Effect of thermal cycling on the damping behavior in alumina borate whisker with and without Bi₂O₃ coating reinforced pure aluminum composites

Alumina borate whiskers with and without Bi₂O₃ coatings reinforced pure aluminum composites were fabricated by squeeze casting. The damping behavior of the composites was described. Samples had undergone thermal cycling during the damping measurement. For the Al₁₈B₄O₃₃w/Al composite, two damping peaks are present either in the heating or in the cooling process. For the Al₁₈B₄O₃₃w/Al composite with whisker coatings, there are also two damping peaks in the heating process, but there are three damping peaks in the cooling process. The research results indicate that a distinct difference presents in the damping-temperature curves for the Al₁₈B₄O₃₃w/Al composite with and without whisker coatings. The damping behavior and damping mechanism in the composites during thermal cycling are explained through dislocation motion, interfacial and grain boundary slip.