Comparative analysis of the structure and internal stress in Ti-6Al-4V alloys manufactured by 3D printing and processing with screw extrusion

Study is based on the compare characterization of the structure and evaluation of the residual internal stresses in Ti-6Al-4V samples manufactured by the 3D printing (selective laser melting) and in the Ti-6Al-4V samples obtained with using of the severe plastic deformation by screw extrusion. The microstructure and residual stresses were examined by transmission electron microscope and X-ray diffractometer. High tensile internal residual stresses in the 3D printed sample were found. The high compressive residual internal stresses were found in the hot pressed and in the twisted samples. It was shown that arising of the high residual stresses in the studied samples under various technological processes occurred in various ways. The residual stresses in the severe plastic deformed samples arose due to non-uniform volumetric plastic deformation. In 3D printed sample, the residual tensile stresses arose from both phase (martensitic) transformation and thermal deformation. © Published under licence by IOP Publishing Ltd

Oxygen and nitrogen concentrations in the Ti-6Al-4V alloy manufactured by direct metal laser sintering (DMLS) process

Published ArticleTwo machines from two scientific centers (Russia and South Africa) were used for the manufacturing of the Ti6Al4V alloys by the direct metal laser sintering. The chemical composition of powders complies with the ASTM F-136 (grade 5), ASTM B348 (grade 23) standard for medical applications. Analysis of the oxygen and nitrogen contamination in DMLS alloys was done with Van de Graaff accelerator with two Mega Volts. It is found that structures of the samples manufactured with two different machines used the same regimes are close to each other. TEM studies found the metastable martensitic structure and silicon nitride Si3N4. It was found that the oxygen and nitrogen contents in both samples are within the normal range for medical grade titanium alloys

Investigation of the Mechanical Properties and Structure of AlSi10Mg Aluminum Alloy Samples Manufactured by Selective Laser Melting Technology

В докладе представлены результаты исследования механических свойств, микро- и макроструктуры образцов, изготовленных по технологии селективного лазерного сплавления (СЛС) из порошка алюминиевого сплава AlSi10Mg.The report presents the results of a study of the mechanical properties, micro- and macrostructure of samples manufacturing by the selective laser melting technology (SLM), from AlSi10Mg aluminum powder