The Influence of TiB₂ Particles on the Artificial Aging Behavior of TiB₂/Al–5Cu Composite

This study investigated the artificial aging process of TiB₂/Al–5Cu composite, with a focus on the influence of TiB₂ particles on the precipitation behavior of the composite. Additionally, a comparative analysis of the microhardness and tensile properties between the TiB₂/Al–5Cu composite and the Al–5Cu alloy was conducted. X-ray Diffraction (XRD) analysis reveals that the TiB₂/Al–5Cu composite consists of TiB₂ and Al₂Cu phases. The Scanning Electron Microscopy (SEM) imagery demonstrates a predominantly cellular crystal composition in the composite. Notably, as the aging time progresses, there’s an initial increase followed by a subsequent decrease in the gray grain boundaries of the composite. Transmission Electron Microscopy (TEM) images uncover the presence of needle-like θ phase, TiB₂, and dislocations within the TiB₂/Al–5Cu composite. The incorporation of TiB₂ particles has emerged as a pivotal factor in significantly curtailing the artificial aging duration. With the peak hardness aging time determined at a mere 8 h, the TiB₂/Al–5Cu composite showcases substantially higher hardness levels compared to the Al–5Cu base alloy. Remarkably, the optimum aging time for achieving the best mechanical properties in the composites is reduced from 20 to 8 h. Directly comparing the TiB₂/Al–5Cu composite to the Al–5Cu alloy under peak aging conditions, notable enhancements in both yield strength (22%) and tensile strength (41%) are observed. Additionally, a slight increase in elongation is observed in the TiB₂/Al–5Cu composite.