Bulletin PNRPU. Mechanical engineering, materials science

The regularities of manifestation of refractory interstitial phases (RIP) chemical activity in reactions of the solid-gas type are discussed. It is established that interaction of RIP components with different oxygen containing mediums is selective. Demonstrated a correlation between the oxygen chemisorptions on the RIP surface and the density of Ti3d-states at the Fermi level. It is shown that the near-stoichiometric carbides, in contrast to the sub-stoichiometric carbides, are chemically active in pure hydrogen. It is concluded that the regularities of interaction of RIP with aggressive gaseous media are a consequence of their solid solution nature.

Classification of factors which influence the stress-strain conditions of a billet during forging processes was proposed. The approach was to determine the relative significance of shape factor which involves tool shape and initial billet shape, the kinematic factor which is defined by the kinematics of impact tools on the billet and the mechanical regime of the forging process and the temperature factor, involving the temperature field and temperature state of the billet. The well known techniques which are used in manufacturing were considered within the limits of each of these factors. The volume of research which was devoted to each of the factors was determined along with the direction of further research in the development of new heavy forging techniques which are managed by the stress-strain state of the billet with high efficiency.

This work describes the endurance tests of end mills with HCN, HCS, DCL coating as well as synthetic diamond coating. There was made a comparison analysis on the wear rate of the tool cutting edge.

The literature review of the research on methods for the analysis of the stability of various multilevel objects that are formed in a continuous exposure to external factors. The algorithm of fractal analysis, allowing to identify the relationship between the fractal dimension and properties level and established a unified numerical parameter to describe structures, is considered. Major areas of use of fractal analysis in materials science: Structure formation of metals, porous structure evolution by the depth of the oxidized coating, the possibility of application of the method to predict and evaluate the stability level of economic systems dynamic index.

Introduced the technology of automatic submerged arc welding assemblies of steel welded edges with thickness from 45 to 70 mm combined method.

The analysis methods of fatigue crack resistant of welding metal of low carbon steel, middle- and high-ligature steel is considered.

At the article the concept 'form' is presented. The definition to 'forms of professional education' and classification of forms are given. The author describes preconditions to a choice of actual forms of professional education in polytechnic higher education institution.