Effects of Solution Treatment and Artificial Aging on the Microstructure and Mechanical Properties of TiB2/7050 Composites

This study investigates the solution and artificial aging processes of TiB2/7050 composites. Using microscopic and mechanical tests, we systematically evaluate the material’s microstructural evolution and mechanical performance, aiming to optimize heat treatment parameters. The study shows that a solution temperature of 475 °C for 1 h is optimal for fully dissolving the second-phase particles. Regarding artificial aging, peak hardness of 246 HV is achieved at 140 °C for 16 h. Analysis of the phases and microstructure in O and T6-states shows that strengthening occurs through grain boundary hardening and precipitation hardening. The effect of TiB2 particles on the above process was also explored. During solidification, TiB2 particles were pushed by the advancing solid–liquid interface and primarily distributed along grain boundaries. This distribution subsequently slowed the solid solution process by reducing the contact area between the η(MgZn2) phase and the α(Al) matrix. During aging, they enhance grain boundary precipitates (GBPs) in particle-rich regions and inhibit the formation of precipitate-free zones (PFZs), with a concentration of the η’ phase forming around the particles. Beyond a certain distance from the particles, there is a decrease in η’ phase concentration. This study is expected to contribute to advanced lightweight materials research and development, opening up new opportunities for their application in various industries.