Effect of Cyclic Warm-Rolling Technique on Mechanical Properties of MoCu30 Thin Plates with Heterogeneous Structure

Abstract

By employing a cyclic warm rolling technique, MoCu30 alloy sheets of different thicknesses were prepared to investigate the effects of various rolling reduction rates on the microstructure and mechanical properties of MoCu30 alloys. Additionally, the evolution of microscale heterogeneous deformation during the tensile process was observed based on DIC technology. This study reveals that Mo–Cu interfaces at different deformation rates exhibit an amorphous interlayer of 0.5–1.0 μm thickness, which contributes to enhancing the bond strength of Mo–Cu interfaces. As the rolling reduction rate increased, the grain size of the MoCu30 alloy gradually decreased, whereas the dislocation density and hardness increased. Furthermore, the yield strength and tensile strength of the MoCu30 alloy increased gradually, whereas the elongation decreased. At a deformation rate of 74% (2 mm), the yield strength, tensile strength, and elongation of the MoCu30 alloy were 647.9 MPa, 781.8 MPa, and 11.7%, respectively. During the tensile process of Mo–Cu dual-phase heterogeneous material, a unique hierarchical strain banding was formed, which helps to suppress strain localization and prevent premature plastic instability.

Keywords

• cyclic warm rolling
• MoCu30 alloy
• amorphous interlayer
• hierarchical strain band