阅读说明：本技术 一种金属预制材料及其制备方法 (Metal prefabricated material and preparation method thereof ) 是由 曾晓雁 胡乾午 于 2015-02-12 设计创作，主要内容包括：本发明公开了一种金属预制材料及其制备方法,该材料的基体为金属或合金,在基体上分布有由选区强韧化处理所获得的同素异构型增强相,该材料在保持基体重量基本不变的情况下,既有金属平衡态组织高延性、可焊性特点,又兼具金属亚稳态组织的高强度、高耐磨性能。该方法采用包括高功率激光束或电子束、离子束以及感应热源在内的能量束/场,利用所述能量束/场对金属或合金材料的基体进行对材料进行选区强韧化处理,在基体获得同素异构型增强相。所述基体具有相变硬化特性,或者通过先固溶再时效强化获得。该预制材料尤其适用于制造运载工具。(The invention discloses a metal prefabricated material and a preparation method thereof, wherein a matrix of the material is metal or alloy, allotropic isomeric reinforced phases obtained by selective strengthening and toughening treatment are distributed on the matrix, and the material has the characteristics of high ductility and weldability of a metal equilibrium structure and also has the high strength and high wear resistance of a metal metastable structure under the condition of keeping the weight of the matrix basically unchanged. The method adopts energy beams/fields including high-power laser beams or electron beams, ion beams and induction heat sources, and performs selective strengthening and toughening treatment on a metal or alloy material matrix by using the energy beams/fields to obtain an isomerous enhancement phase on the matrix. The matrix has phase change hardening properties or is obtained by solution prior to aging strengthening. The prefabricated material is particularly suitable for use in the manufacture of vehicles.)

1. A metal prefabricated material is characterized in that the thickness of the metal prefabricated material is 0.3-5 mm, the metal prefabricated material is a metal matrix composite material, a matrix is metal or alloy, isomorphic reinforcing phases obtained by selective toughening treatment are distributed on the matrix, a plurality of reinforcing phase units are distributed in one surface or two surfaces of the matrix in a dispersing way, the reinforcing phase units distributed in the dispersing way form an array type, the metal matrix is in a continuous state, the array type reinforcing phase is distributed in a predetermined part of the matrix in a dispersing way or distributed in the whole part of the matrix, but the whole of the predetermined part is the reinforcing phase without the matrix, and no large continuous and non-array type reinforcing phase exists in any part of the matrix;

The reinforcing phase itself is also a metallic material, which is of the same composition as the matrix but of a different microstructure to the metallic matrix;

The isomeric metal matrix composite material can be designed according to the mechanical property requirement of a metal prefabricated material, wherein the areal density of the reinforcing phase distributed in the metal matrix is 25-95%; the shape, size, distribution mode, organization structure and performance of the reinforcing phase pattern can be regulated and controlled according to the mechanical property requirement of the metal prefabricated material;

The metal prefabricated material has ductility and weldability of a metal equilibrium structure and has strength and wear resistance of a metal metastable structure under the condition of keeping the weight of a matrix basically unchanged.

2. The metal preform of claim 1, wherein the matrix has phase change hardening properties, or the matrix is obtained by solution-first and then age-hardening.

3. The metal preform of claim 1, wherein the reinforcing phase units are in the form of strips, granules or other states on the substrate, and the distribution area of the reinforcing phase units is pre-planned according to performance requirements and processing requirements.

4. The metal preform of claim 1, wherein the material is a plate or a profile and the substrate is of uniform or non-uniform thickness.

5. The metal preform of any of claims 1 to 4, wherein the substrate is a steel material or a non-ferrous material including an aluminum alloy or a titanium alloy.

6. A method for preparing metal prefabricated material is characterized in that energy beams/fields including high-power laser beams or electron beams, ion beams and induction heat sources are adopted, the energy beams/fields are utilized to carry out selective strengthening and toughening treatment on metal or alloy materials with the thickness of 0.3 mm-5 mm, homomorphic heterogeneous enhanced phases are obtained on a matrix of the metal or alloy materials,

By controlling the energy beam/field to form a plurality of reinforcing phase units, the reinforcing phase units are distributed in one or two surfaces of the matrix in a dispersed way, the reinforcing phase units distributed in a dispersed way form an array, the metal matrix is in a continuous state, the array reinforcing phase is distributed in a predetermined part of the matrix in a dispersed way or distributed in the whole part of the matrix, but the whole predetermined part is the reinforcing phase without the matrix, and no large continuous and non-array reinforcing phase exists in any part of the matrix,

The method can design the isomerous metal matrix composite material according to the mechanical property requirement of the metal prefabricated material, wherein the areal density of the reinforcing phase distributed in the metal matrix is 25-95 percent, the shape, the size, the distribution mode, the tissue structure and the performance of the reinforcing phase pattern can be regulated and controlled according to the mechanical property requirement of the metal prefabricated material,

The metal prefabricated material prepared by the method has ductility and weldability of a metal equilibrium structure and has strength and wear resistance of a metal metastable structure under the condition of keeping the weight of a matrix basically unchanged.

7. The preparation method according to claim 6, wherein the selective strengthening and toughening treatment is selective strengthening and toughening treatment for changing tissue structure and performance, particularly selective strengthening and toughening treatment based on solid-state phase change or selective strengthening and toughening treatment based on laser rapid melting and quenching.

8. The method of claim 7, wherein the method uses a matrix having phase change hardening properties or the matrix is obtained by solution-prior-to-age strengthening.

9. The preparation method of claim 6 or 7, wherein the composition, size, quantity and/or distribution of the reinforcing phase are adjusted to form the metal matrix composite material with different structural and performance requirements.

Technical Field

The invention belongs to the field of materials, and particularly relates to a metal prefabricated material and a preparation method thereof.

Background

In modern manufacturing industry, how to improve the toughness of materials is a constantly pursued goal of enterprises and engineers. The following will specifically describe the automobile manufacturing industry as an example.

The lightweight of the automobile is beneficial to environmental protection and energy conservation, and the selection and application of the materials are the key points of the lightweight automobile, and mainly appear in three aspects: (1) the steel plate with higher strength is used for replacing a common steel plate, and the thickness and the weight of parts are reduced on the premise of meeting the requirement of the same strength; (2) developing a new material processing technology, optimizing a plate structure, and realizing the light weight of vehicle body parts, such as continuously extruded variable cross-section sectional materials, metal matrix composite plates, laser welded plates, rolled differential thickness plates and the like; (3) the novel light material with high strength and low density is developed to replace the traditional steel parts so as to reduce the dead weight of the automobile, such as metal materials of magnesium, aluminum alloy and the like, and non-metal materials of plastic polymer, ceramic, composite materials and the like. Obviously, through measures such as structure optimization, application of high-strength materials and light materials, innovation of material processing technology and the like, the realization of the light weight of the automobile body is one of important development directions of the current automobile manufacturing while the strength of the whole automobile is maintained.

In addition, in the manufacture of automobiles, particularly passenger cars, various high-strength steels or profiles are often used in order to reduce the weight of the automobiles and to provide good flow line appearance to the automobile bodies. In particular, in recent years, an unequal thickness plate (also referred to as a differential thickness plate) based on a laser welding technique has been widely used as a structural material of a vehicle body or a door. The main bearing part is generally made of a steel plate with larger thickness, the secondary bearing part or the part without bearing force is generally made of a thinner steel plate, the main bearing part and the secondary bearing part are connected by laser welding to ensure the strength of the structural part, and finally, the structural part is formed by punching.

In addition to the unequal thickness plates, the covering panels and the roof panels of the automobile, the frame structure of the automobile body, and the like are also formed by processing plates. In fact, there is a problem of how to reduce the weight of a vehicle and improve transportation efficiency not only in automobile manufacturing but also in manufacturing of aerospace vehicles, ships, high-speed trains, and the like. The best technical route for reducing the self weight of the components is to adopt high-strength steel or even ultrahigh-strength steel. However, this technical route has a major problem in that the welding characteristics and the punching characteristics of the high-strength steel or the ultra-high-strength steel are insufficient, and thus it is difficult to achieve both high strength and good processing characteristics.

Therefore, on the premise of ensuring safety, how to further reduce the thickness of the plate and improve the performance of the plate becomes a target for pursuing by the industry of vehicle manufacturing such as airplanes, space shuttles and automobiles. Therefore, there is a need for a material having both high strength and high rigidity and having good weldability and punching properties. Obviously, the conventional metallic materials cannot satisfy the above requirements.

Disclosure of Invention

The invention aims to provide a metal prefabricated material and a preparation method thereof, wherein the prefabricated material has the characteristics of high ductility and weldability of a metal equilibrium structure, high strength and high wear resistance of a metal reinforced structure, high toughness and light weight.

The invention provides a metal prefabricated material which is characterized in that a matrix of the material is metal or alloy, allotropic isomeric reinforced phases obtained by selective strengthening and toughening treatment are distributed on the matrix, and the material not only has high ductility and weldability of a metal equilibrium structure, but also has high strength and high wear resistance of a metal metastable structure under the condition of keeping the weight of the matrix basically unchanged.

The invention provides a preparation method of a metal prefabricated material, which is characterized in that an energy beam/field comprising a high-power laser beam or an electron beam, an ion beam and an induction heat source is adopted, the energy beam/field is utilized to carry out selective toughening treatment on a metal or alloy material, an isomerous reinforcing phase is obtained on a matrix of the metal or alloy material, and the metal or alloy material not only has ductility and weldability of a metal equilibrium structure but also has high strength and high wear resistance of a metal metastable structure under the condition of keeping the weight of the matrix basically unchanged.

The substrate can be a plate with equal thickness or different thicknesses; the substrate can be made of steel materials, and can also comprise non-ferrous metal materials such as aluminum alloy, titanium alloy and the like.

The reinforcing phase is the same isomorphous form as the base metal, provided that a metal or alloy material with phase change hardening characteristics or solid solution + age strengthening characteristics is adopted as a matrix. The reinforcing phase can be in a linear shape, a spherical particle shape or a semispherical shape or other shapes on the matrix, and the shape and the distribution area of the reinforcing phase are planned in advance according to the performance requirement and the processing requirement. The reinforcing phases distributed on different areas of the matrix can be selected according to the requirements on the material, and when the performance requirements of the material on different areas are inconsistent, the strength, hardness, quantity, size and distribution density of the reinforcing phases are correspondingly changed according to the requirements.

The material thickness may be the same as the base material thickness for replacing the unequal thickness plates. Or the member can be a plate with different thicknesses, but the strength of the whole member is obviously improved or the thickness of the member can be greatly reduced compared with the original requirement. Such materials may be sheets or profiles.

The selective strengthening and toughening treatment refers to the selective change of the tissue structure or the performance of the material, and specifically is the selective strengthening and toughening treatment mainly based on solid-state phase transition or rapid fusion quenching, or the selective strengthening and toughening treatment can be the treatment of first laser solid solution and then aging treatment (also called laser solid solution quenching). The method can also ensure that the formed material structure and performance meet the service requirements of parts by adjusting the components, the size, the quantity or the distribution mode of the reinforcing phase.

The strength of the metal prefabricated material formed by the invention is greatly improved, and the change of the plasticity index is small, so that the thickness of the structural member can be reduced on the premise of ensuring that the overall mechanical property of the member is not reduced. For unequal thick plates widely used in car manufacturing, even only the bearing part in a metal thin plate part with uniform thickness needs to be subjected to region selection treatment to form a metal matrix composite, and the secondary bearing part or the non-bearing part is not or slightly treated to keep the toughness of the original plate, so that the strength and the performance of the car body of the car can be ensured, and the weight of the car body can be greatly reduced. Of course, if the original thickness difference and the original thin portion are processed separately, the performance of the material can be improved more greatly, and the thickness of the plate material can be reduced.

Compared with the prior art, the invention has the following technical characteristics:

(1) the components and the structure of the metal matrix are basically unchanged, and the reinforcing phase is formed in situ: in the preparation process of the metal prefabricated material, the original components and the organizational structure state of the main body part of the metal matrix are unchanged, and the local area in the matrix is changed in components, organizational structures and performance only by a process method of zone selection strengthening and toughening, so that the components, organizational structures and performance are converted into a reinforcing phase in the metal matrix composite material in situ. Because the reinforcing phase is a metal material, the formed metal matrix composite material has great difference with the previously known metal matrix composite material, and belongs to a novel metal matrix composite material; the corresponding process is also a brand new preparation process of the metal matrix composite.

(2) The manufacturing process is diversified: the selective toughening treatment process can be carried out by adopting laser beams, electron beams, ion beams, plasma arcs, induction heat sources or other modes, and the common characteristics of the energy sources are that the energy input quantity, the input mode and the track (figure) can be conveniently regulated and controlled, and the change of the organization structure and the performance of the base metal can be selectively realized. In other words, the design of the metal matrix composite material can be individually designed and processed according to the performance requirement of the part, so that the performance of the metal matrix composite material meets the working condition requirement, which cannot be realized in the manufacturing process of other metal matrix composite materials.

(3) The structure form, the mechanical property and the manufacturing mode of the reinforcing phase are diversified: according to the difference of the components and the characteristics of the structure of the metal matrix, a laser (or other heat sources) selective quenching process based on solid-state phase change can be adopted, and a selective melting process based on rapid melting-solidification phase change can also be adopted to form the isomeric metal matrix composite. According to the characteristics of some materials, the isomeric metal matrix composite can be formed by adopting a laser solution heating-aging treatment mode.

(4) The method can carry out metal-based composite treatment on the formed metal parts again: for some metal parts with complex requirements on subsequent processing (such as milling, cutting, welding and stamping), metal-based composite materials can be prefabricated only for materials which do not need subsequent processing according to the requirements of parts to be processed, and after the processing is finished, the processing area is subjected to composite treatment to form the metal-based composite materials, so that the integral performance of the component is not reduced.

(5) The metal prefabricated material can be a metal plate, a metal section or any other shape. Particularly, the area for forming the reinforcing phase can be planned in advance, for example, the area needing to be deformed or the area needing to be welded can not form the reinforcing phase firstly, and the reinforcing phase is supplemented at the area according to the requirement after the deformation or welding is completed, so that the problem that the existing metal matrix composite material is difficult to perform subsequent forming processing is solved.

(6) The range of suitable materials is wide: the invention is not only suitable for steel materials, but also suitable for non-ferrous metal materials; the method is not only suitable for iron-based alloys capable of generating martensite phase transformation, but also suitable for iron-based, cobalt-based, nickel-based, copper-based, aluminum-based, titanium-based and other non-ferrous material systems hardened in other modes such as solid solution strengthening and the like to form corresponding metal-based composite materials such as aluminum-based, magnesium-based, titanium-based, nickel-based, iron-based and copper-based composite materials.

The prefabricated material provided by the invention is particularly suitable for manufacturing vehicles such as airplanes, space shuttles, automobiles and the like.

Drawings

FIG. 1 is a schematic diagram of a lattice-shaped metal preform implemented by the present invention.

FIG. 2 is a schematic diagram of a metal preform in the form of a through-line strip according to the present invention.

FIG. 3 is a diagram of a short bar-shaped wire-shaped metal prefabricated material realized by the invention.

FIG. 4 is a schematic diagram of a metal prefabricated material with a vertical staggered short rod array realized by the invention.

Detailed Description

The invention provides a new process and a new method for changing the organization structure and the performance of a metal material through region selection, forming a reinforced phase and obtaining a metal prefabricated material for the first time. The tool used for preparation may be a laser beam, an electron beam, an ion beam, or an induction heat source, etc.

The matrix of the prefabricated material provided by the invention is metal or alloy, the reinforcing phase obtained by selective toughening treatment is distributed on the matrix, the components of the reinforcing phase are basically the same as those of the metal matrix, but the microstructure and the mechanical property have obvious difference. The composite material can keep the weight of the matrix basically unchanged, has the characteristics of high ductility and weldability of a metal equilibrium structure, and also has the high strength and high wear resistance of a metal reinforced structure, so that the toughness of the composite material is greatly improved compared with that of the original base material. Therefore, the thickness or the self weight of the component can be greatly reduced on the premise of ensuring that the performance of the component is not reduced, and the component can be widely applied to the industrial fields of automobiles, airplanes, ships, trains and the like. It should be noted that the prefabricated material of the present invention is particularly suitable for use as a material for sheet metal formed members.

Compared with the existing metal material system, the metal prefabricated material provided by the invention is an isomerous metal-based composite material. The specific implementation mode is as follows: the reinforcing phase is prepared on the metal matrix by adopting a selective solid phase transition process, so that the components of the metal matrix and the reinforcing body are not different, the reinforcing phase and the metal matrix have no obvious geometric interface on the chemical components, but the microstructure and the mechanical property of the reinforcing phase and the metal matrix are obviously different, and the isomerous metal matrix composite is formed. In the novel metal matrix composite material, the metal matrix is in a continuous state like other traditional metal matrix composite material systems, and the reinforcing phase can be designed into a linear (strip) shape, a spherical shape, a hemispherical granular shape or any other state according to requirements. Because the reinforcing phase and the metal matrix are isomeric, no obvious component gradient exists between the reinforcing phase and the metal matrix, and only the obvious difference between the microstructure and the mechanical property exists. In other words, the novel metal matrix composite is all-metal structured, except that the microstructure of the reinforcing phase and the matrix metal are completely different, and thus results in significant differences in properties.

The selective heating makes the metal matrix locally and rapidly melt-condense, and the isomerous metal matrix composite material can be formed. Because the laser rapid melting is higher than the laser power and the laser power density allowed by pure laser quenching, and the cooling speed of the molten pool condensation is also higher, the structure and the performance matching of the reinforcing phase are more superior to the partial performance of the isomerous metal matrix composite material formed by solid phase transformation. The laser consolidation process has a disadvantage in that it causes damage to the surface roughness of the laser irradiated area, which may affect the use of the part in some cases if proper post-processing is not performed.

For some special alloy systems subjected to solid solution-aging strengthening treatment, the method can be used for obtaining the isomeric metal matrix composite material. For example, for some stainless steel systems, neither laser quenching nor laser fusion quenching can be used to directly strengthen the treated area. However, the isomerous metal matrix composite material can also be obtained by carrying out selective laser heating solution treatment to make alloy elements in a laser treatment region to be in solution treatment and then carrying out aging strengthening treatment.

The mechanical properties of the metal prefabricated material provided by the invention are determined by the properties of the selected base metal or alloy, and are closely related to the characteristics, content, size, distribution, shape, interface state and other parameters of the reinforcement. The composite material through optimized design not only has the characteristics of high ductility and weldability of a metal equilibrium state structure, but also has the performances of high strength, high wear resistance and the like of a metal metastable state structure, so that the composite material has excellent comprehensive mechanical properties.

In summary, unlike the prior art in which the reinforcement phase is formed by a high temperature chemical metallurgical process of an addition method or an in-situ reaction formation method in which a foreign material is added, the metal preform material provided by the present invention does not require an additional reinforcement phase, and can form an unstable high performance second phase in situ by heating a metal matrix in a selected region to cause a local solid phase change or a rapid melting-solidification phase change, thereby obtaining a corresponding metal matrix composite.

the basic condition for preparing the metal prefabricated material provided by the invention is that the adopted metal matrix has phase change behavior under the action of heat, and the organization structure and the performance of a heated area can be changed accordingly. By reasonably selecting the processing technology, the size, shape, distribution, organization structure and even mechanical property of the reinforcing phase can be conveniently controlled, thereby opening up a brand new way for preparing the metal matrix composite material.

The implementation steps for preparing the metal prefabricated material by the high-power energy beam/field are as follows:

(1) Selecting a base metal material with a proper composition: these base metal materials may be conventional steels such as 15 steel, 20 steel, 30 steel, 45 steel, 42CrMo, 65Mn, 70SiMn, etc.; or automotive steels such as DP dual phase steels, TRIP steels, CP complex phase steels; but also nonferrous metals such as aluminum alloy, titanium alloy, copper alloy and the like. As long as the materials have phase-change hardening characteristics or solid solution + age-hardening characteristics, or can enable the strength and hardness of the materials to be remarkably improved through rapid fusing treatment; or after local heating, the microstructure of the heating area can be changed, and the microstructure and the performance of the formed metal matrix composite material are obviously changed through subsequent aging or tempering treatment. The purpose of cleaning the surface of the workpiece is to remove oil stains on the surface so as to ensure the effect of surface treatment.

Thickness of the material: the thickness can be designed into various thicknesses of 0.5mm, 1mm, 1.5mm, 2mm, 3mm, 4mm, 5mm, 8mm and the like according to needs.

(2) According to the characteristics of parts required to be manufactured, the size, the quantity and the distribution mode of the reinforcing phase in the metal matrix composite material to be manufactured are designed, so that the manufactured metal matrix composite material meets the requirements on structure and performance: the shape, size and distribution mode of the reinforcing phase can be conveniently regulated and controlled, and the strength, rigidity, elongation, stamping property, ductility, weldability, wear resistance and other properties of the formed isomeric metal-based composite material are regulated and controlled to meet the requirements of different working conditions, so that the design of the shape, the tissue structure and the properties of the reinforcing phase pattern is one of the key steps of the method.

(3) The high-power energy beam/field comprises a high-power laser beam or electron beam, an ion beam, an induction heat source and the like, and the high-power energy beam/field is adopted to carry out selective strengthening and toughening treatment on the material to form the metal matrix composite material: according to the design of the pattern and the performance of the metal matrix composite material in the step 2, the metal base material is subjected to selective toughening treatment by adopting surface processing technologies such as high-power laser beams or electron beams, ion beams, induction heat sources and the like, so that the size, the shape and the distribution of the reinforcing phase of the base material meet the design requirements, and the mechanical performance of the prepared metal matrix composite material meets the use requirements.

when the metal prefabricated material is manufactured, the strengthening and toughening treatment process is preferably as follows: during actual treatment, according to different types of selected base materials, the strengthening and toughening treatment based on solid-state phase change can be selected to obtain the isomeric metal matrix composite; or selective strengthening and toughening treatment based on rapid melting is mainly adopted to obtain the isomerous metal-based composite material with finer grains. However, the former can be used without substantially damaging the original surface roughness of the metal substrate, and the latter can be reduced in surface roughness. And the toughening treatment can be carried out by selecting a laser or electron beam solution-aging treatment mode according to the adopted material system.

(4) Designing a numerical control program for the selective toughening treatment, and carrying out the selective toughening treatment on the workpiece until the selective toughening treatment of the whole workpiece is completed.

The metal-based composite plate prepared by high-power energy beam/field preparation selective toughening treatment can be directly supplied as a structural material; or machining modes such as laser cutting, plasma cutting or stamping are adopted to process the processed metal matrix composite material (process modes such as stamping, bending, cutting, welding and the like can be adopted) into the shape of the required part, so that the final size and performance requirements of the part are met. In addition, the metal material can be processed into a required shape, and then the region selection strengthening and toughening treatment is carried out to obtain the isomeric metal-based composite material component.

Taking an automobile as an example, the prefabricated material provided by the invention can be used for manufacturing an A column reinforcing plate, an A column plate, a top rib plate, an inner baffle plate, a wheel cover plate, a rear door inner plate, a front door inner plate, a floor, a side beam plate, a bumper, an engine base plate, a shock absorber cover plate, a front beam, a top beam, a front reinforcing beam, a rear reinforcing beam, a reinforcing plate, a connected beam, a cabin seat plate, a bottom beam and the like.

Example (c):