Role of A2 and A50 process on the oxide dispersion strengthened ferritic alloy fabricated by mechanical alloying

This study has investigated the effects of adding occasion of Stearic Acid (SA) on the characteristics of powder and properties of bulk with nominal composition of Fe–12Cr–2.5 W–0.4Ti–0.3Y₂O₃, which was fabricated by mechanical alloying and vacuum sintering. SA was milling with the powder mixture with 50 h (added before milling, A₅₀) or 2 h (added after 48 h milling, A₂). The resulted showed: SA could inhibit the agglomeration and retard the alloying process. Powders through A₂ process achieved alloying with high powder yield, while the A₅₀ powders presented alloying extent, and the yield of A₀ powder presented low powder yield. SA added in A₅₀ was almost dissolved into the matrix for the long milling duration, but SA added in A₂ was mostly volatilized during heating. A₂ bulk alloy was of better strength for the finer, more uniform grain and second phase and higher density than A₅₀ bulk.