阅读说明：本技术 激光选区熔化-激光表面织构混合制造高性能医用金属的方法 (Method for manufacturing high-performance medical metal by mixing selective laser melting and laser surface texture ) 是由 周圣丰 张文财 刘莹 杨俊杰 李卫 于 2021-07-20 设计创作，主要内容包括：本发明公开了一种激光选区熔化-激光表面织构混合制造高性能医用金属的方法,该方法包括：将医用金属零件CAD模型分层切片,生成一系列二维扫描轨迹；根据该扫描轨迹,采用激光选区熔化方法将医用金属粉末逐点、逐线、逐层堆积成三维多孔结构,孔型采用拓扑优化设计；在该多孔结构表面进行飞秒激光微加工,生成亲水结构；医用金属粉末由纯铜粉末和316L不锈钢粉末或钛合金粉末组成。本发明制备的医用金属具有细小显微结构,不仅能提高医用金属耐蚀性、生物相容性与抗菌性能,还大幅度提高医用金属的骨整合性能,作为骨植入体极大地改善了与骨头弹性模量不匹配引起的“应力屏蔽”效应、手术易感染与克服“抗菌－骨整合”两种性能之间的矛盾。(The invention discloses a method for manufacturing high-performance medical metal by mixing selective laser melting and laser surface texture, which comprises the following steps: slicing a CAD model of the medical metal part in a layering manner to generate a series of two-dimensional scanning tracks; according to the scanning track, the medical metal powder is piled up layer by layer point by point, line by line and layer by adopting a selective laser melting method to form a three-dimensional porous structure, and the hole pattern is designed by adopting topological optimization; performing femtosecond laser micromachining on the surface of the porous structure to generate a hydrophilic structure; the medical metal powder consists of pure copper powder and 316L stainless steel powder or titanium alloy powder. The medical metal prepared by the invention has a fine microstructure, not only can improve the corrosion resistance, biocompatibility and antibacterial performance of the medical metal, but also greatly improves the osseointegration performance of the medical metal, and greatly improves the stress shielding effect caused by mismatching of the elastic modulus of the bone and the surgical susceptibility and overcomes the contradiction between the two performances of antibacterial-osseointegration when used as a bone implant.)

1. A method for manufacturing high-performance medical metal by selective laser melting-laser surface texture mixing, which is characterized by comprising the following steps:

layering and slicing the CAD models of the copper-containing antibacterial stainless steel and copper-containing antibacterial titanium alloy parts, and generating a series of laser selective melting and forming two-dimensional scanning tracks according to the slice outline information;

copper-containing antibacterial stainless steel powder and copper-containing antibacterial titanium alloy powder are used as forming powder for selective laser melting; the copper-containing antibacterial stainless steel powder consists of pure copper powder and 316L stainless steel powder, and the copper-containing antibacterial titanium alloy powder consists of pure copper powder and titanium alloy powder;

placing the formed powder into a charging hopper of a selective laser melting forming chamber; the forming chamber is vacuumized and filled with argon; heating 316L stainless steel and TC4 titanium alloy base materials with surfaces subjected to rust removal and sand blasting treatment to 100-200 ℃; according to the generated two-dimensional scanning track, a three-dimensional porous copper-containing antibacterial stainless steel and copper-containing antibacterial titanium alloy are piled up layer by layer point by point, line by line and by adopting a selective laser melting method;

carrying out surface grinding and polishing treatment on copper-containing antibacterial stainless steel and copper-containing antibacterial titanium alloy which are melted and formed in a selective laser area, carrying out ultrasonic cleaning for 10-20 minutes in absolute ethyl alcohol, and drying to prepare for laser surface texture treatment;

and adjusting the energy density of the femtosecond laser, and scanning the surfaces of the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy by using a group of parallel grating paths to generate a hydrophilic microstructure.

2. The method as claimed in claim 1, wherein the copper-containing antibacterial stainless steel powder consists of pure copper powder and 316L stainless steel powder, wherein the mass percentage of the pure copper powder in the copper-containing stainless steel powder is 0.5-7.5%, and the chemical components of the 316L stainless steel powder are as follows: cr 17.52 wt.%, Ni 12.27 wt.%, Mo 0.74 wt.%, C0.04 wt.%, Si 1.03 wt.%, O0.05 wt.%, B0.68 wt.%, the balance being Fe;

the copper-containing antibacterial titanium alloy powder comprises 0.5-9% of pure copper powder and 0.5-9% of titanium alloy powder, the titanium alloy powder is TC4 or Ti2448, and the TC4 titanium alloy powder comprises the following chemical components in percentage by mass: al 6.01 wt.%, V3.97 wt.%, Fe 0.02 wt.%, C0.01 wt.%, N0.001 wt.%, O0.03 wt.%, H0.001 wt.%, balance Ti, the chemical composition of the Ti2448 titanium alloy being: nb 23.2 wt.%, Zr 3.85 wt.%, Sn 8.1 wt.%, O0.15 wt.%, N <0.005 wt.%, and the balance Ti.

3. The method of claim 2, wherein the pure copper powder has a particle size of 20 to 30 μm, the 316L stainless steel powder has a particle size of 30 to 48 μm, and the titanium alloy powder has a particle size of 20 to 50 μm.

4. The method according to claim 1, characterized in that, a selective laser melting method is adopted, and the set process parameters are as follows:

the wavelength of a laser is 1060nm, the laser power is 50-100W, the laser scanning speed is 500-800 mm/s, the thickness of a layered slice is 30-60 mu m, and the lap joint rate is 70%; the technological parameters for preparing the porous part are as follows: the laser power is 150-500W, the laser scanning speed is 500-5000 mm/s, the thickness of the layered slice is 50-100 mu m, the lap joint rate is 60-70%, the hole type structure adopts a topological optimization design, and the hole type structure is formed by adopting a way of rotating a 67-degree path in the continuous laser scanning direction between two layers.

5. The method of claim 1, wherein the microstructure characteristics of the copper-containing antimicrobial stainless steel and the copper-containing antimicrobial titanium alloy are each:

the metal matrix consists of fine equiaxed crystals and columnar crystals, and the edge of the molten pool consists of cellular and columnar sub-crystals which are mutually communicated; nanometer epsilon-Cu particles with a cubic structure are uniformly distributed at the grain boundary of the metal matrix.

6. The method according to claim 5, wherein the size of the fine equiaxed crystal and the columnar crystal is 300-800 nm; the nano epsilon-Cu particles have a face-centered cubic structure.

7. The method according to claim 1, wherein the femtosecond laser has a near infrared wavelength of 1030 to 1040nm, an output power of 30 to 50W, a spot radius of 20 to 30 μm, a circularity of 85 to 100%, and a pulse duration of 3 x 10^-13～4×10^-13s, setting the frequency to be 100-500 kHz, setting the single pulse energy to be 120-600 muJ, and setting the laser scanning speed to be 5-15 m/s;

the femtosecond laser scans the surfaces of the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy to generate a periodic structure.

8. The method of claim 1, wherein the hydrophilic microstructures are: etching copper-containing antibacterial stainless steel and copper-containing antibacterial titanium alloy by a grid line path to generate a conical micron-sized structure, wherein the conical micron-sized structure also has nanostructure protrusions;

or the hydrophilic microstructure is:

the hydrophilic microstructure further comprises the step of etching the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy in mutually parallel straight paths to generate a regular trapezoid micron-sized structure, and meanwhile, periodic grooves are formed in the surface of the regular trapezoid micron-sized structure.

9. The method according to claim 8, wherein the surface wettability of the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy is represented by hydrophilicity, the contact angle is increased to 90-150 degrees, and the dissociation and desorption of bacterial cells on the surface of the medical metal are facilitated; when tested in a series of biological electrolytes of human serum, phosphate buffer solution and 0.9M NaCl solution, the copper-containing stainless steel and the copper-containing titanium alloy manufactured by mixing the selective laser melting and the laser surface texture show higher charge transfer resistance and higher breakdown potential, and the electrochemical corrosion resistance of the copper-containing stainless steel and the copper-containing titanium alloy is higher than that of cast stainless steel and cast titanium alloy.

Technical Field

The invention belongs to the technical field of laser additive manufacturing (3D printing), and particularly relates to a method for manufacturing high-performance medical metal by mixing selective laser melting and laser surface texture.

Background

Copper-containing stainless steel and copper-containing titanium alloy have broad-spectrum antibacterial properties and good biocompatibility, and have been widely used as implants in the field of medical care and health. However, the copper ions precipitated on the metal surface can damage the integrity of the passive film and greatly reduce the corrosion resistance, thereby greatly limiting the application of the copper ions in the aspect of medical implants. Currently, surface treatment techniques are commonly used to improve the corrosion resistance of copper-containing stainless steels and copper-containing titanium alloys, including ion implantation, galvanic coating, and vapor deposition. However, the high energy bombarded ions may adversely affect the topography of the material surface, which may result in reduced mechanical and mechanical properties of the implant, and at the same time, the implant has poor antimicrobial durability after surface treatment, and the coating is easily abraded during service, thereby losing the protection effect on the metal substrate.

Generally, although the elution of copper ions from the metal surface can exert an antibacterial action, the corrosion resistance of the implant is lowered, and thus the antibacterial property and the corrosion resistance are in a mutually contradictory relationship. The bottle neck problem that the antibacterial property and the corrosion resistance of a copper-containing metal material are difficult to be considered and the scientific development and the engineering application of an implant are hindered is solved, and people carry out extensive research work. In recent years, researchers have discovered that a refined grain structure inside the implant material can significantly enhance the diffusion of cationic species to the oxide/electrolyte interface and rapidly form a dense, minimally defective oxide film, thereby improving the corrosion resistance of the implant material. Meanwhile, the fine crystal material has higher grain boundary density, which can provide energy for cell growth and metabolism, thereby improving the biocompatibility of the implant material.

Currently, there are two common methods for obtaining nano-to submicron-sized grain structures in implanted materials: the first method is to break large grains into fine grains by plastic deformation; the second mode causes the coarse parent phase to re-grow into finer grains by dynamic recrystallization during induced thermal strain. However, the former method has a great limitation in preparing a structural member of a complicated size; the latter method has complex procedures and low production efficiency, and is difficult to realize industrial application.

In addition, the femtosecond laser treatment can change the microstructure of the surface of the implant material, and the formed grooves and micropores can increase the effective area of the interface and increase the mechanical locking capacity between the bone tissue and the implant; the hydrophilicity of the implant material is increased, the retention and residue of bacteria can be reduced, the adhesion and differentiation behaviors of osteoblasts are facilitated, the immune microenvironment of bone tissues is regulated to promote the bone behaviors, such as promoting macrophage cell M2 phenotype polarization, and promoting the osteoblasts to secrete BMP2 and VEGF growth factors, so that the implant material has very important functions. However, the technology of combining selective laser melting and laser surface texture is adopted to prepare the medical metal with two excellent performances of antibiosis and osseointegration promotion, and the literature report is not available yet.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a method for manufacturing high-performance medical metal by mixing selective laser melting and laser surface texture, and the method adopts femtosecond laser treatment, so that the surface wettability behaviors of copper-containing antibacterial stainless steel and copper-containing antibacterial titanium alloy are represented as hydrophilicity, bacterial cells are favorably dissociated and desorbed on the surface of the medical metal, and the medical metal is endowed with excellent osseointegration performance; under the synergistic effect of copper ions and a hydrophilic structure, the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy have excellent antibacterial performance and corrosion performance.

A method of selective laser melting-laser surface texture hybrid fabrication of high performance medical metals, the method comprising:

layering and slicing the CAD models of the copper-containing antibacterial stainless steel and copper-containing antibacterial titanium alloy parts, and generating a series of laser selective melting and forming two-dimensional scanning tracks according to the slice outline information;

copper-containing antibacterial stainless steel powder and copper-containing antibacterial titanium alloy powder are used as forming powder for selective laser melting; the copper-containing antibacterial stainless steel powder consists of pure copper powder and 316L stainless steel powder, and the copper-containing antibacterial titanium alloy powder consists of pure copper powder and titanium alloy powder;

placing the formed powder into a charging hopper of a selective laser melting forming chamber; the forming chamber is vacuumized and filled with argon; heating 316L stainless steel and TC4 titanium alloy base materials with surfaces subjected to rust removal and sand blasting treatment to 100-200 ℃; according to the generated two-dimensional scanning track, a three-dimensional porous copper-containing antibacterial stainless steel and copper-containing antibacterial titanium alloy are piled up layer by layer point by point, line by line and by adopting a selective laser melting method;

carrying out surface grinding and polishing treatment on copper-containing antibacterial stainless steel and copper-containing antibacterial titanium alloy which are melted and formed in a selective laser area, carrying out ultrasonic cleaning for 10-20 minutes in absolute ethyl alcohol, and drying to prepare for laser surface texture treatment;

and adjusting the energy density of the femtosecond laser, and scanning the surfaces of the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy by using a group of parallel grating paths to generate a hydrophilic microstructure.

Further, the copper-containing antibacterial stainless steel powder consists of pure copper powder and 316L stainless steel powder, wherein the mass percentage of the pure copper powder in the copper-containing stainless steel powder is 0.5-7.5%, and the chemical components of the 316L stainless steel powder are as follows: cr 17.52 wt.%, Ni 12.27 wt.%, Mo 0.74 wt.%, C0.04 wt.%, Si 1.03 wt.%, O0.05 wt.%, B0.68 wt.%, the balance being Fe;

the copper-containing antibacterial titanium alloy powder comprises 0.5-9% of pure copper powder and 0.5-9% of titanium alloy powder, the titanium alloy powder is TC4 or Ti2448, and the TC4 titanium alloy powder comprises the following chemical components in percentage by mass: al 6.01 wt.%, V3.97 wt.%, Fe 0.02 wt.%, C0.01 wt.%, N0.001 wt.%, O0.03 wt.%, H0.001 wt.%, balance Ti, the chemical composition of the Ti2448 titanium alloy being: nb 23.2 wt.%, Zr 3.85 wt.%, Sn 8.1 wt.%, O0.15 wt.%, N <0.005 wt.%, and the balance Ti.

Furthermore, the granularity of the pure copper powder is 20-30 μm, the granularity of the 316L stainless steel powder is 30-48 μm, and the granularity of the titanium alloy powder is 20-50 μm.

Further, a selective laser melting method is adopted, and the set process parameters are as follows:

the wavelength of a laser is 1060nm, the laser power is 50-100W, the laser scanning speed is 500-800 mm/s, the thickness of a layered slice is 30-60 mu m, and the lap joint rate is 70%; the technological parameters for preparing the porous part are as follows: the laser power is 150-500W, the laser scanning speed is 500-5000 mm/s, the thickness of the layered slice is 50-100 mu m, the lap joint rate is 60-70%, the hole type structure adopts a topological optimization design, and the hole type structure is formed by adopting a way of rotating a 67-degree path in the continuous laser scanning direction between two layers.

Furthermore, the microstructure characteristics of the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy are as follows:

the metal matrix consists of fine equiaxed crystals and columnar crystals, and the edge of the molten pool consists of cellular and columnar sub-crystals which are mutually communicated; nanometer epsilon-Cu particles with a cubic structure are uniformly distributed at the grain boundary of the metal matrix.

Further, the sizes of the fine equiaxed crystals and the columnar crystals are both 300-800 nm; the nano epsilon-Cu particles have a face-centered cubic structure.

Further, it is characterized byThe femtosecond laser has near-infrared wavelength of 1030-1040 nm, output power of 30-50W, spot radius of 20-30 μm, roundness of 85-100%, and pulse duration of 3 × 10^-13～4×10^{- 13}s, setting the frequency to be 100-500 kHz, setting the single pulse energy to be 120-600 muJ, and setting the laser scanning speed to be 5-15 m/s;

the femtosecond laser scans the surfaces of the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy to generate a periodic structure.

Further, the hydrophilic microstructure is: etching copper-containing antibacterial stainless steel and copper-containing antibacterial titanium alloy by a grid line path to generate a conical micron-sized structure, wherein the conical micron-sized structure also has nanostructure protrusions;

or the hydrophilic microstructure is:

the hydrophilic microstructure further comprises the step of etching the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy in mutually parallel straight paths to generate a regular trapezoid micron-sized structure, and meanwhile, periodic grooves are formed in the surface of the regular trapezoid micron-sized structure.

Furthermore, the surface wettability of the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy is hydrophilic, the contact angle is increased to 90-150 degrees, and the dissociation and desorption of bacterial cells on the surface of the medical metal are facilitated; when tested in a series of biological electrolytes of human serum, phosphate buffer solution and 0.9M NaCl solution, the copper-containing stainless steel and the copper-containing titanium alloy manufactured by mixing the selective laser melting and the laser surface texture show higher charge transfer resistance and higher breakdown potential, and the electrochemical corrosion resistance of the copper-containing stainless steel and the copper-containing titanium alloy is higher than that of cast stainless steel and cast titanium alloy.

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

1. the individualized design and manufacture of the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy can be realized.

2. The copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy mainly comprise fine honeycomb-shaped and cylindrical crystal grains, the size of the crystal grains is 300-800 nm, the edge of a molten pool is composed of cellular and columnar subgrain tissues which are well oriented and mutually communicated, and nano epsilon-Cu particles are uniformly distributed in a matrix.

3. After the femtosecond laser treatment is adopted, the surface wettability behaviors of the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy are represented as hydrophilicity, so that the dissociation and desorption of bacterial cells on the surface of the medical metal are facilitated, and the medical metal is endowed with excellent osseointegration performance.

4. Under the synergistic effect of copper ions and a hydrophilic structure, the copper-containing antibacterial stainless steel and the copper-containing antibacterial titanium alloy have excellent antibacterial performance and corrosion performance.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1(a) is a schematic diagram of selective laser melting for preparing antibacterial medical metal.

FIG. 1(b) is a schematic diagram of the generation of a hydrophilic structure on the surface of an antibacterial medical metal by femtosecond laser treatment.

Fig. 2 shows a hole pattern structure obtained by using a topology optimization design.

Wherein in FIG. 1: 1 is a selective laser melting laser head; 2 is a formed antibacterial medical metal porous; 3 is unmelted metal powder; 4 is a metal substrate; 5 is a laser head for femtosecond laser processing; 6 is a femtosecond processing track; 7 is gridline scanning to generate conical substructures; and 8, scanning a straight line to generate a regular trapezoid substructure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer and more complete, the technical solutions in the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments, and all other embodiments obtained by a person of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the protection scope of the present invention. It should be understood that the description of the specific embodiments is intended to be illustrative only and is not intended to be limiting.

Example 1:

the stainless steel after rust removal and sand blasting is used as a base material, the copper-containing antibacterial stainless steel is prepared by adopting selective laser melting forming and combining with laser surface texture, and the obtained copper-containing antibacterial stainless steel has the microstructure characteristics that: as a matrix, the size of fine honeycomb and cylindrical face-centered cubic austenite grains is 500-800 nm, and the edge of a molten pool is composed of cellular and columnar subgrain structures which are well oriented and mutually communicated; nano epsilon-Cu particles with a face-centered cubic structure formed by self-assembly due to liquid phase separation are uniformly distributed in gamma-Fe; after the femtosecond laser treatment is adopted, the surface wettability behavior of the copper-containing antibacterial stainless steel is represented as hydrophilicity, the contact angle is increased to 90-100 degrees, and the dissociation and desorption of bacterial cells on the surface of the copper-containing antibacterial stainless steel are facilitated; when the antibacterial stainless steel is tested in human serum biological electrolyte, the charge transfer resistance and the breakdown potential of the antibacterial stainless steel formed by selective laser melting are respectively 2.23M omega cm2 and 984mV, while the charge transfer resistance and the breakdown potential of the antibacterial stainless steel prepared by the casting method are respectively 1.66M omega cm2 and 409mV, and the electrochemical corrosion resistance of the antibacterial stainless steel is superior to that of the copper-containing stainless steel prepared by the casting method; under the synergistic effect of copper ions and a hydrophilic structure, the antibacterial rate of the copper-containing antibacterial stainless steel to escherichia coli and escherichia coli reaches 99.98%, the bacteria residue on the surface of the copper-containing antibacterial stainless steel subjected to femtosecond laser treatment is reduced by 61.63% along with the time extension, and the osseointegration time is about 3.5-4.2 months. The specific implementation process is as follows:

(1) slicing a CAD model of the copper-containing antibacterial stainless steel part in a layering manner, and generating a series of laser selective melting and forming two-dimensional scanning tracks according to the slice outline information;

(2) using copper-containing antibacterial stainless steel powder as formed powder for selective laser melting, wherein the copper-containing antibacterial stainless steel powder is composed of pure copper powder and 316L stainless steel powder according to the proportion of 316L-0Cu (wt.%), 316L-1.5Cu (wt.%), 316L-4.5Cu (wt.%) and 316L-7.5Cu (wt.%), and the chemical composition of the 316L stainless steel powder is as follows: 17.52 wt.% of Cr, 12.27 wt.% of Ni, 0.74 wt.% of Mo, 0.04 wt.% of C, 1.03 wt.% of Si, 0.05 wt.% of O, 0.68 wt.% of B, and the balance of Fe, wherein the particle size of 316L stainless steel powder is 38-48 microns; the particle size of the pure copper powder is 45 microns;

(3) vacuumizing a selective laser melting forming chamber, and then filling argon; heating the stainless steel with the surface subjected to rust removal and sand blasting treatment to 100-200 ℃; according to the generated scanning track, the three-dimensional porous copper-containing antibacterial stainless steel is piled up layer by layer point by point, line by adopting a selective laser melting method, as shown in figure 1;

(4) polishing the copper-containing antibacterial stainless steel by using 400-3000-mesh silicon carbide abrasive paper until the surface has uniform roughness; polishing the metal porous by using diamond polishing paste with the diameter of 3.5-0.5 mu m to a mirror surface without scratches, then ultrasonically cleaning the metal porous in absolute ethyl alcohol for 5-10 minutes, and drying the metal porous, thereby preparing for femtosecond laser treatment;

(5) and adjusting a femtosecond laser, using a group of parallel grating paths, and selecting the required energy density to scan on the surface of the copper-containing antibacterial stainless steel to generate a hydrophilic microstructure.

The process parameters for preparing the support structure are as follows: the wavelength of a laser is 1060nm, the laser power is 56W, the laser scanning speed is 500mm/s, the thickness of the layered slice is 30 mu m, and the lap joint rate is 70%; the technological parameters for preparing the copper-containing antibacterial stainless steel part are as follows: the laser power is 180W, the laser scanning speed is 800mm/s, the thickness of the layered slice is 60 μm, the lap joint rate is 60%, and the hole type structure adopts the topological optimization design, as shown in FIG. 2; and forming in a way of rotating a 67-degree path in the laser scanning direction between two successive layers until the copper-containing antibacterial stainless steel part is manufactured.

The technological parameters of the femtosecond laser treatment are as follows: the near infrared wavelength of the laser is 1030nm, the output power is 30W, the radius of a light spot is 20 mu m, the roundness is 85%, the pulse duration is (pulse width) 3 multiplied by 10 < -13 > s, the frequency is 250kHz, the laser scanning speed is 5m/s, and the copper-containing antibacterial stainless steel surface is burned according to the scheme to generate a periodic structure.

Example 2:

the stainless steel after rust removal and sand blasting is used as a base material, the copper-containing antibacterial stainless steel is prepared by adopting selective laser melting forming and femtosecond laser processing, and the microstructure characteristics of the obtained copper-containing antibacterial stainless steel are as follows: as a matrix, the size of fine honeycomb and cylindrical face-centered cubic austenite grains is 500-800 nm, and the edge of a molten pool is composed of cellular and columnar subgrain structures which are well oriented and mutually communicated; nano epsilon-Cu particles with a face-centered cubic structure formed by self-assembly due to liquid phase separation are uniformly distributed in the gamma-Fe crystal lattice; after the femtosecond laser treatment is adopted, the surface wettability behavior of the copper-containing antibacterial stainless steel is represented as hydrophilicity, the contact angle is increased to 90-100 degrees, and the dissociation and desorption of bacterial cells on the surface of the copper-containing antibacterial stainless steel are facilitated; when the test is carried out in phosphate buffer solution which is a biological electrolyte, the charge transfer resistance and the breakdown potential of the stainless steel formed by selective laser melting are respectively 2.21M omega cm2 and 1038mV, while the charge transfer resistance and the breakdown potential of the stainless steel prepared by the casting method are respectively 1.42M omega cm2 and 403mV, and the electrochemical corrosion resistance of the stainless steel is better than that of the stainless steel prepared by the casting method; under the synergistic effect of copper ions and a hydrophilic structure, the antibacterial rate of the copper-containing antibacterial stainless steel to escherichia coli reaches 99.98%, the bacteria residue on the surface of the copper-containing antibacterial stainless steel treated by the femtosecond laser is reduced by 70.3% along with the prolonging of time, and the osseointegration time is about 3.0-3.5 months. The specific implementation process is as follows:

(1) slicing a CAD model of the copper-containing antibacterial stainless steel part in a layering manner, and generating a series of laser selective melting and forming two-dimensional scanning tracks according to the slice outline information;

(2) using copper-containing antibacterial stainless steel powder as formed powder for selective laser melting, wherein the copper-containing antibacterial stainless steel powder is composed of pure copper powder and 316L stainless steel powder according to the proportion of 316L-0Cu (wt.%), 316L-1.5Cu (wt.%), 316L-4.5Cu (wt.%) and 316L-7.5Cu (wt.%), and the chemical composition of the 316L stainless steel powder is as follows: cr 17.52 wt.%, Ni 12.27 wt.%, Mo 0.74 wt.%, C0.04 wt.%, Si 1.03 wt.%, O0.05 wt.%, B0.68 wt.%, balance Fe, pure copper powder particle size of 45 microns, 316L stainless steel powder particle size of 38-48 microns;

(3) vacuumizing a selective laser melting forming chamber, and then filling argon; heating the stainless steel with the surface subjected to rust removal and sand blasting treatment to 100-200 ℃; according to the generated scanning track, the three-dimensional porous copper-containing antibacterial stainless steel is piled up layer by layer point by point, line by adopting a selective laser melting method, as shown in figure 1;

(4) polishing the copper-containing antibacterial stainless steel by using 400-3000-mesh silicon carbide abrasive paper until the surface has uniform roughness; polishing the metal porous by using diamond polishing paste with the diameter of 3.5-0.5 mu m to a mirror surface without scratches, then ultrasonically cleaning the metal porous in absolute ethyl alcohol for 5-10 minutes, and drying the metal porous, thereby preparing for femtosecond laser treatment;

(5) and adjusting a femtosecond laser, using a group of parallel grating paths, and selecting the required energy density to scan on the surface of the copper-containing antibacterial stainless steel to generate a hydrophilic microstructure.

The process parameters for preparing the support structure are as follows: the wavelength of a laser is 1060nm, the laser power is 56W, the laser scanning speed is 500mm/s, the thickness of the layered slice is 30 mu m, and the lap joint rate is 70%; the technological parameters for preparing the copper-containing antibacterial stainless steel part are as follows: the laser power is 190W, the laser scanning speed is 1100mm/s, the thickness of the layered slice is 90 μm, the lap joint rate is 65%, and the hole type structure adopts the topological optimization design, as shown in FIG. 2; and forming in a way of rotating a 67-degree path in the laser scanning direction between two successive layers until the copper-containing antibacterial stainless steel part is manufactured.

The technological parameters of the femtosecond laser treatment are as follows: the near infrared wavelength of the laser is 1030nm, the output power is 30W, the radius of a light spot is 20 mu m, the roundness is 95%, the pulse duration (pulse width) is 4 multiplied by 10 < -13 > s, the frequency is 300kHz, the laser scanning speed is 8m/s, and the copper-containing antibacterial stainless steel surface is burned according to the scheme to generate a periodic structure.

Example 3:

the titanium alloy subjected to rust removal and sand blasting is used as a base material, the copper-containing antibacterial titanium alloy is prepared by adopting selective laser melting forming and femtosecond laser processing, and the microstructure characteristics of the obtained copper-containing antibacterial titanium alloy are as follows: as a matrix, the size width of fine acicular martensite crystal grains can reach hundreds of nanometers to several micrometers, the length can reach tens of micrometers, and the edge of a molten pool is formed by sub-crystal structures which are well oriented and mutually communicated; nano epsilon-Cu particles with a face-centered cubic structure formed by self-assembly due to liquid phase separation are uniformly distributed in a martensite crystal lattice; after femtosecond laser treatment is adopted, the surface wettability behavior of the copper-containing antibacterial titanium alloy is represented as hydrophilicity, the contact angle is increased to 90-100 degrees, and the dissociation and desorption of bacterial cells on the surface of the copper-containing antibacterial stainless steel are facilitated; when the test is carried out in a biological electrolyte of 0.9M NaCl, the charge transfer resistance and the breakdown potential of the titanium alloy formed by selective laser melting are respectively 0.62M omega cm2 and 920mV, while the charge transfer resistance and the breakdown potential of the titanium alloy prepared by the casting method are respectively 0.26M omega cm2 and 200mV, and the electrochemical corrosion resistance of the titanium alloy is better than that of the titanium alloy prepared by the casting method; under the synergistic effect of copper ions and a hydrophilic structure, the antibacterial rate of the copper-containing antibacterial titanium alloy to escherichia coli reaches 99.98%, the bacteria residue on the surface of the copper-containing antibacterial titanium alloy treated by the femtosecond laser is reduced by 75.6% along with the prolonging of time, and the osseointegration time is about 2.5-3.2 months. The specific implementation process is as follows:

(1) slicing the CAD model of the copper-containing antibacterial titanium alloy part in a layering manner, and generating a series of laser selective melting and forming two-dimensional scanning tracks according to the slice outline information;

(2) the copper-containing antibacterial titanium alloy powder is used as forming powder for selective laser melting, the copper-containing antibacterial titanium alloy powder consists of pure copper powder and titanium alloy powder TC4, the mass percentage of pure copper in the copper-containing titanium alloy powder is 0.5-9%, and the titanium alloy powder TC4 comprises the following chemical components: 6.01 wt.% of Al, 3.97 wt.% of V, 0.02 wt.% of Fe, 0.01wt.% of C, 0.001 wt.% of N, 0.03 wt.% of O, 0.001 wt.% of H, and the balance of Ti, wherein the particle size of the pure copper powder is 20-30 μm, and the particle size of the titanium alloy powder TC4 is 20-50 μm;

(3) vacuumizing a selective laser melting forming chamber, and then filling argon; heating the titanium alloy substrate with the surface subjected to rust removal and sand blasting treatment to 100-200 ℃; according to the generated scanning track, a three-dimensional porous copper-containing antibacterial titanium alloy is accumulated layer by layer point by point, line by adopting a selective laser melting method, as shown in figure 1;

(4) polishing the copper-containing antibacterial titanium alloy by using 400-3000-mesh silicon carbide abrasive paper until the surface has uniform roughness; polishing the metal porous by using diamond polishing paste with the diameter of 3.5-0.5 mu m to a mirror surface without scratches, then ultrasonically cleaning the metal porous in absolute ethyl alcohol for 5-10 minutes, and drying the metal porous, thereby preparing for femtosecond laser treatment;

(5) and adjusting a femtosecond laser, using a group of parallel grating paths, and selecting the required energy density to scan on the surface of the copper-containing antibacterial titanium alloy to generate a hydrophilic microstructure.

The process parameters for preparing the support structure are as follows: the wavelength of a laser is 1060nm, the laser power is 56W, the laser scanning speed is 500mm/s, the thickness of the layered slice is 30 mu m, and the lap joint rate is 70%; the technological parameters for preparing the copper-containing antibacterial titanium alloy part are as follows: the laser power is 200W, the laser scanning speed is 1400mm/s, the thickness of the layered slice is 120 μm, the lap joint rate is 70%, and the hole type structure adopts the topological optimization design, as shown in FIG. 2; and forming in a way of rotating a 67-degree path in the laser scanning direction between two continuous layers until the copper-containing antibacterial titanium alloy part is manufactured.

The technological parameters of the femtosecond laser treatment are as follows: the near infrared wavelength of the laser is 1030nm, the output power is 30W, the radius of a light spot is 20 mu m, the roundness is 100%, the pulse duration (pulse width) is 4 multiplied by 10 < -13 > s, the frequency is 350kHz, the laser scanning speed is 12m/s, and the copper-containing antibacterial stainless steel surface is burned according to the scheme to generate a periodic structure.

Example 4:

the titanium alloy subjected to rust removal and sand blasting is used as a base material, the copper-containing antibacterial titanium alloy is prepared by adopting selective laser melting forming and femtosecond laser processing, and the microstructure characteristics of the obtained copper-containing antibacterial titanium alloy are as follows: as a matrix, the size width of fine acicular martensite crystal grains can reach hundreds of nanometers to several micrometers, the length can reach tens of micrometers, and the edge of a molten pool is formed by sub-crystal structures which are well oriented and mutually communicated; nano epsilon-Cu particles with a face-centered cubic structure formed by self-assembly due to liquid phase separation are uniformly distributed in a martensite crystal lattice; after femtosecond laser treatment is adopted, the surface wettability behavior of the copper-containing antibacterial titanium alloy is represented as hydrophilicity, the contact angle is increased to 90-100 degrees, and the dissociation and desorption of bacterial cells on the surface of the copper-containing antibacterial stainless steel are facilitated; when the test is carried out in a biological electrolyte of 0.9M NaCl, the charge transfer resistance and the breakdown potential of the titanium alloy formed by selective laser melting are respectively 0.71M omega cm2 and 1040mV, while the charge transfer resistance and the breakdown potential of the titanium alloy prepared by the casting method are respectively 0.35M omega cm2 and 578mV, and the electrochemical corrosion resistance of the titanium alloy is better than that of the titanium alloy prepared by the casting method; under the synergistic effect of copper ions and a hydrophilic structure, the antibacterial rate of the copper-containing antibacterial titanium alloy to escherichia coli reaches 99.99%, the bacteria residue on the surface of the copper-containing antibacterial titanium alloy treated by the femtosecond laser is reduced by 85.9% along with the time extension, and the osseointegration time is about 1.8-2.5 months. The specific implementation process is as follows:

(1) slicing the CAD model of the copper-containing antibacterial titanium alloy part in a layering manner, and generating a series of laser selective melting and forming two-dimensional scanning tracks according to the slice outline information;

(2) the copper-containing antibacterial titanium alloy powder is used as forming powder for selective laser melting, the copper-containing antibacterial titanium alloy powder consists of pure copper powder and titanium alloy powder Ti2448, the mass percentage of pure copper in the copper-containing titanium alloy powder is 0.5-9%, and the titanium alloy Ti2448 comprises the following chemical components: nb 23.2 wt.%, Zr 3.85 wt.%, Sn 8.1 wt.%, O0.15 wt.%, N <0.005 wt.%, and the balance Ti; the granularity of the pure copper powder is 20-30 mu m, and the granularity of the titanium alloy powder Ti2448 is 20-50 mu m;

(3) vacuumizing a selective laser melting forming chamber, and then filling argon; heating the titanium alloy substrate with the surface subjected to rust removal and sand blasting treatment to 100-200 ℃; according to the generated scanning track, a three-dimensional porous copper-containing antibacterial titanium alloy is accumulated layer by layer point by point, line by adopting a selective laser melting method, as shown in figure 1;

(4) polishing the copper-containing antibacterial titanium alloy by using 400-3000-mesh silicon carbide abrasive paper until the surface has uniform roughness; polishing the metal porous by using diamond polishing paste with the diameter of 3.5-0.5 mu m to a mirror surface without scratches, then ultrasonically cleaning the metal porous in absolute ethyl alcohol for 5-10 minutes, and drying the metal porous, thereby preparing for femtosecond laser treatment;

(5) and adjusting a femtosecond laser, using a group of parallel grating paths, and selecting the required energy density to scan on the surface of the copper-containing antibacterial titanium alloy to generate a hydrophilic microstructure.

The process parameters for preparing the support structure are as follows: the wavelength of a laser is 1060nm, the laser power is 56W, the laser scanning speed is 500mm/s, the thickness of the layered slice is 30 mu m, and the lap joint rate is 70%; the technological parameters for preparing the copper-containing antibacterial titanium alloy part are as follows: the laser power is 180W, the laser scanning speed is 800mm/s, the thickness of the layered slice is 60 μm, the lap joint rate is 60%, and the hole type structure adopts the topological optimization design, as shown in FIG. 2; and forming in a way of rotating a 67-degree path in the laser scanning direction between two continuous layers until the copper-containing antibacterial titanium alloy part is manufactured.

The technological parameters of the femtosecond laser treatment are as follows: the near infrared wavelength of the laser is 1030nm, the output power is 30W, the radius of a light spot is 20 mu m, the roundness is 100%, the pulse duration (pulse width) is 4 multiplied by 10 < -13 > s, the frequency is 350kHz, the laser scanning speed is 15m/s, and the copper-containing antibacterial stainless steel surface is burned according to the scheme to generate a periodic structure.

It should be noted that although the method operations of the above-described embodiments are depicted in the drawings in a particular order, this does not require or imply that these operations must be performed in this particular order, or that all of the illustrated operations must be performed, to achieve desirable results. Rather, the depicted steps may change the order of execution. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step execution, and/or one step broken down into multiple step executions.

The above description is only for the preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution and the inventive concept of the present invention within the scope of the present invention.