Structural Studies of the “Nitride Coating/Silumin Substrate” System after Pulsed Electron Beam Treatment

The work is aimed to study the features of the formation of the surface layer of samples after combined treatment, including vacuum-arc deposition of titanium nitride coatings on silumin of eutectic composition and subsequent treatment of the “nitride coating/silumin substrate” system with a pulsed electron beam of submillisecond duration. Detailed studies of samples treated with an electron beam according to optimal modes were carried out by the transmission electron microscopy methods. Peculiarities of the structure and phase composition of the system were revealed depending on the electron beam processing mode. The treatment according to the optimal electron beam treatment modes to obtain the surface layer of the “TiN coating/silumin substrate” system with high wear resistance, adhesion and hardness does not exceed the temperature of 1150°C and does not lead to destruction of the coating according to TEM analysis results. The coating consists of nanosized TiN and Ti2N crystallites, which are combined into columns with subnanometer transverse dimensions. The electron beam treatment of the “TiN coating/silumin substrate” system leads to the formation of a cellular crystallization structure, where aluminum-based cells are separated from each other by silicon-based particles with nano-sized dimensions. The system has high properties: hardness HV ≈ 2 GPa, wear parameter ≈1 × 10–4 mm3 N–1 m–1 and high adhesion strength (L > 2.5 N).