Abstract: Spray deposition was applied to produce deposited billets of rapidly solidified Al-8.7Fe-1.3V-1.8Si aluminum alloy in the atomization medium of nitrogen gas. Microstructural features and mechanical properties of the spray deposited billets were studied by means of optical microscopy (OM), X-ray diffraction (XRD), transmission electron microscopy (TEM) with energy dispersive X-ray (EDX) spectrometer and measurement of tensile properties. The results show that, the spray deposited billets of Al-Fe-V-Si alloy consist of platelets (powder particles) with various size and shape, deposited and solidified from the atomized liquid droplets, and a large amount of irregular porosity (or pinhole) and prior particle boundaries also exist in the as-solidified deposit. The spray deposited billets consist of two phases mixture of α(Al) and Al₁₂(Fe, V)₃Si (bcc, a≈1.260 nm), which is characterized generally as the fine Al₁₂(Fe, V)₃Si particles dispersed uniformly in the α(Al) matrix. However, the various powder particles have different microstructural morphologies and thus the spray deposited billets exhibit structural inhomogeneity on the micro scale. The mechanical properties of the spray deposited materials are mightily dependent on relative compacted density of the billets, and the large amount of irregular porosity (or pinhole) and prior particle boundaries result in that the tensile strength and elongation of the billets are at the low level.

Key words: Al-Fe-V-Si alloy; heat-resistant aluminum alloy; spray deposition; rapid solidification