Investigation of the Formation of a Fine-Crystalline Alumina Coating on the Surface of a Blank Aluminum Powder Coating Test Panel as a Result of its Filtration Combustion

Abstract

Formation of a fine-crystalline α-Al₂O₃ coating on the surface of an aluminum blank powder coating test panel by filtration combustion (FC) in air was investigated. Finely ground sodium silicate glass (1 vol.%) introduced into the composition of the blank aluminum panels was used as the activating agent of the filtration combustion. It was found that a fine-crystalline aluminum oxide coating with a thickness of 30 – 50 μm with crystals ranging 0.1 – 2.0 μm in size forms over the entire surface of the sample upon completion of the filtration combustion. The properties of the produced samples were as follows: density 2.3 g/cm², open porosity 15%, ultimate bending stress 120 MPa, fracture toughness 3.6 MPa·m^1/2, Brinell hardness 32.