Influence of a new AlTiC–B master alloy on the casting and extruding behaviors of 7050 alloys

Abstract

In this paper, a new kind of AlTiC–B master alloy, containing large amounts of nano‒sized TiC particles, has been applied in 7050 alloy. The influence of master alloy addition on the casting microstructures, extrusion behaviors and mechanical properties of 7050 has been investigated. It is found that 0.5 wt% addition of AlTiC–B master alloy exhibits the most attractive performance, resulting in much finer matrix grains and less casting defects. After hot extrusion, typical <100> and <111> fiber textures co‒exist in the microstructure of original 7050 alloy, whereas the alloys with AlTiC–B inoculation possess a higher intensity of <111> fiber texture. Besides, the inoculated alloys show better anti–recrystallization performance and larger local misorientation. It has been confirmed that a proper addition of AlTiC–B master alloy is beneficial for the mechanical properties of extruded 7050, which may be due to its refining effect on α–Al grains and its improvement for the precipitation of L12–ZrAl3. The Brinell hardness, ultimate tensile strength, yield strength and elongation of 7050 alloy with 0.5 wt% addition of AlTiC–B addition are 174 HBW, 665 MPa, 724 MPa and 9.8%, respectively. This work provides a promising prospect of AlTiC–B master alloy for applying in 7050 alloy in industries.