Enhanced mechanical properties of in situ aluminium matrix composites reinforced by alumina nanoparticles

Abstract

In-situ fabrication of metal matrix nano composites has various advantages such as the formation of clean particle-metal interface with strong bonding. In this study, three types of metal oxides powders (commercial TiO2, commercial ZnO, and recycled Pyrex) were used to inject into the pure aluminium melt to fabricate in-situ aluminium matrix nano composites via liquid-state stir casting at 850 °C followed by a hot rolling process. SEM and FESEM microstructural characterizations, as well as EDAX analysis, were used to show if in-situ reactions occurred between molten aluminium and metal oxides to form nano alumina particles as the reinforcement. Tensile and microhardness tests were also applied on the rolled nano composites to identify the effect of metal oxide type and amount on the mechanical properties. It was found that using recycled Pyrex crushed powders led to the formation of a uniform distribution of alumina nanoparticles, while fine-micron ZnO and especially TiO2 powders could not be uniformly distributed into the melt for complete reaction occurrence.

Dimensionless Analysis for Investigating the Quality Characteristics of Aluminium Matrix Composites Prepared through Fused Deposition Modelling Assisted Investment Casting

“…This method of reinforcement results in poor wettability between the reinforcement and the matrix due to the increased surface area and presence of surface contamination on the reinforcements [17]. In order to overcome the interface issue, recent trends have been shifted towards the use of reinforcements within the cavity or mould itself [18]. As defined in the literature, there are various routes, commercially available, for the preparation of AMC.…”

A comparative study of the mechanical and tribological behaviours of different aluminium matrix–ceramic composites

“…The influence of machining parameters on the surface roughness of MMC was analysed [5]. However, some major inconsistencies in the mechanical properties were detected because the reinforcements were not distributed uniformly in the matrix [6].…”

Electron Microscopy Investigations of А356 Alloy Modified with Nanoparticles

“…Alternatively, many researchers worked on improving the wear properties of the cast Al alloys via addition of micro particles, which form after solidification so-called micro composite structure [29][30][31]. In the last 2 decades the idea of using small quantities of nanoparticles (up to 0.1 wt.%) for modification and refining of metallic alloys is being explored by many researchers [32][33][34][35][36][37][38][39][40][41][42]. Some special properties of refractory nanoparticles, like high area/volume ratio in the particles size range from 1 to 100 nm as well as very high melting temperature, are considered as promising for their behavior when introduced in a molten metal.…”