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CN-121976154-A - Antibacterial wear-resistant composite coating for biological sample drilling and preparation method thereof

CN121976154ACN 121976154 ACN121976154 ACN 121976154ACN-121976154-A

Abstract

The invention discloses an antibacterial wear-resistant composite coating for biological sample drilling and a preparation method thereof, belonging to the technical field of surface coatings, wherein the composite coating sequentially comprises a CrN bonding layer, a TiAlN/CrN nano multilayer hard layer, an Ag/Cu doped TiAlN antibacterial functional layer and an a-C H diamond-like carbon antifouling surface layer from the outside of a substrate, the nano multilayer structure has the hardness of 30-35GPa, the antibacterial rate is more than 99.9%, the friction coefficient is less than 0.15, and the surface energy is less than 35mN/m. The method is suitable for drilling hard biological samples such as bones, teeth, tortoise shells, fossils and the like, can prolong the service life of tools by 5-8 times, eliminates the inhibition of metal ions on PCR, prevents the cross contamination of microorganisms, and meets the field requirements of customs quarantine, forensic identification, ancient DNA research and the like.

Inventors

  • YANG DAWEI
  • Xu Nianai
  • Zhu Huangxin
  • YE PENG
  • KONG FANDE

Assignees

  • 厦门海关技术中心

Dates

Publication Date
20260505
Application Date
20260205

Claims (10)

  1. 1. The antibacterial and wear-resistant composite coating for drilling biological samples is characterized by sequentially comprising a bonding layer, a hard wear-resistant layer, an antibacterial functional layer and an anti-fouling surface layer from the surface of a substrate to the outside, wherein the bonding layer is a CrN layer, the hard wear-resistant layer is of a TiAlN/CrN nano multilayer structure, the antibacterial functional layer is an Ag-TiAlN layer or a Cu-TiAlN layer doped with nano silver particles or nano copper particles, and the anti-fouling surface layer is a hydrogenated diamond-like a-C: H film layer.
  2. 2. The antibacterial wear-resistant composite coating according to claim 1, wherein the thickness of the CrN bonding layer is 0.3-0.5 μm, the total thickness of the TiAlN/CrN nano multi-layer structure is 2-4 μm, the TiAlN single layer and the CrN single layer are alternately deposited to form a periodic structure, the modulation period is 5-20nm, and the thickness ratio of the TiAlN layer to the CrN layer is 1:0.8-1.2.
  3. 3. The antibacterial wear-resistant composite coating according to claim 1, wherein in the TiAlN/CrN nano-multilayer structure, the atomic ratio of Ti to Al of the TiAlN layer is 45-55:55-45, the hardness of the nano-multilayer structure is 30-35GPa, and the elastic modulus is 350-450GPa.
  4. 4. The antibacterial and wear-resistant composite coating according to claim 1, wherein the thickness of the antibacterial functional layer is 0.2-0.5 μm, the content of nano silver particles or nano copper particles is 0.5-3at%, and the particle size of the nano particles is 5-30nm, and the nano particles are uniformly dispersed in a TiAlN matrix.
  5. 5. The antimicrobial wear-resistant composite coating according to claim 1, wherein the a-C H film layer has a thickness of 0.5-1 μm, an sp3 hybridized carbon content of 40-60% and a hydrogen content of 15-30at%, the a-C H film layer has a coefficient of friction of less than 0.15, a surface energy of less than 35mN/m, and a water contact angle of greater than 90 °.
  6. 6. The antibacterial and wear-resistant composite coating according to claim 1, wherein a metal transition layer is arranged between the a-C H film layer and the antibacterial functional layer, and is a Cr layer or a Ti layer, and the thickness of the metal transition layer is 50-150nm.
  7. 7. The method for preparing the antibacterial wear-resistant composite coating according to any one of claims 1 to 6, which is characterized by comprising the following steps: Placing the drilling tool matrix in a vacuum coating chamber, vacuumizing to a background vacuum degree of 1X 10 −3 -5×10 −3 Pa, and introducing Ar gas to carry out glow discharge cleaning and Ar + ion etching; A CrN bonding layer deposition step, namely adopting a multi-arc ion plating technology, taking a Cr target as a cathode, introducing mixed gas of N 2 and Ar, and depositing a CrN bonding layer on the surface of a substrate; The TiAlN/CrN nano multilayer deposition step comprises alternately starting a TiAl target and a Cr target by adopting a multi-arc ion plating and magnetron sputtering composite technology, and alternately depositing a TiAlN layer and a CrN layer in an N 2 atmosphere to form a nano multilayer periodic structure; the antibacterial functional layer deposition step comprises the steps of adopting a magnetron sputtering co-deposition technology, simultaneously starting a TiAl target and an Ag target or a Cu target, and depositing an Ag-TiAlN layer or a Cu-TiAlN layer in an N 2 atmosphere; and a step of depositing an a-C H film layer, which is to deposit the a-C H film layer on the surface of the antibacterial functional layer by adopting a plasma enhanced chemical vapor deposition technology and taking C 2 H 2 and CH 4 as carbon source gases.
  8. 8. The preparation method according to claim 7, wherein in the TiAlN/CrN nano multilayer deposition step, the Ti to Al atomic ratio of the TiAl target is 50:50, the purity of the target is more than or equal to 99.9%, the purity of the Cr target is more than or equal to 99.9%, the deposition temperature is 200-400 ℃, the substrate bias is-50 to-150V, the partial pressure of N 2 is 0.3-0.8Pa, and the modulation period of 5-20nm is realized by controlling the opening time and the rotating speed of each target.
  9. 9. The method according to claim 7, wherein in the step of depositing the antibacterial functional layer, sputtering power of the Ag target or the Cu target is 50-200W, arc current of the TiAl target is 60-100A, and the content of the nano silver particles or the nano copper particles is controlled to be 0.5-3at% by adjusting the sputtering power of the Ag target or the Cu target.
  10. 10. The method of claim 7, wherein in the a-C/H thin film layer deposition step, the C 2 H 2 flow is 30-80sccm, the CH 4 flow is 20-60sccm, the Ar flow is 10-30sccm, the RF power is 500-1500W, the pulse bias is-500 to-2000V, the pulse frequency is 1000-5000Hz, the duty ratio is 10-30%, and a Cr or Ti metal transition layer of 50-150nm is deposited before the deposition to improve the bonding force of the a-C/H thin film.

Description

Antibacterial wear-resistant composite coating for biological sample drilling and preparation method thereof Technical Field The invention belongs to the technical field of surface coating, in particular to an antibacterial wear-resistant composite coating for biological sample drilling and a preparation method thereof, which are suitable for surface treatment of sampling drill bits of hard biological materials such as bones, teeth, tortoise shells, fossils, natural bezoar and the like, so as to meet the requirements of no pollution and cross infection prevention on samples in the fields of nucleic acid extraction, species identification, forensic inspection, customs inspection and the like. Background Biological sample drilling is an important means for obtaining hard biological material powder samples such as bones, teeth, tortoise shells, fossils, natural bezoar and the like, and is widely applied to the fields of customs quarantine species identification, forensic science DNA typing, archaeological ancient DNA research, archaeological fossil analysis and the like. These application scenarios place special demands on the drilling tool, on the one hand, requiring the drill bit to have sufficient hardness and wear resistance to cope with the processing of high hardness biological materials, and on the other hand, ensuring that the sampling process does not introduce exogenous contaminants to interfere with subsequent molecular biological detection. In the prior art, the tools for biological sample drilling mainly adopt a hard alloy drill bit or a high-speed steel drill bit. Cemented carbide drill bits typically use tungsten carbide as the matrix and cobalt as the binder phase. However, during drilling, metallic elements such as Co 2+、W6+ in the base material are released into the sample as the heat and wear from drilling. Studies show that when the Co 2+ concentration reaches 10 −4 mol/L, the activity of Taq polymerase can be obviously inhibited, so that the PCR amplification is failed, and the accuracy of nucleic acid detection is seriously affected. The Chinese patent with publication number of CN116676563A discloses a high-hardness Ti-TiN-TiAlN-TiAlCrN multilayer coating and a preparation process thereof, wherein the coating adopts a gradient structure design, and realizes higher hardness and good binding force through the combination of a Ti priming layer, a TiN intermediate layer, a TiAlN transition layer and a TiAlCrN surface layer. However, the coating has the following defects that firstly, an antibacterial functional layer is lacking, the requirement of preventing microorganism cross contamination in the biological sample sampling process cannot be met, particularly, in a customs quarantine batch detection scene, a high cross contamination risk exists when a plurality of samples are continuously sampled, secondly, an antifouling surface layer with low surface energy is lacking, the surface energy of the coating is high, biological macromolecules such as proteins and nucleic acids are easy to adsorb, so that the samples are lost, and thirdly, the diffusion of matrix metal ions into the samples cannot be effectively prevented without adopting a chemically inert surface layer design. In addition, the existing cutter coating technology is mainly developed aiming at the field of metal cutting processing, emphasizes high-temperature hardness, wear resistance and oxidation resistance, and lacks systematic consideration on the characteristics of antibacterial property, biological inertia, metal ion pollution prevention and the like required for biological sample sampling. Therefore, development of a multifunctional composite coating specially aiming at biological sample drilling application is needed to realize the synergistic optimization of high hardness, wear resistance, antibiosis, antifouling and chemical inertness. Disclosure of Invention Aiming at the defects of the prior art, the invention provides an antibacterial wear-resistant composite coating for biological sample drilling and a preparation method thereof. The composite coating adopts a four-layer functionally gradient structural design, and sequentially comprises a CrN binding layer, a TiAlN/CrN nano multilayer hard layer, an Ag/Cu doped TiAlN antibacterial functional layer and an a-C/H diamond-like carbon antifouling surface layer from the matrix to the outside, so that the multifunctional synergy of high hardness, wear resistance, continuous antibacterial property, low surface energy antifouling property and chemical inert barrier is realized, the composite coating is suitable for drilling hard biological samples such as bones, teeth, tortoise shells, fossils, natural bezoar and the like, the service life of tools can be effectively prolonged, the inhibition effect of metal ion pollution on PCR amplification is eliminated, the cross contamination of microorganisms is prevented, and the sample adsorption loss is reduced. The technical schem