Ti-Zr-Nb based BCC alloy containing Mo prepared by laser directed energy deposition—ω phase and cellular structure

Abstract

This study focuses on the fabrication of Ti-Zr-Nb β-Ti alloys via laser direct energy deposition (DED) technique using pre-alloyed powder with and without having Mo traces. Microstructural analysis revealed the presence of cellular structures within the grains, resembling dendritic solidification, although no discernible dendritic segregation was observed. Nano-scale solute element clustering, particularly the formation of Nb depletion pockets, led to the development of the ω phase within the β matrix. Strengthening effects resulting from the presence of the ω phase were confirmed through TEM analysis. The DED-fabricated β-Ti alloy exhibited enhanced strength (∼1 GPa), significant elongation (∼15%), and a low elastic modulus (∼65 GPa), positioning it as a promising candidate for load-bearing biomedical implants.