Исследование содержания кислорода и азота в плазменных покрытиях на основе никеля

Abstract

Studies were carried out on the oxygen and nitrogen content of nickel-based powders and plasma coatings therefrom. The Ni-based sprayed materials were divided into four groups according to the mechanism of their interaction with oxygen. The first group includes Ni, the second alloys alloyed with Cr, the third additionally alloyed with Al, the fourth alloys having more complex alloying with Cr, C, B, Si elements that actively interact with oxygen, including with the formation of gaseous oxides. Alloying 20 % Cr reduces the oxygen content of the coating by 35 %, alloying 17 % Cr – 10 % Al reduces the oxygen content of the coating by 57 %, more complex alloying 13.5 % Cr – 2.7 % Si – 1.65 % B – 0.36 % C — reduces the oxygen content of the coating by 92 %. Increasing the plasma jet power increases the oxygen content of the Ni20Cr coating from 0.55 to 1.6 %. Increasing the plasma jet power and preheating the substrate prior to sputtering results in a limited increase in the oxygen content of Ni – 17 % Cr – 10 % Al – 1 % Y and Ni – 15 % – Cr 4 % – Fe 0.8 % C – 4.1 % Si — 3.1% B coatings using a plasma nozzle to eliminate the thermal effects of the plasma jet. The Ni – 17 % Cr – 10 % Al – 1 % Y coating sprayed with the nozzle contains 0.48 % O and 0.14 % N instead of 2.31 % O and 0.37 % N when sprayed without the nozzle. An increase in the oxygen and nitrogen content in the coatings Ni, Ni – 20 Cr and Ni – 40 Cr together with the formation of a liquid-hardened structure in these coatings determines an increase in microhardness relative to the value for the powder by 1.6 – 1.9 times.