Effect of hot-rolling temperature and reduction ratio on tensile properties of B4C–cBN reinforced aluminum matrix composite

This study explores the effects of hot-rolling parameters on the microstructural evolution and tensile properties of aluminium (Al) matrix composites reinforced with boron carbide (B 4 C) and cubic boron nitride (cBN), fabricated via stir casting. Rolling was conducted at three different temperatures (150℃, 300℃ and 450℃) and reduction ratios (40%, 55% and 70%). X-ray diffraction and electron back-scattered diffraction analyses revealed that both dynamic recovery (DRV) and dynamic recrystallization (DRX) were pronounced with increasing rolling-temperature and -reduction levels, resulting in the decreases of dislocation density and the increase of recrystallized grain fractions. Although the microstructural softening and dislocation recovery leads to a trade-off between strength and ductility, this study observed simultaneous increases in the ultimate strength (131.9 MPa), and the uniform elongation (0.52%) and fracture elongation (3.07%) with increasing reduction ratio. This anomaly is attributed to reinforcement fragmentation and redistribution, which promoted the Taylor strengthening and load transfer effects. These results suggest that optimized hot-rolling parameters can effectively enhance the mechanical performance of B 4 C-cBN reinforced Al matrix composites for neutron-absorbing applications. • Al-B 4 C/cBN composite samples were fabricated with various hot-rolled temperature and reduction ratio conditions. • Tensile behaviors were analyzed by DIC technique. • As increase the hot-rolling reduction ratios, tensile strength and ductility increase simultaneously. • Dynamic softening behavior and size distribution of ceramic reinforcements were affected by hot-rolling conditions.