Influence of Shielding Gas and Mechanical Activation of Metal Powders on the Quality of Surface Sintered Layers

The thesis analyses the influence of argon shielding gas and mechanical activation of PMS-1 copper powder and DSK-F75 cobalt chrome molybdenum powder on the surface sintered layer quality under various sintering conditions. Factors affecting the quality of the sintered surface and internal structure are studied. The obtained results prove positive impact of the shielding gas and mechanical activation. Sintering PMS-1 copper powder in argon shielding gas after mechanical activation leads to reduced internal stresses and roughness, as well as improved strength characteristics of the sintered surface. Analysis of sintered samples of mechanically activated DSK-F75 cobalt chrome molybdenum powder shows that the strength of the sintered surface grows porosity and coagulation changes

Improvement of the Sintered Surface and Bulk of the Product Via Differentiating Laser Sintering (Melting) Modes

Selective laser sintering (melting) enables using metal powdered materials to manufacture products of any geometrical complexity, requiring no preliminary costs to prepare processing equipment. However, quality of the sintered surface is often inadequate as against the product manufactured traditionally. Manufacturing a high quality product requires solution of such vital task as prediction of the sintered surface roughness. The authors address to the effect of laser sintering modes on roughness of the surface, sintered of copper powdered material PMS-l (IIMC-1). The dependence of roughness of the surface layer sintered of copper powder material PMS-l upon sintering process conditions is expressed mathematically. The authors suggest differentiating sintering modes to improve the sintered surface and the bulk of the product and dividing them into rough, semi-finishing, and finishing ones

Process Conditions of Forming the Surface Layer of Aluminum Powder Product by Layer-by-layer Laser Sintering

The paper presents data on state of the art in selective laser sintering of products. Layer-by-layer sintering is shown to be a future-oriented technology, making it possible to synthesize products of metal powder materials. Factors, influencing the quality of a sintered product, are revealed in the paper. It presents outcomes of experiments, focused on the dependence of surface layer thickness of sintered aluminum powder PA-4 on laser processing conditions. Basic factors, influencing the quality of a sintered surface layer include laser power, speeds of scanning and moving the laser beam on the layer of powder. Thickness of the sintered layer varies from 0.74 to 1.55 mm, as the result of changing the laser processing conditions

Organizational-administrative Features of the Implementation of Educational Services in the Two-level System of Training of Highly Qualified Personnel

It is education - the system of formation of the nation's intellectual capital and as one of the main areas of production innovation - creating the basic conditions for intensive growth of the markets on the basis of rapid updating of technologies and products. Education acts as the first link "education - research - innovation development of mass" of the innovation cycle. This educational sphere acts not only as a necessary element of reproduction of intellectual capital, but also as a dominant element of economic growth, which determines the stability of the external and internal competitive advantages of national economic systems. From the power of the national economy play an individual and a public intellectual capital, which implements the level of economic thinking of the nation, it is largely determined by economic strength, well-being, and the choice of its strategy and the subsequent trajectory of development in a global world order. In this connection, the Russian education there are urgent tasks related to the need to comply with the transformation of the education sector changes. Keywords: economic growth, educational service, training, educational organization JEL Classifications: G20, L00, O4

Влияние продолжительности термической обработки на структуру и фазовый состав образцов сплава Co-Cr-Mo, полученных с помощью аддитивных технологий

Laser powder bed fusion (LPBF) requires application of powders with specific characteristics. These are near-spherical shape of particles, uniform elemental composition, typical particle size of 5 - 70 mu m, etc. Such powders are produced by spheroidization methods. They have such disadvantages as high cost and sale only in large quantities. There are publications describing application in LPBF powders, produced by the methods, alternative to spheroidiz,ation. In the current study, powders of pure raw Co, Cr and Mo were used for the production of Co-Cr-Mo powder mixture. Samples of Co-28 wt.% Cr-6 wt.% Mo alloy were produced by LPBF from this powder mixture. Due to the difference between melting temperatures of Co, Cr and Mo, inclusions of Cr and Mo were formed within the bulk of samples. Studies of phase and elemental composition, structure and microhardness of the as-produced samples and after post-treatment with varied duration are represented. As-produced samples have non-uniform elemental composition and are represented by the main Co-based phase. Increasing the annealing duration leads to the sequential dissolution of un-melted Cr and Mo inclusions. Complete dissolution of Cr particles was observed at 10 hours of treatment and complete dissolution of Mo particles was not observed after 20 hours of annealing. Microhardness non-linearly changes with the increasing duration of annealing. This is due to the phase transformations and diffusion processes occurring at such type of post-treatment. Complete dissolution of Mo-particles could be achieved by further increasing the annealing time or by varying the mode of laser powder bed fusion