阅读说明：本技术 一种环抱式锌合金肋骨接骨板、加工方法及柔性成形装置 (Surrounding type zinc alloy rib bone fracture plate, processing method and flexible forming device ) 是由 王鲁宁 曹猛 石章智 孙金岭 姚生莲 李祯 李长恒 于 2021-10-26 设计创作，主要内容包括：本发明公开了一种环抱式锌合金肋骨接骨板,接骨板采用医用可降解锌合金制造,锌合金的力学强度达到TA1纯钛水平,降解速率适中,腐蚀均匀,无需二次手术,降低了病人的痛苦和医疗费用。还公开了接骨板加工方法,关键步骤采用交叉热温轧制,得到的锌合金板材沿初始轧向与垂直初始轧向的内部组织各向异性程度低,力学性能各向同性程度高,差异小于15%,进一步通过热塑成形得到锌合金肋骨接骨板,其抗弯性能优于TA1工业纯钛肋骨接骨板。还公开了柔性成形装置,可通过调节两个凸模的间距与两个凹模的间距,制备不同厚度、不同宽度肋骨接骨板。将所述凸模与凹模更换为不同侧面边缘曲率、不同长度的凸模与凹模,能够制备不同过渡圆弧曲率与不同长度接骨板。(The invention discloses an encircling type zinc alloy rib bone fracture plate which is made of medical degradable zinc alloy, the mechanical strength of the zinc alloy reaches the TA1 pure titanium level, the degradation rate is moderate, the corrosion is uniform, a secondary operation is not needed, and the pain and the medical expense of a patient are reduced. The zinc alloy rib bone fracture plate is further obtained through thermoplastic forming, and the bending resistance of the zinc alloy rib bone fracture plate is superior to that of a TA1 industrial pure titanium rib bone fracture plate. The flexible forming device can be used for preparing rib bone fracture plates with different thicknesses and different widths by adjusting the distance between the two male dies and the distance between the two female dies. The male die and the female die are replaced by the male die and the female die with different side edge curvatures and different lengths, so that bone fracture plates with different transition circular arc curvatures and different lengths can be prepared.)

1. The encircling type zinc alloy rib bone fracture plate is characterized in that the bone fracture plate is in an encircling type and is made of medical degradable zinc alloy materials.

2. The encircling zinc alloy rib bone plate according to claim 1, wherein the bone plate comprises a plate body and encircling claws connected to two sides of the plate body, the encircling claws are symmetrically distributed on two sides of the plate body, an included angle of 80-100 degrees is formed between the plate body and the encircling claws in a natural state, and an included angle of 140-180 degrees is formed between the plate body and the encircling claws in an implanted state.

3. The wrap around zinc alloy rib bone plate of claim 2, wherein a locking hole is provided in the plate body at the intersection of the plate body centerline and the wrap around claw centerline.

4. The encircling zinc alloy rib bone plate according to claim 2, wherein the end of the encircling claw far from the plate main body is provided with a circular arc structure, and the joint of the encircling claw and the plate main body is in circular arc transition connection.

5. A processing method of an encircling zinc alloy rib bone plate is characterized in that the processing method is used for manufacturing the encircling zinc alloy rib bone plate according to any one of claims 1 to 4, and the processing method comprises casting, cross hot-temperature rolling, processing of a blank of the rib bone plate, flexible forming and surface treatment.

6. The method for processing the encircling zinc alloy rib bone plate according to claim 5, wherein the casting comprises:

preparing a high-purity metal raw material according to alloy components, putting the raw material into smelting equipment for smelting, wherein the melt refining temperature is 500-750 ℃, pouring the melt into a mold supported by graphite, steel and the like after refining and heat preservation for 5-15 minutes, and cooling to obtain a zinc alloy ingot.

7. The method for processing the encircling zinc alloy rib bone plate according to claim 5, wherein the cross hot rolling comprises cross hot rolling and cross hot rolling;

the cross hot rolling comprises: rolling the zinc alloy cast ingot at 210-380 ℃ for at least 2 passes, wherein the single-pass deformation is 10-60%, rotating the rolled plate for 30-90 degrees every 1-2 passes, and feeding the rolled plate into a rolling mill, so that the rolling direction included angle of the rolled plate before and after rotation is 30-90 degrees, and obtaining a zinc alloy hot rolled plate;

the cross warm rolling comprises: rolling the zinc alloy hot rolled plate at 80-200 ℃ for at least 2 times, wherein the single-pass deformation is 20-70%, rotating the rolled plate at 30-90 degrees every 1-2 times, feeding the rolled plate into a rolling mill, enabling the rolling direction included angle of the rolled plate before and after rotation to be 30-90 degrees, and quenching to rapidly reduce the temperature of the plate to room temperature after cross warm rolling to obtain the zinc alloy plate.

8. The method for processing the encircling zinc alloy rib bone plate according to claim 5, wherein the processing of the rib bone plate blank comprises:

and cutting the zinc alloy plate according to a blank drawing to obtain a blank shape, and processing a locking hole to obtain the bone fracture plate blank.

9. The method for processing the encircling zinc alloy rib bone plate according to claim 5, wherein the flexible forming comprises:

placing the flexible forming device and the bone fracture plate blank into a heating furnace at 100-300 ℃ for preheating for 5-20 minutes;

placing the bone plate blank into the flexible forming device, and then placing the bone plate blank into a heating furnace for isothermal thermoplastic forming, wherein the forming temperature is 100-300 ℃, and the forming rate is 10^-5~10^-1s^-1After 10 minutes to 5 hours, the bone fracture plate is tightly attached to the female die, the encircling claw is bent by 80 to 100 degrees, and the thermoplastic forming is finished;

taking out the finished bone plate and cooling to room temperature.

10. A flexible forming device of an encircling zinc alloy rib bone fracture plate, which is used for processing the encircling zinc alloy rib bone fracture plate according to any one of claims 1 to 4, and is applied to the flexible forming process in the method for processing the encircling zinc alloy rib bone fracture plate according to any one of claims 5 to 9, wherein the flexible forming device comprises two upper die bases which are symmetrically distributed, upper die base screws capable of adjusting the distance between the two upper die bases are arranged on the two upper die bases, and a male die is arranged at the lower part of each upper die base;

the die comprises an upper die base and two lower die bases which are symmetrically distributed, wherein the two lower die bases are provided with lower die base screws capable of adjusting the distance between the two lower die bases, the upper part of each lower die base is provided with a female die, and the center of each lower die base screw is provided with a guide pillar which can penetrate through a limiting hole on the upper die base screw;

a forming cavity is formed between the male die and the female die;

keeping the distance between the two lower die seats unchanged, and adjusting the distance between the two upper die seats to change the gap distance between the male die and the female die and change the thickness of the bone plate; the space between the two upper die holders and the space between the two lower die holders are cooperatively adjusted, the gap distance between the male die and the female die is kept unchanged, and meanwhile, the space between the two male dies and the space between the two female dies are changed, so that the width of the bone fracture plate main body is changed.

Technical Field

The invention relates to a degradable metal medical implant instrument and the technical field of preparation and processing thereof, in particular to a surrounding type zinc alloy rib bone fracture plate, a processing method and a forming device.

Background

With the social development and the gradual popularization of vehicles, serious chest trauma caused by the fracture of a plurality of ribs of a victim in a traffic accident becomes a common symptom. The conservative treatment has many complications, the fixation by a rib bone fracture plate gradually becomes a trend, and the recovery effect is widely accepted.

At present, the rib bone fracture plate applied to clinical treatment is made of inert metal, and the utility model patent (ZL 201720848094.7) discloses a claw-shaped memory alloy rib bone fracture plate. The claw-shaped rib bone fracture plate is also called an encircling rib bone fracture plate and is characterized in that the encircling claw is used for fixing and combining the bone fracture plate and the ribs without using bone nails. In the operation, the embracing claw is bent by using a specific clip applier until the clip is tightly buckled on a broken rib to achieve the fixing effect, and at the moment, the embracing claw is bent to be close to 180 degrees. Common shape designs for such bone plates are as follows: the bone fracture plate main body is in a plate strip shape, two symmetrical groups of encircling claws are distributed on two sides of the plate main body, the encircling claws and the bone fracture plate main body form an included angle of 90 degrees, and the bone fracture plate is manufactured by deep processing of plates. Meanwhile, the bending part of the encircling claw has good plasticity so as to ensure that no fracture occurs in the surgical clamping process, and enough mechanical property is still kept after further bending, so that the rib and the bone fracture plate are firmly combined.

The existing bone fracture plate made of inert medical metal meets the requirements of strength and shape, but needs to be taken out by secondary operation, brings operation risk, and increases the pain of patients and medical expenses. In addition, inert metal rib plates have no biological activity and are difficult to perform medical functions of promoting bone tissue regeneration.

Among the degradable materials, the strength of the degradable metal is much higher than that of the high polymer material, and the utility model patent (ZL 201520145649.2) discloses a biodegradable magnesium alloy claw-shaped rib bone fracture plate. However, magnesium alloys corrode too quickly and produce hydrogen gas, resulting in the risk of premature failure of the bone plate.

Meanwhile, the sizes of the ribs of patients are different due to different ages, different body types and different injured parts, so that bone plates with different sizes and models are needed. The utility model patent (CN 201642285U) proposes the model classification of different length, width, height and embracing claw quantity. The use of conventional methods to prepare bone plates of different sizes requires corresponding multiple molds, which increases the cost of design and manufacture and makes it difficult to optimize the bone plates.

Disclosure of Invention

The invention provides an encircling zinc alloy rib bone fracture plate, a processing method and a flexible forming device, the bone fracture plate made of inert medical metal has the following problems that the bone fracture plate needs to be taken out by a secondary operation, the operation risk is brought, and the pain and the medical expense of a patient are increased; the bone fracture plate capable of degrading magnesium alloy has the following problems that the magnesium alloy is corroded too fast and generates hydrogen, so that the bone fracture plate has the risk of early failure; the traditional method has the following problems of high design and manufacturing cost and difficulty in optimizing and improving the bone fracture plate.

To solve the above technical problem, an embodiment of the present invention provides the following solutions:

the embodiment of the invention provides an encircling type zinc alloy rib bone fracture plate which is of an encircling type and is made of medical degradable zinc alloy materials.

Preferably, the bone fracture plate comprises a plate main body and surrounding claws connected to two sides of the plate main body and symmetrically distributed, an included angle of 80-100 degrees is formed between the plate main body and the surrounding claws in a natural state, and an included angle of 140-180 degrees is formed between the plate main body and the surrounding claws in an implanted state.

Preferably, a locking hole is formed in the plate main body at the intersection of the central line of the plate main body and the central line of the encircling claw.

Preferably, the end part of the encircling claw, which is far away from the plate main body, is of an arc-shaped structure, and the connection part of the encircling claw and the plate main body is in arc transition connection.

The embodiment of the invention provides a processing method of an encircling zinc alloy rib bone fracture plate, which is used for manufacturing the encircling zinc alloy rib bone fracture plate and comprises the steps of casting, cross hot-temperature rolling, processing of a rib bone fracture plate blank, flexible forming and surface treatment.

Preferably, the casting comprises:

preparing a high-purity metal raw material according to alloy components, putting the raw material into smelting equipment for smelting, wherein the melt refining temperature is 500-750 ℃, pouring the melt into a mold supported by graphite, steel and the like after refining and heat preservation for 5-15 minutes, and cooling to obtain a zinc alloy ingot.

Preferably, the cross hot warm rolling comprises cross hot rolling and cross warm rolling;

the cross hot rolling comprises: rolling the zinc alloy cast ingot at 210-380 ℃ for at least 2 passes, wherein the single-pass deformation is 10-60%, rotating the rolled plate for 30-90 degrees every 1-2 passes, and feeding the rolled plate into a rolling mill, so that the rolling direction included angle of the rolled plate before and after rotation is 30-90 degrees, and obtaining a zinc alloy hot rolled plate;

the cross warm rolling comprises: rolling the zinc alloy hot rolled plate at 80-200 ℃ for at least 2 times, wherein the single-pass deformation is 20-70%, rotating the rolled plate at 30-90 degrees every 1-2 times, feeding the rolled plate into a rolling mill, enabling the rolling direction included angle of the rolled plate before and after rotation to be 30-90 degrees, and quenching to rapidly reduce the temperature of the plate to room temperature after cross warm rolling to obtain the zinc alloy plate.

Preferably, the processing of the rib bone plate blank comprises the following steps:

and cutting the zinc alloy plate according to a blank drawing to obtain a blank shape, and processing a locking hole to obtain the bone fracture plate blank.

Preferably, the flexible shaping comprises:

placing the flexible forming device and the bone fracture plate blank into a heating furnace at the temperature of 100-300 ℃ for preheating for 5-20 minutes;

placing a bone fracture plate blank in the flexible forming device, and then placing the bone fracture plate blank in a heating furnace for isothermal thermoplastic forming, wherein the forming temperature is 100-300 ℃, and the forming rate is 10^-5~10^-1s^-1After 10 minutes to 5 hours, the bone fracture plate is tightly attached to the female die, the encircling claw is bent by 80 to 100 degrees, and the thermoplastic forming is finished;

taking out the finished bone plate and cooling to room temperature.

The embodiment of the invention provides a flexible forming device for an encircling zinc alloy rib bone fracture plate, which is used for processing the encircling zinc alloy rib bone fracture plate and applied to the flexible forming process in the method for processing the encircling zinc alloy rib bone fracture plate, wherein the flexible forming device comprises two upper die bases which are symmetrically distributed, upper die base screws capable of adjusting the distance between the two upper die bases are arranged on the two upper die bases, and a male die is arranged at the lower part of each upper die base;

the die comprises an upper die base and two lower die bases which are symmetrically distributed, wherein the two lower die bases are provided with lower die base screws capable of adjusting the distance between the two lower die bases, the upper part of each lower die base is provided with a female die, and the center of each lower die base screw is provided with a guide pillar which can penetrate through a limiting hole on the upper die base screw;

a forming cavity is formed between the male die and the female die;

keeping the distance between the two lower die seats unchanged, and adjusting the distance between the two upper die seats to change the gap distance between the male die and the female die and change the thickness of the bone plate; the space between the two upper die holders and the space between the two lower die holders are cooperatively adjusted, the gap distance between the male die and the female die is kept unchanged, and meanwhile, the space between the two male dies and the space between the two female dies are changed, so that the width of the bone fracture plate main body is changed.

The scheme of the invention at least comprises the following beneficial effects:

in the scheme, the encircling zinc alloy rib bone fracture plate is made of medical degradable zinc alloy, the mechanical strength of the zinc alloy reaches the TA1 pure titanium level, the degradation rate is moderate, the corrosion is uniform, the problem that the existing inert metal rib bone fracture plate needs to be taken out through a secondary operation is avoided, the inert metal rib bone fracture plate does not need to be taken out through the secondary operation, and the pain and medical expense of a patient are obviously reduced;

the processing method of the encircling zinc alloy rib bone fracture plate adopts a cross hot-warm rolling process to process the bone fracture plate, the zinc alloy plates obtained by cross hot-warm rolling have low anisotropy degree of internal tissues along the initial rolling direction and the vertical initial rolling direction, the isotropy degree of mechanical properties is high, the difference is less than 15%, and the bending resistance of the prepared zinc alloy rib bone fracture plate is superior to that of a TA1 industrial pure titanium rib bone fracture plate;

the movement of the upper die seat and the lower die seat of the flexible forming device is independent and does not influence each other; keeping the distance between the two lower die seats unchanged, adjusting the distance between the two upper die seats, and changing the gap distance between the male die and the female die, wherein the distance corresponds to the thickness of the rib bone fracture plate, and the adjustable range is 0-3 mm, so that the function of preparing rib bone fracture plates with different thicknesses is realized. The space between the two upper die holders and the space between the two lower die holders are cooperatively adjusted, so that the space between the two male dies can be simultaneously changed under the condition of keeping the gap distance between the male dies and the female dies unchangedWith two die intervals, this interval has corresponded the width of coaptation board main part, and adjustable range is 5~30mm, realizes the function of preparation different width coaptation boards from this. The male die and the female die are replaced by the male die and the female die with different side edge curvatures and different lengths, so that the function of preparing bone fracture plates with different transition circular arc curvatures and different lengths is realized, and the curvature range is 3-6 mm^-1The length range is 20-200 mm, rib bone fracture plates with various sizes and models can be prepared, the efficiency of iterative design is improved, and the range of application to patients and damage degree is wide; the guide pillar can be spacing upper die base, terrace die and coaptation board blank motion in vertical direction, makes it not take place the skew of horizontal direction in the hot plastic forming process, has guaranteed the accuracy nature of shaping, and shaping is effectual, and size precision is high.

Drawings

FIG. 1 is a blank view of a bone plate of the wrap-around zinc alloy rib bone plate of the present invention;

FIG. 2a is a front view of the encircling zinc alloy rib bone plate of the present invention;

FIG. 2b is a left side view of the encircling zinc alloy rib bone plate of the present invention;

FIG. 2c is a top view of the wrap-around zinc alloy rib bone plate of the present invention;

FIG. 3 is a product drawing of the encircling Zn-0.5Li alloy rib bone plate of the invention;

FIG. 4 is a first flowchart of a method for processing the encircling zinc alloy rib bone plate according to the present invention;

FIG. 5 is a second flowchart of the processing method of the encircling zinc alloy rib bone plate of the invention;

FIG. 6 is a microstructure of an encircling Zn-0.5Li alloy rib bone plate of the present invention;

FIG. 7 is a force-displacement curve for a biomechanical test for three metal rib plates;

FIG. 8 is a front view of the flexible forming apparatus of the present invention;

FIG. 9 is a perspective view of the flexible forming apparatus of the present invention.

Reference numerals:

11. a plate main body; 12. encircling the claw;

20. an upper die holder; 21. an upper die base screw; 22. a guide post; 23. a lower die holder; 24. a lower die base screw; 25. a male die; 26. and (5) forming a concave die.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

Example one

As shown in fig. 1, fig. 2a, fig. 2b, fig. 2c and fig. 3, the present embodiment provides an encircling type zinc alloy rib bone plate, wherein the bone plate is in an encircling type, and the bone plate is made of a medical degradable zinc alloy material. The encircling type zinc alloy rib bone fracture plate of the embodiment is made of medical degradable zinc alloy, the mechanical strength of the zinc alloy reaches the TA1 pure titanium level, the degradation rate is moderate, the corrosion is uniform, the problem that the existing inert metal rib bone fracture plate needs to be taken out through a secondary operation is avoided, the inert metal rib bone fracture plate does not need to be taken out through the secondary operation, and the pain and the medical expense of a patient are obviously reduced.

The bone fracture plate comprises a plate main body 11 and surrounding claws 12 which are symmetrically distributed on two sides of the plate main body 11, wherein the length of the plate main body 11 is 20-200 mm, the width of the plate main body is 5-30 mm, the thickness of the plate main body is 0.7-2.0 mm, the length of the surrounding claws 12 is 8-16 mm, the surrounding claws 12 are in arc transition connection with the joint of the plate main body 11, and the curvature of the surrounding claws is 3-6 mm^-1. Under a natural state, an included angle of 80-100 degrees is formed between the plate main body 11 and the surrounding claws 12, under an implantation state, the surrounding claws 12 are further bent under the force application of the bone fracture plate clamping forceps to tightly clamp the ribs, and an included angle of 140-180 degrees is formed between the plate main body 11 and the surrounding claws 12. The plate main body 11 is provided with a locking hole at the intersection of the central line of the plate main body 11 and the central line of the encircling claw 12, the end part of the encircling claw 12 far away from the plate main body 11 is of an arc-shaped structure, and the joint of the encircling claw 12 and the plate main body 11 is of an arc shapeTransition connection with curvature of 3-6 mm^-1. The size design of the bone plate of the embodiment can be applied to rib repair of patients of different ages and different damage degrees; the locking hole can provide a limiting function in the thermoplastic forming process, so that the forming accuracy of the bone fracture plate is ensured; the end part of the encircling claw 12 is provided with an arc-shaped structure, so that compared with the shape with sharp corners, the stress corrosion is effectively relieved, and the stimulation to biological tissues is weakened; the connection part of the encircling claw 12 and the plate main body 11 is in arc transition connection, so that stress concentration can be effectively relieved, and the fracture resistance of the device is improved.

The bone fracture plate is made of a medical degradable zinc alloy material, wherein the medical degradable zinc alloy material comprises Zn and at least one of Mn, Mg, Li, Ti, Cu, Ca, Sr, Fe, Ag, Zr, Ge, Nd, Y, La, Ce and Pr. The content of the alloying elements is (by default, the mass fraction): 0-10% of Mn, 0-10% of Mg, 0-5% of Li, 0-2% of Ti, 0-10% of Cu, 0-5% of Ca, 0-5% of Sr, 0-5% of Fe, 0-10% of Ag, 0-5% of Zr, 0-5% of Ge, 0-5% of Nd, 0-5% of Y, 0-10% of La, 0-10% of Ce, 0-10% of Pr and 0-10% of Pr, wherein the different percentages are 0. The addition of Mn, Cu and Ag can improve the plastic forming capability of the rolled plate, the addition of Mg, Li, Cu, Ca and Fe can improve the strength of the rib bone fracture plate, the addition of Ti, Zr and Ge can improve the degradation uniformity of the rib bone fracture plate, and the addition of Mg, Ca and Sr can improve the bone performance.

Example two

As shown in fig. 4, the present embodiment provides a processing method for manufacturing an encircling zinc alloy rib bone plate, wherein the processing method includes casting, cross hot rolling, processing of a rib bone plate blank, flexible forming and surface treatment. In the embodiment, the bone fracture plate is processed by adopting a cross hot-rolling process, the zinc alloy plate obtained by cross hot-rolling has low anisotropy degree of internal tissues along the initial rolling direction and the vertical initial rolling direction, the isotropy degree of mechanical properties is high, the difference is less than 15%, and the bending resistance of the prepared zinc alloy rib bone fracture plate is superior to that of a TA1 industrial pure titanium rib bone fracture plate.

As shown in fig. 5, the processing method of the encircling zinc alloy rib bone plate of the present embodiment may further include a step of applying a drug coating.

EXAMPLE III

As shown in fig. 4, the invention provides a processing method of an encircling zinc alloy rib bone fracture plate, which comprises the following steps:

and S1, casting, namely preparing a high-purity metal raw material according to alloy components, putting the raw material into a smelting device for smelting, wherein the melt refining temperature is 500-750 ℃, pouring the melt into a mold supported by graphite, steel and the like after refining and heat preservation for 5-15 minutes, and cooling to obtain the zinc alloy cast ingot. The raw material is preferably placed in a melting apparatus such as a vacuum induction melting furnace.

S2, performing cross hot-warm rolling, wherein the cross hot-warm rolling comprises cross hot rolling and cross warm rolling;

the cross hot rolling comprises: rolling the zinc alloy cast ingot at 210-380 ℃ for at least 2 passes, wherein the single-pass deformation is 10-60%, rotating the rolled plate for 30-90 degrees every 1-2 passes, and feeding the rolled plate into a rolling mill, so that the rolling direction included angle of the rolled plate before and after rotation is 30-90 degrees, and obtaining a zinc alloy hot rolled plate; the anisotropy degree of the internal structure of the hot rolled plate is obviously reduced, and the isotropy degree of the mechanical property of the hot rolled plate is obviously improved;

the cross warm rolling comprises: rolling the zinc alloy hot rolled plate at 80-200 ℃ for at least 2 passes, wherein the single-pass deformation is 20-70%, rotating the rolled plate at 30-90 degrees every 1-2 passes, feeding the rolled plate into a rolling mill, so that the rolling direction included angle of the rolled plate before and after rotation is 30-90 degrees, quenching, and rapidly cooling the temperature of the plate to room temperature after cross warm rolling to obtain a zinc alloy plate, wherein the zinc alloy plate has low anisotropy degree of an internal structure along the initial rolling direction and the vertical initial rolling direction, and has high isotropy degree of mechanical properties, and the difference is less than 15%;

in the process of cross hot-temperature rolling of the zinc alloy cast ingot, zinc grains are dynamically recrystallized in the rolling process, and the size (default equivalent diameter) is thinned to be less than 10 mm; the shape of the zinc crystal grain is mainly isometric crystal (namely the length/width ratio of the crystal grain is less than or equal to 2), and the proportion of the isometric crystal is more than 90 percent.

The cross hot-temperature rolling is particularly suitable for preparing hypereutectic Zn-Li-based zinc alloy (the Li content is more than 0.44 percent and the default is mass fraction) plates with high strength and high plasticity. Cross hot rollingSimultaneously refines the soft metal Zn phase and the hard intermetallic compound LiZn₄The grain structure of the phase is induced not only in the Zn phase during the cross warm rolling processPhase transition to form nano-network LiZn₄Precipitated phase, also in LiZn₄Induction in phaseThe phase transformation forms needle-shaped Zn precipitation phase, and simultaneously realizes Zn phase strengthening and LiZn₄And phase plasticization is carried out, so that the two phases have high strength and high ductility. The hypereutectic Zn-Li-based zinc alloy plate with high strength and high plasticity is obtained, has the room-temperature elongation of more than 20 percent and is suitable for deep processing into a rib bone fracture plate. In contrast, the existing hot-rolled hypereutectic Zn-Li-based zinc alloy plate has poor plasticity and room-temperature elongation of less than 5 percent, and is difficult to be deeply processed into the rib bone fracture plate.

S3, the processing of the rib bone plate blank comprises the following steps: and cutting the zinc alloy plate according to a blank drawing to obtain a blank shape, and processing a locking hole to obtain the bone fracture plate blank. Specifically, according to a blank drawing, a blank appearance is processed by means of linear cutting and the like, and a locking hole is processed by means of a bench drilling machine and the like.

S4, flexible forming comprises the following steps:

placing the flexible forming device and the bone fracture plate blank into a heating furnace at the temperature of 100-300 ℃ for preheating for 5-20 minutes;

placing a bone fracture plate blank in the flexible forming device, and then placing the bone fracture plate blank in a heating furnace for isothermal thermoplastic forming, wherein the forming temperature is 100-300 ℃, and the forming rate is 10^-5~10^-1s^-1After 10 minutes to 5 hours, the bone fracture plate is tightly attached to the female die 26, the encircling claw 12 is bent by 80 to 100 degrees, and the thermoplastic forming is finished;

taking out the finished bone plate and cooling to room temperature.

Specifically, the flexible forming device is adjusted to a specific size corresponding to the bone plate, a male die 25 and a female die 26 of the specific size are installed, and the bone plate blank is placed into a heating furnace at 100-300 ℃ to be preheated for 5-20 minutes. Spraying the male die 25 and the female die 26And a demolding agent is sprayed, so that demolding after forming is facilitated. The rib bone fracture plate blank is placed on the lower die base 23, the guide post 22 penetrates through a lock hole of the bone fracture plate, the upper die base 20 is assembled, and the guide post 22 penetrates through a limiting hole on the screw 21 of the upper die base. The flexible forming device and the bone fracture plate are placed in a heating furnace for isothermal thermoplastic forming, the forming temperature is 100-300 ℃, and the forming speed is 10^-5~10^-1s^-1. After 10 minutes to 5 hours, the rib bone fracture plate is tightly attached to the female die 26, the embracing claw 12 is bent by 80 to 100 degrees, and the thermoplastic forming is finished. And taking down the upper die base 20, taking out the finished product of the rib bone fracture plate, and cooling to room temperature.

S5, surface treatment, namely, grinding the surface of the finished bone fracture plate product by using sand paper until the finished bone fracture plate product has fresh metallic luster, grinding sharp edges introduced in the processing process, and cleaning the sharp edges by using water to obtain the rib bone fracture plate with a low-roughness clean surface, wherein the rib bone fracture plate is used as an implantation device and exerts the bone promoting effect of the zinc alloy.

As shown in fig. 5, the method for processing the encircling zinc alloy rib bone plate of the present embodiment may further include coating a drug coating;

s6, coating a drug coating, adding a polylactic acid elution coating on the surface of the bone fracture plate, wherein the thickness of the coating is 10-30 mm, and adding bioactive substances with the effect of promoting osteoblast proliferation, such as bone morphogenetic protein, parathyroid hormone and the like.

Specifically, in the process of coating the drug coating, the surface of the medical degradable zinc alloy rib bone plate of the embodiment is coated with the therapeutic drug and the coating, the thickness of the coating is 20mm, the coating is a polylactic acid elution coating, and meanwhile, bone morphogenetic protein with the effect of promoting osteoblast proliferation is added.

The processing method of the encircling zinc alloy rib bone fracture plate can prepare the zinc alloy plate with high strength, high plasticity and small structural property anisotropy by using the cross hot-temperature rolling technology, and the rib bone fracture plate prepared by the method has strong mechanical supporting capability and high degradation uniformity and can well realize rib repair.

The embodiment provides a processing method applied to a rib bone fracture plate with the thickness of 1.2mm, the width of a plate main body 11 of 15mm and the surrounding Zn-0.5Li alloy, and the processing method comprises the following steps:

s1, casting to obtain zinc alloy ingots with the components shown in the table 1, and performing primary refining on as-cast zinc alloy grains by using modes such as modification treatment, magnetic stirring and the like when smelting zinc alloy to obtain the zinc alloy ingots. The alloy components are defaulted to mass fractions;

s2, hot rolling the zinc alloy ingot into a plate by adopting a plastic deformation method of cross hot-temperature rolling, wherein the hot rolling temperature is 350 ℃, the warm rolling temperature is 100 ℃, and the plate is rotated by 90 ℃ in each pass. Controlling the total plastic deformation to be more than 90 percent to obtain the zinc alloy plate with the average grain size (equivalent diameter) of less than 10mm, wherein the thickness of the plate is 1.2 mm. Performing mechanical test on the zinc alloy plate along the initial rolling direction and the vertical initial rolling direction, wherein the difference between the tensile strength, the yield strength and the plasticity of the material in the two directions is less than 10 percent;

s3, cutting the zinc alloy plate by using a linear cutting method, and processing a locking hole by using a bench drilling machine to obtain a rib bone fracture plate blank;

s4, utilizing a flexible forming device, wherein the flexible forming device is matched with the rib bone plate with the thickness of 1.2mm and the width of the plate body 11 of 15mm in size. Carrying out isothermal thermoplastic forming on the bone plate blank by using the processing method of the third embodiment of the processing method to obtain a finished product of the rib bone plate;

and S5, processing the surface of the bone plate to eliminate machining residues and surface attachments. Specifically, the surface of the bone plate was sanded with fresh metallic luster, and sharp edges introduced during the processing were ground off, followed by washing with water.

The bone plate of the embodiment has the physical shape as shown in fig. 3, and the surface of the product is smooth and has no burrs. The microstructure is shown in FIG. 6, the alloy consists of equiaxed Zn grain structure and Zn + LiZn₄A lamellar structure in which the Zn grain structure has an average grain size (i.e., equivalent diameter) of 9.0. + -. 1.0mm, and Zn + LiZn₄The lamella spacing of the lamella tissue is 0.51 +/-0.10 mm.

The biomechanical bending test of the rib bone plate of the embodiment and a TA1 and pure Zn rib bone plate with the same size is shown in FIG. 7. The bending resistance of the Zn-0.5Li alloy rib bone plate is obviously superior to that of a pure Zn rib bone plate and also superior to that of a TA1 industrial pure titanium rib bone plate, and the fracture does not occur after a pressure head is pressed down for 10mm, so that the bending resistance is good. According to the standard GB10124-88, the rib bone plate is subjected to in-vitro degradation test for 30 days in simulated body fluid, and the degradation is uniform, and the corrosion rate is 20-80 mm/y within 30 days.

Processing the alloy ingots of Zn-0.5Li, Zn-0.8Li, Zn-0.5Li-0.1Ca, Zn-0.5Li-0.5Mg, Zn-0.8Li-0.1Ca and Zn-0.8Li-0.5Mg by using the traditional unidirectional hot rolling process, wherein the hot rolling temperature is 300 ℃ and the deformation is 90 percent. And performing linear cutting to obtain a blank of the rib bone fracture plate, wherein the surrounding claw 12 direction is along the rolling direction of the rolling plate during cutting. Although the direction of the encircling claw 12 which has the requirement on plasticity is along the rolling direction of the rolled plate during cutting, the hot rolling process causes poor plasticity of the zinc alloy, less than 5%, and part of the rib bone fracture plate blank is brittle-broken in the thermoplastic process. For the rest rib bone fracture plates capable of being normally formed, in a biomechanical bending test, because the plate main body 11 of the bone fracture plate is subjected to bending stress vertical to the rolling direction of the rolling plate, and the plasticity of the alloy vertical to the rolling direction is further inferior to that of the alloy along the rolling direction by more than 40%, the rib bone fracture plate is fractured in the test process, and the effect of fixing fractured ribs cannot be achieved. The bone fracture plate processed by the rib bone fracture plate processing method of the embodiment has the advantages of no fracture and good bending resistance.

The Zn-0.5Li zinc alloy rib bone plate of the embodiment is implanted into an adult sheep body (55 kg). The seventh rib of the experimental sheep was first beveled at 45 °, and then the fractured ribs were fixed using the rib bone plate of this example. After the operation, the implantation position of the rib bone fracture plate is observed by using X-rays, and the rib bone fracture plate has good visibility under the X-rays. The activity behaviors and physiological conditions of the experimental sheep are regularly checked during the experiment period, and no abnormality is found. After 3 months, the seventh rib and bone plate of some experimental sheep were removed, and the rib was evaluated histologically and the condition of the bone plate was evaluated. The bone integration level of the bone plate and the ribs is found to be good, the condition that the bone plate is loosened or fails does not occur, no crack exists at the bent part of the surrounding claw 12, and the bone plate begins to degrade. The fracture of the rib has obvious new bone tissue and blood vessel growth, the cortical bridging level is good, and the number of the bone body integral is restored to be close to the normal level. After 6 months, the seventh ribs and the bone fracture plate of the rest experimental sheep are taken out, and the bone fracture plate is found to be further degraded, so that the fracture lines basically disappear. The encircling medical degradable zinc alloy rib bone fracture plate can provide stable mechanical support for damaged bones, maintain mechanical properties until the damaged ribs are completely recovered, and can be gradually degraded in vivo.

TABLE 1 Zinc alloy ingot composition table

Example four

As shown in fig. 8-9, the present embodiment provides a flexible forming device for an encircling zinc alloy rib bone plate, which is used for processing the encircling zinc alloy rib bone plate, and which is applied to a flexible forming process in a method for processing an encircling zinc alloy rib bone plate, wherein the flexible forming device comprises two symmetrically distributed upper die bases 20, an upper die base screw 21 for adjusting the distance between the two upper die bases 20 is mounted on the two upper die bases 20, and a male die 25 is mounted on the lower portion of each upper die base 20; the die comprises an upper die base and two lower die bases 23 which are symmetrically distributed, wherein the two lower die bases 23 are provided with lower die base screws 24 capable of adjusting the distance between the two lower die bases 23, the upper part of each lower die base 23 is provided with a female die 26, the center of each lower die base screw 24 is provided with a guide pillar 22, the diameter of the guide pillar 22 is preferably 0.5-2 mm, and the guide pillar 22 can penetrate through a limiting hole on the upper die base screw 21; a forming cavity is formed between the male die 25 and the female die 26; keeping the distance between the two lower die holders 23 unchanged, and adjusting the distance between the two upper die holders 20 to change the gap distance between the male die 25 and the female die 26 and change the thickness of the bone plate; the distance between the two upper die holders 20 and the distance between the two lower die holders 23 are cooperatively adjusted, the gap distance between the male die 25 and the female die 26 is kept unchanged, and the width of the bone fracture plate main body 11 is changed by changing the distance between the two male dies 25 and the distance between the two female dies 26.

In the flexible forming device of the present embodiment, the movement of the upper die base 20 and the movement of the lower die base 23 are independent from each other and do not affect each other; keeping the distance between the two lower die holders 23 unchanged, adjusting the distance between the two upper die holders 20, and changing the gap distance between the male die 25 and the female die 26, wherein the distance corresponds to the thickness of the rib bone fracture plate, and the adjustable range is 0-3 mm, so that the function of preparing rib bone fracture plates with different thicknesses is realized. The space between the two upper die holders 20 and the space between the two lower die holders 23 are adjusted in a coordinated manner, so that the space between the two male dies 25 and the space between the two female dies 26 can be changed simultaneously under the condition that the gap distance between the male dies 25 and the female dies 26 is not changed, the space corresponds to the width of the bone fracture plate main body 11, and the adjustable range is 5-30 mm, so that the function of preparing bone fracture plates with different widths is realized. The male die 25 and the female die 26 are replaced by the male die 25 and the female die 26 with different side edge curvatures and different lengths, so that the function of preparing bone fracture plates with different transition circular arc curvatures and different lengths is realized, and the curvature range is 3-6 mm^-1The length range is 20-200 mm, the flexible forming device can be adjusted at will, rib bone fracture plates with various sizes and models can be prepared, the efficiency of iterative design is improved, and the range of application to patients and damage degree is wide; the guide pillar 22 of the embodiment can limit the movement of the upper die base 20, the male die 25 and the bone plate blank in the vertical direction, so that the movement does not generate horizontal deviation in the thermoplastic forming process, the forming accuracy is ensured, the forming effect is good, and the size precision is high.

Specifically, the two upper die holders 20 are connected by an upper die holder screw 21 which is horizontally arranged, the upper die holder 20 is horizontally moved by the upper die holder screw 21, the distance between the two upper die holders 20 is changed, and the position is fixed by a nut; the two lower die bases 23 are connected by a horizontally arranged lower die base screw rod 24, the lower die base screw rod 24 is utilized to realize the horizontal movement of the lower die base 23, the distance between the two lower die bases 23 can be changed, and the position fixation is carried out by utilizing nuts. The male die 25 and the upper die holder 20 can be connected through a bolt or a mortise and tenon structure, and the female die 26 and the lower die holder 23 can be connected through a bolt or a mortise and tenon structure.

Specifically, the shapes and positions of the male dies 25 and the female dies 26 are corresponding, the bottom profiles of the two male dies 25 enclose a rectangle, the bottom profiles of the two female dies 26 also enclose a rectangle, the long side of the rectangle corresponds to the length of the bone plate body 11, and the wide side of the rectangle corresponds to the width of the bone plate body 11. The edges of the side surfaces of the male die 25 and the female die 26 are arc-shaped, the radian is kept consistent, and the curvature is 3-6 mm^-1The curvature corresponds to the curvature of the circular arc at the connecting section of the plate body 11 and the surrounding claw 12 formed by the bone fracture plate through thermal plastic forming.

The dead weights of the upper die base 20 and the male die 25 of the embodiment are both 0.5-5 kg; the application means includes hydraulic pressure, placing a weight on the upper die holder 20, and the like. The flexible forming device is prepared from one or more of 15CrMo, 12Cr1MoV, 16Mo, 10Cr2Mo1, 25Cr2Mo1V and other heat-resistant steels.

EXAMPLE five

Application examples of the flexible forming device of the invention:

the size of the flexible forming device is adjusted through the upper die base screw rod 21 and the lower die base screw rod 24, and the curvature of the edge of the installation side surface is 3mm^-1A 40mm long punch 25 matched with a 1mm thick plate body 11 with a width of 11mm and a transition arc curvature of 3mm^-1A bone plate with the length of 20 mm;

placing the flexible forming device and the bone plate blank with the corresponding size into a 200 ℃ heating furnace for preheating for 15 minutes, and spraying a release agent on the male die 25 and the female die 26 after taking out;

placing a bone fracture plate blank on a lower die base 23, enabling a locking hole of the bone fracture plate to penetrate through a guide pillar 22 to ensure that the position of the bone fracture plate is accurate, pressing an upper die base 20 and a male die 25 on the bone fracture plate blank, and simultaneously enabling the guide pillar 22 to penetrate through a limiting hole of an upper die base screw 21 to ensure that the upper die base 20 and the male die 25 are always in the vertical direction in the pressing process;

and placing the combined bone fracture plate blank and the flexible forming device in a high-temperature resistance furnace, carrying out isothermal thermoplastic forming on the rib bone fracture plate, and pressing down by virtue of the self weights of the upper die holder 20 and the male die 25. Forming temperature 300 ℃ and strain rate 10^{- 4}s^-1After 30 minutes of forming, the bone plate is tightly attached to the lower die base 23 and the knot is formed by thermal formingBundling;

the upper die base 20 is taken down, the finished bone fracture plate is taken out, the temperature is cooled to the room temperature, and the encircling claw 12 has no rebound phenomenon. This results in a bone plate that is suitable for smaller sized, less damaged ribs.

EXAMPLE six

Another application embodiment of the flexible forming apparatus of the present invention:

the size of the flexible forming device is adjusted through the upper die base screw rod 21 and the lower die base screw rod 24, and the curvature of the edge of the installation side surface is 5mm^-1A punch 25 with a length of 100mm, and the thickness of the punch 25 is 1.5mm, the width of the plate body 11 is 15mm, and the curvature of the transition arc is 5mm^-1And a rib bone plate with the length of 100 mm. The bone plate blank is processed in the manner of the first embodiment to obtain the bone plate suitable for the ribs with larger size and higher damage degree.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.