Double-laser selective melting direct manufacturing method for gradient functional partition of femoral prosthesis

Abstract

The invention discloses a double-laser selective melting direct manufacturing method for gradient functional partitions of a femoral prosthesis. The method comprises the following steps that a process database of double-laser printing parameters and corresponding metal material phases and a database of the phases and part performance are established; obtaining use performance requirements of the to-be-manufactured femoral prosthesis, and obtaining phase characteristics and distribution of different areas of the to-be-manufactured femoral prosthesis according to the phase and material performance database; layering and slicing the three-dimensional model of the femoral prosthesis to be manufactured to obtain a slice file; the slice file is imported into double-laser powder bed melting additive manufacturing equipment, corresponding double-laser collaborative printing process parameters are selected for different areas of the to-be-manufactured femoral prosthesis according to a process database, and a printing file is formed; and the printing file is imported into double-laser same-breadth printing equipment, and the femoral prosthesis to be manufactured is manufactured. According to the method, regulation and control of metal phases are achieved by changing dual-laser collaborative parameters, then integrated manufacturing of the gradient performance of the femoral prosthesis is achieved, functional partition direct manufacturing of the femoral prosthesis is finally achieved, and the manufacturing automation degree is improved while the comprehensive performance of the femoral prosthesis is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of metal manufacturing and application, and in particular relates to a double laser selective melting direct manufacturing method for gradient functional partitioning of a femoral prosthesis. Background Art

[0002] Selective laser melting (SLM) has the characteristics of adapting to the formation of digital complex components, flexible and rapid development, and high material utilization. It has now become an important technical means to solve the bottleneck of high-performance overall manufacturing of complex components. In SLM technology, the laser spot quickly melts the metal powder on the powder bed of the forming platform, and then the laser spot scans according to the preset path, and finally forms a complete metal component through the 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, and a molten pool is formed at this point. The depth and size of the molten pool are often related to the laser parameters. The molten pool moves with the movement of the spot, and new molten pools are continuously generated, and the old molten pools solidify immediately, so that the powder constituting the metal part entity is melted and solidified into a metal entity organization; therefore, the change of laser parameters will affect the generation of the molten pool, the solidification rate of the molten metal in the molten pool, and the uniformity of the molten temperature field in the molten pool, which will affect the phase of the metal material in the molten pool, and the composition and proportion of the phase have an important influence on the performance of the final component.

[0003] 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 the femoral prosthesis, its exterior needs to have high wear resistance and high strength, and its interior needs to have high toughness to better match its 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 the 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

[0004] In order to meet the requirements of modern medicine for the rapid integrated manufacturing of femoral prostheses with 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 at the problem that the current single laser powder bed melting forming of metal cannot solve the problem that the parts can not have multi-dimensional excellent performance during micro-manufacturing.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: The first purpose is to provide a dual laser selective melting direct manufacturing method for gradient functional zoning of femoral prosthesis, comprising the following steps: According to the growth relationship between the dual laser printing parameters and the metal material phase, a process database of the dual laser printing parameters and the corresponding metal material phase is established; 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 partition 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, to form a print file in CLI format; The print file in CLI format is imported into the dual laser same-format printing device to manufacture the femoral prosthesis to be manufactured.

[0006] As a preferred technical solution, the process database of establishing dual laser printing parameters and corresponding metal material phases is specifically as follows: According to the single laser printing process of the metal material required for preparing 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 test samples were metallographically prepared, and the phase morphology and phase ratio were obtained through electron backscatter diffraction; The phase morphology and phase ratio of the corresponding metal materials under different dual laser printing parameters are associated to obtain a process database of dual laser printing parameters and corresponding metal material phases.

[0007] As a preferred technical solution, the same-width partition 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 partition scanning forming, dividing the area to be formed into two, so that the metal material is quickly cooled at a scanning rate of 1000 mm / s to form a high-temperature stable phase structure; The high-speed following mode refers to a working 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.

[0008] 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 , in, V 1 is the first laser scanning rate, in m / s; V 2 is the second laser scanning rate, in m / s; S 1 is the first laser scanning interval, in mm; S 2 is the second laser scanning interval, in mm; P 1 is the first laser power, in W; P 2 is the second laser power, in W.

[0009] As a preferred technical solution, the establishment of a database of metal material phases and material properties is specifically as follows: According to the single laser printing process for preparing the materials required for 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 database of metal material phase and metal material performance is established As a preferred technical solution, the performance requirements include corrosion resistance, tensile strength, elongation, yield strength and wear resistance.

[0010] As a preferred technical solution, the femoral prosthesis to be manufactured is made of cobalt-chromium-molybdenum alloy.

[0011] As a preferred technical solution, the slicing file is formed by segmenting different regions of the femoral prosthesis to be manufactured using slicing software.

[0012] 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 on 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 various metallographic structures is obtained.

[0013] The second purpose is to provide a dual laser selection melting direct manufacturing system for gradient functional partitioning of femoral prosthesis, including a process database construction module, a performance database construction module, a metallographic feature acquisition module, a layered slicing module, a printing file formation module and a manufacturing module; The process database building module is used to establish a process database of dual laser printing parameters and corresponding metal phases according to the growth relationship between dual laser printing parameters and 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 building module is used to establish a physical phase and material performance database according to the corresponding relationship between the physical phase and the 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 according to the physical phase and the performance database of the metal material, and distinguish the internal region and the external region according to 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 printing 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, so as to form a print file in CLI format; The manufacturing module is used to import the print file in CLI format into a dual-laser same-format printing device to manufacture the femoral prosthesis to be manufactured.

[0014] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. Improved the 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 zoning organization regulation in the heat treatment process. The present invention proposes a same-width partition 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 means of a high cooling rate; a high-speed following mode is adopted for the outside of the femoral prosthesis, and a high-strength, high-wear-resistant, low-stress, high-stacking fault, and high-proportion ε-HCP martensite phase structure is achieved on the outside of the part by means of dual laser two-step organization regulation.

[0015] 2. Greatly improve the manufacturing speed of femoral prosthesis: The present invention adopts the same-width partition scanning mode for the internal area of ​​the femoral prosthesis, and uses dual lasers to scan and fill the internal area together, which greatly shortens the part filling time and improves the printing efficiency of the femoral prosthesis. In addition, the present invention directly adjusts the microstructure of the femoral prosthesis by partitioning through dual lasers to achieve integrated forming of function and performance, eliminating the subsequent heat treatment process and further improving manufacturing efficiency.

[0016] 3. Improved the comprehensive mechanical properties of femoral prosthesis: The existing heat treatment tissue control method can only achieve single tissue control of the femoral prosthesis. If the proportion of the γ-FCC phase after heat treatment is high, the wear resistance and strength of the femoral prosthesis will be insufficient. If the proportion of the ε-HCP martensite phase after heat treatment is high, the elongation of the femoral prosthesis will be low. The present invention realizes the zoning performance control of the femoral prosthesis through programmable dual laser process parameters, taking into account both the high-strength and high-wear-resistant area and the high-ductility and toughness area in one femoral prosthesis, breaking the "strength-toughness" trade-off rule in tissue and performance control, realizing the direct manufacturing of the femoral prosthesis and improving the comprehensive mechanical properties of the femoral prosthesis.

[0017] 4. Improved the automation level of femoral prosthesis manufacturing: The present invention adopts a direct manufacturing method that integrates part shape manufacturing and organizational control, avoiding the labor and time costs caused by the original multi-process manufacturing of wire forming and post-heat treatment. By completing the direct manufacturing of shape and performance in one device, the manual addition of intermediate processes is eliminated, the degree of automation of part manufacturing is improved, and it is suitable for the future development direction of intelligent manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. 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 creative work.

[0019] Figure 1 The present invention is a flowchart of a dual laser selective melting direct manufacturing method for gradient functional zoning of a femoral prosthesis in an embodiment of the present invention.

[0020] Figure 2 Schematic diagram of dual laser beam cooperative scanning in high-speed following mode in an embodiment of the present invention.

[0021] Figure 3 Schematic diagram of the division of the inner area and the outer area of ​​the femoral prosthesis in an embodiment of the present invention.

[0022] Figure 4 Schematic diagram of the proportion of high γ-FCC phase inside and high ε-HCP phase outside the femoral prosthesis in an embodiment of the present invention.

[0023] Figure 5 Schematic diagram of the structure of the dual laser selective melting direct manufacturing system for gradient functional zoning of femoral prosthesis in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0025] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0026] like Figure 1 As shown, this embodiment provides a dual laser selective melting direct manufacturing method for gradient functional partitioning of a femoral prosthesis, comprising the following steps: S1. According to the growth relationship between dual laser printing parameters and 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 (such as 200 W), second laser power (such as 160 W), first laser scanning rate (such as 500 m / s), second laser scanning rate (such as 1000 m / s), first laser scanning interval (such as 0.12 mm), second laser scanning interval (such as 0.06 mm), first laser spot size and second laser spot size, etc.; dual laser collaborative scanning mode includes high-speed following mode and same-width partition scanning mode; S2. Establish a database of physical phases and metal material properties based on the corresponding relationship between the physical phase ratio, strength and elongation of the dual laser forming material; S3, 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 according to the physical phase and metal material performance database, and distinguishing the internal region and the external region according to 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 slicing file; S5, importing the slice file into the dual-laser powder bed fusion additive manufacturing equipment, selecting 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 selecting 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; S6. Import the print file in CLI format into a dual laser powder bed fusion additive manufacturing device to manufacture the femoral prosthesis to be manufactured.

[0027] Furthermore, in order to quickly determine the manufacturing process of the parts, a process database can be established according to the performance requirements of different regions of the femoral prosthesis to be manufactured to quickly match the corresponding dual-laser collaborative printing parameters, specifically: S101. Designing different combinations of dual laser printing parameters according to a single laser printing process for preparing metal materials required for 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 dual laser printing parameters and corresponding metal material phases.

[0028] Furthermore, the dual laser collaborative scanning mode in the present application includes a same-radial partition scanning mode and a high-speed following mode, wherein the same-radial partition 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 partition 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.

[0029] High-speed following mode means: a working 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, and transforms the large low-temperature phase and large-sized grains in the first laser beam formed structure into dispersed fine low-temperature phases and small-sized grains by forming a small-sized remelting pool.

[0030] Among them, there is a laser start time interval between the first laser beam and the second laser beam. By adjusting the laser start 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.

[0031] Furthermore, in the high-speed following mode, the second laser beam follows the first laser beam at an equal distance to satisfy the following relationship: V 2 × S 2 = V 1 × S 1 , P 1 > P 2 , in, V 1 is the first laser scanning rate, in m / s; V 2 is the second laser scanning rate, in m / s; S 1 is the first laser scanning interval, in mm; S 2 is the second laser scanning interval, in mm; P 1 is the first laser power, in W; P 2 is the second laser power, in W.

[0032] like Figure 2 As shown in the figure, this relationship requires that the first laser beam is 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 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) to ensure that the first laser beam is followed at an equal distance while 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.

[0033] Furthermore, the metal material phase and material properties database is established as follows: S201, designing different combinations of dual laser printing parameters according to a single laser printing process for preparing materials required for a femoral prosthesis, and printing a test sample using a dual laser powder bed fusion additive manufacturing device; S202, testing the mechanical properties and corrosion resistance of the printed test samples by using a universal testing machine, an electrochemical corrosion device and a microhardness tester, and obtaining 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.

[0034] 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. Figure 3 As shown, the structure is divided into an inner area and an outer area; the inner area is formed by the same-width partition scanning mode to improve the forming efficiency and obtain a γ-FCC phase fine-grained structure with good toughness by virtue of the high cooling rate; the outer area is formed by high-speed following mode scanning, and the first laser beam with high power and low scanning rate forms a low-stress, high-stacking fault and high-proportion ε-HCP martensitic phase structure with high strength and high wear resistance. The second laser beam with low power and high scanning rate further refines and homogenizes the structure formed by the first laser beam through small molten pool remelting, and avoids the problem of uncontrollable remelting time caused by inconsistent interlayer scanning area of ​​a single laser beam through dual laser beam collaborative forming.

[0035] 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 slicing 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 exemplary purposes.

[0036] 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 region, and the rest as the inner layer as the inner region. Figure 4 As shown, after slicing, according to the requirements of use, the external area adopts a high-speed following mode, and relies on dual laser two-step tissue regulation to ensure high strength and high wear resistance; the internal 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, ensuring its high strength and toughness.

[0037] Furthermore, a print file in CLI format containing laser energy and scanning path information is generated.

[0038] In this embodiment, after determining the physical phase morphology and proportion of different regions of the femoral prosthesis to be manufactured, the dual laser printing parameters are obtained from the process database according to the physical phase of the metal material. For the femoral prosthesis, the forming strategy of 200 W laser power of the forming laser and 5 ms remelting time interval and the forming strategy of 160 W laser power of the remelting laser and 5 ms remelting time interval are adopted for its external region to form a low stress, high stacking fault and high proportion ε-HCP martensite phase structure with high strength and high wear resistance. The same-width partition scanning forming strategy with 180 W laser power of the forming laser is adopted for its internal region to increase the proportion of high ductility γ-FCC phase inside the femoral prosthesis by high cooling rate.

[0039] Further, 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, importing the print file in CLI format into the dual-laser same-format printing device, and setting the dual-laser collaborative printing parameters on the dual-laser powder bed fusion additive manufacturing device operating software: setting the internal area of ​​the femoral prosthesis to be manufactured to the same-format partition scanning mode, and setting the external area of ​​the femoral prosthesis to be manufactured to the high-speed following mode, so as 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 plurality of metallographic structures.

[0040] 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.

[0041] Based on the same idea as the dual laser selective melting direct manufacturing method for gradient functional zoning of femoral prosthesis in the above-mentioned embodiment, the present invention also provides a dual laser selective melting direct manufacturing system for gradient functional zoning of femoral prosthesis, which can be used to execute the dual laser selective melting direct manufacturing method for gradient functional zoning of femoral prosthesis. 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 prosthesis only shows the parts related to the embodiment of the present invention. Those skilled in the art can understand that the illustrated structure does not constitute a limitation on the device, and may include more or fewer components than shown in the diagram, or combine certain components, or arrange the components differently.

[0042] See also Figure 5In another embodiment of the present application, a dual laser selective melting direct manufacturing system for gradient functional partitioning of femoral prosthesis is provided, including a process database construction module, a performance database construction module, a metallographic feature acquisition module, a layered slicing module, a print file formation 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 according to the growth relationship between dual laser printing parameters and 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 regions of the metal parts to be manufactured are obtained, and the internal and external regions 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 printing file forming 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, so as to form a print file in CLI format; The manufacturing module is used to import the print file in CLI format into the dual-laser same-format printing device to manufacture the femoral prosthesis to be manufactured.

[0043] 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 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, which will not be repeated here. This is hereby declared.

[0044] 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.

[0045] The technical features of the above embodiments may be arbitrarily combined. 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.

[0046] 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 equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A dual laser selective melting direct manufacturing method for gradient functional zoning of femoral prosthesis, characterized in that: The steps include: According to the growth relationship between the dual laser printing parameters and the metal material phase, a process database of the dual laser printing parameters and the corresponding metal material phase is established; 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 partition scanning mode; According to the corresponding relationship between the physical phase ratio characteristics and the strength and elongation of the dual laser formed materials, a performance database of physical 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, to form a print file in CLI format; The print file in CLI format is imported into the dual laser same-format printing device to manufacture the femoral prosthesis to be manufactured.

2. The dual laser selective melting direct manufacturing method for gradient functional zoning of femoral prosthesis according to claim 1 is characterized in that: The process database of establishing dual laser printing parameters and corresponding metal material phases is specifically as follows: According to the single laser printing process of the metal material required for preparing 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; 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 associated 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 femoral prosthesis according to claim 1 is characterized in that: The same-radial partition 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 partition scanning forming, dividing the area to be formed into two, and at the same time rapidly cooling the metal material at a scanning rate of more than 1000 mm / min to form a high-temperature stable phase structure; The high-speed following mode refers to a working 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 method for direct manufacturing of femoral prosthesis gradient functional zoning by double laser selective melting according to claim 3 is 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 ， in, V 1 is the first laser scanning rate, in m / s; V 2 is the second laser scanning rate, in m / s; S 1 is the first laser scanning interval, in mm; S 2 is the second laser scanning interval, in mm; P 1 is the first laser power, in W; P 2 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 is characterized in that: The establishment of a database of metal material phases and material properties is specifically as follows: According to the single laser printing process for preparing the materials required for 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 method for direct manufacturing of femoral prosthesis gradient functional zoning by double laser selective melting according to claim 1, characterized in that: The performance requirements include tensile strength, elongation, yield strength and wear resistance.

7. The method for direct manufacturing of femoral prosthesis gradient functional zoning by double laser selective melting according to claim 1, characterized in that: The femoral prosthesis to be manufactured is made of cobalt-chromium-molybdenum alloy.

8. The method for direct manufacturing of femoral prosthesis gradient functional zoning by double laser selective melting according to claim 1, characterized in that: The slice file is formed by segmenting different regions of the femoral prosthesis to be manufactured using slice software.

9. The method for direct manufacturing of femoral prosthesis gradient functional zoning by double laser selective melting according to claim 1, characterized in that: The manufacturing of the femoral prosthesis to be manufactured is specifically as follows: Import the print file in CLI format into the dual-laser same-format printing device, and set the dual-laser collaborative printing parameters on 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 various metallographic structures is obtained.

10. Dual laser selective melting direct manufacturing system for gradient functional zoning of femoral prosthesis, characterized in that: The system includes a process database building module, a performance database building module, a metallographic feature acquisition module, a layered slicing module, a print file forming module and a manufacturing module; The process database building module is used to establish a process database of dual laser printing parameters and corresponding metal phases according to the growth relationship between dual laser printing parameters and 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 building module is used to establish a physical phase and material performance database according to the corresponding relationship between the physical phase and the 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 according to the physical phase and the performance database of the metal material, and distinguish the internal region and the external region according to 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 printing 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, so as to form a print file in CLI format; The manufacturing module is used to import the print file in CLI format into a dual-laser same-format printing device to manufacture the femoral prosthesis to be manufactured.

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