Investigation of TiB distribution characteristics on the microstructure of in situ TiB/Ti6Al4V-ELI manufactured by laser metal deposition

• Published in: MATEC web of conferences 2023, Vol.388, p.3015
• Main Authors: Lekoadi, Paul, Tlotleng, Monnamme, Siyasiya, Charles, Masina, Bathusile
• Format: Article
• Language: English
• Subjects: Electron back scatter; Laser deposition; Mechanical properties; Microhardness; Microstructure; Optical microscopes; Optical properties; Particulate composites; Titanium base alloys; Titanium diboride
• ISSN: 2261-236X; 2274-7214; 2261-236X
• DOI: 10.1051/matecconf/202338803015

This study presents the investigation of TiB distribution characteristics on the microstructure of in-situ synthesized TiB/Ti6Al4V single-track composites manufacture with laser metal deposition. Ti6Al4V alloy was reinforced by adding TiB 2 ceramic at mass volumes of 0%, 1% and 2% for microstructure modification and mechanical properties enhancement. The TiB/Ti6Al4V composite was characterized using optical microscope (OM), scanning electron microscope (SEM), electron backscatter diffraction (EBSD) and microhardness. It was found that the addition of TiB 2 resulted in the transformation of the prior β-grain into two types of morphologies of dendritic and columnar microstructures. Furthermore, the increase in the amount of TiB 2 resulted in the reduction of the volume fraction of β-Ti phase, with the in situ formed TiB replacing and occupying the β-Ti positions. Deposition at 2% promoted the formation of unmelted TiB 2 particles which promoted hardness increase to 496 ± 17 HV.