CN111910151A

CN111910151A - Bullet body, preparation method thereof and medical instrument

Info

Publication number: CN111910151A
Application number: CN202010815890.7A
Authority: CN
Inventors: 唐鹏; 郭朝乾; 洪悦; 苏一凡; 王红莉; 汪唯; 唐春梅; 王磊; 韦春贝; 石倩; 林松盛; 代明江
Original assignee: Guangdong Institute of New Materials
Current assignee: Guangdong Institute of New Materials
Priority date: 2020-08-14
Filing date: 2020-08-14
Publication date: 2020-11-10

Abstract

The invention discloses a bullet body, a preparation method thereof and a medical instrument, and relates to the technical field of surface coating. The bullet body comprises a bullet body and a composite film layer coated on the surface of the bullet body, wherein the composite film layer sequentially comprises a nitride film layer, a metal carbide film layer and a diamond-like carbon film layer from inside to outside. The preparation method of the bullet body is to form a composite film layer on the bullet body, the medical instrument comprises the bullet body, the composite film layer is a self-lubricating film layer with high hardness, high binding force, low friction coefficient and high wear resistance, and the bullet body has excellent wear resistance and self-lubricating performance after the diamond-like composite film layer is deposited on the surface, so that the frictional wear failure process of the bullet body under high-speed motion can be effectively delayed, the service life of the bullet body is obviously prolonged, and the medical instrument has wide application prospects.

Description

Bullet body, preparation method thereof and medical instrument

Technical Field

The invention relates to the technical field of surface coating, and particularly relates to a bullet body, a preparation method thereof and a medical apparatus.

Background

The friction wear failure is a main failure mode of a key part of a medical instrument in high-speed motion, and takes a pneumatic ballistic shock wave therapeutic apparatus with great efficacy for treating diseases such as delayed union of fracture, calcified tendonitis and the like as an example, a bullet of the key part of the therapeutic apparatus in high-speed motion moves back and forth in a ballistic trajectory at high speed, and is easy to fail due to long-time and frequent friction with the inner wall of a cylinder.

At present, the use frequency of the bullet body of the imported shock wave therapeutic apparatus is generally 100-500 ten thousand times, while the use frequency of the bullet body made in China is only about 10 ten thousand times. The bullet body is used as a consumable part, needs to be replaced together with the cylinder after failure, cannot be independently purchased with the cylinder and needs to be purchased with the whole machine. That is, the service life of the bullet body directly determines the use efficiency and the operation cost of the pneumatic ballistic shockwave treatment apparatus. If the technical problem that the bullet body is worn out due to friction and is invalid can be solved, the domestic manufacture of the shock wave therapeutic apparatus can be realized, and the bullet body and the cylinder only need to be replaced, so that the method has important significance for the domestic manufacture of medical instruments.

However, the present invention is provided for solving the problems of poor wear resistance and low strength of the existing bullet body.

Disclosure of Invention

The invention aims to provide a bullet body, which aims to improve the wear resistance of the bullet body and delay the frictional wear failure of the bullet body under high-speed motion.

Another object of the present invention is to provide a method for preparing a bullet body, which effectively solves the problem of frictional wear failure of the bullet body and significantly prolongs the service life of the bullet body.

A third object of the present invention is to provide a medical device which has an advantage of long service life and can significantly extend the replacement cycle of parts such as bullets.

The technical problem to be solved by the invention is realized by adopting the following technical scheme.

The invention provides a bullet body which is used for reciprocating in a medical instrument and comprises a bullet body and a composite film layer coated on the surface of the bullet body, wherein the composite film layer sequentially comprises a nitride film layer, a metal carbide film layer and a diamond-like carbon film layer from inside to outside.

The invention also provides a preparation method of the bullet body, which comprises the following steps: and forming a composite film layer on the bullet body.

The invention also provides a medical apparatus comprising the bullet body.

The embodiment of the invention provides a bullet body and a preparation method thereof, and the bullet body has the beneficial effects that: the nitride film layer, the metal carbide film layer and the diamond-like carbon film layer are sequentially formed on the bullet body, so that the wear resistance and the wear reduction performance of the bullet body can be effectively improved, and the service life of the bullet body is prolonged.

The embodiment of the invention also provides a medical apparatus which comprises the bullet body, and through the improvement of the bullet body, the frictional wear failure of the bullet body under the high-speed motion is delayed, and the service life of equipment is prolonged.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic structural diagram of a projectile according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a film structure of a bullet surface according to an embodiment of the present invention;

FIG. 3 is a graph showing the results of a dry friction performance test of a surface coating based on a bullet according to an embodiment of the present invention;

FIG. 4 is a scratch pattern of a surface coating on a bullet-shaped substrate according to an embodiment of the present invention.

Icon: 100-a bullet body; 101-a body of a bullet; 102-a composite film layer; 103-a nitride film layer; 104-a metal film layer; 105-a metal carbide film layer; 106-diamond-like film layer with dopant; 107-diamond-like carbon film layer.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The following provides a detailed description of a bullet, a method for preparing the same, and a medical device.

Referring to fig. 1-2, an embodiment of the present invention provides a bullet 100 for reciprocating in a medical device, including a bullet body 101 and a composite film layer 102 coated on a surface of the bullet body 101, wherein the composite film layer 102 sequentially includes a nitride film layer 103, a metal film layer 104, a metal carbide film layer 105, a diamond-like film layer 106 with dopants, and a diamond-like film layer 107 from inside to outside.

It should be noted that, by sequentially depositing five film layers, namely, a nitride film layer 103, a metal film layer 104, a metal carbide film layer 105, a diamond-like film layer 106 with dopants and a diamond-like film layer 107, on the bullet body 101, the inventor remarkably improves the wear resistance of the bullet body 100, effectively improves the overall hardness, bonding force, wear resistance and self-lubricating property of the surface of the bullet body, delays the frictional wear failure of the bullet body under high-speed motion, and prevents the economic loss caused by frequently replacing the bullet body 100.

In some embodiments, the metal film layer 104 and the diamond-like film layer 106 with dopant may not be introduced, which still has better friction resistance, but the bonding force of the film layer will be reduced to some extent.

Further, the nitride film layer 103 is a film layer formed of a nitride of at least one element of Cr, Ti, and Zr; preferably CrN; preferably, the thickness of the nitride film layer 103 is 0.2um to 1.5 um. The inventor finds that the wear resistance and strength of the material can be further improved by adopting the film layer formed by CrN compared with other nitrides.

Further, the metal film layer 104 is a film layer formed of at least one metal of Cr, Ti, Zr, and W; more preferably a film layer formed of Cr; preferably, the thickness of the metal film layer 104 is 0.1um to 1 um. And meanwhile, Cr is used as a coating material of the metal film layer, so that the wear resistance of the film layer can be further improved, and the service life of the bullet body is prolonged.

Further, the metal carbide film layer 105 is obtained by alternately depositing a metal film layer and a carbide film layer; preferably, the metal film layer in the metal carbide film layer 105 is a film layer formed of at least one of Zr, Ti, Cr, and W; the carbide film layer in the metal carbide film layer 105 is a film layer formed by at least one of ZrC, TiC, CrC and WC; preferably, the metal carbide film layer 105 has a thickness of 0.1um to 1 um. The mode of alternately depositing the metal film layer and the carbide film layer is favorable for obtaining the self-lubricating film layer with high hardness, high binding force, low friction coefficient and high wear resistance, so that the frictional wear failure of the bullet body under high-speed motion can be effectively delayed, and the service life of the bullet body is obviously prolonged.

In some preferred embodiments, the metal film layer of the metal carbide film layer 105 is a film layer formed of Cr, the carbide film layer of the metal carbide film layer 105 is a film layer formed of WC, and the wear resistance of the film layer can be further improved by matching the Cr film layer with the WC film layer.

Further, the doping element in the diamond-like film layer 106 with the dopant is selected from at least one of Cr, Ti, Zr, and W; preferably, the doping element is W, and the thickness of the diamond-like film layer 106 with the dopant is 0.2um to 1.5 um; the diamond-like film layer 106 with the dopant can significantly improve the bonding force between the film layers, and is beneficial to further improving the hardness and wear resistance of the film layers.

Further, the diamond-like carbon film layer 107 is an amorphous carbon film; preferably, the diamond-like film layer 107 is selected from any one of a metal-doped amorphous carbon film, a hydrogen-containing amorphous carbon film, and a metal-doped hydrogen-containing amorphous carbon film; the thickness of the diamond-like carbon film layer 107 is 0.5um to 3 um. The diamond-like film layer 107 may be made of any material, such as a diamond-like film. The diamond-like film layers are all the existing film layer materials and are not described in detail.

The inventor needs to point out that the surface roughness of the diamond-like carbon film layer is Ra0.03-0.1 um, the film-substrate bonding force is 50-100N, the friction coefficient is 0.05-0.2, and the microhardness is Hv 2000-7000 through the improvement of the bullet body 100 film layer. The composite film layer 102 is a self-lubricating film layer with high hardness, high binding force, low friction coefficient and high wear resistance, can remarkably improve the wear resistance of the bullet body, further prolongs the service life of the bullet body, and has a very good application prospect.

The embodiment of the invention also provides a preparation method of the bullet body, which comprises the following steps: the composite film layer is formed on the bullet body, so that the wear resistance and the wear reduction performance of the film layer can be effectively improved, and the service life of the bullet body is prolonged.

Specifically, each layer in the composite film layer is formed in a manner independently selected from any one of a Physical Vapor Deposition (PVD) method, a plasma enhanced chemical vapor deposition (PE-CVD) method and an ion source coating method, wherein the PVD method is a magnetron sputtering method or an arc ion plating method. The above coating methods are all the existing methods, and the principle thereof is not described in detail.

In a preferred embodiment, the nitride film layer 103, the metal film layer 104, the metal carbide film layer 105 and the diamond-like film layer 106 with dopant are all formed by magnetron sputtering, and the diamond-like film layer is formed by plasma enhanced chemical vapor deposition or ion source coating. The inventor further improves the binding force of the film layers by selecting the forming mode of each film layer, and is beneficial to improving the wear-resisting and friction-reducing performances of the film layers.

In a preferred embodiment, before coating on the bullet body, a plasma etching method is adopted for pretreatment, so as to improve the deposition effect of the film layer and further improve the bonding force of the film layer.

Further, in the process of forming the nitride film layer 103 by using the magnetron sputtering method, the deposition time is 70-80 min, the nitrogen flow is 50-70 mL/min, the sputtering power is 4.5-5.5 kw, and the argon flow is 110-130 mL/min. In the process of forming the metal film layer 104 by adopting a magnetron sputtering method, the deposition time is 10-15 min, the sputtering power is 4.5-5.5 kw, and the argon flow is 110-130 mL/min. In the process of forming the metal carbide film layer 105 by adopting a magnetron sputtering method, metal and carbide are alternately deposited, the deposition time is 15-25min, the sputtering power of a metal target and the sputtering power of a carbide target are both 0.5-5.0 kw, and the flow of argon is 110-130 mL/min. In the process of forming the diamond-like film layer 106 with the dopant by adopting a magnetron sputtering method, the deposition time is 40-60 min, the sputtering power is 4.5-5.5 kw, the acetylene flow is 40-50 mL/min, and the argon flow is 110-130 mL/min. In the process of forming the diamond-like carbon film layer 107 by adopting a plasma enhanced chemical vapor deposition method, the deposition time is 250-350 min, the bias voltage is 0-750V, and the acetylene flow is 200-500 mL/min.

It should be noted that the inventor further optimizes the coating process of each film layer, and further ensures the binding force and wear-resistant performance of the film layer, thereby prolonging the service life of the bullet body.

The embodiment of the invention also provides a medical apparatus, which comprises the bullet body; the medical apparatus is selected from one of shock wave therapeutic apparatus and vibration type physical therapeutic apparatus. The bullet-shaped.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

The embodiment provides a preparation method of a bullet body, which comprises the following steps:

s1: cleaning bullet body 101 in full-automatic cleaning line for 40min, clamping, placing in vacuum chamber, heating to 100 deg.C, evacuating to 4 × 10%^-3Vacuum degree above Pa.

S2: the cleaned bullet body 101 is pretreated by adopting a plasma etching technology of multifunctional vacuum coating equipment, wherein plasma etching parameters are as follows: bias voltage 200V, auxiliary anode current 65A, argon flow 60 mL/min.

S3: the pretreated bullet body 101 is subjected to magnetron sputtering technology of multifunctional vacuum coating equipment, a TiN film layer (nitride film layer 103) is deposited firstly, the deposition time is 75min, and magnetron sputtering parameters are as follows: the nitrogen flow is 60mL/min, the Ti target power is 5kw, and the argon flow is 120 mL/min.

S4: and (5) depositing a metal Ti film layer (a metal film layer 104) by adopting a magnetron sputtering technology on the basis of the step S3 for 12min, wherein the magnetron sputtering parameters are as follows: the Ti target power was 5kw, and the argon flow was 120 mL/min.

S5: and (3) depositing a metal Ti film layer and a WC film layer alternating film layer (a metal carbide film layer 105) by adopting a magnetron sputtering technology on the basis of the step S4, wherein the deposition time is 18min, and magnetron sputtering parameters are as follows: the Ti target power is 3kw, the WC target power is 3kw, and the argon flow is 120 mL/min.

S6: depositing a tungsten-doped diamond-like film layer (the diamond-like film layer 106 with dopants) by adopting magnetron sputtering and PE-CVD composite on the basis of the step S5, wherein the deposition time is 50min, and magnetron sputtering parameters are as follows: the WC target power is 5kw, the acetylene gas flow rate is 45mL/min, and the argon flow rate is 120 mL/min.

S7: and (5) depositing a diamond-like film layer (diamond-like film layer 107) by adopting a PE-CVD technology on the basis of the S6, wherein the deposition time is 300min, and the PE-CVD deposition parameters are as follows: the bias voltage was 500V and the acetylene flow rate was 200 mL/min.

S8: when the temperature in the furnace is lower than 150 ℃, the bullet body of the moving part of the medical instrument with the multi-layer structural film layer can be obtained.

Example 2

s1: cleaning bullet 100 in full-automatic cleaning line for 40min, clamping, heating to 100 deg.C, pumping to 4 × 10^-3Vacuum degree above Pa.

S2: and (3) carrying out pretreatment on the cleaned bullet body substrate by adopting a plasma etching technology of multifunctional vacuum coating equipment, wherein plasma etching parameters are as follows: bias voltage 220V, auxiliary anode current 80A, argon flow 60 mL/min.

S3: the pretreated bullet body substrate is subjected to magnetron sputtering technology of multifunctional vacuum coating equipment, a CrN film layer (nitride film layer 103) is deposited firstly, the deposition time is 75min, wherein magnetron sputtering parameters are as follows: the nitrogen flow is 60mL/min, the Cr target power is 5kw, and the argon flow is 120 mL/min.

S4: and (5) depositing a metal Cr film layer (a metal film layer 104) by adopting a magnetron sputtering technology on the basis of the step S3, wherein the deposition time is 12min, and magnetron sputtering parameters are as follows: the Cr target power was 5kw, and the argon flow was 120 mL/min.

S5: and (3) depositing a metal Cr film layer and a WC film layer alternating composite film layer (a metal carbide film layer 105) by adopting a magnetron sputtering technology on the basis of the step S4, wherein the deposition time is 18min, and magnetron sputtering parameters are as follows: the Cr target power is 3kw, the WC target power is 3kw, and the argon flow is 120 mL/min.

S6: and (3) depositing a tungsten-doped diamond-like film layer (the diamond-like film layer 106 with dopants) by adopting magnetron sputtering and PE-CVD technology on the basis of the step S5 for 50min, wherein magnetron sputtering parameters are as follows: the WC target power is 5kw, the acetylene gas flow rate is 45mL/min, and the argon flow rate is 120 mL/min.

S7: and (5) depositing a diamond-like film layer (diamond-like film layer 107) by adopting a PE-CVD technology on the basis of the S6, wherein the deposition time is 300min, and the PE-CVD deposition parameters are as follows: bias voltage 750V, acetylene flow 500 mL/min.

S8: when the temperature in the furnace is lower than 150 ℃, the bullet body of the medical apparatus and instrument high-speed movement key part with the multi-layer structure film layer can be obtained.

Example 3

This example provides a method for preparing a bullet, which is different from example 2 only in S3-S7, specifically as follows:

s3: the pretreated bullet body matrix is subjected to magnetron sputtering technology of multifunctional vacuum coating equipment, a ZrN film layer (nitride film layer 103) is firstly deposited for 70min, wherein magnetron sputtering parameters are as follows: the nitrogen flow rate was 50mL/min, the Zr target power was 4.5kw, and the argon flow rate was 110 mL/min.

S4: and (5) depositing a metal Zr film layer (a metal film layer 104) by adopting a magnetron sputtering technology on the basis of the step S3 for 10min, wherein the magnetron sputtering parameters are as follows: the Zr target power was 4.5kw, and the argon flow was 110 mL/min.

S5: and (3) depositing a metal Zr film layer and a WC film layer alternating composite film layer (a metal carbide film layer 105) by adopting a magnetron sputtering technology on the basis of the step S4, wherein the deposition time is 15min, and magnetron sputtering parameters are as follows: the Zr target power is 0.5kw, the WC target power is 0.5kw, and the argon flow is 110 mL/min.

S6: and (3) depositing a tungsten-doped diamond-like film layer (the diamond-like film layer 106 with dopants) by adopting magnetron sputtering and PE-CVD technology on the basis of the step S5 for 40min, wherein magnetron sputtering parameters are as follows: the WC target power is 4.5kw, the acetylene gas flow is 40mL/min, and the argon flow is 110 mL/min.

S7: and (5) depositing a diamond-like film layer (diamond-like film layer 107) by adopting a PE-CVD technology on the basis of the S6, wherein the deposition time is 250min, and the PE-CVD deposition parameters are as follows: the bias voltage was 500V and the acetylene flow rate was 200 mL/min.

Example 4

s3: the pretreated bullet body substrate is subjected to magnetron sputtering technology of multifunctional vacuum coating equipment, a CrN film layer (nitride film layer 103) is firstly deposited for 80min, wherein magnetron sputtering parameters are as follows: the nitrogen flow is 70mL/min, the Cr target power is 5.5kw, and the argon flow is 130 mL/min.

S4: and (5) depositing a metal Cr film layer (a metal film layer 104) by adopting a magnetron sputtering technology on the basis of the step S3 for 15min, wherein the magnetron sputtering parameters are as follows: the Cr target power was 5.5kw, and the argon flow was 130 mL/min.

S5: and (3) depositing a metal Cr film layer and a WC film layer alternating composite film layer (a metal carbide film layer 105) by adopting a magnetron sputtering technology on the basis of the step S4, wherein the deposition time is 25min, and magnetron sputtering parameters are as follows: the Cr target power is 5kw, the WC target power is 5kw, and the argon flow is 130 mL/min.

S6: and (3) depositing a tungsten-doped diamond-like film layer (the diamond-like film layer 106 with dopants) by adopting magnetron sputtering and PE-CVD technology on the basis of the step S5 for 60min, wherein magnetron sputtering parameters are as follows: the WC target power is 5.5kw, the acetylene gas flow is 50mL/min, and the argon flow is 130 mL/min.

S7: and (5) depositing a diamond-like film layer (diamond-like film layer 107) by adopting a PE-CVD technology on the basis of the S6, wherein the deposition time is 350min, and the PE-CVD deposition parameters are as follows: bias voltage 750V, acetylene flow 500 mL/min.

Example 5

This example provides a method for preparing a bullet, which is different from example 2 only in that: the coating of the metal film layer 104 and the diamond-like film layer 106 with dopants is not performed.

Comparative example 1

This comparative example provides a method of making a ballistic body, differing from example 2 only in that: without S5, the diamond-like film 106 with dopant is deposited directly on the basis of step S4.

Comparative example 2

This comparative example provides a method of making a ballistic body, differing from example 2 only in that: without S4, the metal carbide film layer 105 was deposited directly on the basis of S3.

Experimental example 1

The surface film layers provided in the examples were subjected to performance tests, and the results are shown in fig. 3, and the dry friction coefficient and wear life of the workpiece surface coating were evaluated by using an MS-T3000 friction wear tester, and the specific experimental conditions were: the friction experiment adopts a ball-disk circumferential sliding mode, the atmospheric environment, the temperature is 20-23 ℃, the relative humidity is 55-70%, the friction dual ball is a Si3N4 ball with phi 4mm, the rotating radius is 18mm, the load is 500g, the rotating speed is 400r/mim, and the friction time is 150 min.

The test result shows that: the workpiece surface coating of example 2 had an average coefficient of friction of 0.14 and a wear rate of 6.63X 10^-17m³/Nm。

The workpiece surface coating of example 5 had an average coefficient of friction of 0.16 and a wear rate of 2.54X 10^-18m³/Nm。

The average friction coefficient of the surface coating of the workpiece in comparative example 1 was 0.15 and the wear rate was 8.94X 10^-17m³/Nm。

The average friction coefficient of the surface coating of the workpiece in comparative example 2 was 0.14 and the wear rate was 9.95X 10^-17m³/Nm。

Experimental example 2

The bonding force of the surface film layer provided by the embodiment is evaluated, and the experimental conditions are as follows: the base material is YG6, the sample flatness is 0.01mm, the loading rate is 100N/min, the moving rate is 5mm/min, the radius of the pressure head tip is 0.2mm, the temperature is 20-22 ℃, the relative humidity is 55-60%, 5 lines are drawn, and the average value is taken.

Referring to fig. 4, the test results of example 2 show that: the average film-substrate binding force of the film layer is 100N, no peeling occurs at the scratch edge, and the coating binding force is good.

The average film-based bonding force of the film layer in example 5 was 51N.

The average film-based bonding force of the film layer in comparative example 1 was 67N.

The average membrane-based bonding force of the membrane layer in comparative example 2 was 69N.

Experimental example 3

The surface coatings provided in the examples were subjected to vickers microhardness testing, and the hardness of the coatings was evaluated using an MH-5D type microhardness tester under the following specific experimental conditions: the load is 25g, the time is 15s, the temperature is 20-23 ℃, the relative humidity is 55-70%, 5 points are measured, and the average value is taken.

The test results show that examples 2 and 5 and comparative examples 1 and 2 all provide film layers with average hardness exceeding 2000HV0.025, which is much higher than the hardness of the bullet body (about 500HV 0.025).

Experimental example 4

The number of uses of the neutron elastomers in examples 2, 5 and comparative examples 1, 2 was tested, test method: collaboratively developed medical device companies provide data.

The test results showed that the numbers of times of use of the neutron elastomers in examples 2 and 5 were 500 ten thousand and 100 ten thousand or more, respectively, and the numbers of times of use of the neutron elastomers in comparative examples 1 and 2 were 200 ten thousand or more and 220 ten thousand or more, respectively.

In summary, according to the bullet body and the preparation method thereof provided by the invention, the nitride film layer, the metal carbide film layer and the diamond-like carbon film layer are sequentially formed on the bullet body, so that the wear resistance and the wear reduction performance of the bullet body can be effectively improved, and the service life of the bullet body is prolonged.

The invention also provides a medical apparatus which comprises the bullet body, and through the improvement of the bullet body, the frictional wear failure of the bullet body under the high-speed motion is delayed, and the service life of equipment is prolonged.

The embodiments described above are some, but not all embodiments of the invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Claims

1. A bullet body is used for reciprocating in a medical instrument and is characterized by comprising a bullet body and a composite film layer coated on the surface of the bullet body, wherein the composite film layer sequentially comprises a nitride film layer, a metal carbide film layer and a diamond-like carbon film layer from inside to outside.

2. The bullet body according to claim 1, wherein said nitride film layer is a film layer formed of a nitride of at least one element of Cr, Ti and Zr; preferably CrN;

preferably, the thickness of the nitride film layer is 0.2 um-1.5 um.

3. The bullet body of claim 1 wherein said metal carbide film layers are alternately deposited with metal film layers and carbide film layers;

preferably, the metal film layer in the metal carbide film layer is a film layer formed of at least one of Zr, Ti, Cr and W; the carbide film layer in the metal carbide film layer is a film layer formed by at least one of ZrC, TiC, CrC and WC;

more preferably, the metal film layer in the metal carbide film layer is a film layer formed of Cr; the carbide film layer in the metal carbide film layer is a film layer formed of WC;

preferably, the thickness of the metal carbide film layer is 0.1um to 1 um.

4. The bullet body of claim 1 wherein said diamond-like film layer is an amorphous carbon film; preferably, the diamond-like film layer is selected from any one of a metal-doped amorphous carbon film, a hydrogen-containing amorphous carbon film and a metal-doped hydrogen-containing amorphous carbon film;

preferably, the thickness of the diamond-like carbon film layer is 0.5 um-3 um.

5. The bullet body of claim 1 further including a metal film layer disposed between said nitride film layer and said metal carbide film layer;

preferably, the metal film layer is a film layer formed by at least one metal of Cr, Ti, Zr and W; more preferably a film layer formed of Cr;

preferably, the thickness of the metal film layer is 0.1um to 1 um.

6. The bullet body of claim 5 further coated with a doped diamond-like film layer between said metal carbide film layer and said diamond-like film layer, wherein the doping element in said doped diamond-like film layer is selected from at least one of Cr, Ti, Zr, and W; preferably, the doping element is W;

preferably, the thickness of the diamond-like carbon film layer with the dopant is 0.2um to 1.5 um;

preferably, the surface roughness of the diamond-like carbon film layer is Ra0.03-0.1 um, the film-substrate bonding force is 50-100N, the friction coefficient is 0.05-0.2, and the microhardness is Hv 2000-7000.

7. A method of making the bullet body of any one of claims 1 to 6, comprising: forming the composite film layer on the bullet body.

8. The preparation method according to claim 7, wherein each layer of the composite film layer is formed by a method independently selected from any one of physical vapor deposition, plasma enhanced chemical vapor deposition and ion source coating, wherein the physical vapor deposition is magnetron sputtering or arc ion plating;

preferably, the nitride film layer, the metal carbide film layer and the diamond-like film layer with dopant are all formed by magnetron sputtering, and the diamond-like film layer is formed by plasma enhanced chemical vapor deposition or ion source coating;

preferably, a pre-treatment is performed by plasma etching before coating on the bullet body.

9. The preparation method according to claim 8, wherein in the process of forming the nitride film layer by magnetron sputtering, the deposition time is 70-80 min, the nitrogen flow is 50-70 mL/min, the sputtering power is 4.5-5.5 kw, and the argon flow is 110-130 mL/min;

preferably, in the process of forming the metal film layer by adopting a magnetron sputtering method, the deposition time is 10-15 min, the sputtering power is 4.5-5.5 kw, and the argon flow is 110-130 mL/min;

preferably, in the process of forming the metal carbide film layer by adopting a magnetron sputtering method, metal and carbide are alternately deposited, the deposition time is 15-25min, the sputtering power of a metal target and the sputtering power of a carbide target are both 0.5-5.0 kw, and the flow of argon is 110-130 mL/min;

preferably, in the process of forming the diamond-like carbon film layer with the dopant by adopting a magnetron sputtering method, the deposition time is 40-60 min, the sputtering power is 4.5-5.5 kw, the acetylene flow is 40-50 mL/min, and the argon flow is 110-130 mL/min;

preferably, in the process of forming the diamond-like carbon film layer by adopting a plasma enhanced chemical vapor deposition method, the deposition time is 250-350 min, the bias voltage is 0-750V, and the acetylene flow is 200-500 mL/min.

10. A medical device comprising the bullet body according to any one of claims 1 to 6 or the bullet body prepared by the method according to any one of claims 7 to 9;

preferably, the medical device is selected from any one of a shock wave therapy device and a vibrating physiotherapy device.