STUDYING THE PROPERTIES OF COATINGS BASED ON ALUMINUM CREATED BY COLD GAS-DYNAMIC SPRAYING

Abstract

The paper researches the cold gas-dynamic spraying of aluminum powder on steel surface.

The object of study is a coating of aluminum powder on the surface of the parts.
The purpose of the paper is to determine the effect of spraying modes on the utilization of aluminum powder, determination of the ultimate strength of shear adhesion coating of substrate, and determining the porosity of the coating. The method of research  is research settlement.

The aim of the study is to determine the utilization rate of aluminum powder, depending on the modes of spraying, determination of the strength of adhesion spots coating with the substrate, and determining the porosity of the coating.

The aluminum powder brand PA-4 with particle size of 40 - 100 microns was used for the study. A portion of the powder was 0.47 g, the spraying distance is 15 mm. The steel plate with thickness of 1 mm is used as the substrate. The surface of the wafer during spraying previously not treated.

When using "centrobaric characteristics" Compass program identified a lot of spots covering of solid material for aluminum A0 GOST 11069-2001, which has a density ρ₁ = 0,002700 g / mm³

Coating density ρ₂ is defined as the ratio of the mass-weighted spots covering its designed capacity.

Porosity J stain coating was determined by the formula

J = ((ρ₁ - ρ₂) / ρ₁) * 100%.

That determined the percentage of the volume of air contained in the spot coverage.

The study found that with increasing spraying temperature from 320 to 460 °C powder utilization rate increased from 8 to 42.5%, while the shear strength stain coating with the substrate decreased from 5.9 to 2.6 MPa, and the porosity the coating increased from 41 to 58%.