Analysis of Changes in the Phase and Structural State of an Aluminum Alloy 1933 Surface Layer, Melted by a Pulsed Electron Beam

Abstract

The structural and phase changes in the surface layer of an aluminum alloy 1933 caused by the action of a relativistic pulsed electron beam are studied. The structural and phase state of this layer is determined by the impact action of the electron beam and by the kinetics of crystallization from the melt under ultrafast cooling. The impact of a pulsed electron beam is accompanied by the formation of a developed surface relief and the appearance of microcracks on it. The structure of the modified layer is nonequilibrium. X-ray diffraction studies and the results of energy dispersive X-ray microanalysis made it possible to determine that magnesium oxide inclusions are present in the remelted layer. MgO inclusions are generally uniformly distributed in the remelted layer. The maximum size of MgO inclusions does not exceed 1 μm. The causes and mechanisms of the formation of magnesium oxide during the action of a pulsed electron beam are discussed.