Control of the interfacial reaction in aluminum borate whisker-reinforced 6061Al composite by sol-gel alumina coating

Research work is presented, which indicates that during the squeeze-casting process, an interfacial reaction of the AlBO whiskers with magnesium-containing aluminum alloys often occurs. Although a better wetting of the whisker and the matrix can be achieved, this spinel reaction always has a detrimental effect on the subsequent heat treatment and some of the composites mechanical properties. A sol-gel alumina coating method is employed to achieve a kind of interface design and to modify the interface properties. Results indicates that, α-Al2O3 coating is an effective barrier coating for controlling the interfacial reaction of the AlBO whisker-reinforced Al-Mg matrix composites.