Open AccessLiterary searches of Kazakh dramaturgy in totalitarian system
Author(s) -
S.U. Takirov
Publication year - 2021
Publication title -
ķaraġandy universitetìnìn̦ habaršysy. fizika seriâsy/ķaraġandy universitetìnìņ habaršysy. fizika seriâsy
Language(s) - English
Resource type - Journals
eISSN - 2663-5089
pISSN - 2518-7198
DOI - 10.31489/2021ph2/6-13
Subject(s) - detonation , materials science , annealing (glass) , metallurgy , aluminium , aluminum oxide , oxide , hardness , composite material , chemistry , organic chemistry , explosive material
The article examines the effect of annealing on the structure and properties of alumina-based coatings obtained by detonation spraying. Coated samples were kept separately at temperatures of 500, 700, 800 and 1200 °C at a pressure of 3.6*10-4 Pa for more than 1 hour. It was found that the microhardness of coatings made of alumina increases by 15-30 % after annealing depending on annealing temperature. The results of nanoindentation show that at 1200 °C the nanohardness of coatings after annealing increases by almost 100%. Aluminum oxide coating is characterized by high strength and density of the coating before and after annealing, and slight porosity. Results of X-ray analysis showed that the alumina powder consists of α-Al2O3 lattice, and after detonation injection coating cubes are converted into a semi-γ-cubic lattice. It was found that during the annealing of the coating at 1200 °C all cells of γ-phase completely transit to the α-phase. It was found that the increase in hardness after annealing of alumina coating at 500, 700, 800 and 1200 °C is associated with an increase in volume fraction of α-Al2O3 phase.