Superior role of LaB6 in enhancing O-scavenging efficiency during sintering Ti alloy from electrostatic self-assemble LaB6-coated Ti powder

LaB 6 has been demonstrated as an effective O-scavenger for powder metallurgy (PM) Ti alloys to mitigate the detrimental effect of solid-solution O on the ductility. However, conventional mechanical mixing methods lead to the agglomeration and non-uniform distribution of LaB 6 , resulting in partial deactivation and reduced O-scavenging efficiency during sintering. Aiming at this issue, we propose an electrostatic self-assembly strategy that combined surface functional modification of LaB 6 with solid-liquid fluidized bed powder coating treatment to synthesize a novel LaB 6 -coated Ti composite powder. Compared to traditional LaB 6 additives in powder mixtures, the LaB 6 -coating particles exhibited excellent O-scavenging efficiency and higher utilization rate. Even at a low coating-content of 0.3 wt% LaB 6 , the tensile strength and elongation of the as-sintered Ti samples increased from 461 ± 26 to 579 ± 13 MPa and 5.6 ± 1.4% to 14.2 ± 0.3%, respectively. The achieved improvement rate (∼95%) in tensile elongation was significantly superior to the previously reported data of the rare-earth O-scavengers.