Application of the hottest filtered cathode vacuum

2022-08-14
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Application of filtered cathode vacuum arc ion coating technology in Engineering (Part 2)

in order to assess the stability of the coating process and the repeatability of coating wear resistance, 84 heats of high-speed steel test pieces and 50 heats of 142 stainless steel test pieces installed in different positions were coated with amorphous diamond film at 120~150nm, and then the wear resistance test was carried out. The results are shown in Figure 2 and figure 3 respectively. Figure 2 shows that on the high-speed steel substrate, the minimum wear life of amorphous diamond film is 21410 revolutions, and the maximum life is 63996 revolutions, accounting for 73.81% in the range of 30000~50000 revolutions. Figure 3 shows that the wear life of amorphous diamond film on stainless steel substrate is 48001. Check whether all parts of the equipment are normal and whether the power supply is stable before starting up~ 36000 revolutions, of which 83.8% are more than 12000 revolutions. It can be seen that the quality stability of the amorphous diamond film prepared by the coating equipment and process used is very good

under the wear condition of laboratory standard plug plate, the wear resistance of high-speed steel increases 106~319 times after plating amorphous diamond film; The wear resistance of stainless steel is increased by 480~3600 times. On these substrates, although the coating is very thin, it can extremely effectively improve the pain, long-term and arduousness of structural adjustment. We should have a full understanding and ideological preparation, and have high wear resistance

2.6. Weather resistance of amorphous diamond film

according to users, some diamond-like carbon films plated in some units have peeling and peeling after three months of storage, and they are more worried about the decline of adhesion and structural degradation under long-term ultraviolet radiation. Therefore, we have carried out outdoor exposure test, strong ultraviolet irradiation test and salt water boiling test on the amorphous diamond film to assess the weatherability of the amorphous diamond film

2.6.1. Outdoor exposure test:

five watch slides were used as the substrate, plated with 30~40nm amorphous diamond film, and exposed outdoors (Xi'an area). After 100 days, the test pieces were taken back for detection. Under the stereomicroscope, the observation was magnified by 80 times, and no blistering, peeling and peeling were found. After the bolt disc wear test, its wear resistance is the same as that before outdoor exposure, and there is no obvious change

2.6.2. Strong ultraviolet irradiation test

glass slides are used as substrates, amorphous diamond films of 30~40nm are plated, placed under strong ultraviolet light of 3300w/m2, irradiated for 240 hours, and then taken out for testing. No blistering, peeling and peeling were found under the 80x microscope, and its wear resistance was no different from that before illumination

2.6.3. Salt water boiling test

use 3 pieces of 40 15mm Al Si window glass as the substrate, coat 40~50nm amorphous diamond film, boil it in 5% NaCl aqueous solution for 4 hours, and then take it out and cool it to room temperature. After two boiling cooling cycles, no blistering, peeling and peeling were found under the microscope

the above tests show that the amorphous diamond film deposited on the glass substrate often needs to add elastomer to increase its toughness, which has very excellent weather resistance, the coating does not deteriorate, and has sufficient adhesion

2.7. Corrosion resistance of amorphous diamond film

2.7.1 Salt spray test

cu/ni/au electroplated parts are used as the substrate, and the thickness of the gold layer on the surface is 30~50nm. According to the ISO neutral salt spray test standard, the salt spray test is carried out in fqy025 salt spray test chamber, the medium is 5% NaCl aqueous solution, the temperature is 37 ℃, and 5 test pieces of uncoated and 20~30nm amorphous diamond film are plated respectively. The test results show that after 120~240 hours of salt spray test, the surface of the specimen coated with amorphous diamond film has no corrosion spots, and the color of the gold layer is the same as that before the test. After 40~90 hours, there are a large number of corrosion spots on the uncoated parts, which cannot be erased, or wipe with a rag, and the gold layer will peel off. These test results show that even if only amorphous diamond film with a thickness of 20~30nm is plated, the corrosion resistance of electroplated gold parts can be effectively improved

2.7.2. Ammonium sulfide corrosion resistance test of amorphous diamond film on silver coins

silver coins with 50mm and 99.9% purity are used as the substrate, which has words and patterns. The amorphous diamond film with nm is coated. According to QJ standard, 0.0006% (v/v) ammonium sulfide solution is used as the corrosion medium, a drop of test solution is dropped on the test piece with a drip tube, and at the same time, press the stopwatch to record the time when the surface of the test piece begins to turn brown or black, The corrosion resistance of the test piece is evaluated by this corrosion resistance time

the test results show that the silver coins without coating turn pale brown after only 70 seconds, and turn brown after 90 seconds. Silver coins plated with amorphous diamond film for a longer time than wood at the same time, and no discoloration trace was found until 20 minutes. This shows that the corrosion resistance life of silver coins is increased by at least 16 times after plating amorphous diamond film. However, the amorphous diamond film with a thickness of nm did not change the white luster of silver coins, and the coating had excellent wear resistance. Therefore, amorphous diamond film is an excellent protective coating for silver coins

amorphous diamond film is a chemically inert material, which will not react in acid, alkali, salt and other media, which has been confirmed by many studies. The gold-plated parts and silver coins were plated with nm and nm amorphous diamond films respectively, and the samples showed excellent resistance to salt spray corrosion and ammonium sulfide corrosion, indicating that the coating has eliminated pinholes and can play a complete protective role on the substrate. This feature of coating benefits from FCVA technology

2.8. Transmittance of amorphous diamond film

glass and Suna brand resin lens are used as substrates, and the amorphous diamond film is plated with nm. The visible light transmittance VIS is measured on TOPCON CL-100 focimeter. The measurement results are shown in Table 6 (E is the transmittance before plating, at is the transmittance after plating). The results show that the amorphous diamond film is transparent to visible light in the thickness range of nm. On glass and resin lenses, the transmittance decreases by only%

table6 transparency test (nm)

use Schott borofloat glass as the substrate, coat 120nm amorphous diamond film, and measure the light transmittance on the 19 spectrophotometer of American PE company. The measurement results are shown in Figure 4. The test shows that even if the coating thickness is 120nm and the appearance is slightly brown, the light transmittance of the coated glass can still reach 72.5~74.5% at the wavelength of 650nm, which is 17~19 percentage points lower than that of the unplated glass (91.9%). It can be seen from Figure 4 that the light transmittance of coated glass increases with the increase of light wavelength. According to this extrapolation, the light transmittance will be better in the infrared band. Some studies have also proved that this amorphous diamond film has better light transmittance in the infrared band, and even has 1~3% antireflection effect due to its antireflection effect [2]. The optical properties of amorphous diamond film combined with its wear resistance and weather resistance can be used as an excellent protective film for many optical elements

2.9. Biocompatibility of amorphous diamond film [7]

biocompatibility refers to the reaction of living tissue to inactive materials. Good biocompatibility is the prerequisite for the application of amorphous diamond films in the medical field. In order to find out the biocompatibility of amorphous diamond films, we cooperated with the school of Stomatology of the Fourth Military Medical University to carry out experimental research on the biocompatibility of amorphous diamond films

2.9.1. Cytotoxicity test

pure titanium was used as the substrate, divided into groups a, B and C, which were plated with 105, 140 and 175nm amorphous diamond films respectively, group D was not coated, and group E was the anode control material pure copper. In accordance with the requirements of ISO and gb/t16886.5 standards, tetramethylazozolium salt Microenzyme reaction Colorimetry (MTT method) was used to culture cells on samples, and the cell proliferation rate (RGR) was measured, and then the RGR of each group was transformed into a grade material toxicity rating. The test results are listed in Table 7 and table 8. The results showed that the cytotoxicity of amorphous diamond film was grade 0, and its cytotoxicity was slightly lower than that of pure titanium

Table7 MTT measurement( s,n=5)

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