Electrodynamic Treatment of Structural Elements Made of Aluminium and Magnesium Alloys

The article discusses the electrodynamic treatment (EDT) of thin-walled welded structures and EDT equipment, presents results of mathematical modelling concerning the effect of EDT on stresses in welded sheets made of aluminium alloy AMg6 as well as discusses the effect of EDT on the plastic strain mechanism. In addition, the article presents tests results concerning the effect of EDT during the welding of ship structures made of AMg6 plates and discusses the role of EDT in bulge formation. In addition, the article discusses the application of EDT during the repair welding of aero-engine nacelles made of magnesium alloy ML10 and the effect of EDT on openings in an airplane wing stinger in relation to its service life.

Stability of Strength Characteristics of Hardened by Deformation AMg6 Alloy during High-Speed Heating

The results were shown in influence of fast heating parameters on the structure and properties of cold-worked alloy AMg6 with original hot-forged structure. Based on the measured data, the change of mechanical properties of cold-worked alloy AMg6 during the process of short duration heating was evaluated. There was reviewed the role of the temperature and the time of heat on the processes of softening the samples of cold-worked alloy AMg6. The stability of mechanical characteristics of hammer-hardened alloy AMg6 under elevated test temperatures was evaluated. It is shown that the return processes in cold-deformed AMg6 alloy during heating in the temperature range studied receive the most intensive development in the first 5–10 minutes, reducing the hardening effect from cold deformation, determined by tensile strength, respectively: by 8–9% with 100 °C; 26–27% at 150 °C; 37–38% at 200 °C; 42–44% at 250 °C and 50% at 300 °C. A decrease in the yield strength during high-speed heating in the temperature range studied is much faster ,compared with the change in the tensile strength. Hour exposure at 200 °C reduces the hardening effect on the yield strength from 340 MPa to 258 MPa, while the tensile strength decreases from 430 MPa to 385 MPa.

Features of the structure and properties formation of AMG6 alloy under the equal channel angular pressing

The results of experimental studies of changes in the structure, microhardness, and wear resistance of the AMG6 aluminum alloy during equal channel angular pressing (ECAP) are presented in this work. The evolution of the fine structure and the formation of secondary phases in the AMG6 alloy during ECAP were studied. The dark-field image of the structure of the AMg6 alloy in the matrix reflex showed the splitting of the material into small disoriented fragments of about 0.5 μm in size with a small-angle disorientation boundary (about 2–5°). Optimal method and modes of ECAP of the AMG6 aluminum alloy were selected of the bases of experimental research, which make it possible to obtain a workpiece with enhanced tribological and mechanical characteristics. It was established that the most intensive grinding of the grain structure in the AMG6 alloy occurs at ECAP-12 at a channel angle intersection of 120°. It is shown that with a decrease in grain size, the microhardness of the alloy AMG6 after ECAP increases by 4 times, compared with the initial state.The results of the test samples for abrasive wear showed a decrease in mass loss after 12 passes of ECAP, which indicates an increase in the wear resistance of the alloy AMG6 by 13–14 %, compared with the initial state.

Simulation of heat transfer at welding with oscillating electron beam

This work presents a numerical model of the temperature distribution during electron beam welding, performed by circular and elliptical beam oscillation. The numerical calculations have been done using Green’s functions. A method of finding the dependence between the source power and the weld’s depth is proposed. We present the calculated temperature distribution in electron beam welded aluminium alloy AMg6 with circular and elliptical oscillating beam for different technological parameters. The experimental shape of the weld and the calculated one show a good correspondence.