Erosive wear properties of ZA-27 alloy-based nanocomposites: Influence of type, amount and size of nanoparticle reinforcements

Abstract

Metal matrix nanocomposites (MMnCs) consist of a metal matrix filled with nano-size reinforcements featuring physical and mechanical properties very different from those of the matrix. In ZA- 27 alloy-based nanocomposites metal matrix provide ductility and toughness, while usually used ceramic reinforcements give high strength and hardness. Tested ZA-27 alloy-based nanocomposites, reinforced with different types (SiC and Al2O3), amounts (0.2, 0.3 and 0.5 wt. %) and sizes (25, 50 and 100 nm) of nanoparticles, were produced through the compocasting process with mechanical alloying pre-processing (ball milling). It was previously shown that the presence of nanoparticles in ZA-27 alloy-based nanocomposites led to the formation of a finer structure in the nanocomposites matrix and improvement of the basic mechanical properties (hardness and compressive yield strength), through the enhanced dislocation density strengthening mechanism. Erosive wear testing showed that these improvements were followed with the increase of the erosive wear resistance of tested nanocomposites, as well. Additionally, by analysing the influences of type, amount and size of nanoparticles on the erosive wear resistance of nanocomposites, it is shown that there is an optimal amount of nanoparticles, which in our case is 0.3 wt. %, and that the presence of SiC nanoparticles, as well as, presence of smaller nanoparticles in nanocomposites showed more beneficial influence on erosive wear resistance.Metal matrix nanocomposites (MMnCs) consist of a metal matrix filled with nano-size reinforcements featuring physical and mechanical properties very different from those of the matrix. In ZA- 27 alloy-based nanocomposites metal matrix provide ductility and toughness, while usually used ceramic reinforcements give high strength and hardness. Tested ZA-27 alloy-based nanocomposites, reinforced with different types (SiC and Al2O3), amounts (0.2, 0.3 and 0.5 wt. %) and sizes (25, 50 and 100 nm) of nanoparticles, were produced through the compocasting process with mechanical alloying pre-processing (ball milling). It was previously shown that the presence of nanoparticles in ZA-27 alloy-based nanocomposites led to the formation of a finer structure in the nanocomposites matrix and improvement of the basic mechanical properties (hardness and compressive yield strength), through the enhanced dislocation density strengthening mechanism. Erosive wear testing showed that these improvements were followed with the increase of the erosive wear resistance of tested nanocomposites, as well. Additionally, by analysing the influences of type, amount and size of nanoparticles on the erosive wear resistance of nanocomposites, it is shown that there is an optimal amount of nanoparticles, which in our case is 0.3 wt. %, and that the presence of SiC nanoparticles, as well as, presence of smaller nanoparticles in nanocomposites showed more beneficial influence on erosive wear resistance.