Mikhail A. Gulov

Results of tensile and low-cycle fatigue testing of samples made of an aluminum–lithium alloy of the Al–Mg–Li system obtained by plasma-assisted laser cutting performed by a pulsed CO₂ laser in an argon jet with the laser beam and optical discharge plasma simultaneously affecting the material are reported. Low-cycle fatigue tests show that the number of loading cycles survived by the sample obtained by plasma-assisted laser cutting is more than twice greater than the number of cycles survived by the samples obtained by conventional laser cutting with a continuous beam.

This paper is devoted to the influence of substrate preheating on the structure of cermet coatings made of TI–6AL–4V alloy reinforced with B₄C particles using direct metal deposition. Coatings with a 15% mass fraction of B₄C were obtained for the first time. It is shown that substrate preheating makes it possible to produce cermet coatings without cracks. In tribological tests, the wear scar volume of the cermet coating decreased by a factor of eight compared to the coating with a 10% mass fraction of B₄C.

The deposition process of a nickel-based cermet coating with a high (60 wt.%) mass content of tungsten carbide was investigated. The results showed preheating the substrate to 500°C prevented the formation of cracks and pores in the coating. This is because preheating reduces the thermal shock between the substrate and the coating, leading to better adhesion and fewer defects. Additionally, synchrotron radiation was used to analyze the phase composition of the resulting composite. It was found that additional heating of the sample to 500°C during surfacing did not cause significant changes in the phase composition of the composite.

Carbon nanotubes (CNTs) are used in applications ranging from electrical engineering to medical device manufacturing. It is well known that the addition of nanotubes can influence the mechanical properties of various industrial materials, including plastics. Electrospinning is a popular method for fabricating nanomaterials, widely suggested for polymer scaffold manufacturing. In this study, we aimed to describe the influence of single-walled carbon nanotube (SWCNT) suspensions on polymeric poured films and electrospun scaffolds and to investigate their structural and mechanical properties obtained from various compositions. To obtain films and electrospun scaffolds of 8 mm diameter, we used poly-ε-caprolactone (PCL) and poly(cyclohexene carbonate) (PCHC) solutions containing several mass fractions of SWCNT. The samples were characterized using tensile tests, atomic force and scanning electronic microscopy (AFM and SEM). All the studied SWCNT concentrations were shown to decrease the extensibility and strength of electrospun scaffolds, so SWCNT use was considered unsuitable for this technique. The 0.01% mass fraction of SWCNT in PCL films increased the polymer strength, while fractions of 0.03% and more significantly decreased the polymer strength and extensibility compared to the undoped polymer. The PHCH polymeric films showed a similar behavior with an extremum at 0.02% concentration for strength at break.