Precipitation and Recrystallization in Al-(Zr)-(Pr)-(Cr) Alloys

Structure and thermal stability of nano-sized dispersoids in Al-(Zr)-(Pr)-(Cr) alloys have been revealed by conventional and high-resolution transmission electron microscopes. Results show that Al-0.16Zr-0.26Pr-0.18Cr alloy (wt%) exhibits significant precipitation strengthening, thermal stability and recrystallization-resistant ability by forming a relatively high density of well-dispersed Pr-containing (Al, Cr)3Zr dispersoid (15∼20 nm) with L12 structure. The dispersoid is coherent even exposed at 500 °C for 400 h. Pr-containing (Al, Cr)3Zr dispersoid is finer and coarsening-resistant around 500 °C, as compared with L12-structured Al3Zr and Pr-containing Al3Zr dispersoids.