Study on the composition and performance of Cr/CrN/Cu-TiN film

In order to make surgical instruments hydrophobic and antibacterial, we prepared Cr/CrN/Cu-TiN film with micro-nano structure on the surface of surgical instruments. Chemical etching is used for micro-nanoization of the substrate surface, high-power pulsed magnetron sputtering is used for film preparation, SEM, EDS, contact angle measuring instrument and coating adhesion automatic scratching instrument are used for sample inspection. The antibacterial element Cu content of the sample film decreased from 3.09% to 1.77% with the increase of the bias voltage; the film-base binding force first increased and then decreased with the increase of the bias voltage, and the maximum film-base binding force was 34 N at -50 V; Comparing the hydrophobicity of the samples without substrate etching treatment and micro-nano etching treatment, the difference is obvious, the water contact angle of the former is 78°, and the water contact angle of the latter is 132°.

Under the situation of rapid development of contemporary medical science and diagnosis and treatment technology, with the development of difficult operations such as human organ transplantation, heart surgery, artificial joint replacement, microsurgery, and minimally invasive surgery, surgical technology cleans, disinfects and disinfects surgical instruments. Sterilization requirements are getting higher and higher. The surgical instruments currently in clinical use are all Ni or Cr-plated stainless steel and titanium alloy instruments. They have no antibacterial and anti-adhesive properties. They must undergo complex cleaning, disinfection and sterilization after the operation, and the surgical instruments must be thoroughly cleaned, disinfected and sterilized. Need to purchase a complete set of expensive equipment. For medical institutions that are generally unable to purchase expensive equipment, postoperative surgical instruments are incompletely cleaned, disinfected and sterilized, which eventually leads to cross-infection of patients in clinical operations.

At present, there is no literature report on the deposition of antibacterial and anti-mucosa on the surface of surgical instruments. In view of the above-mentioned defects of surgical instruments, we propose to prepare Cr/CrN/Cu-TiN antibacterial and anti-mucosa on the surface of surgical instruments by high-power pulsed magnetron sputtering. /CrN is the transition layer, whose function is to improve the adhesion of the film base. Cu-TiN is the surface working layer, in which Cu is the antibacterial element, and TiN has good wear resistance, corrosion resistance and biocompatibility. Compared with the conventional magnetron sputtering method, the high-power pulsed magnetron sputtering method has a higher ionization rate, and the deposited thin film film base has better bonding strength, density, uniformity and diffraction. The research content of this paper is the influence of bias on membrane composition, membrane base binding force and the influence of surface topography on membrane hydrophobicity.

The high-power pulsed magnetron sputtering deposition system used in the experiment is shown in the following figure, which is mainly composed of target power supply, bias power supply, excitation power supply, vacuum system, cooling system and gas supply system.

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The target materials used in the experiment are 99.99% pure Cr target and 99.99% pure self-made Ti embedded Cu target, working gas is 99.999% Ar and N2, and the matrix is 1Cr18Ni9Ti stainless steel sheet. First clean the stainless steel sheet with alcohol and distilled water, and then use the prepared chemical etching solution (4 g FeCl 3.6 H2O, 2 ml HCl solution, 2 ml H3PO4 solution, 30 ml distilled water) to etch for 10 min, and then clean the engraved with distilled water. The etched stainless steel sheet is blown dry, and then put into the vacuum chamber of the deposition system to clean and deposit Cr/CrN/Cu-TiN film by high-power pulsed magnetron sputtering.

A scanning electron microscope was used to analyze the surface morphology of the sample, and an energy spectrometer was used to determine the percentage of film composition. The WS-2005 coating adhesion automatic scratch tester was used to measure the film-base adhesion of the sample. The loading load was 50 N, the loading speed was 50 N/S, and the scratch length was 4 mm. The JC2000C contact angle measuring instrument detects the anti-adhesiveness of the sample and is characterized by the contact angle.

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Energy spectra of Cr/CrN/Cu-TiN films prepared under different bias voltages

The interface bonding strength between the film and the substrate is one of the most important properties of the film, and its value directly affects the actual use effect. The residual stress of the film consists of two parts, which are the thermal stress caused by the different thermal expansion coefficients of the film and the base material and the internal stress caused by the internal structure of the film. It is the scratch morphology of the Cr/CrN/Cu-TiN film prepared under different bias voltages. With the increase of the bias voltage, the bonding force of the film base increases first and then decreases, reaching the maximum at -50 V, reaching 34 N. As the bias voltage increases, the ions are accelerated to obtain higher energy, and the bombardment effect on the membrane is enhanced. The membrane structure not only changes from loose to dense, but also the pseudo diffusion layer is broadened, and the binding force of the membrane base is improved. After the pressure increases to a certain value, the ion energy is too high. This bombardment effect causes high-pressure internal stress caused by the internal structural defects of the membrane, and the bonding force of the membrane base decreases.

Scratch morphology of Cr/CrN/Cu-TiN films prepared under different bias voltages

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Cr/CrN/Cu-TiN film was deposited by high-power pulsed magnetron sputtering on the stainless steel substrate without chemical etching treatment and micro-nano-etching treatment. The composition and performance analysis of the sample obtained the following conclusions:

(1) The substrate bias voltage is -30 V, -50 V, -70 V and -90 V, and the antibacterial element Cu content in the film decreases from 3.09% to 1.77% as the bias voltage increases;

(2) The substrate bias voltage is -30 V, -50 V, -70 V and -90 V. With the increase of the bias voltage, the binding force of the membrane substrate first increases and then decreases, and the magnitudes are 28 N, 34 N, 23 N and 15.5 respectively N;

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(3) The film without chemical etching treatment and micro-nano etching treatment on the substrate exhibits significantly different hydrophobicity. Micro-nanoization significantly increases the hydrophobicity of the film. The former has a water contact angle of 78°, the latter has a water contact angle. The contact angle is 132°.

Founded in 2015,Zunhua Baorui Titanium Equipment Co.,Ltd. is a manufacturer specializing in pvd vacuum ion coating equipment. The company’s products mainly include large plate coating machine, large tube collating machine, tool coating machine and LOW-E glass production line. Mr.Wang baijiang ,general manager of the company ,has been engaged in vacuum coating industry for more than 30 years. He continuously improve production technology, improve product performance and devote himself to provide customers with better product experience and higher production efficiency.