Wear behavior of magnesium based nanocomposites

摘要

In the present work, wear behavior of magnesium based nanocomposites reinforced with different nanoparticles were investigated by using pin-on-disc configuration under dry sliding conditions.;In the first group of materials, dry sliding wear behavior of AZ31 magnesium alloy and its nanocomposites reinforced with 1.5 vol.% Al2O 3 and 1 vol.% CNT were studied within a load range of 5-20 N at sliding speeds of 1, 2 and 5 m/s for sliding distance up to 2500 m. The test results showed that the wear rates of the magnesium alloy increases with the addition of reinforcement. Scanning electron microscopy (SEM) identified abrasion, oxidation, delamination, adhesion and thermal softening as the dominant wear mechanisms. The high wear rates in the nanocomposites were attributed to higher ductility, porosity and mismatch of thermal expansion coefficients between the reinforcement and matrix alloy.;In the second group of materials, dry sliding wear behavior of Mg/Y2O3 nanocomposites reinforced with varying amounts of nickel from 0.3-1.0 vol.% were studied within a load range of 5-30 N at a constant sliding speed 0.5 m/s for sliding distance up to 1000 m. The test results showed that the wear rates of the Mg/Y2O3 nanocomposites decreases with increase in amount of Ni. The improvement in wear resistance of the nanocomposites was attributed to the improved hardness and strength of the material with increase in Ni content. Scanning electron microscopy (SEM) identified abrasion, oxidation, delamination, adhesion as the dominant wear mechanisms.;In the third group of materials, dry sliding wear behavior of Mg/Y 2O3 nanocomposites reinforced with varying amounts of copper from 0.3-1.0 vol.% were studied within a load range of 5-30 N at a constant sliding speed 1 m/s for sliding distance up to 1000 m. The test results showed slight improvement in the wear resistance of Mg/Y2O3 nanocomposite with 1.0 vol.% Cu. The improvement in wear resistance of the nanocomposites was attributed to the improved hardness of the material with increase in Cu content. Scanning electron microscopy (SEM) identified abrasion, oxidation, adhesion and mild delamination as the dominant wear mechanisms.