Search

The paper presents the results of model experimental studies of the adhesion frictional interaction of alloy 2024 with a counterbody of complex shape made of steel 420 and comparison of the formed structure with that formed during friction stir processing/welding. The obtained correlations of plastic flow of material along the contour of the counterbody indicate that in the process of frictional contact the grain structure is refined to the ultrafine state and the material extrudes from the friction zone. When the loading force, sufficient to fully press the counterbody, is reached, the disconnected material flows, extruded initially in the form of overlaps on the edges of the counterbody, are compacted to form a monolithic mixing zone with an ultrafine-dispersed grain structure. [ABSTRACT FROM AUTHOR]

Products from aluminum-magnesium alloy were produced by electron-beam additive technology. In this work, the microstructure and mechanical properties of the entire height of the grown product were investigated. The study of the microstructure showed that the grown sample has inhomogeneities and microdefects. At the bottom area a large number of β-phase intermetallic compounds of the MgAl system were appearing and at the top area the amount of intermetallic compounds was noticeably less, but a large amount of pores was observed. Mechanical properties were determined by compression testing. The results of mechanical tests indicate that the highest strength of the material is observed in samples cut out near the substrate. [ABSTRACT FROM AUTHOR]

The paper analyzes the effect of friction stir processing (FSP) on the structure and phase state of two titanium– nickel alloys: Ti–50.9Ni and Ti–50.2Ni (at %). The analysis shows that with the FSP modes and equipment chosen, the treatment creates no macroscopic defects in the stir zone, dissolves the initial texture of the alloys, and weakly influences their structure and phase state. In the internal volumes of the track region, Ti–50.9Ni preserves its B2 phase and Ti– 50.2Ni undergoes R → B2 transition with its B19′ phase kept intact. The oxide layer thickness is smaller than 50 µm. [ABSTRACT FROM AUTHOR]