Effect of Trace B on the Microstructure and Mechanical Properties of a Newly Near α High Temperature Titanium Alloy

In this study, the microstructural evolution and mechanical properties of a newly near alpha titanium alloy with trace additions of B by in situ casting route are investigated. The results show that the coarse prior beta grain and alpha lath within matrix alloy are gradually refined with increasing of B addition. The relative refinement mechanism of prior beta grain and alpha lath width is analyzed and discussed. In addition, it is shown that both of ultimate compressive strength (UCS) and yield strength (UYS) increase with B addition, which is mainly attributed to microstructural refinement. However, the compressive ductility and fracture toughness decrease with increasing of B addition, which is due to the cracking of TiB, leading to the acceleration of crack extension.