CN113441733B - Shape control and property control method in heat preservation sulfur pump impeller additive manufacturing process - Google Patents

Shape control and property control method in heat preservation sulfur pump impeller additive manufacturing process Download PDF

Info

Publication number
CN113441733B
CN113441733B CN202110723824.1A CN202110723824A CN113441733B CN 113441733 B CN113441733 B CN 113441733B CN 202110723824 A CN202110723824 A CN 202110723824A CN 113441733 B CN113441733 B CN 113441733B
Authority
CN
China
Prior art keywords
area
laser
laser beam
turned
scanning
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.)
Active
Application number
CN202110723824.1A
Other languages
Chinese (zh)
Other versions
CN113441733A (en
Inventor
梁静静
王道红
刘金灿
张鹏
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jiangsu Feiyue Pump Group Co ltd
Original Assignee
Jiangsu Feiyue Pump Group Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Jiangsu Feiyue Pump Group Co ltd filed Critical Jiangsu Feiyue Pump Group Co ltd
Priority to CN202110723824.1A priority Critical patent/CN113441733B/en
Publication of CN113441733A publication Critical patent/CN113441733A/en
Application granted granted Critical
Publication of CN113441733B publication Critical patent/CN113441733B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/80—Data acquisition or data processing
    • B22F10/85—Data acquisition or data processing for controlling or regulating additive manufacturing processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/20—Direct sintering or melting
    • B22F10/28—Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
    • 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
    • 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
    • B33Y40/00—Auxiliary operations or equipment, e.g. for material handling
    • B33Y40/10—Pre-treatment
    • 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
    • B33Y50/00—Data acquisition or data processing for additive manufacturing
    • B33Y50/02—Data acquisition or data processing for additive manufacturing for controlling or regulating additive manufacturing processes
    • 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
    • B33Y70/00—Materials specially adapted for additive manufacturing
    • B33Y70/10—Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
    • 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
    • B33Y80/00—Products made by additive manufacturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
    • B22F2009/043—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by ball milling
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Ceramic Engineering (AREA)
  • Civil Engineering (AREA)
  • Composite Materials (AREA)
  • Structural Engineering (AREA)
  • Powder Metallurgy (AREA)

Abstract

The invention relates to the field of additive manufacturing of metal components, in particular to a shape control method in the additive manufacturing process of an impeller of a heat-preservation sulfur pump. The method comprises the following specific steps: firstly, mixing metal powder for impeller additive manufacturing with heterogeneous nuclear refiner powder; secondly, slicing and scanning path area discretization planning are carried out on the digital-analog of the impeller component to be formed by using slicing software; step three, changing laser energy input into discontinuous input according to a planned scanning path; and fourthly, performing laser additive manufacturing. The discretization of the laser forming process area and the grain refinement of the heterogeneous nucleation refiner are combined together, so that the temperature gradient in the impeller forming process can be reduced, the residual stress can be reduced, the volume fraction of equiaxed grains in the impeller can be improved, and the grain structure can be refined. The method has strong applicability, can be used for the additive manufacturing of the impeller, can be used for the repairing and remanufacturing of the impeller, and is easy to popularize.

Description

Shape control and property control method in heat preservation sulfur pump impeller additive manufacturing process
Technical field:
the invention relates to the field of additive manufacturing of metal components, in particular to a shape control method in the additive manufacturing process of an impeller of a heat-preservation sulfur pump.
The background technology is as follows:
the laser stereo forming technology is one advanced manufacture technology capable of realizing no-grinding tool, fast and full compact near net forming of high performance complicated metal part. The three-dimensional forming manufacturing of the parts is realized by using laser with high energy density as a heat source and in a layer-by-layer stacking mode. Compared with the traditional processing technology, the laser three-dimensional forming technology has the following characteristics: (1) the solidification rate is fast, and the non-equilibrium fast solidification is realized; (2) the tooling die is not needed, and the flexibility degree in the manufacturing process is high; (3) the product has short development period and high processing speed; (4) the prepared part has fine microstructure and excellent mechanical property and chemical property; (5) the size and the complexity of the part have small influence on the processing difficulty; (6) there is a wide space for further reducing the processing cost. At present, the laser additive manufacturing technology is widely applied to metal materials such as titanium alloy, superalloy and the like, and the prepared parts are also used in the aerospace field. However, during additive manufacturing, there is a large residual stress in the component due to the extreme non-uniformity in the heat input in space, which is very likely to cause deformation cracking of the component.
The solidification behavior involved in the laser additive manufacturing process is different from that of other preparation technologies, and belongs to non-interface thermal resistance unbalanced rapid solidification of a laser metallurgy high-temperature molten pool on a solid metal substrate, the solidification structure is easy to inherit the crystal orientation of a substrate, a directional structure with a certain crystal orientation is formed, and the microstructure is obviously refined. This fine, grain structure with a certain crystallographic orientation gives the component an anisotropy in microstructure and mechanical properties. For some metal components, such as: the impeller of the heat-preserving sulfur pump needs to ensure isotropy of mechanical properties. How to make the additive manufactured component have isotropic grain structure and eliminate anisotropy in terms of macroscopic performance is a problem to be solved in the field of additive manufacturing at present.
The invention comprises the following steps:
the invention aims to provide a shape control method in the additive manufacturing process of an impeller of a heat-preservation sulfur pump, which is used for reducing the temperature gradient in the laser forming process, weakening the residual stress in a component and refining the grain structure.
In order to achieve the purpose of the invention, the technical scheme of the invention is as follows:
a shape control method in the process of heat preservation sulfur pump impeller additive manufacturing comprises the following specific steps: firstly, mixing metal powder for impeller additive manufacturing with heterogeneous nuclear refiner powder; secondly, slicing and scanning path area discretization planning are carried out on the digital-analog of the impeller component to be formed by using slicing software; step three, changing laser energy input into discontinuous input according to a planned scanning path; and fourthly, performing laser additive manufacturing.
In the shape control method in the heat preservation sulfur pump impeller material increase manufacturing process, in the first step, heterogeneous nucleation refiners and metal powder for impeller material increase manufacturing are mixed by adopting a ball milling process, so that the heterogeneous nucleation refiners are adhered to the surface of the metal powder; wherein, the heterogeneous nucleation refiner is one or more than two powders of nano-scale, submicron-scale and micron-scale of refractory metal simple substance, carbide or nitride, the metal powder is powder of nickel-based alloy, iron-based alloy or cobalt-based alloy, the granularity of the metal powder is 53-105 mu m, and the heterogeneous nucleation refiner is 1-10% of the mass of the metal powder.
In the second step, the scanning path of each layer is planned according to regional discretization, namely the part to be formed in each layer is divided into a plurality of independent areas; after the laser beam has scanned one area, it is moved to another area at a distance from the one area for scanning.
The shape control method in the material increase manufacturing process of the heat preservation sulfur pump impeller adopts the existing layering software to carry out layering treatment on the formed components, and plans the scanning path according to the regional discretization method.
In the third step, when the laser beam scans a certain area, the laser beam energy is input in a discontinuous way, namely, when the laser beam moves to a certain position in a scanning path, the laser beam is opened to ensure that the laser beam acts on the position, and the position is a molten pool point or a molten pool short line; after the point or the short line is fully melted and formed, the laser beam is turned off; then the laser beam moves to the next molten pool position, and the two positions of the laser beam, which are scanned sequentially, are planned according to discretization, namely a certain distance exists between the two positions of the current area, which are scanned sequentially; when the laser is moved to another position, the laser beam is turned on, the point or line melts that position until the laser beam is turned off and moves to a third position; the cycle is continued until the laser beam scans across each location of the area.
In the fourth step, each region is formed in a point-by-point melting mode, and the points are overlapped until the formation of the region is completed; then scanning the next area until the whole layer is formed; and finally, performing next layer molding in the same way, and stacking layer by layer to finish the preparation of the impeller.
The technical principle of the invention is as follows:
the invention is mainly aimed at laser additive manufacturing of the heat-preservation sulfur pump impeller, and the direction of the temperature gradient in the additive manufacturing molten pool is easy to promote the upward epitaxial growth of column dendrites in the molten pool along the crystal orientation of crystal grains in a base plate below. If one or more than two kinds of nano-scale, submicron-scale and micron-scale powder of refractory metal simple substance, carbide or nitride contained in the metal are adhered to the surface of the metal powder, the nano-scale powder with higher melting point is very easy to become heterogeneous nucleation refiner in a molten pool, so that the critical supercooling degree required by the nucleation growth of crystal grains in the melt is reduced, and the generation of fine equiaxed crystals is promoted. In addition, refractory metal simple substance, carbide or nitride particles serving as heterogeneous nucleation refiners can also serve as strengthening phases in the alloy to strengthen the alloy.
The discretization of the region in the laser forming includes not only the discretization division of the scanning region, but also the discontinuous control of the laser melting pool when a certain region is scanned. Under the regional discretization scanning strategy, the heat accumulation is relatively small, the temperature gradient between a molten pool and a formed part is small, so that the thermal stress is relatively small, and the deformation cracking in the additive manufacturing process of the component is favorably controlled.
The invention has the advantages and beneficial effects that:
1. the invention can reduce the thermal stress in the component, control the thin wall shape of the heat preservation sulfur pump impeller easily, and improve the mechanical property of the impeller material.
2. The invention has simple implementation process and is beneficial to industrial production.
3. The invention has strong applicability, not only can be used for additive manufacturing of the heat-preservation sulfur pump impeller, but also can be used for remanufacturing of the heat-preservation sulfur pump impeller, and is easy to popularize.
In a word, the method combines the regional discretization of the laser forming process and the grain refinement of the heterogeneous nucleation refiner, so that the temperature gradient in the impeller forming process can be reduced, the residual stress can be reduced, the volume fraction of equiaxed crystals in the impeller can be improved, and the grain structure can be refined.
Description of the drawings:
FIG. 1 is a schematic diagram of a heterogeneous nucleation refiner-containing metal powder for additive manufacturing; wherein 1 is metal powder; 2 is WC powder.
Fig. 2 is a metal powder particle golden phase diagram of a surface-coating refiner.
FIG. 3 is a schematic view of a discretized scan path of a laser forming process region. Where fig. 3 (a) is discretization of the scan area and fig. 3 (b) is discontinuous energy input.
Fig. 4 is a macro-morphology of an additive manufactured sample.
Fig. 5 (a) -5 (b) are additive manufacturing metal microstructures without and with the addition of refiners. Wherein, fig. 5 (a) shows no addition of a refiner, and fig. 5 (b) shows addition of a refiner.
The specific embodiment is as follows:
in the specific implementation process, the shape control method in the impeller additive manufacturing process of the heat-preserving sulfur pump comprises the steps of mixing metal powder for impeller additive manufacturing with heterogeneous nucleation refiner powder; the second step is to use slicing software to carry out slicing and scanning path area discretization planning on the digital-analog of the impeller component to be formed; step three, changing laser energy input into discontinuous input according to a planned scanning path; and the fourth step is to perform laser additive manufacturing.
Before additive manufacturing, the heterogeneous nucleation refiner (such as one or more than two of nano-scale, submicron-scale and micron-scale powder of refractory metal simple substance, carbide or nitride) and the metal powder (such as iron-based or nickel-based alloy powder) for impeller additive manufacturing are mixed by adopting a ball milling process, so that the heterogeneous nucleation refiner is adhered to the surface of the metal powder. The refractory metal simple substance, carbide or nitride nano-scale powder can be used as heterogeneous nucleation particles in the additive manufacturing process, and promote the melt in a laser molten pool to solidify around the melt to form new crystal grains by taking the melt as nucleation particles, and can interrupt the crystal grains which grow from the bottom in the original molten pool to continue growing. Therefore, the columnar crystal structure growth with certain orientation can be inhibited, and the growth of the polycrystalline grain nuclei can be promoted.
Slicing and path planning are carried out on impeller digital-analog by slicing software before additive manufacturing. When the path is planned, ensuring that the scanning path of each layer is planned according to the discretization of the area, namely dividing the part to be formed in each layer into a plurality of independent areas; after the laser beam has scanned one area, it is moved to another area at a distance from the one area for scanning. In this way, continuous heat input in a region during additive manufacturing can be avoided, heat accumulation in the region is reduced, and temperature gradients and internal stresses in the component are reduced.
When the laser beam scans a certain area, the energy of the laser beam is input in a discontinuous mode, namely, when the laser beam moves to a certain position in a scanning path, the laser beam is opened, the laser beam is ensured to act on the position, and the position can be a molten pool point or a molten pool short line; after the spot or stub is sufficiently melted to shape, the laser beam is turned off. The laser beam is then moved to the next bath position, and the two positions of the laser beam scanned sequentially are also programmed in a discretized manner, i.e. there is a certain distance between the two positions of the current region scanned sequentially. When the laser is moved to another position, the laser beam is turned on, the point or line melts that position until the laser beam is turned off and moves to a third position; the cycle is continued until the laser beam scans across each location of the area.
And layering the formed components by adopting the existing layering software, and planning a scanning path according to a regional discretization method. When each area is formed, the forming is carried out according to discontinuous laser energy input, namely, a discretized mode of point-by-point/short line melting, and overlapping is carried out between a point/short line and a point/short line until the forming of the area is completed; then scanning the next area until the whole layer is formed; and finally, forming the next layer in the same way, and stacking the layers to finish the preparation of the impeller.
The invention is described in further detail below with reference to the attached drawings and examples:
example 1:
in the embodiment, a GH4068 superalloy sample is prepared by a laser additive manufacturing method of region discretization and heterogeneous nucleation refiner grain refinement, and the technical process is as follows:
(1) Preparation of metal powder and substrate for additive manufacturing: when the substrate adopts a cast GH3536 alloy plate and the surface to be clad of the substrate is subjected to cleaning treatment, a mechanical method can be adopted to thoroughly remove decaying tissues such as an oxide layer and the like near the defect, so that the inner metal surface is exposed. Preparing GH4068 alloy powder by adopting an inert gas atomization technology, and screening out alloy powder with the particle size of 53-105 mu m for later use; the nano WC powder is selected to be mixed according to 3 percent of the mass fraction of the GH4068 alloy powder.
As shown in fig. 1 and 2, metal powder 1 (GH 4068 alloy powder) was mixed with micron-sized WC powder 2 by ball milling. The nano WC powder 2 is used as a refiner and is adhered to the surface of the metal powder 1.
(2) Determination of basic technological parameters of alloy laser additive manufacturing: slicing and scanning path planning are carried out on UG or CAD digital models of the three-dimensional shape of the sample to be formed by using slicing software such as Magics and the like. As shown in fig. 3 (a) -3 (b), when planning a scanning path, area discretization management is needed, namely, a part to be formed in each layer is divided into a plurality of independent areas; after the laser scans over one area, it is moved to another area at a distance from the area to scan. The cycle is then completed until the repair of the component is completed. When the laser beam scans a certain area, the laser beam is turned on and scans a certain point or a short line when moving to a certain position in a scanning path, after the point or the short line is fully formed, the laser beam is turned off, then the laser beam moves to a position with a certain distance from the current scanning path, at the moment, the laser beam is turned on, and the melting scanning is performed until the laser beam is turned off and moves to a third position; the cycle is continued until the laser beam scans across each location of the area.
As shown in fig. 3 (a), the scanning area is uniformly divided into 1-8 rectangular areas, each rectangular area having an area of 4mm×4mm. The discretization management mode of the scanning area is as follows: the laser beam scanning is performed in the order of 1, 2, 3, 4, 5, 6, 7, 8, and a certain distance exists between adjacent scanning areas of the order. For example: after the laser scans over the area 1, the laser beam is turned off and then moved to the area 2 spaced from the area 1 by two areas for scanning. After the laser scans over the area 2, the laser beam is turned off and then moved to the area 3 spaced from the area 2 for scanning. After the laser scans over the area 3, the laser beam is turned off and then moved to the area 4 spaced three areas apart from the area 3 for scanning. After the laser scans over the area 4, the laser beam is turned off and then moved to the area 5 spaced from the area 4 for scanning. After the laser scans over the area 5, the laser beam is turned off and then moved to the area 6 spaced from the area 5 by two areas for scanning. After the laser scans over the area 6, the laser beam is turned off and then moved to an area 7 spaced one area from the area 6 for scanning. After the laser scans over the area 7, the laser beam is turned off and then moved to an area 8 spaced from the area 7 for scanning.
As shown in fig. 3 (b), each area is uniformly divided into 1 to 9 rectangular positions, and the area of each rectangular position is 1.33mm×1.33mm. When a laser beam scans a certain area, the discontinuous energy input mode of the area is as follows: the point-by-point melting is performed in the order of 1, 2, 3, 4, 5, 6, 7, 8, 9. With a distance between adjacent positions of the sequence. For example: after the laser melts at position 1, the laser beam is turned off and then moved to position 2 spaced from position 1 for melting. After laser melting position 2, the laser beam is turned off and then moved to position 3, which is four positions apart from position 2, for melting. After laser melting position 3, the laser beam is turned off and then moved to position 4 spaced from position 3 for melting. After laser melting position 4, the laser beam is turned off and moved to position 5 spaced from position 4 for melting. After laser melting position 5, the laser beam is turned off and then moved to position 6 spaced two positions from position 5 for melting. After laser melting position 6, the laser beam is turned off and moved to position 7 spaced from position 6 for melting. After laser melting position 7, the laser beam is turned off and moved to position 8 spaced from position 7 for melting. After laser melting position 8, the laser beam is turned off and moved to position 9 spaced from position 8 for melting.
(3) Preparation of the samples:
in order to obtain optimized GH4068 alloy manufacturing basic technological parameters, an orthogonal experiment method is adopted to obtain the influence rules of various technological parameters including laser power, laser working time, laser closing time, powder feeding amount, distance between points, layer thickness and the like on microstructure and metallurgical defects of a forming layer, so that specific technological parameters of GH4068 alloy forming are determined.
In the embodiment, the diameter of the laser beam is 0.8-2.0 mm, the laser power is 500-1200 w, the laser working time is 0.1-0.3 s, the laser closing time is 0.1-0.6 s, the powder feeding amount is 10-20 g/min, the distance between points is 0.5-1.5 mm, and the layer thickness is 0.2-1.0 mm.
And (3) carrying out additive manufacturing on the sample by utilizing the optimized technological parameters to obtain the high-strength high-toughness heat-preservation sulfur pump impeller. As shown in FIG. 4, from the macro morphology of the obtained sample, the member was not deformed, macroscopically cracked, and the like. As can be seen from the microstructure of the metal sample made without the addition of the refiner and with the addition of the refiner additive, the addition of the refiner causes the primary columnar crystal growth to be broken down into equiaxed crystals in the alloy, as shown in fig. 5 (a) -5 (b).
Example results demonstrate that the inventive method utilizes a laser source of conventional additive manufacturing to perform region discretization and heterogeneous nucleation refiner grain refinement during the forming process. Under the action of the discontinuous energy input and the grain refiner, not only can the uniformity of a laser molten pool temperature field be ensured and the thermal stress in the additive manufacturing process of the component be reduced, but also fine grain tissues can be easily formed in the molten pool.

Claims (3)

1. A shape control method in the process of heat preservation sulfur pump impeller additive manufacturing is characterized by comprising the following specific steps: firstly, mixing metal powder for impeller additive manufacturing with heterogeneous nuclear refiner powder; secondly, slicing and scanning path area discretization planning are carried out on the digital-analog of the impeller component to be formed by using slicing software; step three, changing laser energy input into discontinuous input according to a planned scanning path; fourthly, performing laser additive manufacturing;
in the first step, mixing a heterogeneous nucleation refiner and metal powder for impeller additive manufacturing by adopting a ball milling process, so that the heterogeneous nucleation refiner is adhered to the surface of the metal powder; the heterogeneous nucleation refiner is one or more than two of nano-scale, submicron-scale and micron-scale powders of refractory metal simple substances, carbides or nitrides, the metal powder is powder of nickel-based alloy, iron-based alloy or cobalt-based alloy, the granularity of the metal powder is 53-105 mu m, and the mass of the heterogeneous nucleation refiner is 3-10% of the mass of the metal powder;
in the second step, the scanning path of each layer is planned according to regional discretization, namely the part to be formed in each layer is divided into a plurality of independent regions; after the laser beam scans one area, moving to another area with a certain distance from the area to scan;
uniformly dividing a scanning area into 1-8 rectangular areas, wherein the area of each rectangular area is 4mm multiplied by 4mm; the discretization management mode of the scanning area is as follows: scanning laser beams according to the sequence of 1, 2, 3, 4, 5, 6, 7 and 8, wherein a certain distance exists between adjacent scanning areas in the sequence; after the laser scans the area 1, the laser beam is turned off and then moves to an area 2 which is separated from the area 1 by two areas for scanning; after the laser scans the area 2, the laser beam is turned off and then moves to an area 3 which is separated from the area 2 by one area for scanning; after the laser scans the area 3, the laser beam is turned off and then moves to an area 4 which is separated from the area 3 by three areas for scanning; after the laser scans the area 4, the laser beam is turned off and then moves to an area 5 which is separated from the area 4 by an area for scanning; after the laser scans the area 5, the laser beam is turned off and then moves to an area 6 which is separated from the area 5 by two areas for scanning; after the laser scans the area 6, the laser beam is turned off and then moves to an area 7 which is separated from the area 6 by one area for scanning; after the laser scans the area 7, the laser beam is turned off and then moves to an area 8 which is separated from the area 7 by an area for scanning;
in the third step, when the laser beam scans a certain area, the energy of the laser beam is input in a discontinuous way, namely, when the laser beam moves to a certain position in a scanning path, the laser beam is opened, so that the laser beam is ensured to act on the position, and the position is a molten pool point or a molten pool short line; after the point or the short line is fully melted and formed, the laser beam is turned off; then the laser beam moves to the next molten pool position, and the two positions of the laser beam, which are scanned sequentially, are planned according to discretization, namely a certain distance exists between the two positions of the current area, which are scanned sequentially; when the laser is moved to another position, the laser beam is turned on, the point or line melts that position until the laser beam is turned off and moves to a third position; cycling until the laser beam scans across each location of the area;
uniformly dividing each area into 1-9 rectangular positions, wherein the area of each rectangular position is 1.33mm multiplied by 1.33mm; when a laser beam scans a certain area, the discontinuous energy input mode of the area is as follows: carrying out point-by-point melting according to the sequence of 1, 2, 3, 4, 5, 6, 7, 8 and 9, wherein a certain distance exists between adjacent positions of the sequence; after the laser melts the position 1, the laser beam is turned off and then moves to a position 2 which is separated from the position 1 by a distance for melting; after the laser melts the position 2, the laser beam is turned off and then moves to a position 3 which is separated from the position 2 by four positions for melting; after the laser melts the position 3, the laser beam is turned off and then moves to a position 4 spaced from the position 3 for melting; after the laser melts the position 4, the laser beam is turned off and then moved to a position 5 spaced from the position 4 for melting; after the laser melts the position 5, the laser beam is turned off and then moves to a position 6 which is separated from the position 5 by two positions for melting; after the laser melts the position 6, the laser beam is turned off and then moved to a position 7 spaced from the position 6 for melting; after the laser melts the position 7, the laser beam is turned off and then moved to a position 8 spaced from the position 7 for melting; after the laser melts the position 8, the laser beam is turned off and then moved to a position 9 spaced from the position 8 for melting;
performing region discretization and heterogeneous nucleation refiner grain refinement in a forming process by using a laser light source manufactured by traditional additive; under the action of the discontinuous energy input and the grain refiner, the uniformity of a laser molten pool temperature field is ensured, the thermal stress in the additive manufacturing process of the component is reduced, and a fine grain structure is formed in the molten pool.
2. The method for controlling shape and controlling performance in the process of manufacturing the impeller of the heat preservation sulfur pump according to claim 1, wherein the formed components are subjected to layering treatment by adopting existing layering software, and a scanning path is planned according to a regional discretization method.
3. The method for controlling shape and controlling performance in the process of manufacturing the impeller of the heat-preserving sulfur pump according to claim 1, wherein in the fourth step, each region is formed in a mode of 'point-by-point melting', and the overlapping between the 'points' is carried out until the formation of the region is completed; then scanning the next area until the whole layer is formed; and finally, performing next layer molding in the same way, and stacking layer by layer to finish the preparation of the impeller.
CN202110723824.1A 2021-06-29 2021-06-29 Shape control and property control method in heat preservation sulfur pump impeller additive manufacturing process Active CN113441733B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110723824.1A CN113441733B (en) 2021-06-29 2021-06-29 Shape control and property control method in heat preservation sulfur pump impeller additive manufacturing process

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110723824.1A CN113441733B (en) 2021-06-29 2021-06-29 Shape control and property control method in heat preservation sulfur pump impeller additive manufacturing process

Publications (2)

Publication Number Publication Date
CN113441733A CN113441733A (en) 2021-09-28
CN113441733B true CN113441733B (en) 2023-06-23

Family

ID=77813712

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110723824.1A Active CN113441733B (en) 2021-06-29 2021-06-29 Shape control and property control method in heat preservation sulfur pump impeller additive manufacturing process

Country Status (1)

Country Link
CN (1) CN113441733B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023059855A1 (en) * 2021-10-07 2023-04-13 The Regents Of The University Of Michigan Intelligent scan sequence optimization for powder bed fusion additive manufacturing using linear systems theory

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102004031367A1 (en) * 2004-06-28 2006-02-02 Gkss-Forschungszentrum Geesthacht Gmbh Process for producing a grain refining agent for metallic materials, grain refining agent and metal or metal alloying material
GB201420717D0 (en) * 2014-11-21 2015-01-07 Renishaw Plc Additive manufacturing apparatus and methods
CN108161275B (en) * 2018-01-08 2021-02-02 河北工业大学 Nickel-based alloy weld structure grain refinement method and application thereof
CN112025136B (en) * 2020-07-14 2021-12-14 广东省科学院中乌焊接研究所 Aluminum alloy welding wire suitable for arc fuse additive manufacturing and preparation method thereof
CN112974845A (en) * 2021-02-09 2021-06-18 江苏飞跃机泵集团有限公司 Discontinuous laser additive manufacturing method for metal component

Also Published As

Publication number Publication date
CN113441733A (en) 2021-09-28

Similar Documents

Publication Publication Date Title
Saboori et al. An investigation on the effect of powder recycling on the microstructure and mechanical properties of AISI 316L produced by Directed Energy Deposition
US6103402A (en) Crack free metallic articles
Yang et al. Cracking behavior and control of Rene 104 superalloy produced by direct laser fabrication
Wang et al. Understanding melt pool characteristics in laser powder bed fusion: An overview of single-and multi-track melt pools for process optimization
Ma et al. Layer thickness dependence of performance in high-power selective laser melting of 1Cr18Ni9Ti stainless steel
CN108620584B (en) Laser additive manufacturing method and device for full-equiaxed crystal metal component
CN108555296B (en) Additive manufacturing method of K465 alloy powder
CA2230323C (en) Method for producing monocrystalline structures
Yang et al. Microstructure and grain growth direction of SRR99 single-crystal superalloy by selective laser melting
Zhan et al. Modeling and simulation of the columnar-to-equiaxed transition during laser melting deposition of Invar alloy
Adomako et al. Electron and laser-based additive manufacturing of Ni-based superalloys: a review of heterogeneities in microstructure and mechanical properties
EP1798316B1 (en) Repair method of crystalline structures by epitaxy
Cai et al. Fabrication of laminated high entropy alloys using differences in laser melting deposition characteristics of FeCoCrNi and FeCoCrNiAl
Abdulrahman et al. Laser metal deposition of titanium aluminide composites: A review
CN113441733B (en) Shape control and property control method in heat preservation sulfur pump impeller additive manufacturing process
CN112974845A (en) Discontinuous laser additive manufacturing method for metal component
EP4153371A1 (en) Additive manufacturing methods and apparatus for forming objects from a nickel-based superalloy in a layer-by-layer manner
Shao et al. Crystal growth control of Ni-based alloys by modulation of the melt pool morphology in DED
Kulkarni Additive manufacturing of nickel based superalloy
Sanjeeviprakash et al. Additive manufacturing of metal-based functionally graded materials: overview, recent advancements and challenges
JP6819952B2 (en) Laminated molding metal powder and laminated molding using metal powder
JP2017025401A (en) Metal lamination molding method, lamination molding apparatus, and lamination molding article
CN105689711B (en) A kind of electromagnetic agitation auxiliary laser Quick-forming nickel-base alloy part
Suwas et al. Texture Evolution in Metallic Materials During Additive Manufacturing: A Review
Xie et al. Comparative study of microstructural characteristics of electrospark and Nd: YAG laser epitaxially growing coatings

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