Processing of TiB2-Fe Composite Powders Synthesized from Ferroboron and Ferrotitanium as a Starting material of TiB2-Dispersed Steels

Titanium diboride (TiB2) is a candidate of dispersion materials for dispersion-strengthened alloys due to its exceptional hardness and high melting point. This study focuses on the processing condition of TiB2-Fe composite powders synthesized by using a reaction between ferrotitanium (FeTi) and ferroboron (FeB), aiming to a starting material of TiB2-reinforced steels fabricated by the powder metallurgy method. The effects of heat-treatment conditions, B/Ti molar ratios, and scaling up production were investigated. The research demonstrates that TiB2-Fe composite powders with fine TiB2 particles can be fabricated by optimizing heat-treatment at 1200°C and controlling the B/Ti ratio to suppress the formation of undesirable liquid phases. The TiB2 particles were observed to have a homogeneous dispersion in the TiB2-Fe composite powders after crushing and milling, making them suitable for powder metallurgy processes. In addition, scale-up experiments confirmed the feasibility of industrial production, ensuring consistent quality and uniform particle distribution.