Preparation of in-situ AlN-TiC nanoparticles and their refinement and reinforcement effects on Al-Zn-Mn-Cu alloy

Abstract

Compared with the particle reinforced aluminum matrix composites (PRAMCs) with single-phase reinforcing particles, hybrid aluminum matrix composites (HAMCs) have attracted many researchers in the world due to the well performance in industrial production and application, which achieved gratifying results. In this work, in-situ AlN and TiC nanoparticles were produced by high-energy ball milling. To improve the wettability with the aluminum matrix, AlN-TiC/Al composite ribbons were prepared by melt spun. Then, the ribbons were added to the Al-Zn-Mn-Cu alloy to prepare AlN-TiC/Al-Zn-Mn-Cu composite. Meanwhile, the ultrasonic vibration was used to ameliorate the distribution of AlN and TiC nanoparticles in the matrix. The results shown that AlN and TiC nanoparticles had a significant effect on the refinement and reinforcement of the composite. The ultimate tensile strength of the composite had a 10.6% increase, while the increase on the elongation is 20.0%. The excellent mechanical properties were mainly due to the dual-phase enhancement of in-situ AlN and TiC with two sizes of nanoparticles as well as the well-bonded interface between them and the matrix. Moreover, the improvement on the mechanical properties of the composite can benefit from the multiple strengthening mechanisms, including fine grain strengthening, coefficient of thermal expansion (CTE) mismatch strengthening and Orowan strengthening. The microstructure, orientation relationship, mechanical properties and strengthening mechanisms of the AlN-TiC/Al-Zn-Mn-Cu composite were investigated.