Exploring the impact of heat treatment on the microstructural and compressive properties of Al-SiC-MWCNTs hybrid nanocomposites foams

Abstract

The current study focused on the investigation of the microstructural and compressive properties of Al-SiC-MWCNT hybrid composite foams after the implementation of heat treatment. The samples were prepared with varying weight percentages of SiC and MWCNTs, with fixed porosity 86 % (relative density = 0.14). Initially, samples were subjected to solutionizing at 480 °C for 10h, followed by rapid water quenching. Subsequently, artificial aging was conducted by applying three different temperatures (150 °C, 180 °C, and 220 °C) for varying durations, ranging from 2 to 10h. The results revealed that significant improvement in mechanical properties and maximum peak compressive stress and microhardness were achieved between 6 and 8h and 8 and 10h, at the aging temperatures of 220 °C and 180 °C respectively. However, in the case of aging at 150 °C, mechanical properties also increased but at a slow rate, but no clear peak values were observed even after 10h of aging. It was observed that in case of HCF (both MWCNTs and SiC added as reinforcement) the plateau stress increased up to 30 to 40 %, whereas in case of AF, CF1, and CF2 foams the properties improved by 20 to 30 %. Also, by utilizing the established Gibson model, the plateau stresses were predicted and validated with experimental results.