Manufactured single crystal components using Ni-base super alloys are routinely used in the hot sections of aero engines and industrial gas turbines due to their outstanding high temperature strength, toughness and resistance to degradation in corrosive and oxidative environments. To control the quality of the single crystal turbine blades, particular attention has been paid to grain selection,...

Manufactured single crystal components using Ni-base super alloys are routinely used in the hot sections of aero engines and industrial gas turbines due to their outstanding high temperature strength, toughness and resistance to degradation in corrosive and oxidative environments. To control the quality of the single crystal turbine blades, particular attention has been paid to grain selection,...

Introduction: Crystal size distribution (CSD) analysis is a useful technique for quantifying textural information and linking petrographic texture to original crystallization conditions [1]. In previous studies we have conducted CSD analyses of multiple thin sections of nakhlite meteorites [2], and several basaltic and mixed shergottites [3,4]. Based on results of these analyses, we derived cry...

In this paper, a self-consistent plasticity theory is proposed to model the mechanical behaviours of irradiated face-centred cubic nanocrystalline metals. At the grain level, a tensorial crystal model with both irradiation and grain size effects is applied for the grain interior (GI), whereas both grain boundary (GB) sliding with irradiation effect and GB diffusion are considered in modelling t...

Nanocrystalline (NC) metals with grain sizes <100 nm have attracted a lot of attention in the materials science fi eld for more than a few decades because of their ultra-high strength and hardness. Various experimental and computational studies indicate that dislocation-mediated plasticity prevails in NC metals when the grain size is larger than ~10 nm. Recent molecular dynamics (MD) simulation...

Grain refinement through severe plastic deformation enables synthesis of ultrahigh-strength nanostructured materials. Two challenges exist in that context: First, deformation-driven grain refinement is limited by dynamic dislocation recovery and crystal coarsening due to capillary driving forces; second, grain boundary sliding and hence softening occur when the grain size approaches several nan...

We study the combined effects of grain size and texture on the strength of nanocrystalline copper (Cu) and nickel (Ni) using a crystal-plasticity based mechanics model. Within the model, slip occurs in discrete slip events exclusively by individual dislocations emitted statistically from the grain boundaries. We show that a Hall-Petch relationship emerges in both initially texture and non-textu...

The electron scattering at surfaces, interfaces, and grain boundaries is investigated using polycrystalline and single-crystal Cu thin films and nanowires. The experimental data is described by a Fuchs–Sondheimer (FS) and Mayadas–Shatzkes (MS) model that is extended to account for the large variation in the specific resistivity of different grain boundaries as well as distinct top and bottom su...