Method for preparing hydroxyapatite whiskers / WE43 magnesium alloy biological composite material through vacuum pressure impregnation method

Abstract

The invention discloses a method for preparing a hydroxyapatite whisker / WE43 magnesium alloy biological composite material through a vacuum pressure impregnation method, and belongs to the technical field of new materials. The invention aims to solve the problems that the existing hydroxyapatite particle reinforced magnesium-based composite material is relatively high in hydrogen evolution rate, too high in-vitro degradation rate and low in hardness and elasticity modulus, and the hydroxyapatite whisker reinforced magnesium-based composite material is fractured and the length-diameter ratio is obviously reduced. According to the hydroxyapatite whisker / WE43 magnesium alloy biological composite material prepared by using a vacuum pressure impregnation method, good interface bonding can be formed; the added hydroxyapatite whisker effectively refines the grain structure of the WE43 magnesium alloy, and the strengthening effect of grain refinement on the magnesium-based composite material is far better than that of aluminum alloy; compared with a matrix alloy, the hydroxyapatite whisker / WE43 magnesium alloy biological composite material prepared by using a vacuum pressure impregnation method has the advantages that the elasticity modulus and the hardness are obviously improved, and the in-vitro degradation performance is good.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of new materials technology, and particularly relates to a method for preparing hydroxyapatite whisker / WE43 magnesium alloy biological composite material by vacuum pressure impregnation. BACKGROUND

[0002] Magnesium and its alloys have low density (the density of magnesium is 1.8 g / cm 3 , about 1 / 3 of titanium alloy, and 1 / 4 of iron and steel). It is a true light metal, and has high strength, high rigidity, good biodegradation performance and biocompatibility, etc. However, when used as a biological material, its application is limited due to the shortcomings such as hydrogen evolution and too fast degradation rate. The hydrogen evolution rate and in-vitro degradation rate can be controlled by preparing a HAw / magnesium-based biological composite material by adding hydroxyapatite whiskers (HAw) in the matrix, and the hardness, yield strength and elastic modulus can be greatly improved. In the past, the reinforcing phase was mainly hydroxyapatite particles to reinforce the magnesium-based composite material. Studies have shown that, compared with hydroxyapatite particles, the mechanical strength of the hydroxyapatite particles is low, the whisker is a single crystal, has high specific strength, high specific modulus, good creep resistance and high temperature performance; the hydroxyapatite whisker absorbs energy by bridging, crack deflection and pull-out effect, eliminates the stress at the crack tip to enhance the mechanical properties of the material.

[0003] At present, there is a process for preparing hydroxyapatite whisker reinforced magnesium and its alloys by powder metallurgy. In the powder metallurgy mixing process, the mechanical force applied is easy to cause the brittle hydroxyapatite whisker to break, and the aspect ratio decreases significantly. The core advantage of whisker reinforcement is the high aspect ratio, and the breaking will make it degenerate from "whisker" to "short fiber" or "particle", and the reinforcing effect is greatly reduced. SUMMARY

[0004] The present application aims to solve the problems of high hydrogen evolution rate, too fast in-vitro degradation rate, low hardness and elastic modulus of the existing hydroxyapatite particle reinforced magnesium-based composite material, and the breaking of the hydroxyapatite whisker reinforced magnesium-based composite material and the significant decrease of the aspect ratio, and to provide a method for preparing hydroxyapatite whisker / WE43 magnesium alloy biological composite material by vacuum pressure impregnation.

[0005] The application is a magnesium-based composite material with hydroxyapatite whisker as reinforcing phase; because magnesium is easy to oxidize and burn, vacuum pressure infiltration method is adopted in the preparation process; through SEM observation, the combination of hydroxyapatite whisker and magnesium alloy at the interface is good, and there is no interface chemical reaction; the prepared hydroxyapatite whisker / WE43 magnesium alloy biological composite material has a significant increase in elastic modulus and hardness compared with the base alloy, and has good in vitro degradation performance; therefore, the composite material has great potential in the application field of biomaterials, bone substitute materials and the like.

[0006] A method for preparing a hydroxyapatite whisker / WE43 magnesium alloy biological composite material by vacuum pressure impregnation method, specifically completed by the following steps:

[0007] I. Hydroxyapatite whisker is added to deionized water, ultrasonic oscillation is performed, a dispersing agent is added, and stirring is performed to obtain a suspension;

[0008] II. A binder is added to the suspension, stirring is performed to obtain a paste-like solution; the paste-like solution is poured into a mold, the paste-like solution is pressed to the height of the mold, and the paste-like solution is dried at room temperature to obtain a preform;

[0009] III. The preform is first placed in a vacuum freeze dryer for freeze drying, then placed in a drying oven for low-temperature drying, and finally the dried preform is high-temperature sintered to obtain a sintered preform;

[0010] IV. The sintered preform is placed in a quartz mold, then a strip-shaped WE43 magnesium alloy is placed on the sintered preform, the quartz mold is then placed in a graphite crucible, and finally the graphite crucible is placed in a vacuum pressure impregnation device; a mechanical pump is opened to start vacuumizing the vacuum pressure impregnation device, when the vacuum degree of the system reaches 10 Pa to 20 Pa, heating is started, when it reaches 500 °C to 550 °C, it is kept warm, then it is heated to 700 °C to 750 °C, and kept warm, to ensure that the WE43 magnesium alloy is melted; then the vacuum valve is closed, the pressurizing system is opened, Ar gas is introduced, and the pressure is increased to 3.5 MPa to 5 MPa, the pressurizing is stopped, and the pressure is kept; finally, the furnace is cooled to room temperature, to obtain a hydroxyapatite whisker / WE43 magnesium alloy biological composite material.

[0011] The application has the following beneficial effects:

[0012] The vacuum pressure impregnation method adopted by the present application can be used for the compounding of various metal matrices and continuous fibers, short fibers, and whiskers, and the shape, size, and content of the reinforcing material are basically not limited; the method can also directly prepare composite parts, especially parts with complex shapes; impregnation is performed in vacuum under pressure and solidification, and the prepared composite material is free of casting defects such as pores, looseness, and shrinkage holes; the experimental parameters are easy to control, and the temperature, pressure and other parameters can be strictly controlled according to the physical and chemical properties of the reinforcing material and the matrix metal, so as to avoid serious interface reaction;

[0013] The hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared by the vacuum pressure impregnation method of the present application can form a good interface bonding; the added hydroxyapatite whisker effectively refines the grain structure of the WE43 magnesium alloy, and the strengthening effect of the grain refinement on the magnesium-based composite material is much greater than that on the aluminum alloy; the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared by the vacuum pressure impregnation method has a significant improvement in elastic modulus and hardness compared with the matrix alloy, and has good in-vitro degradation performance. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The SEM image of the hydroxyapatite whisker powder;

[0015] Figure 2 The OM image of the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared in Example 1;

[0016] Figure 3 The SEM image of the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared in Example 1;

[0017] Figure 4 The OM image of the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared in Example 2;

[0018] Figure 5 The SEM image of the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared in Example 2;

[0019] Figure 6 The XRD image of the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared in Examples 1-2;

[0020] Figure 7 The hardness image of the WE43 magnesium alloy and the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared in Examples 1-2;

[0021] Figure 8 The elastic modulus image of the WE43 magnesium alloy and the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared in Examples 1-2;

[0022] Figure 9 Degradation rate graph of hydroxyapatite whisker / WE43 magnesium alloy biocomposite prepared for WE43 magnesium alloy, examples 1~2;

[0023] Figure 10 Hydrogen evolution amount graph of hydroxyapatite whisker / WE43 magnesium alloy biocomposite prepared for WE43 magnesium alloy, examples 1~2;

[0024] Figure 11 pH value change graph of hydroxyapatite whisker / WE43 magnesium alloy biocomposite prepared for WE43 magnesium alloy, examples 1~2;

[0025] Figure 12 Potentiodynamic polarization curve graph of hydroxyapatite whisker / WE43 magnesium alloy biocomposite prepared for WE43 magnesium alloy, examples 1~2. DETAILED DESCRIPTION

[0026] Specific implementation method one: this implementation method is a method for preparing hydroxyapatite whisker / WE43 magnesium alloy biocomposite by vacuum pressure impregnation method, which is completed according to the following steps:

[0027] I. Hydroxyapatite whiskers are added to deionized water, ultrasonic oscillation, then a dispersing agent is added and stirred to obtain a suspension;

[0028] II. The binder is added to the suspension and stirred to obtain a paste-like solution; the paste-like solution is poured into a mold, and the paste-like solution is pressed to the height of the mold, and then it is dried at room temperature to obtain a preform;

[0029] III. First, the preform is placed in a vacuum freeze dryer for freeze drying, then placed in a drying oven for low-temperature drying, and finally the dried preform is sintered at high temperature to obtain a sintered preform;

[0030] IV. The sintered preform is placed in a quartz mold, then a strip-shaped WE43 magnesium alloy is placed on the sintered preform, then the quartz mold is placed in a graphite crucible, and finally the graphite crucible is placed in a vacuum pressure impregnation device; open the mechanical pump to start vacuumizing the vacuum pressure impregnation device, when the vacuum degree of the system reaches 10 Pa~20 Pa, start heating, when it reaches 500 °C~550 °C, keep warm, then heat to 700 °C~750 °C, keep warm, ensure that the WE43 magnesium alloy is melted; then close the vacuum valve, open the pressurizing system, and introduce Ar gas to pressurize to 3.5 MPa~5 MPa, stop pressurizing, and keep warm and pressurized; finally, cool to room temperature with the furnace, to obtain a hydroxyapatite whisker / WE43 magnesium alloy biocomposite.

[0031] Specific implementation two: the difference between this embodiment and the first embodiment is that the length-diameter ratio of the hydroxyapatite whisker in step one is 20-50; the frequency of the ultrasonic oscillation in step one is 30 kHz, and the ultrasonic oscillation time is 20 min-40 min. The other steps are the same as those in the first embodiment.

[0032] Specific implementation three: the difference between this embodiment and one of the first embodiment or the second embodiment is that the stirring speed in step one is 100 r / min-200 r / min, and the stirring time is 20 min-40 min; the dispersing agent in step one is sodium polyacrylate. The other steps are the same as those in the first embodiment or the second embodiment.

[0033] Specific implementation four: the difference between this embodiment and one of the first embodiment to the third embodiment is that the mass of the dispersing agent in step one is 5%-6% of the mass of the hydroxyapatite whisker; the mass of the hydroxyapatite whisker in step one to the volume ratio of deionized water is (15 g-25 g):(100 mL-150 mL). The other steps are the same as those in the first embodiment to the third embodiment.

[0034] Specific implementation five: the difference between this embodiment and one of the first embodiment to the fourth embodiment is that the binder in step two is silica gel; the mass of the binder in step two is 10% of the mass of the deionized water in step one. The other steps are the same as those in the first embodiment to the fourth embodiment.

[0035] Specific implementation six: the difference between this embodiment and one of the first embodiment to the fifth embodiment is that the stirring speed in step two is 300 r / min-400 r / min, and the stirring time is 20 min-40 min; the size of the mold in step two is Φ 28 mm x 27 mm; the time of the shade drying in step two is 12 h-20 h. The other steps are the same as those in the first embodiment to the fifth embodiment.

[0036] Specific implementation seven: the difference between this embodiment and one of the first embodiment to the sixth embodiment is that the temperature of the freeze-drying in step three is -70°C--74°C, the vacuum degree during the freeze-drying is 0.1 Pa, the freezing time is 3 h-5 h, and the freeze-drying time is 8 h-10 h; the process of the low-temperature drying in step three is: first drying at 50°C for 12 h-14 h, and then drying at 90°C for 12 h-14 h. The other steps are the same as those in the first embodiment to the sixth embodiment.

[0037] Embodiment eight: the difference between this embodiment and any one of embodiments one to seven is that the high-temperature sintering process in step three is: first sintering at 300°C for 1h~1.5h, then sintering at 800°C for 3h~4h, and finally cooling to room temperature with the furnace. The other steps are the same as embodiments one to seven.

[0038] Embodiment nine: the difference between this embodiment and any one of embodiments one to eight is that the heating rate in step four is 15°C / min~20°C / min; the holding time in step four is 15min~30min; and the holding and pressure-keeping time in step four is 1h~2h. The other steps are the same as embodiments one to eight.

[0039] Embodiment ten: the difference between this embodiment and any one of embodiments one to nine is that the volume fraction of hydroxyapatite whiskers in the hydroxyapatite whisker / WE43 magnesium alloy biological composite material in step four is 20%~30%. The other steps are the same as embodiments one to nine.

[0040] The beneficial effects of the present application are verified by the following examples:

[0041] Example 1: a method for preparing a hydroxyapatite whisker / WE43 magnesium alloy biological composite material by a vacuum pressure impregnation method, specifically completed by the following steps:

[0042] I. Add hydroxyapatite whiskers to deionized water, ultrasonic oscillation for 30min, then add a dispersing agent and stir for 30min to obtain a suspension;

[0043] The aspect ratio of the hydroxyapatite whiskers in step one is 20~50;

[0044] The frequency of the ultrasonic oscillation in step one is 30kHz;

[0045] The stirring speed in step one is 100r / min;

[0046] The dispersing agent in step one is sodium polyacrylate;

[0047] The mass of the dispersing agent in step one is 5.5% of the mass of the hydroxyapatite whiskers;

[0048] The mass of the hydroxyapatite whiskers in step one to the volume of the deionized water is 17g:100mL;

[0049] II. Add a binder to the suspension and stir to obtain a paste-like solution; pour the paste-like solution into a mold, press the paste-like solution to the height of the mold, and let it dry at room temperature for 12h to obtain a preform;

[0050] The binder in step two is silica gel;

[0051] The mass of the binder in step two is 10% of the mass of the deionized water in step one;

[0052] The stirring speed in step two is 300 r / min, and the stirring time is 30 min;

[0053] The size of the mold in step two is Φ 28 mm x 27 mm;

[0054] III. First, the preform is placed in a vacuum freeze dryer for freeze drying, then placed in a drying oven for low-temperature drying, and finally the dried preform is sintered at high temperature to obtain a sintered preform;

[0055] The temperature for freeze drying in step three is -74°C, the vacuum degree during freeze drying is 0.1 Pa, the freezing time is 3 h, and the freeze drying time is 8 h;

[0056] The process for low-temperature drying in step three is: first dried at 50°C for 12 h, then dried at 90°C for 12 h;

[0057] The process for high-temperature sintering in step three is: first sintered at 300°C for 1 h, then sintered at 800°C for 3 h, and finally cooled to room temperature with the furnace;

[0058] IV. The sintered preform is placed in a quartz mold, then a strip-shaped WE43 magnesium alloy is placed on the sintered preform, the quartz mold is then placed in a graphite crucible, and finally the graphite crucible is placed in a vacuum pressure impregnation device; open the mechanical pump to start vacuumizing the vacuum pressure impregnation device, when the system vacuum degree reaches 10 Pa, start heating, when it reaches 500°C, keep warm for 30 min, then heat to 730°C, keep warm for 15 min, to ensure that the WE43 magnesium alloy is melted; then close the vacuum valve, open the pressurization system, and introduce Ar gas to pressurize to 3.5 MPa, stop pressurizing, and keep warm and pressurized for another 90 min; finally, cool to room temperature with the furnace to obtain a hydroxyapatite whisker / WE43 magnesium alloy biological composite material (denoted as HA-20);

[0059] The heating rate in step four is 15°C / min;

[0060] The volume fraction of hydroxyapatite whiskers in the hydroxyapatite whisker / WE43 magnesium alloy biological composite material in step four is 20%.

[0061] Example 2: The difference between this example and Example 1 is that the mass of the hydroxyapatite whiskers to the volume of the deionized water in Step One is 22 g: 100 mL; the volume fraction of the hydroxyapatite whiskers in the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material in Step Four is 30% (denoted as HA-30). The other steps and parameters are the same as those in Example 1.

[0062] The WE43 magnesium alloy is denoted as HA-0.

[0063] Figure 1 The SEM image of the hydroxyapatite whisker powder;

[0064] It can be seen from Figure 1 that the aspect ratio of the hydroxyapatite whiskers is 20-50.

[0065] Figure 2 The OM image of the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared in Example 1;

[0066] It can be seen from Figure 2 that the hydroxyapatite whiskers are uniformly and randomly distributed in the magnesium alloy matrix, there are no obvious matrix defects, the whiskers do not occur segregation, and the grains of the matrix alloy are refined by the whiskers.

[0067] Figure 3 The SEM image of the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared in Example 1;

[0068] It can be seen from Figure 3 that the hydroxyapatite whiskers are white needle-shaped bodies, and the whiskers in the composite material sample are basically planar and randomly distributed and relatively uniformly distributed in the matrix.

[0069] Figure 4 The OM image of the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared in Example 2;

[0070] It can be seen from Figure 4 that the hydroxyapatite whiskers are uniformly and randomly distributed in the magnesium alloy matrix, there are no obvious matrix defects, the whiskers occur partial segregation, and the grains of the matrix alloy are refined by the whiskers.

[0071] Figure 5 The SEM image of the hydroxyapatite whisker / WE43 magnesium alloy biocomposite material prepared in Example 2;

[0072] It can be seen from Figure 5 that the hydroxyapatite whiskers are white needle-shaped bodies, and the whiskers in the composite material sample occur partial agglomeration in the matrix.

[0073] Figure 6XRD pattern of hydroxyapatite whisker / WE43 magnesium alloy biocomposite prepared in Example 1~2;

[0074] From Figure 6 It can be seen that there are HA, Mg, Mg 24 Y5, MgO and Ca3(PO4)2diffraction peaks, MgO, in the process of preparing HAw / WE43 biocomposite, there is free oxygen in the crucible, at the same time, there is a small amount of adsorbed oxygen on the surface of HAw, and these free oxygen forms MgO. Ca3(PO4)2is the product of high temperature and high pressure decomposition of hydroxyapatite.

[0075] Figure 7 Hardness pattern of WE43 magnesium alloy, hydroxyapatite whisker / WE43 magnesium alloy biocomposite prepared in Example 1~2;

[0076] From Figure 7 It can be seen that with the increase of the volume fraction of HAw, the Vickers hardness of the surface of the composite is higher, which is 107 and 127.88HV 0.2 , respectively, which is increased by 58% and 92% compared with the matrix 67.72HV 0.2 , respectively, which shows that hydroxyapatite whisker can play a role in improving the hardness of the material.

[0077] Figure 8 Elastic modulus pattern of WE43 magnesium alloy, hydroxyapatite whisker / WE43 magnesium alloy biocomposite prepared in Example 1~2;

[0078] From Figure 8 It can be seen that with the increase of the volume fraction of HAw, the elastic modulus of the composite is higher, which is 48.73 and 53.65GPa, respectively, which is increased by 18% and 30% compared with the matrix 41.02GPa, respectively, which shows that hydroxyapatite whisker can play a role in improving the elastic modulus of the material.

[0079] The sample was processed into a size of Φ28×5mm sample by wire cutting, polished from 200# to 2000# by SiC sandpaper, and then polished to a bright surface, and cleaned with acetone, anhydrous ethanol and deionized water in an ultrasonic cleaning machine, and the sample was naturally dried. Other non-working surfaces were sealed with silica gel to prevent contact with SBF solution. The medium solution used in the experiment was artificial simulated body fluid (SBF), and the specific composition is shown in Table 1, and the reagents used were all analytical pure. The reference electrode was saturated calomel electrode (SCE), and the platinum electrode (Pt electrode) was the auxiliary electrode. The pH value of the corrosion medium solution was adjusted to 7.20±0.05 by using HCl and NaOH solution, and the experimental temperature was maintained at 37±0.5°C in a constant temperature water bath; the test results are shown inFigure 12 as shown;

[0080] The sample was treated as above, and the sample size was Φ28x5mm. Then the side and bottom of the sample were coated with epoxy resin, leaving only 0.25cm 2 The surface to be tested was washed with a large amount of deionized water, then dried, and the surface adhering impurities were removed, and then placed in the simulated body fluid, and the plastic beaker containing SBF was placed in a 37°C constant temperature water bath, and the amount of hydrogen evolution and the pH value of the simulated body fluid were measured once a day; the test results are shown in Figure 10 、 Figure 11 as shown;

[0081] The degradation behavior of the corrosion sample was further studied by measuring the weight loss of the sample immersed in SBF solution at 37°C for 7 days. The corrosion sample was a Φ28x5mm composite sample. After immersion, the sample was removed and ultrasonically cleaned in a chromic acid solution (200gL -1 CrO3+10gL -1 AgNO3), and then further ultrasonically cleaned with distilled water and ethanol. Then, the sample was weighed to calculate the mass loss, and the surface morphology of the corrosion sample (with and without corrosion products) was characterized by scanning electron microscopy. The formula for calculating the corrosion rate is:

[0082] Corrosion rate (mm / y) = (KxW) / (AxTx D);

[0083] Where K is a constant (8.76x10 -4 ), W is the mass loss (G), A is the surface area of the corrosion sample (cm 2 ), T is the immersion time (H), and D is the density (g.cm -3 ); the test results are shown in Figure 9 as shown.

[0084] Table 1

[0085]

[0086] Figure 9 Degradation rate graph of WE43 magnesium alloy and hydroxyapatite whisker / WE43 magnesium alloy biocomposite prepared in Examples 1-2;

[0087] As can be seen from Figure 9 : the corrosion rates of all hydroxyapatite whisker / WE43 biocomposites are lower than that of WE43 magnesium alloy. This shows that the introduction of 20vol.% hydroxyapatite whiskers can improve the corrosion resistance of the composite material by a corresponding amount. The corrosion resistance of each sample from high to low is: HA-20>HA-30>HA-0, which verifies that the HA-20 composite material has better corrosion resistance.

[0088] Figure 10 Hydrogen evolution curves of hydroxyapatite whiskers / WE43 magnesium alloy biocomposites prepared in Examples 1-2 for WE43 magnesium alloy;

[0089] from Figure 10 It can be seen that the hydrogen evolution amount of each material after immersion, from high to low, is: HA-0 > HA-30 > HA-20. From the perspective of biomedical applications, if the implanted material releases too much hydrogen gas during the corrosion process in the body, it is easy to accumulate around the tissue and form bubbles, thereby delaying the tissue healing process.

[0090] Figure 11 pH value variation graphs of hydroxyapatite whiskers / WE43 magnesium alloy biocomposites prepared in Examples 1-2 for WE43 magnesium alloy;

[0091] from Figure 11 It can be seen that the pH value of the WE43 alloy sample increased most significantly, reaching its highest value within the same time period, indicating that its reaction was the most vigorous and that it released the most OH-. - The highest pH value was observed in the HA-20 sample throughout the immersion process, reflecting its lowest corrosion rate in the simulated body fluid.

[0092] Figure 12 Potentiodynamic polarization curves of hydroxyapatite whiskers / WE43 magnesium alloy biocomposites prepared in Examples 1-2 for WE43 magnesium alloy;

[0093] from Figure 12 It can be seen that when the volume fraction of hydroxyapatite whiskers is 20%, the Jcorr of the composite material is lower than that of the WE43 magnesium alloy, and the corrosion resistance is correspondingly improved. However, when the volume fraction of hydroxyapatite whiskers is 30%, Jcorr increases, indicating that the addition of excessive HAw has an adverse effect on the corrosion resistance of the composite material, making its corrosion resistance lower than that of the matrix alloy. Polarization potential (Ecorr), as a parameter reflecting the intrinsic corrosion potential of a material, usually indicates better corrosion resistance when its value shifts positively.

Claims

1. A method for preparing hydroxyapatite whisker / WE43 magnesium alloy bio-composite by vacuum pressure infiltration method, characterized in that The method is specifically completed in the following steps: I. Hydroxyapatite whiskers are added to deionized water, ultrasonic oscillation is performed, a dispersing agent is added, and stirring is performed to obtain a suspension; II. A binder is added to the suspension, stirring is performed to obtain a paste-like solution; the paste-like solution is poured into a mold, the paste-like solution is pressed to the height of the mold, and the paste-like solution is dried at room temperature to obtain a preform; III. The preform is first placed in a vacuum freeze dryer for freeze drying, then placed in a drying oven for low-temperature drying, and finally dried preform is high-temperature sintered to obtain a sintered preform; IV. The sintered preform is placed in a quartz mold, a strip-shaped WE43 magnesium alloy is placed on the sintered preform, the quartz mold is placed in a graphite crucible, and finally the graphite crucible is placed in a vacuum pressure impregnation device; a mechanical pump is opened to start vacuumizing the vacuum pressure impregnation device, when the vacuum degree of the system reaches 10 Pa-20 Pa, heating is started, when it reaches 500°C-550°C, it is kept warm, then it is heated to 700°C-750°C, and kept warm to ensure that the WE43 magnesium alloy is melted; then the vacuum valve is closed, the pressurizing system is opened, Ar gas is introduced, and the pressure is increased to 3.5 MPa-5 MPa, the pressurizing is stopped, and the pressure is kept; finally, the furnace is cooled to room temperature to obtain a hydroxyapatite whisker / WE43 magnesium alloy biological composite material.

2. A process for the preparation of hydroxyapatite whisker / WE43 magnesium alloy bio-composite by vacuum pressure infiltration as claimed in claim 1 wherein The length-diameter ratio of the hydroxyapatite whiskers in step I is 20-50; the frequency of the ultrasonic oscillation in step I is 30 kHz, and the ultrasonic oscillation time is 20 min-40 min.

3. A process for the preparation of hydroxyapatite whisker / WE43 magnesium alloy bio-composite by vacuum pressure infiltration as claimed in claim 1 wherein The stirring speed in step I is 100 r / min-200 r / min, and the stirring time is 20 min-40 min; the dispersing agent in step I is sodium polyacrylate.

4. A process for the preparation of hydroxyapatite whisker / WE43 magnesium alloy bio-composite by vacuum pressure infiltration as claimed in claim 1 wherein The mass of the dispersing agent in step I is 5%-6% of the mass of the hydroxyapatite whiskers; the mass of the hydroxyapatite whiskers to the volume of the deionized water in step I is (15 g-25 g):(100 mL-150 mL).

5. A process for the preparation of hydroxyapatite whisker / WE43 magnesium alloy bio-composite by vacuum pressure infiltration as claimed in claim 1 wherein The binder in step II is silica gel; the mass of the binder in step II is 10% of the mass of the deionized water in step I.

6. A process for the preparation of hydroxyapatite whisker / WE43 magnesium alloy bio-composite by vacuum pressure infiltration as claimed in claim 1 wherein The stirring speed in step II is 300 r / min-400 r / min, and the stirring time is 20 min-40 min; the size of the mold in step II is Φ28 mm*27 mm; the time of the dry in step II is 12 h-20 h.

7. A process for the preparation of hydroxyapatite whisker / WE43 magnesium alloy bio-composite by vacuum pressure infiltration as claimed in claim 1 wherein The temperature of the freeze drying in step III is -70°C--74°C, the vacuum degree during freeze drying is 0.1 Pa, the freezing time is 3 h-5 h, and the freeze drying time is 8 h-10 h; the low-temperature drying process in step III is: first drying at 50°C for 12 h-14 h, and then drying at 90°C for 12 h-14 h.

8. A process for the preparation of hydroxyapatite whisker / WE43 magnesium alloy bio-composite by vacuum pressure infiltration as claimed in claim 1 wherein The high-temperature sintering process in step III is: first sintering at 300°C for 1 h-1.5 h, then sintering at 800°C for 3 h-4 h, and finally cooling to room temperature.

9. A process for the preparation of hydroxyapatite whisker / WE43 magnesium alloy bio-composite by vacuum pressure infiltration as claimed in claim 1 wherein The temperature increasing speed in step four is 15-20 DEG C / min; the holding time in step four is 15-30 min; and the holding and pressure maintaining time in step four is 1-2 h.

10. A process for the preparation of hydroxyapatite whisker / WE43 magnesium alloy bio-composite by vacuum pressure infiltration as claimed in claim 1 wherein The volume fraction of the hydroxyapatite whisker in the hydroxyapatite whisker / WE43 magnesium alloy biological composite material in step four is 20-30%.

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