Production and Characterization of Aluminum Reinforced with SiC Nanoparticles

Abstract

Aluminum matrix nanocomposites have been the subject of much attention due to their extraordinary mechanical properties and thermal stability. This research focuses on producing and characterizing an aluminum matrix reinforced with silicon carbide (SiC) nanometric particles. The conventional powder metallurgy route was used to produce the nanocomposites, and the dispersion and mixing process was carried out by ultrasonication. The conditions of the dispersion and the volume fraction of the SiC were evaluated in the production of the nanocomposites. Microstructural characterization was carried out using optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and electron backscatter diffraction (EBSD). Mechanical characterization was carried out using hardness and tensile tests. The dispersion agent was investigated, and isopropanol leads to better dispersion with fewer agglomerates. Increasing the volume fraction of the reinforcement improves the hardness of the nanocomposites. However, greater agglomeration of the reinforcement is observed for larger volume fractions. The greatest increase in hardness (77% increase compared to the hardness of the Al matrix) is obtained with 1.0 vol. % of SiC, corresponding to the sample with the best dispersion. The mechanical characterization through tensile tests attests to the effect of the reinforcement on the Al matrix. The main strengthening mechanisms identified were the load transfer, the texture hardening, Orowan strengthening, and the increase in the density of dislocations in the nanocomposites.

Aluminum Nanocomposites Reinforced with Al2O3 Nanoparticles: Synthesis, Structure, and Properties

“…A higher density of dislocations during the production of the nanocomposites is observed due to the presence of the Al2O3 nanoparticles that will significantly affect the mobility of the dislocation. The same result was reported for nanocomposites reinforced with other nanoparticles [11,18]. Different microstructural characteristics are evident between the matrix and the nanocomposites processed under the same conditions.…”

“…This work selected a one-step dispersion and mixing process using ultrasonication. Various dispersion/mixing media (ethanol, isopropanol, and water) and various ultrasonication frequencies (12.0, 15.0, and 20.4 kHz) are based on previous work using other nanoparticles [11,18,19]. Table 1 shows the conditions tested in this work.…”

“…Cold compaction was carried out at 300 MPa and sintering at 640 • C for 90 min. These processing conditions were selected based on the best conditions obtained for Al/SiC and Al/CNT nanocomposites [11,18]. Archimedes' principle was employed to measure the density of the sintered specimens, providing insights into the compaction and porosity levels.…”

“…Various processing techniques were explored to obtain a homogeneous dispersion of the nanoparticles in the aluminum matrix [3,4,6,[11][12][13][14][15]. Stir casting is one of the most popular methods to produce metal matrix composites [13], as the apex has been used to create a good distribution of the reinforcing material in the matrix and has been known as an up-and-coming method for manufacturing the desired shape at minimal cost, with a more incredible bond between the matrix and the particles that are being added.…”

A comprehensive study of Al-Cu-Mg system reinforced with nano-ZrO2 particles synthesized by powder metallurgy technique

“…It is important to emphasize that there are many effective methods to produce Al and its alloy matrix nanocomposites, such as fraction stir 18 , squeeze casting 19 , stir casting 20 , and powder metallurgy (PM) 21 , 22 . The latter is a modern and cost-effective tool for good dispersion of reinforcement in the matrix, giving a uniform distribution of particles in the microstructure 23 , 24 .…”