The effect of SiCp size on high temperature damping capacity and dynamic Young's modulus of hot-pressed AlSi–SiCp MMCs

Abstract

In this study, the effect of the size of SiC particle on high temperature damping capacity and dynamic Young's modulus of hot-pressed AlSi–SiC composites has been investigated. SiC particles with sizes of 13μm, 38.8μm and 118μm were added to AlSi matrix to prepare the hot-pressed AlSi–SiC composites. These composites were characterized using a dynamic mechanical analyser (DMA), over a temperature range of room temperature to 400°C. Regarding damping capacity, all AlSi–SiCp composites exhibited higher damping capacity compared to unreinforced AlSi alloy (for all tested frequencies). AlSi–SiCp(118) composites exhibited the highest improvement in damping capacity. A damping peak was observed near 250°C, as a result of a relaxation process. Regarding dynamic Young's modulus, it was observed that the addition of SiCp to the AlSi alloy improved the Young's modulus. It was also demonstrated that by increasing the SiCp size, a decrease in Young's modulus is attained, with the highest improvement in dynamic Young's modulus being obtained by AlSi–SiCp(13) composite.