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

The current study focused on the investigation of the microstructural and compressive properties of Al-SiCMWCNT 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 degrees C for 10h, followed by rapid water quenching. Subsequently, artificial aging was conducted by applying three different temperatures (150 degrees C, 180 degrees C, and 220 degrees 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 degrees C and 180 degrees C respectively. However, in the case of aging at 150 degrees 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.