Coating structure applied to surface of magnesium alloy biological material and preparation method of coating structure
By preparing a double-layer coating of polytetrafluoroethylene and iron-based materials on the surface of magnesium alloys, the corrosion resistance and biocompatibility issues of magnesium alloy materials were solved, thus expanding the application of magnesium alloy materials in medical implants.
Patent Information
- Application Number
- CN202511077010.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-01
- Publication Date
- 2025-12-16
AI Technical Summary
Magnesium alloys have poor corrosion resistance and corrode too quickly. Existing technologies have not been able to effectively control their corrosion rate, which affects their application in medical implants.
A double-layer coating structure, including a polytetrafluoroethylene coating and an iron-based coating, was prepared on the surface of a magnesium alloy. Taking advantage of the extremely low degradation rate of iron-based materials in physiological environments, a well-bonded iron-based composite coating was formed by magnetron sputtering technology to regulate the corrosion rate of the magnesium alloy and improve its biocompatibility.
It significantly improves the corrosion resistance and biocompatibility of magnesium alloys, reduces corrosion current density, enhances cell proliferation rate and endothelial cell adhesion, has good coating adhesion, is simple to operate, environmentally friendly, and suitable for production and application.
Smart Images
Figure CN121137522A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of metal material surface coating technology, specifically relating to a coating structure and its preparation method for application on the surface of magnesium alloy biomaterials. Background Technology
[0002] Medical implant materials should possess good mechanical properties, corrosion resistance, wear resistance, and excellent biocompatibility. Traditional medical stainless steel and titanium alloys have high mechanical strength and elastic modulus far exceeding that of human bone, easily causing a stress barrier effect. Furthermore, long-term use of medical stainless steel can lead to local infections and allergic reactions. Additionally, both types of implants are non-degradable, requiring secondary surgery for removal after fracture healing, increasing patient suffering and medical costs. Magnesium alloys, due to their good mechanical properties (similar to human bone), biocompatibility, and biodegradability under physiological conditions, hold great potential in the field of medical implants. Magnesium ions, produced by the degradation of magnesium alloys, are the fourth most abundant cation in the human body, playing various important biological functions. However, poor corrosion resistance has always been a major factor limiting the application of magnesium alloys. Furthermore, excessively rapid degradation also causes magnesium alloy implants to lose their early mechanical properties. To enhance the corrosion resistance of magnesium alloy implants, protective coatings are often constructed on the magnesium alloy surface through physical means. Existing research indicates that iron-based materials have good biocompatibility and biodegradability, attracting significant attention as a potential biodegradable metallic material. Furthermore, iron is an essential trace element for the human body, participating in oxygen transport, exchange, and tissue respiration, maintaining normal hematopoietic and immune functions, and playing a vital role in human health. However, the extremely low degradation rate of iron in physiological environments needs improvement to make it compatible with tissue growth. Preparing iron-based coatings on magnesium alloy surfaces to regulate corrosion rates is an effective way to improve magnesium alloy performance. Therefore, researching and realizing the preparation of biocompatible and corrosion-resistant iron-based bio-coatings on magnesium alloy surfaces is of significant practical importance for overcoming technical bottlenecks in the widespread application of bio-magnesium alloy materials, broadening their applicability, and accelerating the localization and upgrading of biodegradable biomedical materials.
[0003] In summary, the main problems with existing technologies are: 1. Magnesium alloys have poor corrosion resistance, and the excessively rapid corrosion rate severely affects the application of bio-based magnesium alloys; 2. Magnesium alloys formed with other metals have significantly improved corrosion resistance compared to pure magnesium; however, there is still a considerable gap in the allowable corrosion rate for medical implants; 3. The use of biodegradable iron-based metal coatings to regulate the corrosion rate of magnesium alloy substrates remains a blank. Summary of the Invention
[0004] The purpose of this invention is to address the problems existing in the prior art by providing a coating structure and its preparation method for magnesium alloy biomaterials, which can improve both the corrosion resistance and biocompatibility of magnesium and magnesium alloys. This coating structure utilizes the extremely low degradation rate of iron-based materials in physiological environments to prepare an iron-based coating on the magnesium alloy surface, thereby controlling the corrosion rate of the magnesium alloy and improving the corrosion resistance of medical magnesium alloy materials while simultaneously ensuring biocompatibility. This has significant practical implications for the widespread application of bio-based magnesium alloy materials. The coating exhibits good adhesion, a convenient and environmentally friendly preparation method, excellent film performance, and stable process, making it suitable for production and application.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a coating structure applied to the surface of a magnesium alloy biomaterial, wherein the magnesium alloy biomaterial can be selected from one of the grades AZ31, AZ61, AZ91, AM50, WE43, etc., the coating structure is a double-layer structure, including a polytetrafluoroethylene coating and an iron-based coating covering it, the polytetrafluoroethylene coating covering the surface of the magnesium alloy biomaterial, and the thickness of both the polytetrafluoroethylene coating and the iron-based coating does not exceed 1 μm.
[0006] Preferably, the iron-based coating is made of stainless steel materials of grades such as 316, 316L, 304, and 304L.
[0007] A method for preparing a coating structure for use on the surface of magnesium alloy biomaterials, comprising the following steps: S1. Surface treatment of medical magnesium alloy samples: The samples were polished in sequence with 400#, 600#, 1000#, 1500# and 2000# sandpaper, polished on a metallographic polishing machine, ultrasonically cleaned with anhydrous ethanol, and dried with cold air before use. S2. Installation: Install the magnesium alloy sample and polytetrafluoroethylene target into the magnetron sputtering cavity, ensuring that the distance between the sample surface and the target is 0-10 cm; S3. Vacuuming: Evacuate the magnetron sputtering cavity to 0.1-2 Pa; S4. Preparation of polytetrafluoroethylene coating by magnetron sputtering: sputtering power 0-200 W, sputtering time 0-10 h, argon flow rate 0-60 sccm; S5. Replace the target: Install the iron-based target into the magnetron sputtering cavity, ensuring that the distance between the sample surface and the target is 0-10 cm; S6. Evacuation: Evacuate the magnetron sputtering cavity to 0.1-2 Pa; S7. Preparation of iron-based coatings on polytetrafluoroethylene coatings by magnetron sputtering: sputtering power 0-200 W, sputtering time 0-10 h, argon flow rate 0-60 sccm; S8. Sample Removal: Unload the sample after magnetron sputtering is complete.
[0008] The beneficial effects of this invention are: 1. This invention solves the technical problem of poor corrosion resistance and excessively fast corrosion rate of biomedical magnesium alloys; 2. The iron-based composite coating prepared by this invention has superior degradation rate and biocompatibility; 3. The coating prepared by this invention has advantages such as convenient operation, environmental friendliness, excellent film performance, low substrate temperature rise, and stable and reliable process, making it suitable for production and application. The resulting coating has good adhesion and uniform structure. Attached Figure Description
[0009] Figure 1 This is a microscopic morphology image of the surface of the coating structure of the present invention; Figure 2 This is a microscopic morphology image of the cross-section of the coating structure of the present invention; Figure 3 (a) is a transmission electron microscope image of the coating structure of the present invention. Figure 3 (b) is a selected area electron diffraction pattern of the coating structure of the present invention; Figure 4 This is the energy spectrum of the coating structure of the present invention; Figure 5 This is a polarization curve of the coating structure and magnesium alloy substrate of the present invention in simulated body fluid; Figure 6 The image shows the CCK-8 results of the coating structure sample and the magnesium alloy substrate of this invention. Figure 7 (a) is a diagram of endothelial cell adhesion on the surface of a magnesium alloy substrate; Figure 7 (b) Endothelial cell adhesion diagram on the surface of the coated structure sample of the present invention; Figure 8 This is a flowchart of the coating structure preparation process of the present invention. Detailed Implementation
[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0011] like Figure 2As shown, the present invention provides a technical solution: a coating structure applied to the surface of magnesium alloy biomaterials. The coating structure is a double-layer structure, including a polytetrafluoroethylene coating and an iron-based coating covering it. The polytetrafluoroethylene coating covers the surface of the magnesium alloy biomaterials, and the thickness of both the polytetrafluoroethylene coating and the iron-based coating does not exceed 1 μm.
[0012] Furthermore, the iron-based coating is made of stainless steel materials of grades such as 316, 316L, 304, and 304L.
[0013] Magnesium alloy surface coating structure preparation, such as Figure 8 As shown in the process flow diagram, this embodiment is carried out according to the following steps: 1. Grinding and cleaning of the surface of medical magnesium alloy AZ31 sample: After grinding the sample with silicon carbide sandpaper of 400#, 600#, 1000#, 1500# and 2000# in sequence, polish it on a metallographic polishing machine, ultrasonically clean it with anhydrous ethanol, and dry it with cold air for later use. 2. Installation: Install the magnesium alloy sample and polytetrafluoroethylene target into the magnetron sputtering cavity, ensuring that the distance between the sample surface and the target is 10 cm; 3. Vacuuming: Evacuate the magnetron sputtering chamber to 0.5 Pa; 4. Preparation of polytetrafluoroethylene coating by magnetron sputtering: sputtering power of 100 W, sputtering time of 5 h, and argon flow rate of 20 sccm; 5. Replace the target: Install the iron-based material (316L stainless steel) target into the magnetron sputtering cavity, ensuring that the distance between the sample surface and the target is 10 cm; 6. Evacuation: Evacuate the magnetron sputtering chamber to 0.5 Pa; 7. Preparation of iron-based coatings on polytetrafluoroethylene coatings by magnetron sputtering: sputtering power of 100 W, sputtering time of 20 min, and argon flow rate of 20 sccm; S8. Sample Removal: Unload the sample after magnetron sputtering is complete.
[0014] like Figure 1 and Figure 2 As shown, the obtained coating structure on the magnesium alloy substrate has good surface quality, uniform and dense particle distribution, and a total thickness of about 800 nanometers. The iron-based coating on the surface is 100 nanometers thick, realizing the technology of preparing iron-based composite bio-coatings on the magnesium alloy surface by magnetron sputtering.
[0015] like Figure 3 As shown, the coating structure is an amorphous structure.
[0016] like Figure 4As shown, the proportions of Fe, Cr, and Ni elements in the iron-based coating are very close to those in the 316L stainless steel target material, and they are uniformly distributed.
[0017] like Figure 5 As shown in the polarization curves, the corrosion current density (Ic) of the iron-based composite coating is lower than that of the magnesium alloy substrate. corr The corrosion current density of the iron-based composite coating was significantly reduced. -6 A / cm 2 The magnesium alloy matrix is 1.90×10 -4 A / cm 2 This demonstrates that radio frequency magnetron sputtering of iron-based composite coatings can improve and enhance the corrosion resistance of magnesium alloys.
[0018] like Figure 6 As shown, the obtained iron-based composite coating significantly improved the endothelial cell proliferation rate compared to the magnesium alloy substrate. At 24 h, the endothelial cell proliferation rate of the iron-based composite coating was 88.1%, higher than the 79.5% of the magnesium alloy substrate. At 72 h, the endothelial cell proliferation rate of the iron-based composite coating was 81.5%, higher than the 72.2% of the magnesium alloy substrate. This demonstrates that radio frequency magnetron sputtering of the iron-based composite coating is beneficial for improving the cell compatibility of magnesium alloys.
[0019] like Figure 7 As shown, the number of endothelial cells adhering to the surface of the obtained iron-based composite coating (b) is much higher than that of the magnesium alloy substrate (a), which proves that the RF magnetron sputtering iron-based composite coating is beneficial to improving the cell compatibility and endothelialization effect of magnesium alloy.
[0020] As described above, these are merely preferred embodiments of the present invention and are not intended to limit the scope of the invention. Any technical solution implemented within the scope of the claims of this application, or any solution made by those skilled in the art using the methods disclosed above, with many possible variations and modifications, shall fall within the protection scope of the present invention.
Claims
1. A coating structure applied to the surface of magnesium alloy biomaterials, characterized in that, The coating structure is a two-layer structure, including a polytetrafluoroethylene coating and an iron-based coating covering it. The polytetrafluoroethylene coating covers the surface of the magnesium alloy biomaterial, and the thickness of both the polytetrafluoroethylene coating and the iron-based coating does not exceed 1 μm.
2. The coating structure applied to the surface of magnesium alloy biomaterials according to claim 1, characterized in that, The iron-based coating is made of stainless steel materials of grades such as 316, 316L, 304, and 304L.
3. A method for preparing a coating structure applied to the surface of a magnesium alloy biomaterial according to any one of claims 1-2, characterized in that, The preparation steps are as follows: S1. Surface treatment of medical magnesium alloy samples: The samples were polished in sequence with 400#, 600#, 1000#, 1500# and 2000# sandpaper, polished on a metallographic polishing machine, ultrasonically cleaned with anhydrous ethanol, and dried with cold air before use. S2. Installation: Install the magnesium alloy sample and polytetrafluoroethylene target into the magnetron sputtering cavity, ensuring that the distance between the sample surface and the target is 0-10 cm; S3. Vacuuming: Evacuate the magnetron sputtering cavity to 0.1-2 Pa; S4. Preparation of polytetrafluoroethylene coating by magnetron sputtering: sputtering power 0-200 W, sputtering time 0-10 h, argon flow rate 0-60 sccm; S5. Replace the target: Install the iron-based target into the magnetron sputtering cavity, ensuring that the distance between the sample surface and the target is 0-10 cm; S6. Evacuation: Evacuate the magnetron sputtering cavity to 0.1-2 Pa; S7. Preparation of iron-based coatings on polytetrafluoroethylene coatings by magnetron sputtering: sputtering power 0-200 W, sputtering time 0-10 h, argon flow rate 0-60 sccm; S8. Sample Removal: Unload the sample after magnetron sputtering is complete.