Formation of nanodispersoids in Fe–Cr–Al/30%TiB 2 composite system during mechanical alloying

Abstract

Mechanical alloying is an effective processing technology which allows the synthesis of nanocrystalline composite materials. In this study, a nanocrystalline Fe–Cr–Al/30%TiB 2 composite material is synthesized without process control agents by the mechanical alloying process using a planetary high-energy ball mill. Crystalline (or grain) size reduction and dispersion behavior of brittle TiB 2 powder during ball milling are investigated together with mechanical alloying behavior of ductile metallic matrix powder for synthesis of the composite. Mechanical alloying between metallic elements is almost completed after approximately 8 h milling. The crystalline size of TiB 2 decreases to 36 nm after 48 h of ball milling, while the average particle size of the composite powder increases in comparison with the initial size. Transmission electron microscopy reveals formation of TiB 2 nanodispersoids of size around 50 nm after 48 h milling.