Novel dynamic compressive and ballistic properties in 7075-T6 Al-matrix hybrid composite reinforced with SiC and B4C particulates

In this study, a hybrid Al-matrix composite reinforced with both SiC and B4C ceramic particulates (SiCp or B4Cp, respectively) was fabricated to increase the volume fraction of ceramics by a liquid pressing process, and its dynamic and ballistic properties were compared with those of monolithic Al-matrix composites reinforced with SiC or B4Cp. The hybrid composite demonstrated a very high dynamic compressive strength (over 1.5 GPa), along with a good total strain of 11.7%, which readily reached an undiscovered strength area (far over 1.2 GPa) of typical composites. This was basically attributed to the highest ceramic fraction (60 vol%), together with strongly-bonded ceramic/Al interfaces and synergetic hybrid effects of SiC(p)s and B(4)C(p)s. After the ballistic test, the hybrid composite was radially cracked with a small hole-mark and a few fallen-off debris, which indicated the higher ballistic properties than those of the SiCp- or B4Cp-reinforced composite because of outstanding dynamic compressive strength and strain.