The microstructures and mechanical properties of hybrid in-situ AlN-TiC-TiN-Al3Ti/Al reinforced Al-Cu-Mn-Ti alloy matrix composites

Abstract

Hybrid aluminum matrix composites (HAMCs) have gotten lots of interest because of the synergy between the multiple phase. The in-situ AlN-TiC-TiN-Al3Ti/Al inoculation ribbons were prepared by powder metallurgy and melt spinning, and then introduced into the Al-Cu-Mn-Ti matrix alloy, assisted by ultrasonic vibration. SEM and TEM were used to examine the microstructures of the inoculant ribbons and Al-Cu-Mn-Ti alloy following inoculation. The test results show that the mechanical properties of the composites have been considerably improved and the grain size has been refined. The ultimate tensile strength, hardness and elongation after fracture have increased from 196 MPa, 82.1 HV and 13.6% to 220 MPa, 98.9 HV and 17.4%, respectively. This can be chiefly because of the good distribution of nano-particles AlN, TiN and TiC in the aluminum matrix and the good interface matching relationship, which has a good refining effect. In addition, Orowan strengthening, fine-grain strengthening, coefficient of thermal expansion (CTE) mismatch strengthening, and load transfer effect multiple strengthening mechanisms work together to enhance the mechanical properties of the material.