High temperature damping behavior and dynamic Young's modulus of AlSi-CNT-SiC_p hybrid composite

Lightweight metal-matrix composites (MMC) are being applied in many fields such as aerospace and automotive, where detailed knowledge about their elastic and inelastic properties is required to make optimal design of the component. In this study the high-temperature damping capacity and dynamic Young's modulus of hot-pressed AlSi-based hybrid composites reinforced with silicon carbide particles (SiC_p) and carbon nanotubes (CNTs) were experimentally measured and compared with AlSi-SiC_p and AlSi-CNT composites. Results show that by reinforcing AlSi-SiC_p with CNTs, the damping capacity is improved without reducing mechanical properties. The highest damping capacity value was attained by AlSi-(CNT-SiC_p) hybrid composite, for all the studied frequencies and temperatures, followed by AlSi-SiC_p and AlSi-CNT composites. The possible damping mechanisms for all these produced composites are presented and discussed. Unlike to damping capacity, the dynamic Young's modulus shows no substantial changes after adding CNTs to AlSi-SiC_p. Results show that by using a proper combination of materials (including different types of reinforcements), scales (nano- and micro-sized reinforcements) and manufacturing processes, the design of a material with required damping capacity and mechanical properties is possible.