Effect of thermal exposure on the microstructure of the interface in a Grf/Al composite

Abstract

The microstructure of the interface in a Grf/Al composite after exposure at high temperature was investigated. The graphite fiber reinforced aluminum matrix composite was prepared by the pressure infiltration method. After being heat treated at 550°C, 600°C and 640°C for different times, the microstructure of the interface in the composite was studied by using transmission electron microscopy (TEM). Furthermore, the content of Al4C3 in the interface was examined using X-ray diffraction (XRD). The results showed that not only the micro morphology but also the content of Al4C3 in the interface varied with the increase in temperature. When the composite was heat treated at 550°C and 600°C, Al4C3 with a big length-to-diameter ratio was observed in the interface, while Al4C3 with a small length-to-diameter ratio was found when the heat treatment temperature was 640°C. With the increase in the time, the content of Al4C3 in the interface increased rapidly when the composite was heat treated at 640°C. Based on the dynamic calculation, the interface reaction diffusion rate constant of the Grf/Al composite increases rapidly when the temperature is higher than 600°C.

Keywords

• al matrix composite
• al4c3
• graphite fiber
• interface