CN-121992401-A - Preparation method of corrosion-resistant wear-resistant high-compatibility biomedical magnesium alloy protective coating

Abstract

The invention discloses a preparation method of a corrosion-resistant wear-resistant high-compatibility magnesium alloy biological protective coating, belongs to the field of biological coatings, and aims to solve the problem that the existing magnesium alloy coating material is degraded too quickly. According to the invention, mg-1.5Zn-0.5Ca alloy is selected as a matrix, firstly, a porous oxide layer is prepared on the surface of the magnesium alloy by utilizing a micro-arc oxidation process to improve the corrosion resistance of the coating, and then a hydroxyapatite coating is prepared on the surface of the oxide layer by utilizing a plasma spraying process to improve the biocompatibility and the wear resistance of the coating. The composite coating prepared by the invention has good performance, and the process is simple and easy for industrial production.

Inventors

• LI YAN
• ZHAO XINGCHUAN
• Lv Meiying

Assignees

• 聊城大学

Dates

Publication Date

20260508

Application Date

20251021

Claims (7)

1. 1. The preparation method of the biomedical magnesium alloy protective coating with corrosion resistance, wear resistance and high compatibility is characterized by comprising the following steps: (1) Selecting Mg-Zn-Ca alloy as a magnesium alloy substrate, and carrying out surface treatment on the magnesium alloy substrate; (2) Taking the polished magnesium alloy substrate obtained in the step (1) as an anode and a stainless steel plate as a cathode, and carrying out micro-arc oxidation treatment on the magnesium alloy substrate in electrolyte to obtain a magnesium alloy sample after the micro-arc oxidation treatment, wherein the electrolyte comprises 10-15g/L of Na 3 PO 4 , 2-5g/L of NaOH and 10-30ml/L of glycol, and the parameters of the micro-arc oxidation treatment comprise 400-600 kHz, 10-30% of duty ratio, 1-3A/square decimeter of current density and 10-15 minutes of treatment time; (3) Placing hydroxyapatite powder into a plasma spraying powder chamber, and spraying the micro-arc magnesium oxide alloy sample obtained in the step (2) by using a plasma spraying machine to obtain a magnesium alloy composite coating sample after micro-arc oxidation/plasma spraying; (4) And (3) carrying out surface cleaning treatment on the magnesium alloy sample obtained in the step (3).
2. 2. The method for preparing the corrosion-resistant wear-resistant high-compatibility biomedical magnesium alloy protective coating according to claim 1, wherein in the step (1), the magnesium alloy substrate comprises the components of Mg-1.5Zn-0.5Ca alloy, and the specific components of the magnesium alloy substrate comprise 1.42-1.69% of Zn,0.41-0.62% of Ca, 0.003% of Fe, 0.06% of Si, 0.002% of Ni and the balance of Mg.
3. 3. The method for preparing the corrosion-resistant wear-resistant high-compatibility biomedical magnesium alloy protective coating according to claim 1, wherein in the step (1), the specific method for surface treatment is that the magnesium alloy is polished from 120 meshes to 2000 meshes by using water sand paper, and then is cleaned by using absolute ethyl alcohol and then is dried by using cold air.
4. 4. The method for preparing the corrosion-resistant wear-resistant high-compatibility biomedical magnesium alloy protective coating according to claim 1, wherein in the step (3), the hydroxyapatite particles are nano-scale hydroxyapatite particles, and the particle size is 20-50nm.
5. 5. The method for preparing the corrosion-resistant wear-resistant high-compatibility biomedical magnesium alloy protective coating according to claim 1, wherein in the step (3), the protective gas adopted by the plasma spraying equipment is nitrogen, the air inlet rate is 30-50L/min, the combustion-supporting gas is helium, and the air inlet rate is 10-20L/min.
6. 6. The method for preparing the corrosion-resistant wear-resistant high-compatibility biomedical magnesium alloy protective coating according to claim 1, wherein in the step (3), the plasma spraying adopts the process parameters of 10-30W of power, 400-800A of current, 40-80mm of spraying distance and 2-6L/min of powder feeding rate.
7. 7. A biomedical magnesium alloy protective coating with corrosion resistance, wear resistance and high compatibility prepared by the method according to any one of claims 1-6.

Description

Preparation method of corrosion-resistant wear-resistant high-compatibility biomedical magnesium alloy protective coating Technical Field The invention belongs to the field of biological coatings, and relates to a preparation method of a biomedical magnesium alloy protective coating with corrosion resistance, wear resistance and high compatibility. Background The incidence rate of bone diseases such as osteoporosis fracture, tumor bone excision, artificial joint replacement and the like is remarkably increased, and more than 2000 ten thousand bone repair materials are implanted every year worldwide. Although the traditional titanium-based or cobalt-chromium alloy implant is mature in clinical application, the permanent implantation characteristics of the traditional titanium-based or cobalt-chromium alloy implant are in intrinsic contradiction with the dynamic reconstruction requirement of human autologous bone, and development of a new generation bone implant material with biodegradability and functional imitation is urgently needed. Magnesium alloy is the most potential biodegradable metal implant candidate material due to its elastic modulus (30-40 GPa), adjustable biodegradation rate (5-15 mmol/m 2/day) and osteointegration promoting potential similar to human skeleton. However, the existing magnesium alloy system generally has the problem of excessively high degradation rate, so that local microenvironment is changed drastically, on one hand, excessive hydrogen gas is separated out to possibly form an air cavity to interfere with tissue repair, and on the other hand, local pH value rise (up to more than 10) can cause alkaline microenvironment to cause cell membrane damage and protein denaturation. The micro-arc oxidation is used as a main technology for improving the corrosion resistance of the surface of the magnesium alloy, provides a new strategy for solving the difficult problem of mechanical-biological adaptation of the magnesium alloy in orthopedics application, and provides convenience for adsorption of osteoblasts due to natural porosity. However, the formation of the micro-arc oxidation coating restricts the biocompatibility of the magnesium alloy to a certain extent. Therefore, in order to further improve the surface biocompatibility, the survivability of the composite hydroxyapatite layer in the osteogenic environment can be effectively improved. As a material surface strengthening and surface modifying technology, plasma spraying has wide application in the aspect of preparing wear-resistant and corrosion-resistant coatings and has large scale industrial production. A hydroxyapatite coating is sprayed by using a plasma spraying technology, so that the protective performance and biocompatibility of the hydroxyapatite coating can be effectively improved. Disclosure of Invention In view of the analysis, the invention aims to provide a preparation method of a biomedical magnesium alloy protective coating with corrosion resistance, wear resistance and high compatibility, which solves the problems of poor corrosion resistance and too fast degradation of magnesium alloy in the prior art and prolongs the service life of the magnesium alloy. The technical scheme of the invention is as follows: A preparation method of a biomedical magnesium alloy protective coating with corrosion resistance and high compatibility comprises the following steps: (1) Selecting Mg-Zn-Ca alloy as a magnesium alloy substrate, and carrying out surface treatment on the magnesium alloy substrate; (2) Taking the polished magnesium alloy substrate obtained in the step (1) as an anode and a stainless steel plate as a cathode, and carrying out micro-arc oxidation treatment on the magnesium alloy substrate in electrolyte to obtain a magnesium alloy sample after the micro-arc oxidation treatment, wherein the electrolyte comprises 10-15g/L of Na 3PO4, 2-5g/L of NaOH and 10-30ml/L of glycol, and the parameters of the micro-arc oxidation treatment comprise 400-600 kHz, 10-30% of duty ratio, 1-3A/square decimeter of current density and 10-15 minutes of treatment time; (3) Placing hydroxyapatite powder into a plasma spraying powder chamber, and spraying the micro-arc magnesium oxide alloy sample obtained in the step (2) by using a plasma spraying machine to obtain a magnesium alloy composite coating sample after micro-arc oxidation/plasma spraying; (4) And (3) carrying out surface cleaning treatment on the magnesium alloy sample obtained in the step (3). Preferably, in the step (1), the magnesium alloy substrate comprises the components of Mg-1.5Zn-0.5Ca alloy, and the specific components of the magnesium alloy substrate comprise 1.42-1.69% of Zn,0.41-0.62% of Ca, 0.003% of Fe, 0.06% of Si, 0.002% of Ni and the balance of Mg. Preferably, in the step (1), the specific method of the surface treatment is that the magnesium alloy is polished from 120 meshes to 2000 meshes by using water sand paper, then is washed by absolute ethyl alcohol a