Computational design of patterned interfaces using reduced order models

Abstract

Patterning is a familiar approach for imparting novel functionalities to free surfaces. We extend the patterning paradigm to interfaces between crystalline solids. Many interfaces have non-uniform internal structures comprised of misfit dislocations, which in turn govern interface properties. We develop and validate a computational strategy for designing interfaces with controlled misfit dislocation patterns by tailoring interface crystallography and composition. Our approach relies on a novel method for predicting the internal structure of interfaces: rather than obtaining it from resource-intensive atomistic simulations, we compute it using an efficient reduced order model based on anisotropic elasticity theory. Moreover, our strategy incorporates interface synthesis as a constraint on the design process. As an illustration, we apply our approach to the design of interfaces with rapid, 1-D point defect diffusion. Patterned interfaces may be integrated into the microstructure of composite materials, markedly improving performance.

Non-coherent Cu grain boundaries driven by continuous vacancy loading

“…However, in some cases, the lowest energy GB structures might not be the ones of interest, e.g., when investigating far from equilibrium states [35,87,88]. Sometimes, the atomic-level state of a GB might not even be relevant, e.g., for determining the distribution of intrinsic defects [89,90].…”

A mesoscopic theory of dislocation and disclination fields for grain boundary-mediated crystal plasticity

“…Bollmann, 1970;Pond and Hirth, 1994;Hirth and Pond, 1996;Hirth et al, 2006;Khater et al, 2012;Vattre et al, 2014). In particular, elasto-static disclination-based approaches have been proposed (Romanov and Kolesnikova, 2009;Romanov et al, 2015;Li, 1972;Shih and Li, 1975;Gertsman et al, 1989), which successfully complemented dislocation-based models and motivated further investigation involving dissipative processes.…”

Effect of low-angle grain boundaries on morphology and variant selection of grain boundary allotriomorphs and Widmanstätten side-plates

“…[65], the results from the continuum approach (used in our current work) show that the interfacial energy and hence the underlying stress field can be drastically different for different dislocation configurations selected. Since the way of calculating the interfacial energy in the atomistic approach is quite different from that in the continuum approach, an agreement of the two approaches on the interfacial energy calculation [65] suggests that the selected dislocation configuration (satisfying the Frank-Bilby equation) can well represent the atomistically stable interface (grain boundary) structure and the contribution due to dislocation reaction can be safely ignored as a first-order approximation. In Ref.…”

“…Our current treatment of approximating the grain boundary structure with two dislocation arrays satisfying the Frank-Bilby equation has been justified recently by Vattré et al [65] using direct atomistic results for twist boundary with misorientation angle of 0°~10°. According to Ref.…”

“…In Ref. [65], there are three independent elementary dislocations available to choose and thus all possible combinations need to be considered to determine the one that can well represent the atomistically calculated interface structure. In our current case, only two independent elementary dislocations (as discussed above), which are widely observed in experiments, are present, giving a unique dislocation configuration that satisfies the Frank-Bilby equation.…”