367 MPa, the elongation is 8.5%, and the hardness is 89 HBW, which is not much different from the performance of the rare earth aluminum alloy material described in Example 3.

Table 1 shows the mechanical properties of the aluminum alloy materials in the comparative examples and the four examples.

It can be known from the above table that the rare earth aluminum alloy material of the present invention has a clear competitive advantage compared to A356 aluminum alloy. The comparative examples of the A356 aluminum alloy and the four examples have similar yields in squeeze casting, but compared with the A356 aluminum alloy, The mechanical properties of the rare earth aluminum alloy material of the present invention are more superior. The tensile strength of the rare earth aluminum alloy material of Example 1 is 1.3 times that of A356 aluminum alloy, and the elongation is 2.7 times that of A356 aluminum alloy; the tensile strength of the rare earth aluminum alloy material of Example 2 is 1.2 times that of A356 aluminum alloy, The elongation is 3.7 times that of the A356 aluminum alloy; the mechanical properties of the rare earth aluminum alloy materials in Examples 3 and 4 are not much different, and the tensile strength and elongation are superior to the A356 aluminum alloy. Therefore, the rare earth aluminum alloy material of the present invention has excellent ductility and high strength, and has great development potential in the fields of automobile lightweight, intelligent robot, aerospace and the like.

The above descriptions are merely preferred embodiments of the present invention, and do not limit the present invention in any form. It should be noted that for those skilled in the art, without departing from the principle of the present invention, several improvements and retouching can be made, and these improvements and retouching should also be regarded as the protection scope of the present invention.

Claims (9)

1. A rare-earth aluminum alloy material with high ductility and high strength, which is characterized in that it includes the following components in terms of mass percentage: 2.0-3.5% Si, 3.5% -5.0% Cu, 0.5% -0.9% Mn, 0.1 % To 0.5% of Re, 0.1% to 0.2% of Ti, 0.005% to 0.05% of Sr, and 80% to 92% of Al. The Re is a mixed rare earth containing Ce and La.
2. The rare-earth aluminum alloy material with high ductility and high strength according to claim 1, wherein the mass percentage of Ce in Re is 50% to 60%.
3. The highly ductile and high-strength rare earth aluminum alloy material according to claim 1 or 2, characterized in that it comprises the following components in terms of mass percentage: 2.4% Si, 4.6% Cu, 0.70% Mn, 0.30% Re, 0.20% Ti, 0.01% Sr, and 91.63% Al, and the balance is impurities.
4. The highly ductile and high-strength rare earth aluminum alloy material according to claim 3, wherein in the Re, the mass ratio of the Ce to the La is 14:11.
5. A method for preparing a rare-earth aluminum alloy material with high ductility and high strength is characterized in that it includes the following steps:

   S1. Prepare each raw material according to mass percentage;

   S2. The prepared Al material, Cu material and Mn material are heated and melted to obtain melt A;

   S3. The melt A is heated to 750 ° C, and then the Si material and the Re material are added, and the mixture is allowed to stand still to obtain the melt B;

   S4. Degassing and purifying the melt B, and adding a refining agent;

   S5. After the refining is completed, slagging is performed, and then Sr material is added, and after stirring, it is left to obtain melt C;

   S6. Transfer the melt C to the extrusion casting machine, and add Ti material to the feeding cylinder of the extrusion casting machine in a wire feeding manner to perform extrusion casting molding;

   S7. After cutting and extruding the sample, the sample is heat-treated to obtain a rare earth aluminum alloy material.
6. The method for preparing a highly ductile and high-strength rare earth aluminum alloy material according to claim 5, wherein the Cu material is a Cu ingot or an Al-10Cu master alloy, and the Mn material is an Al-10Mn master alloy. The Si material is an Al-10Si master alloy, the Re material is an Al-20CeLa master alloy, the Sr material is an Al-20Sr master alloy, and the Ti material is an Al-5Ti-B master alloy.
7. The method for preparing a highly ductile and high-strength rare earth aluminum alloy material according to claim 5, characterized in that in step S5, a graphite rotor gas generator is used to refine and degas the melt, and the refining agent It is argon or nitrogen.
8. The method for preparing a highly ductile and high-strength rare-earth aluminum alloy material according to claim 5, wherein in step S7, indirect extrusion is used for casting and molding, and the casting temperature is 710-730 ° C.
9. The method for preparing a highly ductile and high-strength rare earth aluminum alloy material according to any one of claims 5 to 8, characterized in that, in the step S8, the heat treatment process includes the following steps:

   S8.1. Dissolve the sample at 520 ° C for 9 hours;

   S8.2. Water-quench the sample after solution, and then age for 8 h at 180 ° C;

   S8.3. The sample of step S8.2 will be air-cooled for 24 hours.