Adhesive strength of the coating significantly affects the lifetime of the coating. However, it is still inevitable for the coating, even with strong adhesive strength, to peel off from the substrate after working for a while. In this work, fatigue and wear behaviors were employed to analyze the effect on the mechanics of coating and contribute to a fundamental understanding of peeling of the coating. A small-size Co-cemented tungsten carbide drill bit was selected as the examined substrate to fabricate the diamond coating. Roughening pretreatment with a diamond slurry combined with ultrasonic vibration was performed for the substrate surface to enhance adhesive strength. Meanwhile, a diamond coating without roughening pretreatment was also fabricated for comparison. The lifetime and quality of the coating were evaluated by the drilling test. Although the diamond coating could grow on the substrates with and without roughening pretreatment, the diamond coating with roughening pretreatment possessed a higher lifetime and stronger wear resistance than that without roughening pretreatment. We found that both substrates with and without roughening pretreatment exhibited a coarse surface, whereas the roughening pretreatment could remove the original machined surface of the substrate and thus make the near surface with numerous integrated crystalline grains become the new topmost surface. This increased the contact area and surface energy of the interface, leading to the improvement of adhesive strength. Finally, fatigue strength and contact mechanics were studied to trace the changes in the stress of the diamond coating in the whole process of drilling from a theoretical point of view. We suggest that fatigue strength and contact mechanics may play vital roles on the durability and peeling of the coating.
Diamond coating has gained intensive attraction in the tribological field due to its high hardness. However, its weak flexibility always gives rise to the fragile crack, which causes the delamination and peeling off from substrate. In this work, a novel deposition method combining the conventional hot filament chemical vapor deposition (HFCVD) and particles doping technique is proposed to balance the hardness and flexibility of diamond coating, by which the diamond coating with tungsten particles is deposited on the co-cemented tungsten carbide substrate. The as-deposited diamond coating is characterized by scanning electron microscopy (SEM) analysis, surface roughness and Raman spectrum. The indentation tests are conducted to evaluate the crack propagation of diamond coating. Tribological behavior is examined on a reciprocating ball-on-plate tribometer. The results indicate that tungsten carbide may be formed between tungsten particles and diamond coating. The W–WC–amorphous carbon–diamond structural coating can validly inhibit the crack propagation and decrease the friction coefficient. Hence, adding embedding particles into the diamond coating may provide a useful way in enhancing the mechanical properties of diamond coating.
Artificial intelligence (AI) technology is innovatively combined with participatory video for artistic creation and communication to improve the enthusiasm of art lovers for artistic creation and communication and expand the application range of AI technology. First, the interactive framework of interactive participation video is proposed based on the analysis of the related literature of interactive non-linear video. Then, a questionnaire is designed accordingly to analyze the social needs of people on art social platforms. According to the survey results, the participatory art video online communication platform is designed and preliminarily realized. Finally, a participant video eye movement control experiment is conducted to test the performance of the participatory art video development platform. Meanwhile, the platform is evaluated through field research from two aspects of test efficiency and user experience. The results show that the operation time of the participatory art video development platform is much shorter than that of the control group. It takes only approximately 15 s to complete the annotation operation with low SD, indicating that the system performance is stable. The accuracy of the platform also reaches 100%.
For diamond coating, natural fragile property easily leads to fracture, delamination and peeling, which seriously inhibits the applications in many industrial fields. In order to prolong the lifetime, improving the toughness under impact load is essential for diamond coating. In this work, a novel method was proposed by the conventional CVD diamond technique combining with the particles, with which the nanocrystalline diamond (NCD) coating with W particles (W-NCD) was fabricated to evaluate the impact behavior. The pure NCD coating was also produced for comparison. Repeating impact testing was performed to evaluate the impact resistance of the as-deposited NCD coatings. The results showed that the diamond coating can be fabricated on the substrate with W particles. The indentation scar revealed that the W-NCD coating had the stronger impact resistance than the NCD coating. Ratcheting effect was employed to discuss the impact properties of NCD coating for the first time. The coating integrity played a vital role in ratcheting displacement. Repeating impact can make the NCD and W-NCD coatings soft, and the W particles can accelerate the softening process. Hence, embedding particles can provide a potential and valid method to enhance the impact resistance of diamond coating that was very important for the fragile coating.
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