Effects of annealing temperature on the formability, mechanical and interface properties of laminated metal composite STS304L/Al1050/STS430

Laminated metallic composites (LMCs) produced by cold roll bonding generate high plastic deformation. After the rolling process, it is essential to promote a post-heat treatment (PHT) to increase adhesion, minimize hardening, and enhance the formability of LMCs. In this research, the effects of PHT at low temperatures (250, 350, and 450°C) on LMCs (STS304/Al1050/STS430) obtained by cold rolling were investigated. The Forming Limit Curve (FLC) and mechanical properties such as ultimate tensile strength (σ_UT), yield strength (σ_Y), elongation (ε), and the anisotropy index (r-value) of the LMC were evaluated. Results indicate the best PHT temperature that combines formability, increased adhesion between layers, and better mechanical properties, such as elongation (ε), which increases from 37% to 55%. At this PHT temperature, the brittle intermetallic layer was not detected, and the FLC showed the best performance. Furthermore, in industrial applications, this PHT condition allows energy savings compared to PHT conditions of high process times (>12 h) and/or temperature (>500°C) reported by several works in the literature.