Influence of boride, oxide, and carbide ceramics as secondary reinforcement in T6-A333 functionally graded hybrid composites

Abstract

Hybrid ceramics in functionally graded aluminium hybrid composites are a developing choice for the maritime industries to maximize their daily mechanical and tribological demands. Ceramic types, including borides, oxides, and carbides, have a key impact in regulating the tribo-mechanical performance of hybrid composites. The external addition of Mg potentially lowered the wetting angle along with the matrix-ceramic interface. This study compares the mechanical and tribological performance of 6 wt%B4C/4 wt%TiB2/A333, 6 wt%B4C/4 wt%ZrO2/A333, and 6 wt%B4C/4 wt%TiC/A333 hybrid composites. Hybrid reinforcement in functionally graded composites enable the designers in modern manufacturing to eliminate the challenges like porosity and insufficient wettability. Advance characterizations highlight the morphological phase transformations undergone with heat treatment, contributing towards increase in composite performance. Coarse patches of Mg2Si and air-foil shaped Al2Cu precipitate operate as a strengthening agent that withstands shear. TiC-rich outer wall zone of hybrid composite demonstrated maximum microhardness (202.7 HV) and tensile strength (256.2 MPa). Zonal dominance of ceramic variants as secondary reinforcement minimizes wear and third body abrasion. Wear debris analysis indicates creating a mechanically mixed layer, which affects the friction along with the sliding interface. Passivation and interfacial pitting are the main corrosion mechanisms found in a saline environment when TiC particles act as a secondary ceramic.