CN113084199A - Additive manufacturing method of metal powder bed with refined grains - Google Patents
Additive manufacturing method of metal powder bed with refined grains Download PDFInfo
- Publication number
- CN113084199A CN113084199A CN202110645614.5A CN202110645614A CN113084199A CN 113084199 A CN113084199 A CN 113084199A CN 202110645614 A CN202110645614 A CN 202110645614A CN 113084199 A CN113084199 A CN 113084199A
- Authority
- CN
- China
- Prior art keywords
- scanning
- powder
- metal powder
- powder bed
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B33—ADDITIVE MANUFACTURING TECHNOLOGY
- B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- B33Y10/00—Processes of additive manufacturing
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Powder Metallurgy (AREA)
Abstract
The invention relates to a metal powder bed additive manufacturing method for refining grains. The method comprises the following steps: constructing a three-dimensional model of a workpiece to be processed; slicing the three-dimensional model, and planning a scanning path according to slice data; preheating a powder bed forming bottom plate before powder spreading; laying metal powder on the preheated powder bed forming bottom plate, and preheating a metal powder forming area; carrying out selective melting scanning on the preheated metal powder according to a scanning path, wherein the first scanning path and the second scanning path are respectively used for sequentially scanning a plurality of first scanning straight lines and a plurality of second scanning straight lines along the first direction, and after the scanning is started, each scanning is finishedΔtAfter the first scanning line of time, the scanning is finishedΔtA second scanning straight line of time is scanned until the scanning is finished to obtain a single-layer entity slice layer; repeat the above-mentioned shopThe method comprises a pre-powder preheating process, a powder paving process, a post-powder paving preheating process and a selective melting scanning process until single-layer solid sheet layers are stacked layer by layer to obtain a target workpiece.
Description
Technical Field
The invention relates to the technical field of additive manufacturing, in particular to a metal powder bed additive manufacturing method for refining grains.
Background
As a technology with short period, less working procedures, low cost and clean forming, the metal powder bed additive manufacturing technology has excellent mechanical property of the formed component and has great scientific research value and economic benefit. The application range of the alloy is quite wide, and particularly for refractory and difficult-to-process materials including titanium alloy, titanium-based intermetallic compounds, stainless steel, cobalt-chromium alloy, nickel alloy and the like, the product can achieve high complexity and achieve high mechanical properties. With the continuous development of the metal powder bed additive manufacturing technology, more and more metal materials are added into the additive manufacturing printing field, for example, in the nuclear industry, zirconium and zirconium alloy are used for replacing stainless steel as the structural material of a nuclear reactor, about half of uranium fuel can be saved, and because the metal has good corrosion resistance in high-temperature and high-pressure steam at 300-400 ℃, the metal has quite good neutron irradiation resistance in the reactor, moderate mechanical property, good processing property, good compatibility with the uranium fuel and the like, the metal is often applied to the aspects of fuel cladding materials, pressure pipes, active region supporting parts, nuclear fuel cores and the like. Zirconium alloy implants also have a large number of applications in a new generation of orthopedic implants in the medical field, such as zirconium alloys that are known as permanent implant materials.
The development will bring new problems to a certain extent, such as the problems of coarse grains, uneven fusion, pores, etc. caused by the poor adaptability of the new material and the additive manufacturing technology, and the poor matching of the additive manufacturing technology.
The traditional method for grain refinement mainly adopts the methods of heat treatment, nucleating agent addition, multiple rolling, vibration treatment and the like, but the traditional forging preparation process of the metal structural member is limited and the cost is greatly improved due to the complexity and diversity of the metal biological implant or the new generation of nuclear structural member, the variability of the internal structure of the part, the high requirement of the organizational performance and the like. And because some metals such as zirconium powder are flammable and explosive, the danger is high when the powder metallurgy method is used for processing, and potential safety hazards are formed.
In the related technology, the additive manufacturing technology has the characteristics of realizing rapid forming of parts with complex structures, low-cost manufacturing and the like, and brings feasibility for forming complex fine-grain reinforced metal biological implants or new-generation nuclear structural parts.
Accordingly, there is a need to ameliorate one or more of the problems with the related art solutions described above.
It is noted that this section is intended to provide a background or context to the embodiments of the invention that are recited in the claims. The description herein is not admitted to be prior art by inclusion in this section.
Disclosure of Invention
It is an object of the present invention to provide a method of additive manufacturing of a metal powder bed with refined grains, which in turn overcomes, at least to some extent, one or more of the problems due to the limitations and disadvantages of the related art.
The invention firstly provides a metal powder bed additive manufacturing method for refining grains, which comprises the following steps:
constructing a three-dimensional model of a workpiece to be processed;
slicing the three-dimensional model, and planning a scanning path according to slice data, wherein the scanning path comprises a first scanning path and a second scanning path, and the first scanning path comprises a plurality of first scanning straight lines which reciprocate in parallel along a first direction; the second scanning path comprises a plurality of second scanning straight lines which reciprocate parallelly along the first direction, and the plurality of second scanning straight lines are formed by translating the first scanning straight lines along the first direction by a distance S;
metal powder is loaded into a powder bin of the selective electron beam melting equipment, a powder bed forming bottom plate is lowered by a preset height, and the powder bed forming bottom plate is preheated before powder spreading;
uniformly laying the metal powder in the powder bin on the preheated powder bed forming bottom plate, and preheating the metal powder forming area;
carrying out selective melting scanning on the preheated metal powder according to the scanning path, wherein the first scanning path and the second scanning path are respectively used for sequentially scanning a plurality of first scanning straight lines and a plurality of second scanning straight lines along the first direction, and after the scanning is started, each scanning is finishedΔtAfter the first scanning line of time, the scanning is finishedΔtA second scanning straight line of time is scanned until the scanning is finished to obtain a single-layer entity slice layer;
and repeating the pre-powder-spreading preheating process, the powder-spreading process, the post-powder-spreading preheating process and the selective melting scanning process until the single-layer solid sheet layers are stacked layer by layer to obtain the target workpiece.
In the invention, one high-energy beam gun or two high-energy beam guns are adopted to carry out selective melting scanning on the preheated metal powder.
In the present invention, the
；
Wherein the content of the first and second substances,
the time required for the first stage of superheating the heat of the molten metal,
the time for the second stage metal to cool from the liquidus temperature to the completion of solidification,
in the formula:
-the density of the liquid metal,
-the specific heat capacity of the liquid metal,
-the volume of the molten metal powder,
-the surface area of the molten metal powder,
-the liquidus temperature of the metal and,
-a high-energy beam heat input temperature,
-the temperature of the powder bed,
-the thermal storage coefficient of the metal powder,
-the solidus temperature of the metal,
-the equivalent specific heat capacity of the heat exchanger,
—latent heat of crystallization.
In the invention, when the workpiece to be processed comprises a compact part and a non-compact part, selective melting scanning is firstly carried out on the compact part and then selective melting scanning is carried out on the non-compact part when selective melting scanning is carried out on the preheated metal powder according to the scanning path; wherein the pore diameter is less than 300 μm, the porosity is less than 35%, the non-compact part is the part with the pore diameter of 100 μm-1000 μm, the filament diameter of 100 μm-500 μm and the porosity of more than 35%.
In the invention, the distance between the adjacent first scanning straight lines and the distance H between the adjacent second scanning straight lines are both 0.05mm-0.1mm, and S is (0.3-0.6) H.
In the invention, the thickness of the cutting layer for slicing the three-dimensional model is 0.03-0.1 mm.
In the invention, the metal powder is spherical powder, the sphericity is more than 90%, the particle size of the powder is 45-178 um, and the loose packing density of the graded powder is more than 50% of the theoretical density of each powder; wherein the powder with particle diameter of 45-53 μm accounts for less than 10% of the total mass of the powder.
In the invention, when the powder bed forming bottom plate is preheated before powder spreading, the powder bed forming bottom plate is preheated to the temperature of 600-800 ℃.
In the invention, when the powder bed forming bottom plate is preheated before powder spreading, the scanning current of the electron beam is 5mA-30mA, the scanning speed is 10m/s-25m/s, and the scanning time is 40min-60 min.
In the invention, when the metal powder forming area is preheated, the preheating current of the electron beam is 25mA-38mA, the scanning speed is 10m/s-20m/s, the preheating time is 8s-25s, and the scanning distance is 0.5mm-1.5 mm.
The technical scheme provided by the invention can have the following beneficial effects:
according to the metal powder bed additive manufacturing method for refining the crystal grains, provided by the invention, on one hand, the characteristics that an additive manufacturing technology has no die and can realize parts with any complex shapes are utilized, the defect that the traditional process flow is complex is overcome, the cost is saved and the manufacturing efficiency is high; on the other hand, the scanning method of high supercooling degree during printing and intermittent scanning and melting by adopting two scanning paths can be used for producing metal products with fine grains, uniform fusion and few pores, thereby improving the toughness of parts.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty.
FIG. 1 illustrates a flow chart of steps of a metal powder additive manufacturing method for refining grains in an embodiment of the invention;
FIG. 2 is a schematic diagram of a scanning path of a high energy beam gun in a method for additive manufacturing of metal powder with refined grains according to an embodiment of the present invention;
fig. 3 is a schematic diagram illustrating scanning paths of two high-energy beam guns in a metal powder additive manufacturing method for refining grains according to an embodiment of the invention.
Detailed Description
Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
The embodiment of the invention firstly provides a metal powder additive manufacturing method for grain refinement. Referring to fig. 1, the preparation method may include the steps of:
s101, constructing a three-dimensional model of a workpiece to be processed;
step S102, slicing the three-dimensional model, and planning a scanning path according to slice data, wherein the scanning path comprises a first scanning path and a second scanning path, and the first scanning path comprises a plurality of first scanning straight lines which reciprocate in parallel along a first direction; the second scanning path comprises a plurality of second scanning straight lines which reciprocate parallelly along the first direction, and the plurality of second scanning straight lines are formed by translating the first scanning straight lines along the first direction by a distance S;
step S103, metal powder is loaded into a powder bin of the selective electron beam melting equipment, a powder bed forming bottom plate is lowered by a preset height, and the powder bed forming bottom plate is preheated before powder paving;
step S104, uniformly paving the metal powder in the powder bin on the preheated powder bed forming bottom plate, and preheating the metal powder forming area;
step S105, carrying out selective melting scanning on the preheated metal powder according to the scanning path, wherein the first scanning path and the second scanning path are respectively a plurality of first scanning straight lines and a plurality of second scanning straight lines which are sequentially scanned along the first direction, and after the scanning is started, each scanning is finishedΔtAfter the first scanning line of time, the scanning is finishedΔtA second scanning straight line of time is scanned until the scanning is finished to obtain a single-layer entity slice layer;
and S106, repeating the pre-powder-spreading preheating process, the powder-spreading process, the post-powder-spreading preheating process and the selective melting scanning process until the single-layer solid sheets are stacked layer by layer to obtain the target workpiece.
On one hand, the metal powder additive manufacturing method for refining the crystal grains utilizes the characteristics that the additive manufacturing technology has no die and can realize parts with any complex shapes, gets rid of the defect of complex traditional process flow, saves the cost and has high manufacturing efficiency; on the other hand, the scanning method of high supercooling degree during printing and intermittent scanning and melting by adopting two scanning paths can be used for producing metal products with fine grains, uniform fusion and few pores, thereby improving the toughness of parts.
Specifically, in step S101, a three-dimensional model of the workpiece to be processed is constructed. That is, before manufacturing a desired workpiece to be machined, a three-dimensional model of the workpiece to be machined may be constructed by acquiring three-dimensional data of the workpiece to be machined, but is not limited thereto.
In step S102, a three-dimensional model of the target product may be cut into a series of thin layers by using a computer technology, the three-dimensional data is decomposed to obtain two-dimensional plane data, and then a scanning path is planned according to the cut layer data.
In step S103, in the selective electron beam melting and scanning process, the metal powder laid on the powder bed forming bottom plate is scattered under the action of the electron beam and leaves the preset laying position, i.e. the phenomenon of "powder blowing" in the selective electron beam melting process, which may cause the void defect of the formed workpiece, even cause the forming to be interrupted or failed, and preheating the powder bed forming bottom plate can improve the defect caused by the phenomenon. The metal powder may be, for example, zirconium or a zirconium-niobium alloy, specifically, Zr2, zr2.5nb alloy, or the like, and may be other metal powder, which is not particularly limited herein.
In step S104, the powder bed is slightly sintered by preheating the bottom plate before powder spreading and preheating the powder layer after powder spreading in the forming chamber, so that on one hand, the electrical conductivity is improved, and charge accumulation is reduced, and on the other hand, the slightly sintered powder bed has certain strength, so that charge repulsion can be counteracted, the generation of a powder blowing phenomenon is greatly reduced, and the temperature field of the powder is more stable.
In step S105, that is, for both the first scanning straight line and the second scanning straight line arranged in the first direction, scanning is started in the first direction to scanΔtThe length of time is one group, when scanning, the first group of first scanning straight lines are scanned first, when the first group of first scanning straight lines are scanned, the first group of second scanning straight lines are scanned, the second group of first scanning straight lines and the second group of second scanning straight lines are also specific as the above-mentioned first scanning straight lines of the second group are scanned first and then the second group of second scanning straight lines … …, when only one high-energy beam gun is adopted to scan the first scanning straight lines and the second scanning straight lines, the scanning direction of the nth group of first second scanning straight lines and the scanning direction of the nth group of last first scanning straight lines are scannedOn the contrary, the scanning time can be reduced, and the scanning efficiency can be improved.
In step S106, the powder layer is scanned layer by layer according to the scanning path of the pre-introduction device, and the target workpiece can be obtained finally.
Next, each part of the above-described grain-refined metal powder additive manufacturing method in the present exemplary embodiment will be described in more detail with reference to fig. 1 to 3.
In one embodiment, the preheated metal powder may be subjected to selective melting scanning using one high-energy beam gun or using two high-energy beam guns. When a high-energy beam gun is adopted to perform selective melting scanning on the preheated metal powder according to the scanning path, the scanning is finished along the initial position of the first scanning path in the first direction after the scanning is startedΔtAfter the first scanning straight line of time, the scanning along the first direction at the starting position of the second scanning path is finishedΔtA second scan line of time; then continuously scanning along the first directionΔtAfter the first scanning line of time, continuing to scan along the first directionΔtAnd a second scanning line of time, so as to obtain a single-layer solid slice until the scanning is completed, wherein the high-energy beam gun is an electron gun. Specifically, referring to FIG. 2, for example, after the scan is initiated, the scan is completed using the high energy beam gun at the initial position of the first scan path in the first directionΔtAfter the first scanning straight line of time is scanned, three first scanning straight lines of 1, 2 and 3 are completed, then the scanning of the first scanning straight line is stopped, and the scanning of the second scanning path along the initial position of the second scanning path in the first direction is startedΔtAfter a certain time, the scanning is completed by the second scanning path 4, 5, 6, and then the scanning of the first scanning path 7, 8, 9 … … is continued until the scanning is completed to obtain a single-layer physical slice. When two guns are used for selective melting scanning of preheated metal powder according to the scanning path, the two guns can be a main high-energy beam gun and an auxiliary high-energy beam gun, the main high-energy beam gun is used for scanning a first scanning straight line along the initial position of a first scanning path in a first direction after scanning is started, and when the main high-energy beam gun scansΔtAt time, the secondary high-energy beam gun is adopted to start scanning a second scanning line along the initial position of a second scanning path in the first direction, so thatAnd obtaining a single-layer solid sheet layer until scanning is finished, wherein the main high-energy beam gun is an electron gun, and the auxiliary high-energy beam gun is one of the electron gun or the laser gun. Specifically, referring to FIG. 3, a first scan line 1-6 and a second scan line I-VI are scanned by two high energy beam guns, respectively, and the first scan line is scanned by the main high energy beam gun until the scan is completedΔtStarting the auxiliary high-energy beam gun to scan the second scanning straight line after time, and continuously scanning the first scanning straight line by the main high-energy beam gun when the second scanning straight line is scanned until the first scanning straight line in a single layer is scanned completely; the electron beams or laser beams which are rapidly and crossly scanned are adopted for intermittent melting, so that the effect of vibrating and stirring the molten structure grains is achieved, the diameter growth can be interrupted in the vibrating and stirring process, nucleation particles are provided, the number of the nucleation particles is increased, and the grains are refined; if gas is generated in the powder, power can be provided for the overflow of the gas, so that the gas is overflowed, and the generation of pores in the part is reduced; and disturbing the molten pool during the second scanning to reduce poor fusion caused by segregation. Meanwhile, by surface secondary heating, the surface temperature is increased, the temperature gradient is increased, the supercooling degree delta T is increased, further secondary refinement of metal grains is realized, and the toughness of a metal additive such as a Zr2.5Nb alloy can be improved.
In one embodiment, the
；
Wherein the content of the first and second substances,
the time required for the first stage of superheating the heat of the molten metal,
the time for the second stage metal to cool from the liquidus temperature to the completion of solidification,
in the formula:
-the density of the liquid metal,
-the specific heat capacity of the liquid metal,
-the volume of the molten metal powder,
-the surface area of the molten metal powder,
-the liquidus temperature of the metal and,
-a high-energy beam heat input temperature,
-the temperature of the powder bed,
-the thermal storage coefficient of the metal powder,
-the solidus temperature of the metal,
-the equivalent specific heat capacity of the heat exchanger,
—latent heat of crystallization。
In one embodiment, when the workpiece to be processed comprises a dense part and a non-dense part, when the preheated metal powder is subjected to selective melting scanning according to the scanning path, the selective melting scanning is carried out on the dense part, and then the selective melting scanning is carried out on the non-dense part; wherein, the pore diameter is less than 300 μm, the porosity is less than 35%, the non-compact part is the pore diameter of 100 μm-1000 μm, the filament diameter of 100 μm-500 μm, the porosity is more than 35%. Specifically, the scanning path may further include a third scanning path, where the third scanning path is a scanning path of a profile of the workpiece to be processed; when each layer is scanned and melted, the outer contour of the compact part is scanned and melted firstly, the scanning current is 5mA-8mA, the scanning speed is 0.3m/s-0.8m/s, then the interior of the compact part, namely a first scanning straight line and a second scanning straight line, is scanned, the scanning current of the first scanning straight line is 17mA-20mA, the scanning speed is 4m/s-7m/s, and the scanning current of the second scanning straight line is 15mA-19mA, 5m/s-8 m/s; then scanning and melting the outer contour of the non-compact part, wherein the scanning current is 2.0-5.0 mA, the scanning speed is 0.2-0.6 m/s, then scanning the inner part of the non-compact part, namely the first scanning straight line and the second scanning straight line, the scanning current of the first scanning straight line is 2.0-6.0 mA, the scanning speed is 0.2-1.5 m/s, the scanning current of the second scanning straight line is 1.0-4.0 mA, and the scanning speed is 0.5-1.8 m/s. Specifically, the purpose of the outer contour scanning adopting higher scanning current and lower scanning speed is to provide a sufficient energy density pinning boundary and reduce the thickness of a boundary shrinkage porosity layer, but the energy density of the boundary cannot be raised too high so as to avoid serious edge warping and reduce the surface quality of parts; the internal scanning of the compact part adopts an intermittent scanning melting mode, which is beneficial to refining grains by breaking dendritic crystal growth and providing nucleation particles, and the melting point of metal is about 1800-2000 ℃, the energy density of the metal is required to be more than 29J/mm3, and then scanning current and scanning speed are obtained through a large amount of experiments, but the surface of the part is seriously recessed when the energy density is too high, so that the high-density solid part can be well formed by adopting the process parameters, and finer tissues of the grains can be realized; likewise, the non-dense part also has the same effect gain.
In one embodiment, a pitch between adjacent first scanning lines and a pitch H between adjacent second scanning lines may be 0.05mm to 0.1mm, and S may be (0.3 to 0.6) H. Specifically, the scanning line spacing parameter is determined according to the scanning precision, so that reasonable utilization of scanning energy is facilitated, and the phenomena of too much overlapping and too little overlapping of high-energy beam melting points are avoided; the first and second scanning line spacing is determined according to the single scanning line spacing, so that the dendrite breaking effect is better, the melting energy density is not greatly improved, and the surface quality of the part is poor.
In one embodiment, the thickness of the slice layer for slicing the three-dimensional model may be 0.03-0.1 mm. Specifically, the selection of the slice thickness mainly considers the performance requirements, and the provided high-energy beam scanning current and scanning speed process parameters are suitable for the later layer, so that a compact and high-performance part can be obtained.
In one embodiment, the metal powder can be spherical powder, the mass purity of the metal powder is greater than or equal to 99.9%, the sphericity is greater than 90%, the particle size of the powder is 45 um-178 um, and the loose packing density of the graded powder is more than 50% of the theoretical density of each powder; wherein the powder with particle diameter of 45-53 μm accounts for less than 10% of the total mass of the powder. In particular, since metal powders are more dangerous in use and storage (particularly, fine metal powders are flammable and explosive), the powders are required to have a lower fine powder content for better storage and use, which is beneficial to reduce the threat to the environment, personnel and property.
In one embodiment, when preheating the powder bed forming bottom plate before powder spreading, the temperature of preheating to the powder bed forming bottom plate may be 600-800 ℃. Specifically, the temperature of the powder bed forming bottom plate is preheated to 600-800 ℃ before powder spreading, so that the powder blowing phenomenon can be better improved.
In one embodiment, when the powder bed forming bottom plate is preheated before powder spreading, the scanning current of an electron beam is 5mA-30mA, the scanning speed is 10m/s-25m/s, and the scanning time is 40min-60 min. Specifically, the parameters are beneficial to the uniform heating of the bottom plate, and meanwhile, the printing efficiency cannot be reduced.
In one embodiment, the preheating current of the electron beam is 25mA-38mA, the scanning speed is 10m/s-20m/s, the preheating time is 8s-25s, and the scanning distance is 0.5mm-1.5mm when the metal powder forming area is preheated. Specifically, if the scanning distance is too large, preheating is not uniform, and if the scanning distance is too small, the overlapping part is too large, so that the heat of the overlapping part is too high, preheating is not uniform, and the process time is too long, so that the preheating efficiency is reduced. In particular, the parameters are favorable for stably fixing the powder bed, but the powder bed is not excessively agglomerated, so that powder on the surface of the part is difficult to clean.
On one hand, the metal powder additive manufacturing method for refining the crystal grains utilizes the characteristics that the additive manufacturing technology has no die and can realize parts with any complex shapes, gets rid of the defect of complex traditional process flow, saves the cost and has high manufacturing efficiency; on the other hand, the scanning method of high supercooling degree during printing and intermittent scanning and melting by adopting two scanning paths can be used for producing metal products with finer grains, so that the toughness of the parts is improved.
It is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like in the foregoing description are used for indicating or indicating the orientation or positional relationship illustrated in the drawings, and are used merely for convenience in describing embodiments of the present invention and for simplifying the description, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the embodiments of the present invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, "a plurality" means two or more unless specifically limited otherwise.
In the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrated; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In embodiments of the invention, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise the first and second features being in direct contact, or the first and second features being in contact, not directly, but via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples described in this specification can be combined and combined by those skilled in the art.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
Claims (10)
1. A method for manufacturing a metal powder bed additive for refining grains is characterized by comprising the following steps:
constructing a three-dimensional model of a workpiece to be processed;
slicing the three-dimensional model, and planning a scanning path according to slice data, wherein the scanning path comprises a first scanning path and a second scanning path, and the first scanning path comprises a plurality of first scanning straight lines which reciprocate in parallel along a first direction; the second scanning path comprises a plurality of second scanning straight lines which reciprocate parallelly along the first direction, and the plurality of second scanning straight lines are formed by translating the first scanning straight lines along the first direction by a distance S;
metal powder is loaded into a powder bin of the selective electron beam melting equipment, a powder bed forming bottom plate is lowered by a preset height, and the powder bed forming bottom plate is preheated before powder spreading;
uniformly laying the metal powder in the powder bin on the preheated powder bed forming bottom plate, and preheating the metal powder forming area;
carrying out selective melting scanning on the preheated metal powder according to the scanning path, wherein the first scanning path and the second scanning path are respectively used for sequentially scanning a plurality of first scanning straight lines and a plurality of second scanning straight lines along the first direction, and after the scanning is started, each scanning is finishedΔtFirst sweep of timeAfter the line is drawn, the scanning is finishedΔtA second scanning straight line of time is scanned until the scanning is finished to obtain a single-layer entity slice layer;
and repeating the pre-powder-spreading preheating process, the powder-spreading process, the post-powder-spreading preheating process and the selective melting scanning process until the single-layer solid sheet layers are stacked layer by layer to obtain the target workpiece.
2. The grain refining metal powder bed additive manufacturing method of claim 1, wherein the preheated metal powder is subjected to selective melting scanning using one high energy beam gun or using two high energy beam guns.
3. The grain refined metal powder bed additive manufacturing method of claim 2, wherein the grain refined metal powder bed additive manufacturing method is characterized in that
；
Wherein, among others,
the time required for the first stage of superheating the heat of the molten metal,
the time for the second stage metal to cool from the liquidus temperature to the completion of solidification,
in the formula:
-the density of the liquid metal,
-the specific heat capacity of the liquid metal,
-the volume of the molten metal powder,
-the surface area of the molten metal powder,
-the liquidus temperature of the metal and,
-a high-energy beam heat input temperature,
-the temperature of the powder bed,
-the thermal storage coefficient of the metal powder,
-the solidus temperature of the metal,
-the equivalent specific heat capacity of the heat exchanger,
—latent heat of crystallization.
4. The grain refining metal powder bed additive manufacturing method according to any one of claims 1 to 3, wherein when the workpiece to be processed includes a dense portion and a non-dense portion, when the preheated metal powder is subjected to selective melting scanning according to the scanning path, the selective melting scanning is performed on the dense portion first, and then the selective melting scanning is performed on the non-dense portion; wherein, the compact part is a part with the pore diameter less than 300 μm and the porosity less than 35 percent, and the non-compact part is a part with the pore diameter of 100 μm-1000 μm, the filament diameter of 100 μm-500 μm and the porosity more than 35 percent.
5. The grain refining metal powder bed additive manufacturing method according to claim 1, wherein a pitch between adjacent first scanning lines and a pitch H between adjacent second scanning lines are each 0.05mm to 0.1mm, and S is (0.3 to 0.6) H.
6. The grain refining metal powder bed additive manufacturing method of claim 5, wherein a thickness of a cut layer obtained by slicing the three-dimensional model is 0.03 to 0.1 mm.
7. The grain refining metal powder bed additive manufacturing method according to claim 6, wherein the metal powder is spherical powder, the sphericity is greater than 90%, the powder particle size is 45 um-178 um, and the loose packing density of the graded powder is respectively more than 50% of the theoretical density of each powder; wherein the powder with particle diameter of 45-53 μm accounts for less than 10% of the total mass of the powder.
8. The grain refining metal powder bed additive manufacturing method of claim 7, wherein the preheating is performed before the powder bed forming bottom plate is powdered, and the preheating is performed until the temperature of the powder bed forming bottom plate is 600-800 ℃.
9. The grain refining metal powder bed additive manufacturing method according to any one of claims 5 to 8, wherein when the powder bed forming base plate is preheated before powder spreading, the scanning current of an electron beam is 5mA-30mA, the scanning speed is 10m/s-25m/s, and the scanning time is 40min-60 min.
10. The grain refining metal powder bed additive manufacturing method according to claim 9, wherein a preheating current of an electron beam is 25mA to 38mA, a scanning speed is 10m/s to 20m/s, a preheating time is 8s to 25s, and a scanning pitch is 0.5mm to 1.5mm when the metal powder forming region is preheated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110645614.5A CN113084199B (en) | 2021-06-10 | 2021-06-10 | Additive manufacturing method of metal powder bed with refined grains |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110645614.5A CN113084199B (en) | 2021-06-10 | 2021-06-10 | Additive manufacturing method of metal powder bed with refined grains |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113084199A true CN113084199A (en) | 2021-07-09 |
| CN113084199B CN113084199B (en) | 2021-11-02 |
Family
ID=76665019
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110645614.5A Active CN113084199B (en) | 2021-06-10 | 2021-06-10 | Additive manufacturing method of metal powder bed with refined grains |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113084199B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114535613A (en) * | 2022-03-18 | 2022-05-27 | 中北大学 | Intelligent powder laying planning method based on selective laser melting equipment |
| CN115673339A (en) * | 2023-01-03 | 2023-02-03 | 西安赛隆增材技术股份有限公司 | Three-dimensional manufacturing method of zirconium-niobium alloy orthopedic implant |
| CN116275115A (en) * | 2023-05-16 | 2023-06-23 | 西安空天机电智能制造有限公司 | Electron beam selective material-adding manufacturing method of TiAl alloy |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105537590A (en) * | 2016-02-01 | 2016-05-04 | 合肥中加激光技术有限公司 | Method for reducing hot stack influences of metal SLM three-dimensional printing |
| CN107206494A (en) * | 2014-11-21 | 2017-09-26 | 瑞尼斯豪公司 | Utilize the increasing material manufacturing equipment and correlation technique of special scanning strategy |
| EP3495078A1 (en) * | 2017-12-11 | 2019-06-12 | Rolls-Royce plc | Laser laying patterning |
| CN110340359A (en) * | 2019-07-22 | 2019-10-18 | 西安赛隆金属材料有限责任公司 | Porous tantalum implantation material and porous tantalum increase material preparation method |
| CN111001806A (en) * | 2019-12-27 | 2020-04-14 | 西安赛隆金属材料有限责任公司 | Method and device for refining grains in additive manufacturing |
| CN111203536A (en) * | 2020-04-22 | 2020-05-29 | 中国航发上海商用航空发动机制造有限责任公司 | Method for prefabricating air hole defect by controlling SLM (selective laser melting) process |
| US20200376556A1 (en) * | 2018-02-19 | 2020-12-03 | Eos Gmbh Electro Optical Systems | Additive manufacturing method with controlled solidification and corresponding device |
-
2021
- 2021-06-10 CN CN202110645614.5A patent/CN113084199B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107206494A (en) * | 2014-11-21 | 2017-09-26 | 瑞尼斯豪公司 | Utilize the increasing material manufacturing equipment and correlation technique of special scanning strategy |
| CN105537590A (en) * | 2016-02-01 | 2016-05-04 | 合肥中加激光技术有限公司 | Method for reducing hot stack influences of metal SLM three-dimensional printing |
| EP3495078A1 (en) * | 2017-12-11 | 2019-06-12 | Rolls-Royce plc | Laser laying patterning |
| US20200376556A1 (en) * | 2018-02-19 | 2020-12-03 | Eos Gmbh Electro Optical Systems | Additive manufacturing method with controlled solidification and corresponding device |
| CN110340359A (en) * | 2019-07-22 | 2019-10-18 | 西安赛隆金属材料有限责任公司 | Porous tantalum implantation material and porous tantalum increase material preparation method |
| CN111001806A (en) * | 2019-12-27 | 2020-04-14 | 西安赛隆金属材料有限责任公司 | Method and device for refining grains in additive manufacturing |
| CN111203536A (en) * | 2020-04-22 | 2020-05-29 | 中国航发上海商用航空发动机制造有限责任公司 | Method for prefabricating air hole defect by controlling SLM (selective laser melting) process |
Non-Patent Citations (3)
| Title |
|---|
| 史玉升等: "《3D打印材料(下册)》", 31 March 2019, 华中科技大学出版社 * |
| 孟光等: "《航天航空智能制造技术与装备发展战略研究》", 31 October 2017, 上海科学技术出版社 * |
| 李庆春: "《铸件形成理论基础》", 31 January 1982, 机械工业出版社 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114535613A (en) * | 2022-03-18 | 2022-05-27 | 中北大学 | Intelligent powder laying planning method based on selective laser melting equipment |
| CN114535613B (en) * | 2022-03-18 | 2023-10-17 | 中北大学 | Intelligent powder spreading planning method based on selective laser melting equipment |
| CN115673339A (en) * | 2023-01-03 | 2023-02-03 | 西安赛隆增材技术股份有限公司 | Three-dimensional manufacturing method of zirconium-niobium alloy orthopedic implant |
| CN116275115A (en) * | 2023-05-16 | 2023-06-23 | 西安空天机电智能制造有限公司 | Electron beam selective material-adding manufacturing method of TiAl alloy |
| CN116275115B (en) * | 2023-05-16 | 2023-08-18 | 西安空天机电智能制造有限公司 | Electron beam selective material-adding manufacturing method of TiAl alloy |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113084199B (en) | 2021-11-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113084199B (en) | Additive manufacturing method of metal powder bed with refined grains | |
| Iveković et al. | Selective laser melting of tungsten and tungsten alloys | |
| Murr | A metallographic review of 3D printing/additive manufacturing of metal and alloy products and components | |
| Jia et al. | Scanning strategy in selective laser melting (SLM): a review | |
| Körner | Additive manufacturing of metallic components by selective electron beam melting—a review | |
| Li et al. | Wire and arc additive manufacturing of aluminum alloy lattice structure | |
| Ghayoor et al. | Selective laser melting of austenitic oxide dispersion strengthened steel: Processing, microstructural evolution and strengthening mechanisms | |
| Vasquez et al. | Elaboration of oxide dispersion strengthened Fe-14Cr stainless steel by selective laser melting | |
| JP4802277B2 (en) | Shock absorbing structure and manufacturing method thereof | |
| Yan et al. | Evaluation of light-weight AlSi10Mg periodic cellular lattice structures fabricated via direct metal laser sintering | |
| CN111872395B (en) | Preparation method of nickel-based alloy single crystal or directional solidification part | |
| Yan et al. | Evaluations of cellular lattice structures manufactured using selective laser melting | |
| US7258720B2 (en) | Metal powder composition for use in selective laser sintering | |
| CN111957962B (en) | Additive manufacturing method and additive manufacturing device for selective laser melting for titanium alloy molding | |
| Rashid et al. | A comparative study of flexural properties of additively manufactured aluminium lattice structures | |
| CN112496345B (en) | Hard alloy additive preparation method | |
| Zhang et al. | Simulation and experimental studies on process parameters, microstructure and mechanical properties of selective laser melting of stainless steel 316L | |
| CN112846230B (en) | Method for preparing lattice structure amorphous-nanocrystalline alloy by using laser additive | |
| CN113414407B (en) | Additive manufacturing method of nickel-based alloy and nickel-based alloy part | |
| Hu et al. | Directed energy deposition of zirconia-toughened alumina ceramic: Novel microstructure formation and mechanical performance | |
| Drstvenšek et al. | Influence of local heat flow variations on geometrical deflections, microstructure, and tensile properties of Ti-6Al-4 V products in powder bed fusion systems | |
| Jeong et al. | Effect of electron beam continuity on microstructures and mechanical properties of titanium lattice structures produced with electron beam additive manufacturing | |
| GB2559950A (en) | Metal alloy | |
| Sun et al. | Microstructure, cracking behavior and control of Al–Fe–V–Si alloy produced by selective laser melting | |
| Mohammadhosseini et al. | Flexural behaviour of titanium cellular structures produced by electron beam melting |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: Room 303-46, building a, Kairui, Fengcheng 12th Road, Xi'an Economic and Technological Development Zone, Shaanxi 710018 Patentee after: Xi'an Sailong Additive Technology Co.,Ltd. Address before: Room 303-46, building a, Kairui, Fengcheng 12th Road, Xi'an Economic and Technological Development Zone, Shaanxi 710018 Patentee before: XI'AN SAILONG METAL MATERIALS Co.,Ltd. |