Damping capacity of Al–12Si composites effected by negative thermal expansion of Y2W3O12 particle inclusions

Effects of Y 2 W 3 O 12 particle inclusions and content on damping capacity of Al–12Si composites have been investigated. The Y 2 W 3 O 12 , which is a kind of negative thermal expansion material, can generate high local strain in the composites. Thermal expansion testing shows that the coefficient of thermal expansion (CTE) of Y 2 W 3 O 12 has obvious changes between 100 and 200 °C The Y 2 W 3 O 12 /Al–12Si composites show damping peaks and display higher damping capacities than the pure Al–12Si alloy. The damping capacities of composites strongly depends on the content of Y 2 W 3 O 12 inclusions. A thermal strain damping model is also established. Based on the model analysis results, there is a significant contribution of thermal strain to the damping capacity in the composites; the change in CTE of Y 2 W 3 O 12 could cause the generation of damping peaks. Moreover, dislocation damping and interfacial damping are also main damping mechanisms in the investigated composites.