Microstructural study of laser-clad Fe-Al bronze on Al-Si alloy

Microstructure studies of laser-clad Fe-Al bronze on an Al-Si alloy were ca rried out by OM(optical microscope), SEM(scanning electron microscope), TEM (transmission electron microscope) and XRD(X ray diffraction) analyses. The cross-section of the laser-cladding was divided into clad region and trans itional region. The clad region composes a matrix with a twin structure of needle-like and feathery appearance and a second phase of Cu9Al4. The trans itional region consists of two layers. The layer close to the clad region s hows polygonal crystalline while the layer close to the substrate region di splays a needle-like structure. XRD analyses show that the main phases in t he polygonal crystalline layer and the needle-like structure layer are Cu3A l + Cu9Al4 and CuAl2 + alpha -Al, respectively. Finally, the formation mech anism of two regions was analysed. (C) 2001 Kluwer Academic Publishers.