Influence of pulsed beams of deuterium ions and deuterium plasma on the aluminum alloy of Al-Mg-Li system
Damage and structural state of the surface layer of Al-Li-Mg samples composed of Al+5% Mg+2% Li (wt.%) under pulsed action of power streams of high-temperature deuterium plasma and high-energy deuterium ions in the Plasma Focus (PF) device have been investigated. The radiation power density was q ~ 106 W/cm2, the pulse duration was 50-100 ns. Pulsed thermal heating and rapid cooling is established to lead to the melting and solidiication of a thin surface layer of the alloy for several tens of nanoseconds. At the same time, in the superheated surface layer of the alloy, microcavities of a spherical shape are formed which is associated with intensive evaporation of lithium into micropores within the heated layer. Thermal stresses caused by abrupt heating, melting and cooling of a thin surface layer of metal resulted in formation of microcracks in the near-surface zone of the samples. The evaporation by the power electron beam of the elements of the anode material of the PF device (copper and tungsten) and their subsequent deposition onto the irradiated surface of the investigated samples in the form of droplets of submicron size have been found. It have been shown that the thermal and radiation-stimulated processes generated in the alloy under the action of pulsed energy luxes in the realized irradiation regime lead to the redistribution of elements in the surface layer of the aluminum solution contributing to an increase of magnesium content and the formation of magnesium oxide on the surface