Production of materials with ultrafine-grained structure of aluminum alloy by friction stir processing

Abstract

Methods of optical microscopy, scanning electron microscopy and EBSD analysis have been used to study the structure of ultrafine-grained materials obtained by friction stir processing. The data obtained indicate a complex and inhomogeneous character of the deformation at the processing area. When conducting TEM studies, it was revealed that grains of the a-Al solid solution of the processed material have the zone axis of the type 110. The main differences in the structure of materials obtained by processing with different types of tool are determined. It was revealed that in addition to the difference in the use of the tool with the presence or absence of the so-called "pin", the shape and arrangement of grooves on the end part of the tool, the so-called "shoulders", are of paramount importance. The influence of the shape of the grooves affects both the depth of the processed layer and the average grain size of the stir zone.