SiC/Al interface feature of Al-Fe-V-Si alloy reinforced with SiC particles

SiCp/Al-Fe-V-Si composites were prepared by spray deposition, and the as-deposited preforms were hot pressed and subsequently rolled. The SiC/Al interface of the as-rolled composite sheets was observed by high resolution transmission electron microscopy (HRTEM). The results show that there are two kinds of SiC/Al interfaces in the composites. One is crystalline silicon transition layer with about 3 nm in thickness, and some dispersed Al4C3 phases appear in the matrix near the interface. And the other one is amorphous silica layer with about 5 nm in thickness and SiC particles solve partly to inject Si into the matrix, resulting in Si concentration gradient. Both of the two kinds of interfaces are characterized with good wettability, which contributes to the strong bonding between SiC particles and Al matrix. Coarse Al4C3 phases appear at the SiC/Al interface for the composite exposed at 640 ℃ for 10 h, which result in the interface weakening followed by decrease of the composite strength.