Superior mechanical properties and deformation mechanisms of heterogeneous laminates under dynamic shear loading

Abstract

High-strain rate response of low C steel/304 stainless steel (SS) laminates was characterized by hat-shaped specimen using Hopkinson-bar technique at a strain rate of about 7×10 4 s-1. Better dynamic shear properties were observed in the laminates, compared to the plain low C steel plate and the plain 304 SS plate. The laminates were found to postpone the nucleation of adiabatic shear band (ASB) in the hard zone and to delay the propagation of ASB from the hard zone to the soft zone. The conventional maximum stress criterion on ASB nucleation was found not valid any more in the laminates. The hardness difference between the hard zone and the soft zone in the laminates was found to have great influence on the patterns of ASB evolution. Nanotwins were formed in the 304 SS and grain refinement was observed in the martensite low C steel for strain hardening under dynamic shear loading. The mechanical incompatibility across the interfaces was observed to result in strain gradient and geometrically necessary dislocations at the interfaces under dynamic shear loading, contributing to extra strain hardening. The extra hardening was also found to be triggered at the propagation tip of ASB, which helps for achieving better dynamic ductility in the laminates.

Laser pressure welding of dissimilar aluminium and copper: microstructure and mechanical property

“…During laser pressure welding, the reaction layer underwent severe plastic deformation, resulting in the formation of heterogeneous laminates with dual-phases structure. Based on previous studies [29-31], the lamellar boundary strengthening originated from the nano-lamellar architecture in the heterogeneous laminates resulted in materials with superior mechanical properties.…”

Influence of Interface Type on Dynamic Deformation Behavior of 3D-Printed Heterogeneous Titanium Alloy Materials

“…There are fewer studies on the dynamic deformation behavior and microstructure evolution of HS materials under high-speed-impact conditions [19,20]. He et al [35] characterized the dynamic deformation behavior of HS materials of low-carbon steel/304 stainless steel at high strain rates and found that the difference in hardness between the two components in HS materials is an important factor influencing the extension of the adiabatic shear band (ASB). However, the study is not relevant to titanium alloys.…”

“…Strain-rate strengthening effects, inertia effects, and thermal softening effects all affect the plastic deformation mechanisms and fracture forms of materials [35,[37][38][39][40]. Therefore, although some results of mechanical properties under quasi-static conditions have been available for HS materials, it is still impossible to predict their dynamic deformation behavior simply from the deformation behavior under quasi-static conditions.…”