THE USE OF DIAMOND-LIKE FILMS TO INCREASE THE DURABILITY OF END MILLS

Modern engineering is focused on high-tech reliable automated equipment, the use of which is effective in the presence of high-quality wear-resistant tools. The article discusses the results of the study DLC-films end mills resistance in structural carbon and alloy steels processing. Coatings were obtained by cathodic pulse sputtering of graphite in a vacuum chamber. There are presented results of the study of the influence of diamond-like (DLC) films on the end mills wear resistance. It is shown that the application of diamond-like films on the end mills uniquely increases the resistance of the mills, but differences in this issue for mills of different diameters are revealed. The results of the study of the influence of the pulse frequency of spraying in the formation of the coating on the cutting properties of end mills are also presented. It is established that the increase in the pulse frequency during cathode sputtering of graphite in vacuum when applying a diamond-like film leads to an increase in the resistance of end mills. The results of this work can be useful in Metalworking of structural steels with end mills.

Ultrasound-Pulse Electrodeposition Preparation of Fe-Nano ZrO2 Functional Gradient Coating

Objective On the basis of the experimental investigation of Fe-ZrO2nanocomposite coating, nanoZrO2particles were added to the bath to prepare the nanocomposite coating of Fe-ZrO2with electroplating methods and laser cladding. Methods Study the effects of nanocontent, cathodic pulse current density, duty cycle, the ultrasonic frequency content of the coating surface Nano, orthogonal optimization of process parameters. Results The results show that nanoparticles concentration 10 g/l, the cathode current density pulse 4A/dm2, the duty cycle 20%, ultrasonic frequency 180W, nanocomposite coating capacity of up to 5.5wt%. Conclusion Fe-ZrO2nanocomposite coating improved abrasion and Corrosion of the binary composite coating.

Influence of the Cathodic Pulse on the Formation and Morphology of Oxide Coatings on Aluminium Produced by Plasma Electrolytic Oxidation / Wpływ Impulsu Katodowego Na Tworzenie I Morfologie Warstw Tlenkowych Na Aluminium Otrzymywanych Na Drodze Plazmowego Utleniania Elektrolitycznego

Plasma electrolytic oxidation (PEO) is an effective method to obtain hard ceramic coatings on Al, Mg and Ti alloys. Micro-discharges occurring on the electrode surface during process promote the creation of crystalline oxides phases which improve mechanical properties of the coating. By using alternate current (AC) at some current conditions the process can be conducted in ‘soft’ spark regime. This allows producing thicker layers, increasing growth rate and uniformity of layer, decreasing amount of pores and defects. These facts proof the importance of cathodic pulse in the PEO mechanism; however its role is not well defined. In this work, influence of anodic to cathodic current density ratio on kinetics of coating growth, its morphology and composition were investigated. The PEO process of pure was conducted in potassium hydroxide with sodium metasilicate addition. The different anodic to cathodic average currents densities ratios of pulses were applied. The phase composition of coatings was determined by XRD analysis. Morphology of obtained oxide layers was investigated by SEM observations.

Electrochemical Fabrication of SrTiO3 Nanowires with Nanoporous Alumina Template

Strontium titanate nanowires were electrochemically synthesized with nanoporous alumina template. Both chemical and electrical variables such as electrolyte pH, temperature, and current wave-form were modulated to investigate the synthesis process of SrTiO3 nanowires. Superimposed cathodic pulse and diffusion time accelerated the growth of SrTiO3 nanowires, which suggested that the concentration of H+ and Sr2+ ion inside alumina template had a strong influence on the formation of SrTiO3 nanowires. Morphology and crystallinity of SrTiO3 nanowires were investigated with scanning electron microscope, X-ray diffractometer and energy dispersive X-ray spectroscopy.