The effect of high-temperature exposure on the microstructural evolution in the rapidly solidified Al-8.5Fe-1.3V-1.7Si alloy has been investigated by transmission electron microscopy. Decomposition of the microstructure starts with the formation of vanadium-rich intermetallic particles of composition close to (Al, Si)45(V, Fe)7, isostructural with the monoclinic Al45V7 phase. The appearance of this phase was observed in the specimens subjected to heat treatment at 450°C for 200 hours. Then, at the higher temperature of 500°C, needle-shaped particles of the monoclinic Al13Fe4 structure, 2-3 μm length, grew in the matrix after the exposure for 250 hours. The process was accompanied by significant coarsening of some of the nanoparticles, thus indicating that there exists a correlation between destabilization of α-Al12(Fe,V)3Si nanoparticles and the appearance of vanadium and iron containing phases.
|Number of pages||6|
|Journal||Materials Science Forum|
|Issue number||PART 2|
|State||Published - 1 Jan 1998|
- Aluminium alloys
- Transmission electron microscopy