The article were studied the effect of detonation spraying on the structure and properties of Al 2 O 3 coatings. It was determined that reducing the delay time between shots is leading to increase the hardness and elastic module of Al 2 O 3 coatings. It was found on the basis of X-ray diffraction analysis that the main reason for the increasing in hardness with a decreasing in the delay time between shots is associated with increasing in the volume fraction of α -Al 2 O 3 phase. The studies of X-ray diffraction presented that the highest content of the phase is achieved when the coatings are formed with a delay time between shots of 0.25 s. It was found that increasing in the volume fraction of the α -Al 2 O 3 phase is caused by the secondary recrystallization γ → α , which occurs due to the heating of particles during coating formation, i.e. due to increasing in temperature above 1100 • C in single spots of the coating when they are put each other.