NUST MISIS has developed strengthening modifiers for 3D printing of aluminum composite products for the aerospace industry. Scientists from NUST MISIS have proposed a technology that doubles the strength of composites obtained by 3D printing from aluminum powder and brings the characteristics of the resulting products closer to the quality of titanium alloys: the strength of titanium is about 6 times higher than that of aluminum, but also the density of titanium 1.7 times higher (an aluminum aircraft or spacecraft would be much lighter).
The developed modifiers-precursors based on aluminum nitrides and oxides obtained by combustion became the basis of the new composite. The results of the work were published in the highly rated scientific journal Sustainable Materials and Technologies.
Until two decades ago, die casting was seen as the only cost-effective way to make 3D products. Years passed before a 3D metal printer appeared that could compete with metallurgical methods, and in the future, replace traditional methods of metallurgical production. The advantages of manufacturing products of complex shape using additive technologies are more complex shapes and designs of the resulting products, low cost, and theoretically any combination of materials obtained.
Currently, there are several technologies that are used for metal printing, the main ones being Selective Laser Melting (SLM) and Selective Laser Sintering (SLS). Both of them involve the gradual layering of metallic powder "ink" layer by layer to build a given volumetric figure. SLS or SLM are additive manufacturing technologies based on layer-by-layer sintering of powder materials using a high-power (up to 500 W) laser beam.
Titanium is one of the optimal metals for the manufacture of products for the aerospace industry, but it is not applicable in 3D printing due to the fire and explosion hazard of powders. The alternative is aluminum, lightweight (density 2700 kg / m3) - one of the main requirements of the industry, plastic, with an elastic modulus of ~ 70 MPa, suitable for 3D printing, but not strong enough and hard: the tensile strength even for the Dural alloy is up to 500 MPa, Brinell hardness HB at the level of 20 kgf / mm2.
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The solution to the problem of hardening aluminum 3D printing was proposed by the research team of the Department of Non-Ferrous Metals and Gold at NUST MISIS under the guidance of visiting professor Alexander Gromov.
The development team is currently testing prototypes of products obtained using the new technology.