CN119772197B - Direct manufacturing method for dual laser selective melting of gradient functional partitions of femoral prosthesis - Google Patents

Abstract

The invention discloses a method for directly manufacturing a femur prosthesis by double laser selective melting of gradient functional partitions, which comprises the following steps of establishing a process database of double laser printing parameters and corresponding metal material phases and a phase and part performance database, obtaining the service performance requirements of the femur prosthesis to be manufactured, obtaining the phase characteristics and distribution of different areas of the femur prosthesis to be manufactured according to the object phase and material performance database, carrying out layering slicing on a three-dimensional model of the femur prosthesis to be manufactured to obtain slicing files, guiding the slicing files into double laser powder bed melting additive manufacturing equipment, selecting corresponding double laser collaborative printing process parameters according to different areas of the femur prosthesis to be manufactured according to the process database to form a printing file, and guiding the printing files into double laser identical-breadth printing equipment to manufacture the femur prosthesis to be manufactured. According to the invention, the metal phase is regulated and controlled by changing the dual-laser cooperative parameters, so that the gradient performance of the femoral prosthesis is integrally manufactured, the direct manufacture of the functional partitions provided by the femoral prosthesis is finally realized, the comprehensive performance of the femoral prosthesis is improved, and meanwhile, the manufacturing automation degree is improved.

Description

Direct manufacturing method of femoral prosthesis with gradient functional zoning by dual laser selective melting

Technical Field

The invention belongs to the technical field of metal manufacturing and application, and particularly relates to a dual-laser selective melting direct manufacturing method for gradient functional zoning of a femoral prosthesis.

Background Art

Selective laser melting (SLM) technology, with its adaptability to digital complex component forming, flexible and rapid development, and high material utilization, has become an important technical means to address the bottleneck of high-performance integrated manufacturing of complex components. In SLM technology, a laser spot rapidly melts metal powder on the powder bed of the forming platform. The laser spot then scans along a preset path, ultimately forming a complete metal component through a point-line-surface layer-by-layer printing method. During the laser printing process, the laser spot is focused on a point on the metal powder bed, forming a molten pool at this point. The depth and size of the molten pool are often related to the laser parameters. The molten pool moves as the laser spot moves, and new molten pools are continuously generated while old molten pools solidify, thus melting and solidifying the powder that constitutes the metal part into a metal solid structure. Therefore, changes in laser parameters affect the generation of the molten pool, the solidification rate of the molten metal in the molten pool, and the uniformity of the molten metal temperature field in the molten pool. This will affect the phases of the metal material in the molten pool, and the composition and proportion of the phases have a significant impact on the performance of the final component.

With the further application of SLM technology in the biomedical field, higher requirements are placed on the quality and efficiency of the parts produced by it. For femoral prostheses, their exterior needs to have high wear resistance and high strength, and their interior needs to have high toughness to better match their service conditions. In addition, modern medicine has increasingly higher requirements for the manufacturing time limit of personalized prostheses made by additive manufacturing, and the existing multi-process manufacturing method of single laser printing and post-heat treatment tissue regulation is difficult to meet the requirements. In addition, the existing technology of changing a single laser forming parameter has limited effect on the regulation of the microstructure of parts. Therefore, how to achieve more efficient preparation and more precise tissue regulation of additively manufactured femoral prosthesis parts is a difficult problem faced at this stage.

Summary of the Invention

In order to meet the requirements of modern medicine for the rapid integrated manufacturing of femoral prostheses with both high strength and high wear resistance, the present invention provides a dual-laser selective melting direct manufacturing method for gradient functional zoning of femoral prostheses, aiming to address the problem that the current single laser powder bed melting forming of metal cannot solve the problem that parts cannot have multi-dimensional excellent performance during micro-manufacturing.

In order to achieve the above object, the present invention adopts the following technical solutions:

The first object is to provide a dual laser selective melting direct manufacturing method for gradient functional zoning of a femoral prosthesis, comprising the following steps:

Based on the relationship between dual-laser printing parameters and the growth of metal material phases, a process database of dual-laser printing parameters and corresponding metal material phases is established; the dual-laser printing parameters include a dual-laser collaborative scanning mode, a dual-laser start-up time interval, a first laser power, a second laser power, a first laser scanning rate, a second laser scanning rate, a first laser scanning interval, a second laser scanning interval, a first laser spot size, and a second laser spot size; the dual-laser collaborative scanning mode includes a high-speed following mode and a same-width partitioned scanning mode;

According to the corresponding relationship between the phase ratio characteristics and strength and elongation of the dual laser forming materials, a database of phases and metal material properties is established;

Obtaining the performance requirements of the femoral prosthesis to be manufactured, obtaining the physical phase characteristics and distribution of different regions of the femoral prosthesis to be manufactured based on the physical phase and metal material performance database, and distinguishing the internal region and the external region based on the physical phase characteristics and distribution;

Performing layered slicing on the three-dimensional model of the femoral prosthesis to be manufactured to obtain a slicing file;

Import the slice file into the dual-laser powder bed fusion additive manufacturing equipment, select the dual-laser collaborative printing process parameters corresponding to the same-width partition scanning mode for the internal area of the femoral prosthesis to be manufactured according to the process database, and select the dual-laser collaborative printing process parameters corresponding to the high-speed following mode for the external area of the femoral prosthesis to be manufactured, and generate a CLI format print file;

The CLI format printing file is imported into the dual laser same-format printing device to manufacture the femoral prosthesis.

As a preferred technical solution, the process database of dual laser printing parameters and corresponding metal material phases is established as follows:

Based on the single laser printing process for the metal materials required to prepare femoral prostheses, different combinations of dual laser printing parameters were designed, and test samples were printed using a dual laser powder bed fusion additive manufacturing device.

The test samples were metallographically prepared and the phase morphology and phase ratio were obtained by electron backscatter diffraction;

The phase morphology and phase ratio of the corresponding metal materials under different dual laser printing parameters are correlated to obtain a process database of dual laser printing parameters and corresponding metal material phases.

As a preferred technical solution, the same-width partitioned scanning mode refers to a working mode in which the first laser beam and the second laser beam simultaneously use the first laser power, the first laser scanning rate, and the first laser scanning interval to perform partitioned scanning forming, dividing the area to be formed into two, so that the metal material is rapidly cooled at a scanning rate of 1000 mm/s to form a high-temperature stable phase structure;

The high-speed following mode refers to an operating mode in which the second laser beam follows the printing path of the first laser beam at equal intervals to print, and the second laser beam quickly remelts the formed part of the first laser beam;

There is a laser start time interval between the first laser beam and the second laser beam. The substrate temperature during the remelting process and the equidistant interval between the first laser beam and the second laser beam are controlled by adjusting the laser start time interval. The scanning rate and scanning interval of the first laser beam and the second laser beam are simultaneously adjusted to prevent the second laser beam from exceeding the first laser speed.

As a preferred technical solution, in the high-speed following mode, when the second laser beam follows the first laser beam at an equal distance, the relationship is satisfied:

V ₂ × S ₂ = V ₁ × S ₁ , P ₁ > P ₂ ,

Wherein, V1 is the first laser scanning rate, in m/s; V2 is _the second laser scanning rate, in m/s; S1 is the first laser scanning interval, _in mm; S2 is _the second laser scanning interval, _in mm; P1 is the first laser power, _in W; P2 _is the second laser power, in W.

As a preferred technical solution, the establishment of a database of metal material phases and material properties is specifically as follows:

Based on the single laser printing process for the materials required to prepare the femoral prosthesis, different combinations of dual laser printing parameters were designed, and test samples were printed using a dual laser powder bed fusion additive manufacturing device;

The mechanical properties and corrosion resistance of the printed test samples were tested using a universal testing machine, electrochemical corrosion equipment, and a microhardness tester to obtain the corresponding relationship between dual laser printing parameters and material properties;

According to the dual laser printing parameters and the process database of the corresponding metal material phase, a metal material phase and metal material performance database is established

As a preferred technical solution, the performance requirements include corrosion resistance, tensile strength, elongation, yield strength and wear resistance.

As a preferred technical solution, the femoral prosthesis to be manufactured is made of cobalt-chromium-molybdenum alloy.

As a preferred technical solution, the slicing file is formed by segmenting the different regions of the femoral prosthesis to be manufactured using slicing software.

As a preferred technical solution, the femoral prosthesis to be manufactured is manufactured as follows:

Import the print file into the dual-laser same-format printing device, and set the dual-laser collaborative printing parameters in the dual-laser powder bed fusion additive manufacturing device operating software: set the same-format partition scanning mode for the inner area of the femoral prosthesis to be manufactured, and set the high-speed following mode for the outer area of the femoral prosthesis to be manufactured;

Identify the dual laser collaborative printing process parameters and printing path characteristics of the corresponding area of each slice layer in the slice file;

Printing begins until all slice layers are formed, and a femoral prosthesis with a composite of multiple metallographic structures is obtained.

The second object is to provide a dual laser selective melting direct manufacturing system for gradient functional zoning of femoral prostheses, comprising a process database construction module, a performance database construction module, a metallographic feature acquisition module, a layered slicing module, a print file generation module, and a manufacturing module;

The process database construction module is used to establish a process database of dual laser printing parameters and corresponding metal phases based on the growth relationship between the dual laser printing parameters and the metal phases; the dual laser printing parameters include a dual laser collaborative scanning mode, a dual laser start time interval, a first laser power, a second laser power, a first laser scanning rate, a second laser scanning rate, a first laser scanning interval, a second laser scanning interval, a first laser spot size, and a second laser spot size; the dual laser collaborative scanning mode includes a high-speed following mode and a same-width partitioned scanning mode;

The performance database building module is used to establish a phase and material performance database based on the correspondence between the phase and mechanical properties of the dual laser forming material;

The metallographic feature acquisition module is used to obtain the performance requirements of the femoral prosthesis to be manufactured, obtain the physical phase characteristics and distribution of different regions of the femoral prosthesis to be manufactured based on the physical phase and metal material performance database, and distinguish the internal region and the external region based on the physical phase characteristics and distribution;

The layered slicing module is used to perform layered slicing on the three-dimensional model of the femoral prosthesis to be manufactured to obtain a slicing file;

The print file forming module is used to import the slice file into the dual-laser powder bed fusion additive manufacturing device, select the dual-laser collaborative printing process parameters corresponding to the same-width partition scanning mode for the internal area of the femoral prosthesis to be manufactured according to the process database, and select the dual-laser collaborative printing process parameters corresponding to the high-speed following mode for the external area of the femoral prosthesis to be manufactured, to form a print file in CLI format;

The manufacturing module is used to import the printing file in CLI format into the dual-laser same-format printing device to manufacture the femoral prosthesis to be manufactured.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

1. Improved compatibility between femoral prosthesis and service conditions:

Since the outer surface of the femoral prosthesis needs to be subjected to friction and extrusion, it means that it needs to have high strength and high wear resistance. However, high strength and high wear resistance often mean the sacrifice of the toughness of the femoral prosthesis, which will increase the risk of failure of the femoral prosthesis and shorten its service life. Because, for the femoral prosthesis, its ideal form is high wear resistance and high strength on the outside, high toughness and high elongation on the inside. However, the effect of changing a single laser parameter on the microstructure is currently limited, and it is difficult to achieve efficient and accurate partitioned organization control in the heat treatment process. The present invention proposes a same-width partitioned scanning mode for the inside of the femoral prosthesis, which increases the proportion of the high-ductility γ-FCC phase inside the femoral prosthesis by relying on a high cooling rate; and adopts a high-speed following mode for the outside of the femoral prosthesis, relying on dual laser two-step organization control, to achieve a low-stress, high-stacking fault, and high-proportion ε-HCP martensite phase structure with high strength and high wear resistance on the outside of the part.

2. Significantly improves the manufacturing speed of femoral prosthesis:

This invention utilizes a single-width, zoned scanning mode for the internal area of the femoral prosthesis. Dual lasers scan and fill the internal area, significantly reducing part filling time and improving femoral prosthesis printing efficiency. Furthermore, this invention uses dual lasers to directly adjust the microstructure of the femoral prosthesis in zones, achieving integrated functionality and performance, eliminating subsequent heat treatment steps and further improving manufacturing efficiency.

3. Improved the comprehensive mechanical properties of femoral prosthesis:

Existing heat treatment tissue control methods can only achieve single-tissue control of femoral prostheses. A high proportion of the γ-FCC phase after heat treatment can result in insufficient wear resistance and strength, while a high proportion of the ε-HCP martensite phase can lead to low elongation. This invention, through programmable dual-laser process parameters, achieves zoned performance control of the femoral prosthesis, balancing high-strength and high-wear-resistant regions with high-ductility and toughness regions within a single femoral prosthesis. This overcomes the "strength-toughness" trade-off in tissue and performance control, enabling direct manufacturing of strengthened and toughened femoral prostheses and improving their overall mechanical properties.

4. Improved the automation level of femoral prosthesis manufacturing:

This invention utilizes a direct manufacturing method that integrates part shape manufacturing with structural control, avoiding the labor and time costs associated with the traditional multi-step manufacturing process of wire forming and post-heat treatment. By achieving both shape and performance directly in a single device, manual intervention in intermediate steps is eliminated, improving the automation level of part manufacturing and aligning with the future development of intelligent manufacturing.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

FIG1 is a flow chart of a dual laser selective melting direct manufacturing method for gradient functional zoning of a femoral prosthesis according to an embodiment of the present invention.

FIG2 is a schematic diagram of dual laser beam cooperative scanning in high-speed following mode according to an embodiment of the present invention.

FIG3 is a schematic diagram showing the division of the inner region and the outer region of the femoral prosthesis in an embodiment of the present invention.

FIG4 is a schematic diagram of the high γ-FCC phase ratio inside the femoral prosthesis and the high ε-HCP phase outside the femoral prosthesis according to an embodiment of the present invention.

FIG5 is a schematic structural diagram of a dual laser selective melting direct manufacturing system for gradient functional zoning of a femoral prosthesis according to an embodiment of the present invention.

DETAILED DESCRIPTION

In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

As shown in FIG1 , this embodiment provides a dual laser selective melting direct manufacturing method for gradient functional zoning of a femoral prosthesis, comprising the following steps:

S1. Based on the relationship between dual laser printing parameters and the growth of metal material phases, a process database of dual laser printing parameters and corresponding metal material phases is established; wherein the dual laser printing parameters include dual laser collaborative scanning mode, dual laser start time interval, first laser power (e.g., 200 W), second laser power (e.g., 160 W), first laser scanning rate (e.g., 500 m/s), second laser scanning rate (e.g., 1000 m/s), first laser scanning interval (e.g., 0.12 mm), second laser scanning interval (e.g., 0.06 mm), first laser spot size and second laser spot size, etc.; dual laser collaborative scanning modes include high-speed following mode and same-width partition scanning mode;

S2. Establish a database of phases and metal material properties based on the corresponding relationship between the phase ratio, strength, and elongation of the dual laser forming material;

S3. Obtaining performance requirements for the femoral prosthesis to be manufactured, obtaining physical phase characteristics and distribution of different regions of the femoral prosthesis to be manufactured based on a physical phase and metal material property database, and distinguishing an inner region from an outer region based on the physical phase characteristics and distribution;

S4, performing layered slicing on the three-dimensional model of the femoral prosthesis to be manufactured to obtain a slice file;

S5. Importing the slice file into the dual-laser powder bed fusion additive manufacturing device, selecting dual-laser collaborative printing process parameters corresponding to the same-width partition scanning mode for the inner region of the femoral prosthesis to be manufactured according to the process database, and selecting dual-laser collaborative printing process parameters corresponding to the high-speed following mode for the outer region of the femoral prosthesis to be manufactured, to generate a print file in CLI format;

S6. Import the CLI format printing file into the dual laser powder bed fusion additive manufacturing equipment to manufacture the femoral prosthesis to be manufactured.

Furthermore, to quickly determine the manufacturing process of parts, a process database can be established based on the performance requirements of different regions of the femoral prosthesis to quickly match the corresponding dual-laser collaborative printing parameters, specifically:

S101. Designing different combinations of dual-laser printing parameters based on a single laser printing process for the metal material required to prepare a femoral prosthesis, and printing test samples using a dual-laser powder bed fusion additive manufacturing device.

S102, performing metallographic preparation on the test sample, and obtaining the phase morphology and phase ratio of the metal material by electron backscatter diffraction;

S103 , associating the phase morphology and phase ratio of the corresponding metal material under different dual-laser printing parameters to obtain a process database of the dual-laser printing parameters and the corresponding metal material phases.

Furthermore, the dual-laser collaborative scanning mode in this application includes a same-radius partitioned scanning mode and a high-speed following mode, wherein the same-radius partitioned scanning mode refers to a working mode in which the first laser beam and the second laser beam simultaneously use the first laser power (such as 180 W), the first laser scanning rate (such as 800 m/s), and the first laser scanning interval (such as 0.07 mm) to perform partitioned scanning and forming. On the one hand, the area to be formed is divided into two to reduce the forming time. On the other hand, the metal material is rapidly cooled at a scanning rate of 1000 m/s, and the high-temperature stable phase is stabilized at a low temperature by rapid cooling, thereby forming a high-temperature stable phase structure with a large proportion.

High-speed following mode refers to an operating mode in which the second laser beam follows the printing path of the first laser beam at equal intervals to perform printing. The second laser beam quickly remelts the portion formed by the first laser beam, and by forming a small-sized remelting pool, the large low-temperature phases and large-sized grains in the structure formed by the first laser beam are converted into dispersed small low-temperature phases and small-sized grains.

Among them, there is a laser start-up time interval between the first laser beam and the second laser beam. By adjusting the laser start-up time interval, the substrate temperature during the remelting process and the equidistant interval between the first laser beam and the second laser beam can be controlled, thereby avoiding the high cooling rate of the second laser beam due to rapid scanning, thereby reducing the proportion of the low-temperature phase; and by simultaneously adjusting the scanning rate and scanning interval of the first laser beam and the second laser beam, it is avoided that the high-speed scanning second laser beam exceeds the low-speed scanning first laser beam speed, thereby achieving the constant temperature of the molten pool remelting substrate.

Furthermore, in the high-speed following mode, the second laser beam follows the first laser beam at an equal distance and satisfies the following relationship:

V ₂ × S ₂ = V ₁ × S ₁ , P ₁ > P ₂ ,

Wherein, V1 is the first laser scanning rate, in m/s; V2 is _the second laser scanning rate, in m/s; S1 is the first laser scanning interval, _in mm; S2 is _the second laser scanning interval, _in mm; P1 is the first laser power, _in W; P2 _is the second laser power, in W.

As shown in Figure 2, this relationship requires that the first laser beam be printed at high power (such as 200 W), low scanning rate (such as 500 m/s) and high scanning interval (such as 0.12 mm). At this time, the cooling rate is reduced to form a structure with low stress, high stacking faults and a high proportion of low-temperature phases. The second laser beam is printed at low power (such as 160 W), high scanning rate (such as 1000 m/s) and low scanning interval (such as 0.06 mm). While ensuring that it follows the first laser beam at an equal distance, the formed part of the first laser beam is quickly remelted. By forming a small-sized remelting pool, the large low-temperature phases and large-sized grains in the formed matrix are converted into dispersed fine low-temperature phases and small-sized grains, thereby achieving tissue homogenization.

Furthermore, the metal material phase and material properties database is established as follows:

S201. Designing different combinations of dual-laser printing parameters based on a single laser printing process for preparing materials required for a femoral prosthesis, and printing test samples using a dual-laser powder bed fusion additive manufacturing device.

S202. Testing the mechanical properties and corrosion resistance of the printed test samples using a universal testing machine, electrochemical corrosion equipment, and a microhardness tester to obtain the corresponding relationship between the dual laser printing parameters and the part performance;

S203 , establishing a database of metal material phases and metal material properties according to the dual laser printing parameters and the process database of the corresponding metal material phases.

Furthermore, the performance requirements of the femoral prosthesis to be manufactured include tensile strength, elongation, yield strength, and wear resistance. The femoral prosthesis to be manufactured is made of cobalt-chromium-molybdenum alloy. As shown in Figure 3, it is structurally divided into an inner region and an outer region. The inner region is formed using a same-width partitioned scanning mode to improve forming efficiency and obtain a γ-FCC phase fine-grained structure with good toughness due to a high cooling rate. The outer region is formed using a high-speed following mode scanning. The high-power, low-scanning-rate first laser beam forms a low-stress, high-stacking-fault, and high-proportion ε-HCP martensite phase structure with high strength and high wear resistance. The low-power, high-scanning-rate second laser beam further refines and homogenizes the structure formed by the first laser beam through remelting in a small molten pool. The dual-laser beam collaborative forming method avoids the problem of uncontrollable remelting time caused by inconsistent inter-layer scanning areas in a single laser beam.

Furthermore, in this embodiment, Magic slicing software is used to segment the inner and outer regions of the femoral prosthesis to be manufactured to form a slice file; it should also be noted that other slicing software that can achieve the same effect can also be used, and the Magic slicing software used in this example is only for illustrative purposes.

In this embodiment, Magic slicing software is used to slice the femoral prosthesis to form an outer layer with a thickness of 0.2-0.5 mm as the outer area, and the rest is an inner layer as the inner area, as shown in FIG4 . After slicing, according to the use requirements, the outer area adopts a high-speed following mode, and relies on dual laser two-step tissue control to ensure high strength and high wear resistance; the inner area adopts a same-width partition scanning mode, and relies on a high cooling rate to increase the proportion of the high-ductility γ-FCC phase inside the femoral prosthesis to ensure its high strength and toughness.

Furthermore, a print file in CLI format containing laser energy and scanning path information is generated.

In this example, after determining the physical morphology and proportions of different regions of the femoral prosthesis to be manufactured, dual-laser printing parameters were retrieved from a process database based on the metal material phases. For the femoral prosthesis, a forming strategy with a forming laser power of 200 W and a remelting interval of 5 ms, and a remelting laser power of 160 W and a remelting interval of 5 ms were used for the outer region. These strategies resulted in a low-stress, high-stacking-fault, and high-proportion ε-HCP martensite phase with high strength and wear resistance. For the inner region, a uniform scanning strategy with a forming laser power of 180 W was used, leveraging a high cooling rate to increase the proportion of the highly ductile γ-FCC phase within the femoral prosthesis.

Furthermore, after obtaining the print file in CLI format, it is input into the dual laser powder bed fusion additive manufacturing equipment to manufacture the femoral prosthesis to be manufactured, specifically:

S601. Import the CLI format print file into the dual-laser same-format printing device, and set the dual-laser collaborative printing parameters in the dual-laser powder bed fusion additive manufacturing device operating software: set the internal area of the femoral prosthesis to be manufactured to the same-format partition scanning mode, and set the external area of the femoral prosthesis to be manufactured to the high-speed follow mode to achieve integrated forming of shape and performance;

S602, identifying dual-laser collaborative printing process parameters and printing path characteristics of the corresponding area of each slice layer in the slice file;

S603: Start printing until all slice layers are formed, and obtain a femoral prosthesis with a composite of multiple metallographic structures.

It should be noted that, for the sake of convenience, the aforementioned method embodiments are all expressed as a series of action combinations, but those skilled in the art should know that the present invention is not limited to the described order of actions, because according to the present invention, certain steps can be performed in other orders or simultaneously.

Based on the same concept as the dual laser selective melting direct manufacturing method for gradient functional zoning of femoral prostheses in the above-mentioned embodiment, the present invention also provides a dual laser selective melting direct manufacturing system for gradient functional zoning of femoral prostheses, which can be used to execute the above-mentioned dual laser selective melting direct manufacturing method for gradient functional zoning of femoral prostheses. For ease of explanation, the structural schematic diagram of the embodiment of the dual laser selective melting direct manufacturing system for gradient functional zoning of femoral prostheses only shows the parts related to the embodiment of the present invention. Those skilled in the art will understand that the illustrated structure does not constitute a limitation of the device, and the device may include more or fewer components than shown, or combine certain components, or have different component arrangements.

Referring to FIG. 5 , in another embodiment of the present application, a dual-laser selective melting direct manufacturing system for gradient functional zoning of a femoral prosthesis is provided, comprising a process database construction module, a performance database construction module, a metallographic feature acquisition module, a layered slicing module, a print file generation module, and a manufacturing module;

The process database construction module is used to establish a process database of dual laser printing parameters and corresponding metal phases based on the growth relationship between the dual laser printing parameters and the metal phases; the dual laser printing parameters include dual laser collaborative scanning mode, dual laser start time interval, first laser power, second laser power, first laser scanning rate, second laser scanning rate, first laser scanning interval, second laser scanning interval, first laser spot size and second laser spot size; the dual laser collaborative scanning mode includes high-speed following mode and same-width partition scanning mode;

The performance database construction module is used to establish a physical phase and part performance database based on the correspondence between the physical phase and mechanical properties of the dual laser forming material;

The metallographic feature acquisition module is used to obtain the performance requirements of the metal parts to be manufactured. According to the metal phase and part performance database, the phase characteristics and distribution of different areas of the metal parts to be manufactured are obtained, and the internal and external areas are distinguished according to the phase characteristics and distribution.

The layered slicing module is used to perform layered slicing on the femoral prosthesis to be manufactured to obtain a slicing file;

The print file generation module is used to import the slice file into the dual-laser powder bed fusion additive manufacturing equipment, select the dual-laser collaborative printing process parameters corresponding to the same-width partition scanning mode for the internal area of the femoral prosthesis to be manufactured according to the process database, and select the dual-laser collaborative printing process parameters corresponding to the high-speed following mode for the external area of the femoral prosthesis to be manufactured, to generate a print file in CLI format;

The manufacturing module is used to import the printing file in CLI format into the dual-laser same-format printing device to manufacture the femoral prosthesis to be manufactured.

It should be noted that the dual laser selective melting direct manufacturing system for gradient functional zoning of femoral prosthesis of the present invention corresponds one to one with the dual laser selective melting direct manufacturing method for gradient functional zoning of femoral prosthesis of the present invention. The technical features and beneficial effects described in the embodiment of the dual laser selective melting direct manufacturing method for gradient functional zoning of femoral prosthesis of the above-mentioned are applicable to the embodiment of the dual laser selective melting direct manufacturing system for gradient functional zoning of femoral prosthesis. For specific contents, please refer to the description in the embodiment of the method of the present invention. No further details will be given here. This is hereby declared.

In addition, in the implementation of the dual laser selective melting direct manufacturing system for gradient functional zoning of femoral prosthesis in the above-mentioned embodiment, the logical division of each program module is only an example. In actual application, the above-mentioned functions can be assigned to different program modules as needed, for example, for the convenience of corresponding hardware configuration requirements or software implementation. That is, the internal structure of the dual laser selective melting direct manufacturing system for gradient functional zoning of femoral prosthesis is divided into different program modules to complete all or part of the functions described above.

The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims (10)

1. A method for directly manufacturing a femoral prosthesis with gradient functional zoning by dual laser selective melting, characterized by comprising the following steps: Based on the relationship between dual-laser printing parameters and the growth of metal material phases, a process database of dual-laser printing parameters and corresponding metal material phases is established; the dual-laser printing parameters include a dual-laser collaborative scanning mode, a dual-laser start-up time interval, a first laser power, a second laser power, a first laser scanning rate, a second laser scanning rate, a first laser scanning interval, a second laser scanning interval, a first laser spot size, and a second laser spot size; the dual-laser collaborative scanning mode includes a high-speed following mode and a same-width partitioned scanning mode; According to the corresponding relationship between the phase ratio characteristics and strength and elongation of the dual laser forming materials, a performance database of phases and metal materials is established; Obtaining the performance requirements of the femoral prosthesis to be manufactured, obtaining the physical phase characteristics and distribution of different regions of the femoral prosthesis to be manufactured based on the physical phase and metal material performance database, and distinguishing the internal region and the external region based on the physical phase characteristics and distribution; Performing layered slicing on the three-dimensional model of the femoral prosthesis to be manufactured to obtain a slicing file; Import the slice file into the dual-laser powder bed fusion additive manufacturing equipment, select the dual-laser collaborative printing process parameters corresponding to the same-width partition scanning mode for the internal area of the femoral prosthesis to be manufactured according to the process database, and select the dual-laser collaborative printing process parameters corresponding to the high-speed following mode for the external area of the femoral prosthesis to be manufactured, and generate a CLI format print file; The CLI format printing file is imported into the dual laser same-format printing device to manufacture the femoral prosthesis. 2. The dual laser selective melting direct manufacturing method for gradient functional zoning of a femoral prosthesis according to claim 1 is characterized in that the process database of dual laser printing parameters and corresponding metal material phases is established as follows: Based on the single laser printing process for the metal materials required to prepare femoral prostheses, different combinations of dual laser printing parameters were designed, and test samples were printed using a dual laser powder bed fusion additive manufacturing device. Conduct metallographic preparation on the test samples and obtain the phase morphology and phase ratio of the metal material through electron backscatter diffraction; The phase morphology and phase ratio of the corresponding metal materials under different dual laser printing parameters are correlated to obtain a process database of dual laser printing parameters and corresponding metal material phases. 3. The dual-laser selective melting direct manufacturing method for gradient functional zoning of a femoral prosthesis according to claim 1, characterized in that the same-radial zoning scanning mode refers to a working mode in which the first laser beam and the second laser beam simultaneously use a first laser power, a first laser scanning rate, and a first laser scanning interval to perform zoning scanning forming, dividing the area to be formed into two, and simultaneously rapidly cooling the metal material at a scanning rate of 1000 mm/min or more to form a high-temperature stable phase structure; The high-speed following mode refers to an operating mode in which the second laser beam follows the printing path of the first laser beam at equal intervals to print, and the second laser beam quickly remelts the formed part of the first laser beam; There is a laser start time interval between the first laser beam and the second laser beam. The substrate temperature during the remelting process and the equidistant interval between the first laser beam and the second laser beam are controlled by adjusting the laser start time interval. The second laser beam is prevented from exceeding the first laser beam by simultaneously adjusting the scanning rate and scanning interval of the first laser beam and the second laser beam. 4. The dual laser selective melting direct manufacturing method for gradient functional zoning of a femoral prosthesis according to claim 3, characterized in that in the high-speed following mode, when the second laser beam follows the first laser beam at an equal distance, the relationship is satisfied: V ₂ × S ₂ = V ₁ × S ₁ , P ₁ > P ₂ , Wherein, V1 is the first laser scanning rate, in m/s; V2 is _the second laser scanning rate, in m/s; S1 is the first laser scanning interval, _in mm; S2 is _the second laser scanning interval, _in mm; P1 is the first laser power, _in W; P2 _is the second laser power, in W. 5. The dual laser selective melting direct manufacturing method for gradient functional zoning of femoral prosthesis according to claim 1, wherein the step of establishing a database of metal material phases and material properties comprises: Based on the single laser printing process for the materials required to prepare the femoral prosthesis, different combinations of dual laser printing parameters were designed, and test samples were printed using a dual laser powder bed fusion additive manufacturing device; The mechanical properties and corrosion resistance of the printed test samples were tested using a universal testing machine, electrochemical corrosion equipment, and a microhardness tester to obtain the corresponding relationship between dual laser printing parameters and material properties; According to the dual laser printing parameters and the process database of the corresponding metal material phases, a metal material phase and metal material performance database is established. 6. The dual laser selective melting direct manufacturing method for gradient functional zoning of femoral prosthesis according to claim 1 is characterized in that the performance requirements include tensile strength, elongation, yield strength and wear resistance. 7. The dual laser selective melting direct manufacturing method for gradient functional zoning of femoral prosthesis according to claim 1, characterized in that the femoral prosthesis to be manufactured is made of cobalt-chromium-molybdenum alloy. 8. The dual laser selective melting direct manufacturing method for gradient functional zoning of a femoral prosthesis according to claim 1, wherein the slicing file is formed by segmenting the different regions of the femoral prosthesis to be manufactured using slicing software. 9. The dual laser selective melting direct manufacturing method for gradient functional zoning of a femoral prosthesis according to claim 1, wherein the femoral prosthesis to be manufactured is manufactured by: Import the CLI format print file into the dual-laser same-format printing device, and set the dual-laser collaborative printing parameters in the dual-laser powder bed fusion additive manufacturing device operating software: set the internal area of the femoral prosthesis to be manufactured to the same-format partition scanning mode, and set the external area of the femoral prosthesis to be manufactured to the high-speed following mode; Identify the dual laser collaborative printing process parameters and printing path characteristics of the corresponding area of each slice layer in the slice file; Printing begins until all slice layers are formed, and a femoral prosthesis with a composite of multiple metallographic structures is obtained. 10. A dual-laser selective melting direct manufacturing system for gradient functional zoning of femoral prostheses, characterized in that the system includes a process database construction module, a performance database construction module, a metallographic feature acquisition module, a layered slicing module, a print file generation module, and a manufacturing module; The process database construction module is used to establish a process database of dual laser printing parameters and corresponding metal phases based on the growth relationship between the dual laser printing parameters and the metal phases; the dual laser printing parameters include a dual laser collaborative scanning mode, a dual laser start time interval, a first laser power, a second laser power, a first laser scanning rate, a second laser scanning rate, a first laser scanning interval, a second laser scanning interval, a first laser spot size, and a second laser spot size; the dual laser collaborative scanning mode includes a high-speed following mode and a same-width partitioned scanning mode; The performance database building module is used to establish a phase and material performance database based on the correspondence between the phase and mechanical properties of the dual laser forming material; The metallographic feature acquisition module is used to obtain the performance requirements of the femoral prosthesis to be manufactured, obtain the physical phase characteristics and distribution of different regions of the femoral prosthesis to be manufactured based on the physical phase and metal material performance database, and distinguish the internal region and the external region based on the physical phase characteristics and distribution; The layered slicing module is used to perform layered slicing on the three-dimensional model of the femoral prosthesis to be manufactured to obtain a slicing file; The print file forming module is used to import the slice file into the dual-laser powder bed fusion additive manufacturing device, select the dual-laser collaborative printing process parameters corresponding to the same-width partition scanning mode for the internal area of the femoral prosthesis to be manufactured according to the process database, and select the dual-laser collaborative printing process parameters corresponding to the high-speed following mode for the external area of the femoral prosthesis to be manufactured, to form a print file in CLI format; The manufacturing module is used to import the printing file in CLI format into the dual-laser same-format printing device to manufacture the femoral prosthesis to be manufactured.