Role of YSZ Particles on Microstructural, Wear, and Corrosion Behavior of Al-15%Mg2Si Hybrid Composite for Marine Applications

Abstract

This study aims to investigate the microstructural alterations, mechanical properties, sliding wear behavior, and corrosion properties of Al-15%Mg2Si composites with different contents of yttria-stabilized zirconia (YSZ). Al-15%Mg2Si composites with the different contents of YSZ (0, 3, 6, and 9 wt.%) were fabricated using the stir-casting technique. The fabricated composites were characterized by means of optical microscopy (OM), scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS), Vickers hardness tester, linear reciprocating tribometer (LRT), and electrochemical test. The results showed that with the introduction of YSZ particles, the average size of the primary Mg2Si particles in the base composite was 137.78 µm, which was reduced to 88.36 µm after adding 9 wt.% YSZ. The aspect ratio of Mg2Si particles also decreased from 3, for the base composite, to 1.27 in the composite containing 9 wt.% YSZ. Moreover, the hardness value displays an incremental trend from 102.72 HV, as recorded for the base in situ composite, to 126.44 HV in the composite with 9 wt.% YSZ. On top of that, the Al-15%Mg2Si-9%YSZ demonstrates exceptional wear resistance, with the lowest wear rate of 0.46 mm3/km under a 25 N applied load. Its average coefficient of friction (COF) was recorded at 0.42, which is lower than both the 3 and 6 wt.% of YSZ-containing composites. The smoother worn surface in Al-15%Mg2Si-9%YSZ hybrid composite implies the abrasion phenomenon, as dominant wear behavior is milder than the other fabricated composites. On top of that, the Al-15%Mg2Si-9%YSZ also possesses optimum corrosion resistance. The corrosion rate is 0.080 mmpy, comparable to the 0.164 mmpy rate obtained in the in situ composite.