阅读说明：本技术 激光增材制造结合酸处理获得医用含铜钛合金的方法 (Method for obtaining medical copper-containing titanium alloy by combining laser additive manufacturing with acid treatment ) 是由 王强 于 2021-07-22 设计创作，主要内容包括：本发明涉及一种激光增材制造结合酸洗处理获得医用含铜钛合金的方法,包括步骤如下：混合金属粉末A为TC4金属粉末和铜粉的混合粉末,混合金属粉末B为钛粉和铜粉的混合粉末；将TC4金属粉末、混合金属粉末A和混合金属粉末B分别烘干；钛基板表面进行打磨、清洗并干燥；粉末采用光纤激光器铺粉的方式,进行熔化沉积增材制造,冷却至室温然后进行表面酸洗和超声清洗,获得缺陷少以及表面光滑的激光增材制造医用含铜钛合金。含铜钛合金无细胞毒性且具有抗菌功能性,该方法可以用于加工多孔结构的医用钛合金,获得的多孔含铜钛合金孔径400-700μm。(The invention relates to a method for obtaining a medical copper-containing titanium alloy by combining laser additive manufacturing with acid pickling treatment, which comprises the following steps: the mixed metal powder A is mixed powder of TC4 metal powder and copper powder, and the mixed metal powder B is mixed powder of titanium powder and copper powder; respectively drying TC4 metal powder, the mixed metal powder A and the mixed metal powder B; polishing, cleaning and drying the surface of the titanium substrate; the powder is subjected to melting deposition additive manufacturing in a mode of laying the powder by using a fiber laser, and is cooled to room temperature and then subjected to surface pickling and ultrasonic cleaning, so that the medical copper-titanium-containing alloy for laser additive manufacturing with few defects and smooth surface is obtained. The copper-containing titanium alloy has no cytotoxicity and antibacterial function, and the method can be used for processing medical titanium alloy with a porous structure, and the aperture of the obtained porous copper-containing titanium alloy is 400-700 mu m.)

1. The method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing and acid pickling treatment is characterized by comprising the following steps of: the method comprises the following steps:

respectively taking TC4 metal powder and mixed metal powder as raw materials, wherein the mixed metal powder comprises mixed metal powder A and mixed metal powder B; the mixed metal powder A is mixed powder of TC4 metal powder and copper powder, and the mixed metal powder B is mixed powder of titanium powder and copper powder;

step two, placing TC4 metal powder, mixed metal powder A and mixed metal powder B in a vacuum drying oven at the temperature of 60-80 ℃ respectively, and drying for not less than 24 hours; polishing, cleaning and drying the surface of the titanium substrate for later use;

thirdly, performing melting deposition additive manufacturing on the surface of the pure titanium substrate by adopting a fiber laser powder laying mode to the dried TC4 metal powder, the mixed metal powder A and the mixed metal powder B through laser beam irradiation: under the protection of argon, TC4 metal powder is firstly adopted to melt layer by layer to deposit and form a plurality of deposition layers; then, adopting mixed metal powder A to melt and deposit and form a penultimate layer; finally, adopting mixed metal powder B to melt, deposit and form the last layer;

step four, after the additive manufacturing is finished, the titanium alloy material containing copper on the surface is kept stand and cooled to room temperature under the protection of argon; and then carrying out surface acid washing and ultrasonic cleaning to remove residual metal powder on the surface, thereby obtaining the medical copper-containing titanium alloy with less defects and smooth surface by laser additive manufacturing.

2. The method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing and acid pickling according to claim 1, wherein the method comprises the following steps: in the first step, the copper powder is pure copper powder, the titanium powder is pure titanium powder, and the copper powder, the titanium powder and the TC4 metal powder are all spherical; the mass of copper in the mixed metal powder A is 3-7% of the total mass of the mixed metal powder A; the mass of copper in the mixed metal powder B is 3-7% of the total mass of the mixed metal powder B.

3. The method for obtaining the medical copper-containing titanium alloy by the laser additive manufacturing combined with the acid washing treatment according to claim 1 or 2, wherein the method comprises the following steps: in the first step, the method for obtaining the mixed metal powder A and the mixed metal powder B comprises the following steps: placing spherical pure copper and TC4 metal powder into a ball mill for ball milling to obtain uniform mixed metal powder A; placing spherical pure copper and pure titanium powder in a ball mill for ball milling to obtain uniform mixed metal powder B; the particle size diameter of the mixed metal powder A and the mixed metal powder B after ball milling is not more than 45 mu m.

4. The method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing and acid pickling according to claim 1, wherein the method comprises the following steps: in the second step, the surface of the titanium substrate is ground by 60# -500# sandpaper.

5. The method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing and acid pickling according to claim 1, wherein the method comprises the following steps: in the third step, the laser additive manufacturing method of the fiber laser is to scan layer by layer, and after one layer is continuously scanned, the next layer of laser irradiation treatment is carried out under the condition that the scanning direction is parallel to the scanning direction of the previous layer; the laser processing process parameters are as follows: the laser power is 240-; the laser deposition process adopts TC4 metal powder, mixed metal powder A and mixed metal powder B to build up and form layer by layer in sequence.

6. The method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing and acid pickling according to claim 1, wherein the method comprises the following steps: in the fourth step, the acid washing method comprises the following steps: hydrofluoric acid, nitric acid and distilled water are adopted to prepare a pickling solution, wherein the hydrofluoric acid accounts for 5-30% of the total mass of the pickling solution, the nitric acid accounts for 10-40% of the total mass of the pickling solution, the rest is distilled water, and the pickling time is 1-5 minutes.

7. The method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing and acid pickling according to claim 1, wherein the method comprises the following steps: in the third step, the number of deposited layers formed by melting, depositing and molding the TC4 metal powder layer by layer is more than or equal to 3.

8. The method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing and acid pickling according to claim 5, wherein the method comprises the following steps: and when the mixed metal powder A is subjected to laser melting deposition molding, the scanning speed is controlled to be 900-1000mm/s, and when the mixed metal powder B is subjected to laser melting deposition molding, the scanning speed is controlled to be 1000 mm/s.

Technical Field

The invention belongs to the technical field of functional medical copper-containing titanium alloy materials, and relates to a method for obtaining a medical copper-containing titanium alloy by combining laser additive manufacturing with acid pickling treatment.

Background

The titanium and the titanium alloy can be used for manufacturing titanium plates, titanium meshes, retaining screws or artificial prostheses and the like to repair the defects of the hard tissues of the oral cavity. However, due to the variability of the human body and the complexity of the anatomical structure of the defect site, standardized implants often fail to meet clinical requirements. The titanium alloy as a biological inert metal material has the problems of high elastic modulus, low bone formation speed, biological safety and no antibacterial performance possibly caused by aluminum element and vanadium element, and the like. The additive manufacturing of the porous titanium alloy can effectively solve the problems, provides a strong support for the manufacturing and wide application of personalized, complicated and low-elasticity-modulus antibacterial titanium alloy instruments, and is greatly concerned and rapidly developed by people.

The laser additive manufacturing technology adopts Selective Laser Melting (SLM) characterized by powder spreading in the field of medical metal materials, and is an integrated additive manufacturing and processing method which meets the requirements of precise forming and high performance controllability. The technology can realize the acquisition of novel titanium alloy without harmful elements such as aluminum, vanadium and the like, and simultaneously introduces functional elements such as copper and the like, thereby endowing the material with good mechanical property and biological safety. On one hand, the porous structure of the medical titanium alloy is printed in a 3D mode, so that the elastic modulus of the porous structure can be matched with that of bone tissues, a space is provided for bone tissue to grow into the porous structure, and a firm structure of an implant-bone mechanical locking knot is finally formed. On the other hand, the medical titanium alloy is added with copper element, and the physiological function can be regulated and controlled by utilizing the separation of the copper element in the physiological environment and the valence state conversion in the copper ion oxidation reduction process. Meanwhile, related researches show that the influence of copper ions on the biological performance of cells/bacteria has concentration dependency. Researches show that the surface characteristics of the material and the interaction between the surface and bacteria play an important role in the exertion of the antibacterial function of the material, and different bacteria inoculation modes are adopted to regulate the contact degree of the bacteria and the surface of the copper-containing metal material, so that the material can show excellent antibacterial effect. Therefore, the surface copper-containing titanium alloy with excellent biological performance can be obtained by porous construction and addition of trace functional copper element.

Compared with the traditional manufacturing technology, the additive manufacturing technology has the advantages of short production period and low production cost. The advantages in the aspects of processing and manufacturing of medical instruments with individuation, complex structures, low elastic modulus and antibacterial functions are remarkable. The technology for manufacturing the medical copper-titanium-containing alloy by using the laser additive can improve the design flexibility of products, promote the clinical application of functional and personalized medical instruments and initiate the transformation of the production mode of the medical instruments.

Disclosure of Invention

Object of the Invention

In order to solve the problem of antibacterial functionality of the traditional medical titanium alloy, the invention provides a method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing with acid treatment.

Technical scheme

The method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing with acid pickling treatment comprises the following steps: respectively taking TC4 metal powder and mixed metal powder as raw materials, wherein the mixed metal powder comprises mixed metal powder A and mixed metal powder B; the mixed metal powder A is mixed powder of TC4 metal powder and copper powder, and the mixed metal powder B is mixed powder of titanium powder and copper powder;

step two, placing TC4 metal powder, mixed metal powder A and mixed metal powder B in a vacuum drying oven at the temperature of 60-80 ℃ respectively, and drying for not less than 24 hours; polishing, cleaning and drying the surface of the titanium substrate for later use;

thirdly, performing melting deposition additive manufacturing on the surface of the pure titanium substrate by irradiating laser beams on the dried TC4 metal powder, mixed metal powder A and mixed metal powder B in a mode of laying powder by using a fiber laser: under the protection of argon, TC4 metal powder is firstly adopted to melt layer by layer to deposit and form a plurality of deposition layers; then, adopting mixed metal powder A to melt and deposit and form a penultimate layer; finally, adopting mixed metal powder B to melt, deposit and form the last layer;

step four, after the additive manufacturing is finished, the titanium alloy material containing copper on the surface is kept stand and cooled to room temperature under the protection of argon; and then carrying out surface acid washing and ultrasonic cleaning to remove residual metal powder on the surface, thereby obtaining the medical copper-containing titanium alloy with less defects and smooth surface by laser additive manufacturing.

Further, in the first step, the copper powder is pure copper powder, the titanium powder is pure titanium powder, and the copper powder, the titanium powder and the TC4 metal powder are all spherical; the mass of copper in the mixed metal powder A is 3-7% of the total mass of the mixed metal powder A; the mass of copper in the mixed metal powder B is 3-7% of the total mass of the mixed metal powder B.

Further, in the step one, the mixed metal powder a and the mixed metal powder B are obtained by: placing spherical pure copper and TC4 metal powder into a ball mill for ball milling to obtain uniform mixed metal powder A; placing spherical pure copper and pure titanium powder in a ball mill for ball milling to obtain uniform mixed metal powder B; the particle size diameter of the mixed metal powder A and the mixed metal powder B after ball milling is not more than 45 mu m.

Further, in the second step, the surface of the titanium substrate is ground by 60# -500# sandpaper.

Further, in the third step, the laser additive manufacturing method of the fiber laser is to scan layer by layer, and after one layer is continuously scanned, the next layer of laser irradiation treatment is performed under the condition that the scanning direction is parallel to the scanning direction of the previous layer; the laser processing process parameters are as follows: the laser power is 240-; the laser deposition process adopts TC4 metal powder, mixed metal powder A and mixed metal powder B to build up and form layer by layer in sequence. Further, in the fourth step, the acid washing method comprises the following steps: hydrofluoric acid, nitric acid and distilled water are adopted to prepare a pickling solution, wherein the hydrofluoric acid accounts for 5-30% of the total mass of the pickling solution, the nitric acid accounts for 10-40% of the total mass of the pickling solution, the rest is distilled water, and the pickling time is 1-5 minutes.

Further, in the third step, the number of deposited layers formed by melting, depositing and molding the TC4 metal powder layer by layer is greater than or equal to 3.

Furthermore, the scanning speed is controlled to be 900-1000mm/s when the mixed metal powder A is subjected to laser melting deposition molding, and the scanning speed is controlled to be 1000mm/s when the mixed metal powder B is subjected to laser melting deposition molding.

Advantages and effects

1. The invention adopts a method of combining laser additive manufacturing (powder spreading method) with post-treatment, and compared with the traditional casting and forging processing mode, the invention more efficiently realizes the manufacturing of the medical titanium alloy with a complex porous structure.

2. The invention adopts the method of laser additive manufacturing (powder spreading method) combined with acid pickling treatment to obtain the copper-containing porous medical titanium alloy without cytotoxicity, and has the advantages that residual powder on the surface and metal powder which is not completely melted are removed by the method of acid pickling post-treatment, so that the surface of the material is more uniform and smooth.

3. The invention adopts the combination of laser additive manufacturing (powder spreading method) and post-treatment method to obtain the medical titanium alloy containing copper with antibacterial function, and the antibacterial rate can reach 75-80%.

Drawings

The invention is further described with reference to the following figures and detailed description. The scope of the invention is not limited to the following expressions.

Fig. 1 is a scanning electron micrograph of TC4 alloy powder for additive manufacturing;

fig. 2 is a scanning electron micrograph of pure copper powder for additive manufacturing;

FIG. 3 is a scanning electron microscope photograph of a medical copper-containing titanium alloy manufactured by laser additive before pickling;

FIG. 4 is a scanning electron microscope photograph of the medical copper-containing titanium alloy manufactured by the additive laser after acid cleaning;

FIG. 5 shows the results of cytotoxicity assays at various time points;

FIG. 6 shows the antibacterial effect of Streptococcus mutans at different time points.

Detailed Description

The invention is described in detail below with reference to the accompanying drawings:

the method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing with acid pickling treatment comprises the following steps:

respectively taking TC4(Ti6Al4V) metal powder and mixed metal powder as raw materials, wherein the mixed metal powder comprises mixed metal powder A and mixed metal powder B; the mixed metal powder A is mixed powder of TC4 metal powder and copper powder, and the mixed metal powder B is mixed powder of titanium powder and copper powder; the copper powder is pure copper powder, the titanium powder is pure titanium powder, and the copper powder, the titanium powder and the TC4 metal powder are all spherical; the mass of copper in the mixed metal powder A is 3-7% of the total mass of the mixed metal powder A; the mass of copper in the mixed metal powder B is 3-7% of the total mass of the mixed metal powder B. The method for obtaining the mixed metal powder A and the mixed metal powder B comprises the following steps: placing spherical pure copper and TC4 metal powder into a ball mill for ball milling to obtain uniform mixed metal powder A; placing spherical pure copper and pure titanium powder in a ball mill for ball milling to obtain uniform mixed metal powder B; the particle size diameter of the mixed metal powder A and the mixed metal powder B after ball milling is not more than 45 mu m.

Step two, placing TC4 metal powder, mixed metal powder A and mixed metal powder B in a vacuum drying oven at the temperature of 60-80 ℃ respectively, and drying for not less than 24 hours; polishing, cleaning and drying the surface of the titanium substrate by using 60# -500# abrasive paper for later use;

thirdly, performing melting deposition additive manufacturing on the surface of the pure titanium substrate by irradiating laser beams on the dried TC4 metal powder, mixed metal powder A and mixed metal powder B in a mode of laying powder by using a fiber laser: under the protection of argon, TC4 metal powder is firstly adopted to melt and deposit layer by layer to form 3, 4 and 5 deposition layers; then, adopting mixed metal powder A to melt and deposit and form a penultimate layer; finally, adopting mixed metal powder B to melt, deposit and form the last layer to realize component gradient change, and obtaining alloy surface containing copper; the laser additive manufacturing method of the fiber laser comprises the steps of scanning layer by layer, and after one layer is continuously scanned, carrying out laser irradiation treatment on the next layer under the condition that the scanning direction is parallel to the scanning direction of the previous layer; the laser processing process parameters are as follows: the laser power is 240-; and TC4 metal powder, mixed metal powder A and mixed metal powder B are sequentially adopted in the laser deposition process for layer-by-layer stacking forming to realize component gradient change, and the obtained alloy surface contains copper. Preferably, the scanning speed is controlled to be 800-1000mm/s when the TC4 metal powder is fused, deposited and molded layer by layer, the scanning speed is controlled to be 900-1000mm/s when the mixed metal powder A is fused, deposited and molded by laser, and the scanning speed is controlled to be 1000mm/s when the mixed metal powder B is fused, deposited and molded by laser, so that the molding effect is better.

Step four, after the additive manufacturing is finished, the titanium alloy material containing copper on the surface is kept stand and cooled to room temperature under the protection of argon; and then carrying out surface acid washing and ultrasonic cleaning to remove residual metal powder on the surface, thereby obtaining the medical copper-containing titanium alloy with less defects and smooth surface by laser additive manufacturing. The acid washing method comprises the following steps: hydrofluoric acid, nitric acid and distilled water are adopted to prepare a pickling solution, wherein the hydrofluoric acid accounts for 5-30% of the total mass of the pickling solution, the nitric acid accounts for 10-40% of the total mass of the pickling solution, the rest is distilled water, and the pickling time is 1-5 minutes. The medical copper-containing titanium alloy is manufactured by laser additive after surface pickling, the cytotoxicity is detected through osteoblasts, the toxicity level is 0 level, and the antibacterial function is proved through a bacterial experiment.

Example 1

The method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing with acid pickling treatment comprises the following steps:

respectively taking TC4(Ti6Al4V) metal powder and mixed metal powder as raw materials, wherein the mixed metal powder comprises mixed metal powder A and mixed metal powder B; the mixed metal powder A is mixed powder of TC4 metal powder and copper powder, and the mixed metal powder B is mixed powder of titanium powder and copper powder; the copper powder is pure copper powder, the titanium powder is pure titanium powder, and the copper powder, the titanium powder and the TC4 metal powder are all spherical; the mass of copper in the mixed metal powder A is 5% of the total mass of the mixed metal powder A; the mass of copper in mixed metal powder B was 5% of the total mass of mixed metal powder B. The method for obtaining the mixed metal powder A and the mixed metal powder B comprises the following steps: placing spherical pure copper and TC4 metal powder into a ball mill for ball milling to obtain uniform mixed metal powder A; placing spherical pure copper and pure titanium powder in a ball mill for ball milling to obtain uniform mixed metal powder B; the particle size diameter of the mixed metal powder A and the mixed metal powder B after ball milling is not more than 45 mu m.

Step two, placing TC4 metal powder, mixed metal powder A and mixed metal powder B in a vacuum drying oven at 70 ℃ respectively, and drying for 26 hours; polishing, cleaning and drying the surface of the titanium substrate by using 60# -500# abrasive paper for later use;

thirdly, performing melting deposition additive manufacturing on the surface of the pure titanium substrate by irradiating laser beams on the dried TC4 metal powder, mixed metal powder A and mixed metal powder B in a mode of laying powder by using a fiber laser: under the protection of argon, TC4 metal powder is firstly adopted to melt and deposit layer by layer to form 4 deposition layers; then, adopting mixed metal powder A to melt and deposit and form a penultimate layer; finally, adopting mixed metal powder B to melt, deposit and form the last layer to realize component gradient change, and obtaining alloy surface containing copper; the laser additive manufacturing method of the fiber laser comprises the steps of scanning layer by layer, and after one layer is continuously scanned, carrying out laser irradiation treatment on the next layer under the condition that the scanning direction is parallel to the scanning direction of the previous layer; the laser processing process parameters are as follows: the laser power is 260W, the thickness of each layer is 43 mu m, the laser scanning interval is 48 mu m, the diameter of a laser spot is 70 +/-10 mu m, the scanning speed is controlled to be 800mm/s when TC4 metal powder is melted and deposited layer by layer, the scanning speed is controlled to be 900mm/s when mixed metal powder A is melted and deposited and formed, and the scanning speed is controlled to be 1000mm/s when mixed metal powder B is melted and deposited and formed; and TC4 metal powder, mixed metal powder A and mixed metal powder B are sequentially adopted in the laser deposition process for layer-by-layer stacking forming to realize component gradient change, and the obtained alloy surface contains copper.

Step four, after the additive manufacturing is finished, the titanium alloy material containing copper on the surface is kept stand and cooled to room temperature under the protection of argon; and then carrying out surface acid washing and ultrasonic cleaning to remove residual metal powder on the surface, thereby obtaining the medical copper-containing titanium alloy with less defects and smooth surface by laser additive manufacturing. The acid washing method comprises the following steps: hydrofluoric acid, nitric acid and distilled water are adopted to prepare a pickling solution, wherein the hydrofluoric acid accounts for 18% of the total mass of the pickling solution, the nitric acid accounts for 25% of the total mass of the pickling solution, the rest is distilled water, and the pickling time is 4 minutes. The medical copper-containing titanium alloy is manufactured by laser additive after surface pickling, the cytotoxicity of the alloy is detected by osteoblast MC3T3E1 cells, the toxicity grade is 0 grade, and the alloy is proved to have antibacterial function by a bacterial experiment.

Example 2

The method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing with acid pickling treatment comprises the following steps:

respectively taking TC4(Ti6Al4V) metal powder and mixed metal powder as raw materials, wherein the mixed metal powder comprises mixed metal powder A and mixed metal powder B; the mixed metal powder A is mixed powder of TC4 metal powder and copper powder, and the mixed metal powder B is mixed powder of titanium powder and copper powder; the copper powder is pure copper powder, the titanium powder is pure titanium powder, and the copper powder, the titanium powder and the TC4 metal powder are all spherical; the mass of copper in the mixed metal powder A is 3% of the total mass of the mixed metal powder A; the mass of copper in mixed metal powder B was 7% of the total mass of mixed metal powder B. The method for obtaining the mixed metal powder A and the mixed metal powder B comprises the following steps: placing spherical pure copper and TC4 metal powder into a ball mill for ball milling to obtain uniform mixed metal powder A; placing spherical pure copper and pure titanium powder in a ball mill for ball milling to obtain uniform mixed metal powder B; the particle size diameter of the mixed metal powder A and the mixed metal powder B after ball milling is not more than 45 mu m.

Step two, placing TC4 metal powder, mixed metal powder A and mixed metal powder B in a vacuum drying oven at the temperature of 60 ℃ respectively, and drying for 30 hours; polishing, cleaning and drying the surface of the titanium substrate by using 60# -500# abrasive paper for later use;

thirdly, performing melting deposition additive manufacturing on the surface of the pure titanium substrate by irradiating laser beams on the dried TC4 metal powder, mixed metal powder A and mixed metal powder B in a mode of laying powder by using a fiber laser: under the protection of argon, TC4 metal powder is firstly adopted to melt layer by layer to deposit and form 3 deposition layers; then, adopting mixed metal powder A to melt and deposit and form a penultimate layer; finally, adopting mixed metal powder B to melt, deposit and form the last layer to realize component gradient change, and obtaining alloy surface containing copper; the laser additive manufacturing method of the fiber laser comprises the steps of scanning layer by layer, and after one layer is continuously scanned, carrying out laser irradiation treatment on the next layer under the condition that the scanning direction is parallel to the scanning direction of the previous layer; the laser processing process parameters are as follows: the laser power is 240W, the thickness of each layer is 40 μm, the laser scanning interval is 45 μm, the diameter of a laser spot is 70 +/-10 μm, the scanning speed is controlled to be 800mm/s when TC4 metal powder is melted and deposited layer by layer, the scanning speed is controlled to be 800mm/s when mixed metal powder A is melted and deposited and formed, and the scanning speed is controlled to be 800mm/s when mixed metal powder B is melted and deposited and formed; and TC4 metal powder, mixed metal powder A and mixed metal powder B are sequentially adopted in the laser deposition process for layer-by-layer stacking forming to realize component gradient change, and the obtained alloy surface contains copper.

Step four, after the additive manufacturing is finished, the titanium alloy material containing copper on the surface is kept stand and cooled to room temperature under the protection of argon; and then carrying out surface acid washing and ultrasonic cleaning to remove residual metal powder on the surface, thereby obtaining the medical copper-containing titanium alloy with less defects and smooth surface by laser additive manufacturing. The acid washing method comprises the following steps: hydrofluoric acid, nitric acid and distilled water are adopted to prepare a pickling solution, wherein the hydrofluoric acid accounts for 5% of the total mass of the pickling solution, the nitric acid accounts for 10% of the total mass of the pickling solution, the rest is distilled water, and the pickling time is 5 minutes. The medical copper-containing titanium alloy is manufactured by laser additive after surface pickling, the cytotoxicity of the alloy is detected by osteoblast MC3T3E1 cells, the toxicity grade is 0 grade, and the alloy is proved to have antibacterial function by a bacterial experiment.

Example 3

The method for obtaining the medical copper-containing titanium alloy by combining laser additive manufacturing with acid pickling treatment comprises the following steps:

respectively taking TC4(Ti6Al4V) metal powder and mixed metal powder as raw materials, wherein the mixed metal powder comprises mixed metal powder A and mixed metal powder B; the mixed metal powder A is mixed powder of TC4 metal powder and copper powder, and the mixed metal powder B is mixed powder of titanium powder and copper powder; the copper powder is pure copper powder, the titanium powder is pure titanium powder, and the copper powder, the titanium powder and the TC4 metal powder are all spherical; the mass of copper in the mixed metal powder A is 7% of the total mass of the mixed metal powder A; the mass of copper in mixed metal powder B was 3% of the total mass of mixed metal powder B. The method for obtaining the mixed metal powder A and the mixed metal powder B comprises the following steps: placing spherical pure copper and TC4 metal powder into a ball mill for ball milling to obtain uniform mixed metal powder A; placing spherical pure copper and pure titanium powder in a ball mill for ball milling to obtain uniform mixed metal powder B; the particle size diameter of the mixed metal powder A and the mixed metal powder B after ball milling is not more than 45 mu m.

Step two, placing TC4 metal powder, mixed metal powder A and mixed metal powder B in a vacuum drying oven at 80 ℃ respectively, and drying for 24 hours; polishing, cleaning and drying the surface of the titanium substrate by using 60# -500# abrasive paper for later use;

thirdly, performing melting deposition additive manufacturing on the surface of the pure titanium substrate by irradiating laser beams on the dried TC4 metal powder, mixed metal powder A and mixed metal powder B in a mode of laying powder by using a fiber laser: under the protection of argon, TC4 metal powder is firstly adopted to melt layer by layer to deposit and form 8 deposition layers; then, adopting mixed metal powder A to melt and deposit and form a penultimate layer; finally, adopting mixed metal powder B to melt, deposit and form the last layer to realize component gradient change, and obtaining alloy surface containing copper; the laser additive manufacturing method of the fiber laser comprises the steps of scanning layer by layer, and after one layer is continuously scanned, carrying out laser irradiation treatment on the next layer under the condition that the scanning direction is parallel to the scanning direction of the previous layer; the laser processing process parameters are as follows: the laser power is 270W, the thickness of each layer is 45 microns, the laser scanning interval is 50 microns, the diameter of a laser spot is 70 +/-10 microns, the scanning speed is controlled to be 1000mm/s when TC4 metal powder is melted and deposited layer by layer for forming, the scanning speed is controlled to be 1000mm/s when mixed metal powder A is melted and deposited for forming, and the scanning speed is controlled to be 1000mm/s when mixed metal powder B is melted and deposited for forming; and TC4 metal powder, mixed metal powder A and mixed metal powder B are sequentially adopted in the laser deposition process for layer-by-layer stacking forming to realize component gradient change, and the obtained alloy surface contains copper.

Step four, after the additive manufacturing is finished, the titanium alloy material containing copper on the surface is kept stand and cooled to room temperature under the protection of argon; and then carrying out surface acid washing and ultrasonic cleaning to remove residual metal powder on the surface, thereby obtaining the medical copper-containing titanium alloy with less defects and smooth surface by laser additive manufacturing. The acid washing method comprises the following steps: hydrofluoric acid, nitric acid and distilled water are adopted to prepare a pickling solution, wherein the hydrofluoric acid accounts for 30% of the total mass of the pickling solution, the nitric acid accounts for 40% of the total mass of the pickling solution, the rest is distilled water, and the pickling time is 1 minute. The medical copper-containing titanium alloy is manufactured by laser additive after surface pickling, the cytotoxicity of the alloy is detected by osteoblast MC3T3E1 cells, the toxicity grade is 0 grade, and the alloy is proved to have antibacterial function by a bacterial experiment.

As shown in FIGS. 1 and 2, the TC4 alloy powder and the pure copper powder used were good in sphericity, free from satellite, and had a powder diameter of not more than 45 μm.

Fig. 3 and 4 are scanning electron micrographs of the medical copper-containing titanium alloy manufactured by the laser additive manufacturing method before and after the acid cleaning in example 1, respectively. As can be observed from the figure, the pores of the formed part are internal full-connection through holes, the pore diameter is 400-700 mu m, more residual metal powder exists on the surface of the porous copper-containing titanium alloy before pickling, and the residual metal powder on the surface can be removed by pickling, so that a smooth and uniform surface is obtained.

Fig. 5 shows cytotoxicity test results of laser additive manufacturing medical copper-containing titanium alloy at different time points. The numbers represent 1: additive manufacturing of TC4 alloy before pickling; 2: performing additive manufacturing on TC4 alloy after acid washing; 3: manufacturing a medical copper-containing titanium alloy in an additive mode; 4: and (4) performing additive manufacturing on the medical copper-containing titanium alloy after acid washing. It can be found that the cytotoxicity of the medical copper-containing titanium alloy prepared by the laser additive material after acid washing to MC3T3E1 cells is 0 grade by using a leaching liquor indirect culture mode, and the medical copper-containing titanium alloy has good biological safety.

The obtained alloy material was tested for its antibacterial performance against streptococcus mutans, and fig. 6 shows the antibacterial effect of the laser additive manufacturing titanium-copper alloy after pickling on streptococcus mutans at different time points (the ordinate is the number of colonies, and the abscissa is the test time), and the numbers represent 1: performing additive manufacturing on TC4 alloy after acid washing; 2: and (4) performing additive manufacturing on the alloy containing copper and titanium on the surface after acid washing. The antibacterial rate can reach 75-80%.

The invention provides a digital precision processing mode, which is characterized in that copper element is added into the traditional medical titanium-based material, and a copper-containing titanium alloy with smooth surface, no residual powder, no cytotoxicity and antibacterial function is obtained through a post-treatment mode.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that various changes and modifications can be made on the basis of the above description, and all embodiments cannot be exhaustive, and obvious changes and modifications included in the technical solutions of the present invention are within the scope of the present invention.