Preparation of Metal Matrix Aluminum Alloys Composites Reinforced by Silicon Nitride and Aluminum Nitride through Powder Metallurgy Techniques

Abstract

The aliminium alloys are of particular interest to both the aerospace industry and automotive industry because of their attractive combinations of properties such as medium strength, formability, weldability, corrosion resistance and low cost. Compared with a metal matrix material, significant improvements in the mechanical and physical properties such as strength, toughness, and thermal conductivity can be achievied in metal matrix composites (MMCs). In this work of investigation aluminium alloy AA6061 was reinforced by 5, 10 and 15% (in mass %) of Si3N4 (silicon nitride) and AlN (aluminium nitride) by mechanical alloying in a vibratory type SPEX mill, cold uniaxial compaction and vacuum sitering in order to investigate the influence of the particulate phase in the microstructure and mechanical properties of the composites obtained. The microstructure of the powders and the sintered materials were evaluated by means of SEM and the hardness and were evaluated by hardness test.

Effect of Silicon Nitride and Graphene Nanoplatelets on the Properties of Aluminum Metal Matrix Composites

“…Concurrently, the percentage of porosity was calculated and found to be decreasing after the addition of Si 3 N 4 nanoparticles to the Al matrix (S2), as shown in Table 3 . The good dispersion and uniform distribution of Si 3 N 4 within the Al matrix has resulted in a lack of agglomerations of the reinforcement and thus reduced the porosity of the Al-Si 3 N 4 composite [ 32 ]. However, with the successive addition of GNPs to the composites, the porosity level is noticed to increase due to agglomeration of GNPs in the Al-Si 3 N 4 -GNPs composites (S3, S4, and S5) as presented in Table 3 .These findings are consistent with previous studies [ 33 ].…”