Mullite formation at the interface of CaO-Al{sub 2}O{sub 3} fiber reinforced Al-Si alloy composites

Inviscid melt spun (IMS) calcia-alumina (CA) fiber reinforced aluminum-silicon alloy (4032) composites were produced using melt infiltration technique. The composites processed at 927{degrees}C showed formation of an interphase region of about 10 to 20 {mu}m thickness, as well as excellent interfacial bonding. Energy dispersive x-ray spectroscopy (EDS) analysis gave averaged compositions of this interphase region at 74 wt% of Al and 26 wt% of Si, which corresponds to the composition of mullite (3Al{sub 2}O{sub 3}{center_dot}2SiO{sub 2}). The formation of mullite at the interface was confirmed by x-ray diffraction (XRD).