Magnesium-based materials find their use mainly in manufacturing light-weight constructions in motor-car, airspace industries, and biomedicine due to the low density. This paper provides an overview of introducing magnesium into SLM technology and describes searching experiments to prepare samples of magnesium powder МPF-4 (Russian State Standard 6001-79) conducted in the Laboratory of Yurga Institute of Technology. The study has determined appropriate parameters to synthesize a compact structure: laser output power 100 W, laser beam movement velocity 200 mm/s, scanning pitch 0.1 mm, modulation frequency of laser irradiation m = 2500 Hz, linear energy density Е=5 J/mm2, the process is to be carried out in argon shielding medium.

The influence of the microarc oxidation parameters as electrical voltage and process duration on the surface morphology and topography, wettability and chemical composition of calcium phosphate coatings on the low elastic module Ti-40mas.%Nb (Ti-40Nb) alloy surface has been investigated. The linear growth of thickness and roughness and the linear decrease of the free surface energy with increasing process electrical voltage have been obtained. It was shown that calcium phosphate coatings have low contact angle with liquids and high free surface energy, as a consequence. It indicates a high hydrophilicity. X-ray diffraction analyses showed that the coatings after deposition have X-ray amorphous state that indicates high rate of coating dissolution. The coatings have maximum Ca/P ratio is 0.6. The optimal range of the oxidation voltage from 200 to 250 V and process duration from 5 to 10 min has been found. Such parameters allow to form the coating with the specific morphology, roughness and thickness and high hydrophylicity.

Selective laser melting (SLM) is thought to be a prospective manufacturing technology of complex metal components. Formation of coagulated particles when melting is reported to be an important factor for target mechanical properties of the end product. This paper discusses the effect of SLM parameters, including laser output power, laser movement velocity, preheating temperature of the powder, laser beam diameter on the mechanism of forming coagulated particles in melting cobalt-chromium-molybdenum powdered material. The study shows that a rise of power to 60 W at a scanning velocity 6 mm/s causes coagulated particles to expand to 350 μm; that is far bigger than a size of powder in as delivered state (90 μm). The work investigates the effect of mechanical activation of cobalt-chromium-molybdenum powder on dimensions of coagulated particles. The research data can be applied to the improvement of up-to-date optimization approaches to manufacturing process parameters in SLM technology.

The phase transformations of the alloy Ti-40 mas % Nb after tempering and severe plastic deformation are studied. The phase transformations of the alloy according to the type and conditions of external influences are analyzed using methods of XRD, SEM and optical metallography. It is determined that inverse phase transformation of the metastable α''-phase to equilibrium β-phase is carried out after severe plastic deformation. Complete phase transformation α'' → β is typical for the mode, which consists of three pressing operation with the change of the loading axis in cramped conditions, followed by a multi-pass rolling in grooved rolls.

Four various methods of powder feedstock preparation for laser powder bed fusion are compared. Application of commercial spherical powder leads to the formation of single-phased state. Powder mechanically alloyed during 14 minutes in air atmosphere provides conditions for the formation of double-phased state with nonuniform distribution of components in the samples. Mechanical alloying in Ar-atmosphere during 30 minutes leads to the formation of double-phased state with more uniform distribution of components and precipitations of Cr2O3. Preliminary mechanical sieving of the powder allows to produce double-phased samples with nonuniform distribution of components comparable with that in samples produced from powder mechanically alloyed during 14 minutes in air atmosphere. Microhardness of all the studied samples produced from all the studied powders was comparable. All the proposed methods of powder feedstock preparation are applicable in laser powder bed fusion depending on the required properties, elemental and phase composition of the final product.