Preparation of in situ TiC@TiN core–shell and Ti2N–Al4C3 nanoparticles and their effects on Al–Zn–Mg–Cu alloy

Hybrid aluminum matrix composites have attracted researchers in the world because of their more excellent mechanical properties than metal matrix composites with single reinforcement. In this paper, TiC@TiN–Ti 2 N–Al 4 C 3 /Al composite was prepared by high-energy ball milling and spark plasma sintering (SPS) with Al–10Ti powders and g-C 3 N 4 powders. TiC, TiN, Ti 2 N and Al 4 C 3 reinforcements were synthesized by in situ reaction during the high-energy ball milling and SPS processing. Then, TiC@TiN–Ti 2 N–Al 4 C 3 /Al composite ribbons were prepared by melt spun. Next, the ribbons were added to the Al–Zn–Mg–Cu melt to prepare TiC@TiN–Ti 2 N–Al 4 C 3 /Al–Zn–Mg–Cu composite. It was found that TiC@TiN, Ti 2 N and Al 4 C 3 reinforcements had good refining and reinforcing effects on the Al–Zn–Mg–Cu alloy. The average grain size of the composite is from ~ 95 to ~ 35 μm. Besides, there is a 14.0% increase on the ultimate tensile strength and a 21.9% increase on the elongation of the composite. The microstructure, orientation relationship and mechanical properties of the TiC@TiN–Ti 2 N–Al 4 C 3 /Al–Zn–Mg–Cu composite were investigated. Besides, the strengthening mechanism of the TiC@TiN core–shell structure on the composite was mainly discussed by first principles.