CN114643362A

CN114643362A - Complex-shaped structural member containing high-entropy alloy and formed through additive manufacturing

Info

Publication number: CN114643362A
Application number: CN202210225580.9A
Authority: CN
Inventors: 周香林; 郑杰; 温薇
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2022-03-07
Filing date: 2022-03-07
Publication date: 2022-06-21

Abstract

The invention discloses a structural member with a complex shape and containing high-entropy alloy, which is formed by additive manufacturing, and belongs to the technical field of metal additive manufacturing and surface modification. The additive manufacturing and forming comprises rapid melting and forming modes such as coaxial powder feeding laser cladding, selective laser melting, electron beam melting and the like, wherein alloy powder is obtained by utilizing gas atomization powder preparation, the chemical components of the alloy powder are Al, Co, Cr, Fe and Ni, and the alloy atomic ratio is (0.1-0.5): (0.8-1.1): (0.8-1.1): (0.8-1.1): (1.0-3.0). The invention utilizes a rapid melting forming mode to perform additive manufacturing or repairing on the base material or the metal substrate, and the obtained high-entropy alloy product is compact and firm; the problems that cast ingots are difficult to process and alloy components are easy to segregate in the traditional method adopting vacuum arc casting are solved, and the utilization rate and the production efficiency of the high-entropy material can be effectively improved.

Description

Complex-shaped structural member containing high-entropy alloy and formed through additive manufacturing

Technical Field

The invention belongs to the technical field of metal additive manufacturing and surface modification, and relates to a structural member with a complex shape and containing high-entropy alloy, which is formed through additive manufacturing.

Background

The high-entropy alloy breaks through the traditional alloy design concept, mainly comprises five or more than five components, and the atomic ratio of each element is between 5 and 35 percent. The alloy presents a multi-principal-element high-entropy effect, forms a simple solid solution structure, has excellent comprehensive performance, and becomes one of research hotspots in the field of material science in recent years.

At present, the high-entropy alloy is mainly prepared by vacuum arc melting, casting and other methods, not only can a structural member with a simple shape be prepared, but also contains various main elements, and the melting point and the physicochemical property difference among the elements are large, so that the defects of component segregation, residual stress, gaps and the like are often introduced in the process of casting the high-entropy alloy, and the application of the high-entropy alloy to the structural member with a complex shape is not facilitated.

Although there are many materials with complex shapes of the high-entropy alloy obtained by the existing additive manufacturing, most of the materials are obtained by firstly obtaining a blank by the additive manufacturing and then sintering the blank to obtain a product, and the product is not directly obtained by the additive manufacturing; additive manufacturing is rarely thought of for the preparation of coatings that require improved surface properties of dissimilar materials and the repair of structural defects on the surface of dissimilar materials.

The high-entropy alloy coating is mostly prepared by methods such as laser cladding, cold spraying, thermal spraying, electric spark deposition, plasma spraying-physical vapor deposition, magnetron sputtering and the like, the coating thickness is difficult to accurately control, high-entropy alloy powder adopted in the laser cladding is mostly obtained by crushing and screening a high-entropy alloy ingot prepared by electric arc melting and is coated on the surface of a workpiece as high-entropy alloy slurry, and an organic solvent in the high-entropy alloy powder can hinder the expression of the forming performance of the high-entropy alloy coating.

For example: chinese patent CN113621958A discloses a method for laser cladding of a high-entropy alloy coating on a copper surface, wherein the high-entropy alloy powder is obtained by crushing and screening a high-entropy alloy ingot obtained by arc melting, the alloy component is not high-entropy alloy AlCoCrFeNi, and a binder is required to be added to prepare a paste to be coated on the surface of a copper workpiece, and the binder can negatively influence the tissue structure and performance of the high-entropy alloy coating.

Chinese patent CN113430513A discloses a preparation method of a magnesium alloy surface cold spraying high-entropy alloy coating, wherein the alloy component is not high-entropy alloy AlCoCrFeNi, the adopted mode is the cold spraying of gas atomization powder, the repair of surface structure defects of non-homogeneous materials cannot be well realized, and the coating is not uniform.

Chinese patent CN 112195463A discloses a laser cladding AlCoCrFeNi/NbC gradient high-entropy alloy coating material and a method, wherein the coating is divided into three layers, respective NbC strengthening phases need to be contained in the coating, the powder sources are Al powder, Co powder, Cr powder, Fe powder, Ni powder and NbC powder, it can be seen that high-entropy alloy needs to be formed in the laser cladding process, high-entropy alloy powder is not directly used, the coating quality is poor, the performance of the high-entropy alloy coating cannot be effectively expressed, and the method is not beneficial to industrial large-scale production.

In summary, in order to solve the technical defects, it is necessary to develop a structural member with a complex shape formed by additive manufacturing and containing a high-entropy alloy, wherein the performance of a high-entropy alloy coating can be efficiently expressed, and the structural defect on the surface of a base material can be repaired.

Disclosure of Invention

The invention solves the technical problems that the existing structural member surface structure defect repair utilizes the same components and organizational structures as the base material, the high-entropy alloy is not used for repair, and the non-high-entropy alloy repair is only limited to the structural member with a simple shape and is difficult to carry out on the structural member with a complex shape; the prepared high-entropy alloy coating is not suitable for repairing the surface structure defects of the base material, but is used for improving the surface performance of the base material without the surface structure defects; the prepared high-entropy alloy coating is uneven in thickness, not compact, low in bonding strength and poor in precision.

In order to solve the technical problems, the invention provides the following technical scheme:

a complex-shaped structural member manufactured by additive manufacturing of a high-entropy alloy, comprising the steps of:

s1, proportioning and weighing the raw materials according to the molar ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloy powder by adopting gas atomization of vacuum induction melting;

s2, establishing a three-dimensional model of the structural part on a computer according to the complex shape of the structural part, converting the three-dimensional model of the structural part into an STL format file and importing the STL format file into forming equipment utilizing a laser or electron beam additive manufacturing technology;

s3, putting the high-entropy prealloy powder obtained in the step S1 into a powder feeding mechanism in a forming device of S2, then placing a base material or a metal substrate in a laser or electron beam action area, then selecting the thickness and the layer number N of the high-entropy alloy layer according to an STL format file in S2, and paving the high-entropy prealloy powder on the surface of the base material or the metal substrate through the powder feeding mechanism;

s4, when the high-entropy alloy layer in the S3 selects N as 1, melting and solidifying the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in the step S3 to obtain a complex-shaped structural member containing the high-entropy alloy;

when N is greater than 1 in the high-entropy alloy layer in S3, melting and solidifying the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in step S3 to obtain an N-1 th high-entropy alloy layer, then laying the high-entropy pre-alloy powder on the N-1 th high-entropy alloy layer through a powder feeding mechanism, and finally melting and solidifying to obtain a complex-shaped structural member containing the high-entropy alloy.

Preferably, the chemical composition of the high-entropy alloy in the step S1 is as follows by mass percent: the alloy atomic ratio of Al, Co, Cr, Fe and Ni is (0.1-0.5): (0.8-1.1): (0.8-1.1): (0.8-1.1): (1.0-3.0).

Preferably, the additive manufacturing technique in step S2 is formed by any one of a coaxial powder feeding laser cladding technique, a selective laser melting technique and an electron beam selective melting technique.

Preferably, when the additive manufacturing technology in the step S2 is formed by a coaxial powder feeding laser cladding technology, the method includes the following steps:

s101, proportioning and weighing raw materials according to the mole ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloy powder by adopting gas atomization of vacuum induction melting;

s201, establishing a three-dimensional model of a structural part on a computer according to the complex shape of the required structural part, converting the three-dimensional model of the structural part into an STL format file and introducing the STL format file into coaxial powder feeding laser cladding rapid forming equipment;

s301, putting the high-entropy pre-alloy powder obtained in the step S101 into a powder feeding mechanism in the forming equipment of the step S201, placing a base material or a metal substrate in a laser action area, then selecting the thickness and the number N of layers of the high-entropy alloy layer according to the STL format file in the step S201, and placing the high-entropy pre-alloy powder on the surface of the base material or the metal substrate through the powder feeding mechanism;

s401, when the high-entropy alloy layer in S301 selects N as 1, the high-entropy pre-alloy powder in the step S301 passes through a light beam before reaching a melting zone along with a base material or a metal substrate, is heated to a red hot state, is melted after entering the melting zone, and is formed by a laser cladding technology to obtain a structural member with a complex shape and containing the high-entropy alloy; wherein: the laser power is 800-2000W, the scanning speed is 0.1-1.2mm/s, the thickness of the powder layer is 3-5mm, the scanning interval is 1-2mm, and the powder is protected by inert gas to prevent the powder from being oxidized during forming;

when N is greater than 1 as the high-entropy alloy layer in S301, melting and solidifying the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in S301 according to the forming mode when N is 1 as the high-entropy alloy layer, so as to obtain an N-1 th high-entropy alloy layer, then laying the high-entropy pre-alloy powder on the N-1 th high-entropy alloy layer through a powder feeding mechanism, and finally melting and solidifying according to the forming mode when N is 1 as the high-entropy alloy layer, so as to obtain the complex-shaped structural member containing the high-entropy alloy.

Preferably, the high-entropy pre-alloy powder in the step S101 is selected from alloy powder with the sieving grain diameter of 35-104 μm, and the inert gas used in the forming in the step S401 is Ar gas.

Preferably, when the additive manufacturing technique in the step S2 is formed by a selective laser melting technique, the method includes the following steps:

s102, carrying out proportioning weighing on raw materials according to the molar ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloy powder by adopting gas atomization of vacuum induction melting;

s202, establishing a three-dimensional model of a structural part on a computer according to the complex shape of the structural part, converting the three-dimensional model of the structural part into an STL format file and introducing the STL format file into forming equipment for selective laser melting rapid forming;

s302, putting the high-entropy pre-alloyed powder obtained in the step S102 into a powder feeding mechanism in the forming equipment of S202, placing a base material or a metal substrate in a laser action area and leveling the laser action area, then selecting the thickness and the number N of layers of a high-entropy alloy layer according to the STL format file in the step S202, and placing the high-entropy pre-alloyed powder on the surface of the base material or the metal substrate through the powder feeding mechanism;

s402, when the high-entropy alloy layer in the S302 is selected to be N1, carrying out selective laser melting technology forming on the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in the step S302 to obtain the high-entropy alloy layer, so as to obtain the structural member with the complex shape and containing the high-entropy alloy; wherein: the laser power is 150-250W, the scanning speed is 600-1000mm/s, the thickness of the powder layer is 30-60 μm, the scanning interval is 80-100 μm, and the powder is protected by inert gas to prevent the powder from being oxidized during forming;

when N is greater than 1 as the high-entropy alloy layer in S302, selective laser is performed on the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in step S302 according to a forming mode when N is 1 as the high-entropy alloy layer, the high-entropy pre-alloy powder is solidified and formed to obtain an N-1 th high-entropy alloy layer, then the high-entropy pre-alloy powder is laid on the N-1 th high-entropy alloy layer through a powder feeding mechanism, and finally, selective laser is performed according to a forming mode when N is 1 as the high-entropy alloy layer, and the high-entropy alloy-containing complex-shaped structural member is obtained through solidification and forming.

Preferably, the high-entropy pre-alloy powder in the step S102 is selected from alloy powder with the sieving grain diameter of 15-58 μm, and the inert gas used in the forming in the step S402 is Ar gas.

Preferably, the scanning path of the forming process in step S402 is a grouping direction-changing type, specifically, when N is an odd number, the scanning direction is parallel to the x-axis; when N is an even number, the scanning direction is parallel to the y axis; and (5) scanning the materials by layered reversing, and sequentially superposing to obtain a formed piece.

Preferably, when the additive manufacturing technique in the step S2 is formed by an electron beam selective melting technique, the method includes the following steps:

s103, proportioning and weighing the raw materials according to the molar ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloy powder by adopting gas atomization of vacuum induction melting;

s203, establishing a three-dimensional model of the structural part on a computer according to the complex shape of the required structural part, converting the three-dimensional model of the structural part into an STL format file and introducing the STL format file into a forming device for selective melting forming of an electron beam;

s303, putting the high-entropy pre-alloyed powder obtained in the step S103 into a powder feeding mechanism in a forming device of S203, putting a base material or a metal substrate in an electron beam action area, then selecting the thickness and the number N of layers of a high-entropy alloy layer according to an STL format file in the step S203, and putting the high-entropy pre-alloyed powder on the surface of the base material or the metal substrate through the powder feeding mechanism;

s403, when the high-entropy alloy layer in S303 selects N as 1, rapidly scanning the powder layer by defocusing electron beams to preheat the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in step S303, wherein the preheating temperature is 600-800 ℃; then, selective melting of powder is carried out through focusing of electron beams, and a high-entropy alloy layer is obtained through forming, so that a structural member with a complex shape and containing the high-entropy alloy is obtained; wherein: the beam current of the electron beam is 5-15mA, the scanning speed is 0.2-1.6m/s, the thickness of the powder laying layer is 50-80 μm, and the distance between scanning lines is 15-60 μm; protecting the powder with inert gas to prevent the powder from being oxidized during forming;

when the high-entropy alloy layer in S303 is selected to have N greater than 1, the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in step S303 is subjected to selective electron beam melting and solidification forming according to the forming mode when the high-entropy alloy layer is selected to have N of 1 to obtain an N-1 th high-entropy alloy layer, then the high-entropy pre-alloy powder is laid on the N-1 th high-entropy alloy layer through a powder feeding mechanism, and finally the high-entropy alloy layer is subjected to selective electron beam melting and solidification forming according to the forming mode when the high-entropy alloy layer is selected to have N of 1 to obtain the complex-shaped structural member containing the high-entropy alloy.

S5, alternately carrying out melting forming along with feeding of the high-entropy pre-alloy powder and selective electron beam forming to form a plurality of high-entropy alloy layers, wherein after selective laser melting and solidification are carried out on the Nth high-entropy alloy layer, feeding of the high-entropy pre-alloy powder is carried out to form an N +1 th high-entropy alloy layer, and finally obtaining the high-entropy alloy complex-shaped structural member.

Preferably, the high-entropy pre-alloy powder in the step S103 is selected from alloy powder with the screening grain diameter of 30-125 μm, and the inert gas used in the forming in the step S403 is He gas.

Preferably, in the prepared high-entropy alloy coating of the high-entropy alloy-containing structural part with the complex shape, the microstructure is cellular crystals with different shapes, and accounts for 100 percent; the yield strength of the substrate before the preparation of the high-entropy alloy coating is 330-350MPa, and the yield strength of the substrate after the preparation of the high-entropy alloy coating is 155.842-200 MPa.

The technical scheme provided by the embodiment of the invention at least has the following beneficial effects:

in the scheme, the application range of the high-entropy alloy is widened by fully utilizing the excellent performance of the high-entropy alloy, namely the high-entropy alloy formed by adopting the melting technology has a simple face-centered cubic structure, the original excellent performance of a base material or a metal substrate is reserved, the surface of the base material or the metal substrate has the high density and the good dimensional accuracy of the high-entropy material, and meanwhile, the high-entropy alloy has high strength and can meet the higher performance requirement of the material in the modern industry.

The invention provides a high-entropy alloy AlCoCrFeNi series powder material with a new component ratio, which is used for preparing a high-entropy alloy coating on a substrate by adopting a synchronous powder feeding laser cladding technology and determining an alloy forming process and related organization performance.

The atomic mole ratio of the high-entropy alloy AlCoCrFeNi selected by the invention is as follows: (0.1-0.3): (0.8-1.0): (0.8-1.0): (0.8-1.0): (1.0-2.0) is gas atomized prealloyed powder, the prealloyed powder is spherical, and the purity is not lower than 99.9%.

The laser cladding technology is utilized because the method is pollution-free, the prepared coating is metallurgically bonded with the base material, and the bonding surface is firm; the high-energy laser beam is used for additive manufacturing or repairing of the base material or the metal substrate, and the obtained high-entropy alloy product is compact and firm; the method not only solves the problems that the cast ingot prepared by the traditional method by adopting vacuum arc casting is difficult to process, the alloy components are easy to segregate and the like, but also can effectively improve the utilization rate and the production efficiency of the high-entropy material, greatly reduce the loss cost of parts, and also provides a new application field of the high-entropy alloy.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is an XRD pattern of an AlCoCrFeNi high-entropy alloy coating in a complex-shaped structural member manufactured by additive manufacturing into a high-entropy alloy according to example 1 of the present invention;

fig. 2 is an SEM image of an AlCoCrFeNi high entropy alloy coating in a complex shape structural member manufactured by additive manufacturing of a high entropy alloy according to embodiment 1 of the present invention, wherein: (a) the surface topography of the high-entropy alloy structural member with the complex shape is formed by a laser cladding technology with the laser power of 1000W, the scanning speed of 0.8mm/s, the powder layer thickness of 5mm and the scanning interval of 1.5mm, and (b) the cross-sectional topography of the high-entropy alloy structural member is formed by the laser cladding technology with the laser power of 1000W, the scanning speed of 0.8mm/s, the powder layer thickness of 5mm and the scanning interval of 1.5 mm;

fig. 3 is an EDS diagram of an AlCoCrFeNi high-entropy alloy coating in a complex-shaped structural member manufactured by additive manufacturing into a high-entropy alloy according to example 2 of the present invention, in which: (a) is a cross-sectional profile, (b) is an Al element, (c) is a Co element, (d) is a Cr element, (e) is an Fe element, and (f) is a Ni element;

fig. 4 is an SEM image of an AlCoCrFeNi high-entropy alloy coating in a complex-shaped structural member formed with a high-entropy alloy by additive manufacturing in embodiment 3 of the present invention, specifically, a surface topography of the complex-shaped structural member formed with the high-entropy alloy by a laser cladding technique with a laser power of 1000W, a scanning speed of 0.8mm/s, a powder layer thickness of 5mm, and a scanning pitch of 1.5 mm.

Detailed Description

In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments. It should be noted that technical features or combinations of technical features described in the following embodiments should not be considered as being isolated, and they may be combined with each other to achieve better technical effects. In the drawings of the embodiments described below, the same reference numerals appearing in the respective drawings denote the same features or components, and may be applied to different embodiments.

Example 1

Complex-shaped structural member manufactured into high-entropy alloy through additive manufacturing

As shown in fig. 1, the chemical components of the high-entropy alloy coating in the complex-shaped structural member manufactured into the high-entropy alloy through additive manufacturing are calculated by mass percent: the alloy atomic ratio of Al, Co, Cr, Fe and Ni is 0.15: 1: 1: 1: 1.

the method comprises the following steps of forming a structural member with a complex shape and containing the high-entropy alloy by additive manufacturing, wherein the additive manufacturing technology is formed by a coaxial powder feeding laser cladding technology, and the forming comprises the following steps:

s101, proportioning and weighing raw materials according to the molar ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloyed powder by adopting gas atomization of vacuum induction melting, wherein the high-entropy pre-alloyed powder is selected to be alloy powder with the screening particle size of 50 mu m;

s301, placing the high-entropy prealloy powder obtained in the step S101 into a powder feeding mechanism in forming equipment of S201, placing a base material in a laser action area, selecting the thickness and the number N of layers of the high-entropy alloy layer according to an STL format file in the step S201, and placing the high-entropy prealloy powder on the surface of the base material through the powder feeding mechanism;

s401, when the high-entropy alloy layer in S301 selects N as 1, the high-entropy pre-alloy powder in the step S301 passes through a light beam before reaching a melting zone along with the base material, is heated to a red hot state, is melted after entering the melting zone, and is formed by a laser cladding technology to obtain a structural member with a complex shape and containing the high-entropy alloy; wherein: the laser power is 1000W, the scanning speed is 0.6mm/s, the thickness of a powder layer is 5mm, the scanning interval is 1.5mm, and inert gas Ar gas is used for protecting and preventing the powder from being oxidized during forming;

when the high-entropy alloy layer in S301 selects N to be greater than 1, the high-entropy pre-alloy powder on the surface of the base material in step S301 needs to be melted and solidified and formed according to the forming mode when the high-entropy alloy layer selects N to be 1 to obtain an N-1-th high-entropy alloy layer, then the high-entropy pre-alloy powder is laid on the N-1-th high-entropy alloy layer through a powder feeding mechanism, and finally the high-entropy pre-alloy powder is melted and solidified and formed according to the forming mode when the high-entropy alloy layer selects N to be 1 to obtain the complex-shaped structural member containing the high-entropy alloy.

Wherein: as shown in fig. 2, in the high-entropy alloy coating of the high-entropy alloy-containing complex-shaped structural member, fig. 2(a) shows the surface morphology of the high-entropy alloy-containing complex-shaped structural member formed by the laser cladding technology with the laser power of 1000W, the scanning speed of 0.8mm/s, the powder layer thickness of 5mm and the scanning interval of 1.5mm, which is a cellular crystal structure and accounts for 100%; FIG. 2(b) the microstructure is columnar crystal and cellular crystal, each of which accounts for 50%; the yield strength of the base material before the high-entropy alloy coating is prepared is 340 MPa; the strength after the preparation of the high-entropy alloy coating is 200 MPa.

Example 2

s101, proportioning and weighing raw materials according to the mole ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloy powder by adopting gas atomization of vacuum induction melting, wherein the high-entropy pre-alloy powder is selected from alloy powder with the screening particle size of 50 microns;

s201, establishing a three-dimensional model of a structural part on a computer according to the complex shape of the structural part, converting the three-dimensional model of the structural part into an STL format file and introducing the STL format file into coaxial powder-feeding laser cladding rapid forming equipment;

s301, putting the high-entropy pre-alloy powder obtained in the step S101 into a powder feeding mechanism in the forming equipment of the step S201, placing the metal substrate in a laser action area, then selecting the thickness and the number N of layers of the high-entropy alloy layer according to the STL format file in the step S201, and placing the high-entropy pre-alloy powder on the surface of the metal substrate through the powder feeding mechanism;

s401, when the high-entropy alloy layer in S301 selects N as 1, the high-entropy pre-alloy powder in the step S301 passes through a light beam before reaching a melting zone along with the metal substrate, is heated to a red hot state, is melted after entering the melting zone, and is formed by a laser cladding technology to obtain a structural member with a complex shape and containing the high-entropy alloy; wherein: the laser power is 1000W, the scanning speed is 0.6mm/s, the thickness of the powder layer is 5mm, the scanning distance is 1.5mm, and inert gas Ar gas is used for protecting the powder to prevent the powder from being oxidized during forming;

when the high-entropy alloy layer in S301 is selected to have N greater than 1, the high-entropy pre-alloy powder on the surface of the metal substrate in step S301 needs to be melted and solidified and formed according to the forming mode when the high-entropy alloy layer is selected to have N of 1 to obtain an N-1 th high-entropy alloy layer, then the high-entropy pre-alloy powder is laid on the N-1 th high-entropy alloy layer through a powder feeding mechanism, and finally the high-entropy pre-alloy powder is melted and solidified and formed according to the forming mode when the high-entropy alloy layer is selected to have N of 1 to obtain the complex-shaped structural member containing the high-entropy alloy.

Wherein: as shown in fig. 3, in the high-entropy alloy coating layer of the complex-shaped structural member containing the high-entropy alloy, (a) is a cross-sectional morphology, (b) is an Al element, (c) is a Co element, (d) is a Cr element, (e) is an Fe element, and (f) is an Ni element; wherein, the contents of the elements are respectively 1.41 percent of Al, 22.61 percent of Co, 20.07 percent of Cr, 22.38 percent of Fe and 33.53 percent of Ni: the strength of the metal substrate before the high-entropy alloy coating is prepared is 340 MPa; the strength after the preparation of the high-entropy alloy coating was 180.26 MPa.

Example 3

Complicated-shape structural member manufactured into high-entropy alloy through material increase

s101, proportioning and weighing raw materials according to the mole ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloy powder by adopting gas atomization of vacuum induction melting, wherein the high-entropy pre-alloy powder is selected from alloy powder with the screening particle size of 60 mu m;

s301, putting the high-entropy pre-alloy powder obtained in the step S101 into a powder feeding mechanism in the forming equipment of the step S201, placing the base material in a laser action area, then selecting the thickness and the number N of layers of the high-entropy alloy layer according to the STL format file in the step S201, and placing the high-entropy pre-alloy powder on the surface of the base material through the powder feeding mechanism;

s401, when the high-entropy alloy layer in S301 selects N as 1, the high-entropy pre-alloy powder in the step S301 passes through a light beam before reaching a melting zone along with the base material, is heated to a red hot state, is melted after entering the melting zone, and is formed by a laser cladding technology to obtain a structural member with a complex shape and containing the high-entropy alloy; wherein: the laser power is 1000W, the scanning speed is 0.8mm/s, the thickness of a powder layer is 5mm, the scanning interval is 1.5mm, and inert gas Ar gas is used for protecting and preventing the powder from being oxidized during forming;

when the high-entropy alloy layer in S301 is selected to have N greater than 1, the high-entropy pre-alloy powder on the surface of the base material in step S301 needs to be melted and solidified to form an N-1 th high-entropy alloy layer according to a forming mode when the high-entropy alloy layer is selected to have N of 1, then the high-entropy pre-alloy powder is laid on the N-1 th high-entropy alloy layer through a powder feeding mechanism, and finally the high-entropy pre-alloy powder is melted and solidified to form a complex-shaped structural member containing the high-entropy alloy according to a forming mode when the high-entropy alloy layer is selected to have N of 1.

Wherein: as shown in fig. 4, in the high-entropy alloy coating of the high-entropy alloy-containing structural member with a complex shape, the microstructure of fig. 4 is a cellular crystal with different shapes, and accounts for 100%; the yield strength of the base material before the high-entropy alloy coating is prepared is 340MPa, and the yield strength of the base material after the high-entropy alloy coating is prepared is 155.842 MPa.

Example 4

Forming a complex-shaped structural member containing high-entropy alloy through additive manufacturing, wherein the high-entropy alloy coating in the complex-shaped structural member comprises the following chemical components in percentage by mass: the alloy atomic ratio of Al, Co, Cr, Fe and Ni is 0.3: 0.9: 0.9: 0.9: 1.7.

the method is characterized in that a high-entropy alloy structural member with a complex shape is manufactured by additive manufacturing, when the additive manufacturing technology is formed by a coaxial powder feeding laser cladding technology, the forming comprises the following steps:

s102, proportioning and weighing raw materials according to the molar ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloy powder by adopting gas atomization of vacuum induction melting, wherein the high-entropy pre-alloy powder is selected from alloy powder with the screening particle size of 40 mu m;

s202, establishing a three-dimensional model of the structural part on a computer according to the complex shape of the required structural part, converting the three-dimensional model of the structural part into an STL format file and introducing the STL format file into selective laser melting rapid forming equipment;

s402, when the high-entropy alloy layer in the S302 is selected to be N1, carrying out selective laser melting technology forming on the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in the step S302 to obtain the high-entropy alloy layer, and thus obtaining a structural member with a complex shape and containing the high-entropy alloy; wherein: the laser power is 250W, the scanning speed is 1000mm/s, the thickness of a powder layer is 40 mu m, the scanning interval is 90 mu m, and inert gas Ar gas is used for protecting the powder to prevent the powder from being oxidized during forming;

Wherein: the scanning path of the forming process in the step S402 is a grouped turning type, specifically, when N is an odd number, the scanning direction is parallel to the x axis; when N is an even number, the scanning direction is parallel to the y axis; and (5) scanning the materials by layered reversing, and sequentially superposing to obtain a formed piece.

Wherein: in the high-entropy alloy coating of the high-entropy alloy-containing structural member with the complex shape, the microstructure is cellular crystals with different shapes, and accounts for 100 percent; the yield strength of the base material before the high-entropy alloy coating is prepared is 340MPa, and the yield strength of the base material after the high-entropy alloy coating is prepared is 163.72 MPa.

Example 5

Forming a complex-shaped structural member containing high-entropy alloy through additive manufacturing, wherein the high-entropy alloy coating in the complex-shaped structural member comprises the following chemical components in percentage by mass: the alloy atomic ratio of Al, Co, Cr, Fe and Ni is 0.5: 0.8: 0.8: 0.8: 1.5.

s102, proportioning and weighing raw materials according to the molar ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloy powder by adopting gas atomization of vacuum induction melting, wherein the high-entropy pre-alloy powder is selected from alloy powder with a screening particle size of 54 mu m;

s402, when the high-entropy alloy layer in the S302 is selected to be N1, carrying out selective laser melting technology forming on the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in the step S302 to obtain the high-entropy alloy layer, so as to obtain the structural member with the complex shape and containing the high-entropy alloy; wherein: the laser power is 200W, the scanning speed is 1000mm/s, the thickness of a powder layer is 40 mu m, the scanning interval is 90 mu m, and inert gas Ar gas is used for protecting the powder to prevent the powder from being oxidized during forming;

Wherein: in the high-entropy alloy coating of the high-entropy alloy-containing structural member with the complex shape, the microstructure is cellular crystals with different shapes, and accounts for 100 percent; the yield strength of the base material before the high-entropy alloy coating is prepared is 340MPa, and the yield strength of the base material after the high-entropy alloy coating is prepared is 170.635 MPa.

Example 6

Forming a complex-shaped structural member containing high-entropy alloy through additive manufacturing, wherein the high-entropy alloy coating in the complex-shaped structural member comprises the following chemical components in percentage by mass: the alloy atomic ratio of Al, Co, Cr, Fe and Ni is 0.2: 1: 1: 1: 3.

s102, proportioning and weighing raw materials according to the molar ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloy powder by adopting gas atomization of vacuum induction melting, wherein the high-entropy pre-alloy powder is selected from alloy powder with the screening particle size of 50 microns;

s402, when the high-entropy alloy layer in the S302 is selected to be N1, carrying out selective laser melting technology forming on the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in the step S302 to obtain the high-entropy alloy layer, so as to obtain the structural member with the complex shape and containing the high-entropy alloy; wherein: the laser power is 180W, the scanning speed is 1000mm/s, the thickness of a powder layer is 40 mu m, the scanning interval is 90 mu m, and inert gas Ar gas is used for protecting the powder to prevent the powder from being oxidized during forming;

Wherein: in the high-entropy alloy coating of the high-entropy alloy-containing structural member with the complex shape, the microstructure is cellular crystals with different shapes, and accounts for 100 percent; the yield strength of the base material before the high-entropy alloy coating is prepared is 340MPa, and the yield strength of the base material after the high-entropy alloy coating is prepared is 184.563 MPa.

Example 7

Forming a complex-shaped structural member containing high-entropy alloy through additive manufacturing, wherein the high-entropy alloy coating in the complex-shaped structural member comprises the following chemical components in percentage by mass: the alloy atomic ratio of Al, Co, Cr, Fe and Ni is 0.4: 0.9: 0.9: 0.9: 2.

the method is characterized in that a high-entropy alloy structural member with a complex shape is manufactured by additive manufacturing, the additive manufacturing technology is formed by electron beam selective melting technology, and the forming comprises the following steps:

s103, proportioning and weighing raw materials according to the molar ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloyed powder by adopting gas atomization of vacuum induction melting, wherein the high-entropy pre-alloyed powder is selected to be alloy powder with the screening particle size of 50 mu m;

s403, when the high-entropy alloy layer in the S303 selects N to be 1, rapidly scanning a powder layer by defocusing electron beams to preheat the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in the step S303, wherein the preheating temperature is 800 ℃; then, carrying out selective melting on powder through a focused electron beam, and forming to obtain a high-entropy alloy layer, thereby obtaining a structural member with a complex shape and containing the high-entropy alloy; wherein: the beam current of the electron beam is 10mA, the scanning speed is 1.5m/s, and the thickness of the powder laying layer is 60 mu m, and the distance between scanning lines is 40 mu m; protecting the powder with inert gas He gas during forming to prevent the powder from being oxidized;

S5, alternately carrying out selective melting and forming of electron beams along with the feeding of the high-entropy pre-alloy powder to form a multilayer high-entropy alloy layer, wherein after the N-th high-entropy alloy layer is selectively melted and solidified by laser, the N + 1-th high-entropy alloy layer is formed by feeding the high-entropy pre-alloy powder, and finally the high-entropy alloy complex-shaped structural member is obtained.

Wherein: in the high-entropy alloy coating of the high-entropy alloy-containing structural member with the complex shape, the microstructure is cellular crystals with different shapes, and accounts for 100 percent; the yield strength of the base material before the high-entropy alloy coating is prepared is 340MPa, and the yield strength of the base material after the high-entropy alloy coating is prepared is 170.486 MPa.

Example 8

Forming a complex-shaped structural member containing high-entropy alloy through additive manufacturing, wherein the high-entropy alloy coating in the complex-shaped structural member comprises the following chemical components in percentage by mass: the alloy atomic ratio of Al, Co, Cr, Fe and Ni is 0.35: 1: 1: 1: 2.2.

s103, proportioning and weighing raw materials according to the molar ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloy powder by adopting gas atomization of vacuum induction melting, wherein the high-entropy pre-alloy powder is selected from alloy powder with the screening particle size of 60 mu m;

s403, when the high-entropy alloy layer in the S303 selects N as 1, rapidly scanning a powder layer by defocusing electron beams to preheat the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in the step S303, wherein the preheating temperature is 800 ℃; then, carrying out selective melting on powder through a focused electron beam, and forming to obtain a high-entropy alloy layer, thereby obtaining a structural member with a complex shape and containing the high-entropy alloy; wherein: the beam current of the electron beam is 15mA, the scanning speed is 1.5m/s, and the thickness of the powder laying layer is 60 mu m, and the distance between scanning lines is 40 mu m; protecting the powder with inert gas He gas during forming to prevent the powder from being oxidized;

Wherein: in the high-entropy alloy coating of the high-entropy alloy-containing structural member with the complex shape, the microstructure is cellular crystals with different shapes, and accounts for 100 percent; the yield strength of the base material before the high-entropy alloy coating is prepared is 340MPa, and the yield strength of the base material after the high-entropy alloy coating is prepared is 191.257 MPa.

Example 9

Forming a complex-shaped structural member containing high-entropy alloy through additive manufacturing, wherein the high-entropy alloy coating in the complex-shaped structural member comprises the following chemical components in percentage by mass: the alloy atomic ratio of Al, Co, Cr, Fe and Ni is 0.45: 0.8: 0.9: 1.0: 2.6.

s103, proportioning and weighing raw materials according to the molar ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloy powder by adopting gas atomization of vacuum induction melting, wherein the high-entropy pre-alloy powder is selected to be alloy powder with the screening grain size of 70 mu m;

s403, when the high-entropy alloy layer in the S303 selects N as 1, rapidly scanning a powder layer by defocusing electron beams to preheat the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in the step S303, wherein the preheating temperature is 800 ℃; then, carrying out selective melting on powder through a focused electron beam, and forming to obtain a high-entropy alloy layer, thereby obtaining a structural member with a complex shape and containing the high-entropy alloy; wherein: the beam current of the electron beam is 12mA, the scanning speed is 1.5m/s, and the thickness of the powder laying layer is 60 mu m, and the distance between scanning lines is 40 mu m; protecting the powder with inert gas He gas during forming to prevent the powder from being oxidized;

Wherein: in the high-entropy alloy coating of the high-entropy alloy-containing structural member with the complex shape, the microstructure is cellular crystals with different shapes, and accounts for 100 percent; the yield strength of the base material before the high-entropy alloy coating is prepared is 340MPa, and the yield strength of the base material after the high-entropy alloy coating is prepared is 167.195 MPa.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A complex-shaped structural member containing a high-entropy alloy formed by additive manufacturing, comprising the steps of:

s1, carrying out proportioning weighing on the raw materials according to the molar ratio of each element in the chemical components of the high-entropy alloy, and preparing high-entropy pre-alloy powder by adopting gas atomization of vacuum induction melting;

2. A complex-shaped structural member containing a high-entropy alloy formed by additive manufacturing according to claim 1, wherein the high-entropy alloy in the step S1 has a chemical composition, in mass percent: the alloy atomic ratio of Al, Co, Cr, Fe and Ni is (0.1-0.5): (0.8-1.1): (0.8-1.1): (0.8-1.1): (1.0-3.0).

3. A forming of a high entropy alloy-containing complex-shaped structure by additive manufacturing according to claim 2, wherein the additive manufacturing technique in step S2 is any one of a coaxial powder-feeding laser cladding technique forming, a selective laser melting technique forming, and an electron beam selective melting technique forming.

4. A complex-shaped structural member containing a high-entropy alloy formed by additive manufacturing according to claim 3, wherein when the additive manufacturing technique in step S2 is formed by a coaxial powder-feeding laser cladding technique, the method includes the following steps:

s301, putting the high-entropy prealloy powder obtained in the step S101 into a powder feeding mechanism in forming equipment of S201, placing a base material or a metal substrate in a laser action area, selecting the thickness and the number N of layers of the high-entropy alloy layer according to an STL format file in S201, and placing the high-entropy prealloy powder on the surface of the base material or the metal substrate through the powder feeding mechanism;

5. The forming of a high-entropy alloy-containing complex-shaped structural member by additive manufacturing according to claim 4, wherein the high-entropy pre-alloy powder in the step S101 is an alloy powder with a selective screening grain size of 35-104 μm, and the inert gas used in the forming in the step S401 is Ar gas.

6. A complex-shaped structural member containing a high-entropy alloy formed by additive manufacturing according to claim 3, wherein when the additive manufacturing technique in step S2 is formed by a selective laser melting technique, the method includes the following steps:

7. A structural member with a complex shape containing a high-entropy alloy formed through additive manufacturing according to claim 6, wherein the high-entropy pre-alloy powder in the step S102 is selected from alloy powder with a sieving grain size of 15-58 μm, and the inert gas used in the forming in the step S402 is Ar gas.

8. A complex-shaped structural member containing high-entropy alloy through additive manufacturing and forming according to claim 6, wherein the scanning path of the forming process in the step S402 is a grouping direction-changing type, and particularly when N is an odd number, the scanning direction is parallel to the x axis; when N is an even number, the scanning direction is parallel to the y axis; and (5) scanning the materials by layered reversing, and sequentially superposing to obtain a formed piece.

9. A complex-shaped structural member containing a high-entropy alloy formed by additive manufacturing according to claim 3, wherein when the additive manufacturing technique in step S2 is formed by an electron beam selective melting technique, the method includes the following steps:

s403, when the high-entropy alloy layer in S303 selects N as 1, rapidly scanning the powder layer by defocusing electron beams to preheat the high-entropy pre-alloy powder on the surface of the base material or the metal substrate in step S303, wherein the preheating temperature is 600-800 ℃; then, selective melting of powder is carried out through focusing of electron beams, and a high-entropy alloy layer is obtained through forming, so that a structural member with a complex shape and containing the high-entropy alloy is obtained; wherein: the beam current of the electron beam is 5-15mA, the scanning speed is 0.2-1.6m/s, the thickness of the powder laying layer is 50-80 μm, and the distance between scanning lines is 15-60 μm; the inert gas is used for protecting the powder to prevent the powder from being oxidized during forming;

10. A forming of a complex-shaped structural member containing high-entropy alloy through additive manufacturing according to claim 9, wherein the high-entropy pre-alloy powder in step S103 is selected to have a sieving grain size of 30-125 μm, and the inert gas used in the forming in step S403 is He gas.