Higher Damping Capacities in Gradient Nanograined Metals

Abstract

The capability of damping mechanical energy in polycrystalline metals depends on the activities of defects such as dislocation and grain boundary (GB). However, operating defects has the opposite effect on strength and damping capacity. In the quest for high damping metals, maintaining the level of strength is desirable in practice. In this work, gradient nanograined structure is considered as a candidate for high-damping metals. The atomistic simulations show that the gradient nanograined models exhibit enhanced damping capacities compared with the homogeneous counterparts. The property can be attributed to the long-range order of GB orientations in gradient grains, where shear stresses facilitate GB sliding. Combined with the extraordinary mechanical properties, the gradient structure achieves a strength-ductility-damping synergy. The results provide promising solutions to the conflicts between mechanical properties and damping capacity in polycrystalline metals.

Synergy of Spall Strength and Toughness in Nanograined Metals

“…As for Mode I, where void initiation occurs at the junctions with individualized growth, the incidence of void coalescence is rendered even more challenging, textcolorredthis can be further surpported by flow stress data in Table S3, given that void nucleation and growth are contingent upon plastic flow and stress-driven processes. It is worth noting that the consistent trend in fracture energy (Figure ) and spall strength (Figure ) deviates from the typical trade-off pattern between material strength and toughness observed in quasi-static experiments. − Under low strain rates, increasing GB density hampers dislocation motion while simultaneously diminishing the material’s capacity for intragranular plastic deformation. Experimental research on size effects in strength–toughness consistency has recently commenced and focuses on micrometer-scale dimensions. , In shock scenarios, the significance of void evolution behavior is magnified due to its rapid stress release mechanism .…”

Deformation mechanisms based on the multiscale molecular dynamics of a gradient TA1 titanium alloy

“…Relevant research also shows that the simplified model can be used for the analysis of plastic deformation mechanisms. 29,[32][33][34] Table 1 provides the specific details of the corresponding grain size and number for each layer in the model. The non-uniform temperature field is used to control the formation of the layered gradient grain structure.…”

“…For instance, atomic simulation results demonstrate outstanding damping performance in gradient nanostructured Fe with an FCC crystal structure. 29 In face-centered cubic metals (such as Cu, Al, and Ni), the behavior of dislocations and twinning is dependent on the metal type. 30 The research findings of Korchuganov et al support the view that the plasticity of gradient-structured materials develops through the sequential activation of different mechanisms.…”

A Combined Microscopy Study of the Microstructural Evolution of Ferritic Stainless Steel upon Deep Drawing: The Role of Alloy Composition

“…Therefore, a likely model of the microstructural distortion induced upon drawing the alloys (Figure 11c) is proposed. Importantly, creating nanograined gradients in metals has recently been reported as an efficient route towards tailoring the alloy properties [37][38][39], which might play a vital role in the performance of the materials. A deeper inspection of the LAADF images from the drawn samples provides further insights into the deformation mechanism.…”