Structural Changes in Block-Shaped WEBAM’ed Ti6Al4V Samples after Friction Stir Processing

Abstract

In this paper, the structure and mechanical properties of workpieces made of Ti6Al4V alloy in the shape of blocks manufactured by wire-feed electron beam additive manufacturing and processed by friction stir processing were investigated. Samples were cut from the upper and lower parts of the additive block and processed in the layer deposition direction using different tool loading forces. Studies have shown that the processing of such material forms a clearly defined thermomechanically affected zone represented by nanosized α-grains. In the stir zone, the material is characterized by a fine-dispersed structure with a content of α- and nanosized α″-phase plates. The material after processing demonstrates 24% higher values of the ultimate tensile strength as compared to the base metal in the as-built state.

Keywords

• electron beam additive manufacturing
• friction stir processing
• titanium alloy
• microstructure
• mechanical properties