Scientists at Russia’s National University of Science and Technology MISiS (NUST MISiS) have developed a technology that they state can double the strength of composites obtained by additively manufacturing aluminium powder, advancing the properties to compete with titanium alloys. Titanium’s strength is about 6 times higher than that of aluminium, but the density of titanium is 1.7 times higher.
The developed modifying-precursors, based on nitrides and aluminium oxides and obtained through combustion, have become the basis of the new composite. Aluminium offers some very desirable properties to a number of industries, including aerospace, medical and automotive, primary among them being its very light weight (density 2700 kg/m3) . However aluminium alone is can lack strength and hardness, with the tensile strength even for the alloy Duralumin being 500 MPa, and its Brinell hardness HB 20 kgf/mm2.
This new solution for the strengthening of aluminium composites for metal Additive Manufacturing was proposed by a research team led by Professor Alexander Gromov from the NUST MISIS Department for Non-Ferrous Metals and Gold. He explained, “We have developed a technology to strengthen the aluminium-matrix composites obtained by 3D printing, and we have obtained innovative precursor-modifiers by burning aluminium powders.”
“Combustion products – nitrides and aluminium oxides – are specifically prepared for sintering branched surfaces with transition nanolayers formed between the particles. It is the special properties and structure of the surface that allows the particles to be firmly attached to the aluminium matrix and, as a result, doubles the strength of the obtained composites.”