The hot deformation behavior and processing characteristics of AZ91 alloy and nano-SiCp/AZ91 composite were compared at temperature ranges of 523 K-673 K and strain rates of 0.001-1 s-1. Positive impact of SiC nanoparticles on pinning grain boundaries and inhibiting grain growth was not obvious when deformation temperature was below 623 K, but was remarkable when the temperature was above 623 K...

Creep lifetime of turbine blade material subjected to sustained centrifugal forces at elevated temperatures is limited by accumulated inelastic deformation and creep crack growth (CCG). Creep resistance exhibited in conventionally cast polycrystalline (PC) Ni-base superalloy components has been enhanced via solidification techniques. Directional solidification (DS) results in large grain sizes ...

[1] Lithospheric shear localization, as occurs in the formation of tectonic plate boundaries, is often associated with diminished grain size (e.g., mylonites). Grain size reduction is typically attributed to dynamic recrystallization; however, theoretical models of shear localization arising from this hypothesis are problematic because (1) they require the simultaneous action of two creep mecha...

In this article, we report on the application of our spherical nanoindentation data analysis protocols to study the mechanical response of grain boundary regions in as-cast and 30% deformed polycrystalline Fe–3%Si steel. In particular, we demonstrate that it is possible to investigate the role of grain boundaries in the mechanical deformation of polycrystalline samples by systematically studyin...

In this paper, a generalized expression for the flow field in axisymmetric extrusion process is suggested to be valid for any dies and the boundary shapes of the plastic deformation zone. The general power terms are derived and the extrusion force is calculated by applying upper bound technique for a streamlined die shape and exponential functions for shear boundaries. It is shown that assuming...

The study of the mechanical properties of materials at nanoand sub-micrometer scales is motivated by increasing need for such materials due to miniaturization of engineering and electronic components, development of nanostructured materials, thin film technology and surface science. When the material volume is lowered, characteristic dimensions are reduced that control the material properties a...

The formation mechanism considers fivefold deformation twins originating from the grain boundaries in a nanocrystalline material, resulting in that fivefold deformation twins derived from a single crystal have not been reported by molecular dynamics simulations. In this study, fivefold deformation twins are observed in a single crystal of face-centered cubic (fcc) alloy. A new formation mechani...

We have investigated the rate sensitivity of flow stress and the extent of strengthening in polycrystalline copper containing different volume fractions of nano-sized twins, but having the same average grain size. The specimens were produced by pulsed electrodeposition, wherein the concentration of twins was varied systematically by varying the processing parameters. Depth-sensing instrumented ...

0026-2714/$ see front matter 2012 Elsevier Ltd. A doi:10.1016/j.microrel.2012.01.009 ⇑ Corresponding author at: Department of Materi Shenzhen Graduate School, Harbin Institute of Tec China. Tel.: +86 755 26033463; fax: +86 755 260334 E-mail address: [email protected] (M.Y. Li). Orientation imaging microscopy was adopted to characterize the microstructural changes in Sn–Agbased solder interconnect...