The role of interfaces in governing processing and properties of stacked hot extrusion of multilayered Al composites with amorphous interlayers

Abstract

In order to prepare high-strength lightweight components with aluminum alloys and Zr-based amorphous alloys and to avoid brittle fracture, the fabrication of 7075/Zr44Ti11Cu10Ni10Be25/7075 composites by stacked hot extrusion process is proposed in this study. In the supercooled liquid region (SLR) of Zr44Ti11Cu10Ni10Be25 (Vit1b), experiments were conducted with seven different temperature-velocity combinations, the effects of extrusion conditions on the connected interfaces of 7075/Vit1b/7075 composites and the thickness uniformity of Vit1b interlayers were systematically investigated. The results show that: too fast or slow extrusion speed and too high extrusion temperature can lead to crystallization or phase separation of amorphous alloys. The most uniform and continuous Vit1b interlayers can be obtained under the extrusion conditions of heating temperature 430 °C–440 °C and extrusion speed 2 mm/min-3 mm/min. The hardness of Vit1b interlayers increases with the increase of the extrusion temperature while it decreases as the extrusion speed increases. The holes at the interface between amorphous and aluminum alloys are gradually filled by element diffusion, forming discontinuous diffusion areas at the interface, allowing Vit1b and 7075 to be connected.