Electro-strengthening of the additively manufactured Ti-6Al-4V alloy

Structure-property-processing relationship has been studied in additively manufactured Ti-6Al-4V alloy. The processing was performed using in-situ electron microscope (EM) at a moderate current density of 5 x 10(5) A/cm(2) applied for 5 min, and by suppressing Joule heating with massive heat sinks such that the temperature rise was <180 degrees C and the mechanical properties were not compromised. The results show that while the grain size increased by-15%, the nanohardness increased by 16%. This is attributed to the pronounced dislocation generation, regeneration, and clustering as well as defect healing. Ultimately, there is a reduction in the residual strain and a significant increase in the intrinsic strength as evidenced by the high Taylor factor of the electric current processed specimen. This novel processing technique represents an alternative pathway for active con-trolling of microstructure and internal defects for parts that might be sensitive to high-temperature processing or conventional methods.