Directional solidification features of nickel-based superalloy in the electron beam additive manufacturing process

Abstract

In the present study, wall-shape products from nickel-based superalloy ZhS6U were obtained by the wire-feed electron beam additive manufacturing (3D-printing). Product was formed on the substrate from austenitic steel AISI 321 with water cooling. Investigations provided by optical metallography method, scanning electron microscopy and X-ray diffraction analysis show presence of a microstructural and elemental gradient along the height of the sample. It was established that dendrite growth (by means of primary order symmetry arms) occurs antiparallel to the direction of the temperature gradient. The material of the formed product is made by the focused colonies of column dendrites without internal misorientations. Colonies of columnar dendrites are mainly oriented by crystallographic directions of type «001» along the direction of additive growing of the product.