Periodic spinodal decomposition in double-strengthened medium-entropy alloy.

Achieving an optimal balance between strength and ductility in advanced engineering materials has long been a challenge for researchers. In the field of material strengthening, most approaches that prevent or impede the motion of dislocations involve ductility reduction. In the present study, we propose a strengthening approach based on spinodal decomposition in which Cu and Al are introduced into a ferrous medium-entropy alloy.

Mechanically derived short-range order and its impact on the multi-principal-element alloys.

Chemical short-range order in disordered solid solutions often emerges with specific heat treatments. Unlike thermally activated ordering, mechanically derived short-range order (MSRO) in a multi-principal-element FeMnCrCo (at%) alloy originates from tensile deformation at 77 K, and its degree/extent can be tailored by adjusting the loading rates under quasistatic conditions. The mechanical response and multi-length-scale characterisation pointed to the minor contribution of MSRO formation to yield strength, mechanical twinning, and deformation-induced displacive transformation.

Microstructural, mechanical, and electrochemical analysis of carbon doped AISI carbon steels.

The effect of carbon doping contents on the microstructure, hardness, and corrosion properties of heat-treated AISI steel grades of plain carbon steel was investigated in this study. Various microstructures including coarse ferrite-pearlite, fine ferrite-pearlite, martensite, and bainite were developed by different heat treatments i.e.

Quantitative analysis of retained austenite in Nb added Fe-based alloy.

The use of Pipelines for long-distance transportation of crude oil, natural gas and similar applications is increasing and has pivotal importance in recent times. High specific strength plays a crucial role in improving transport efficiency through increased pressure and improved laying efficiency through reduced diameter and weight of line pipes. TRIP-based high-strength and high-ductility alloys comprise a mixture of ferrite, bainite, and retained austenite that provide excellent mechanical properties such as dimensional stability, fatigue strength, and impact toughness.

Hydrogen-doped viscoplastic liquid metal microparticles for stretchable printed metal lines.

Conductive and stretchable electrodes that can be printed directly on a stretchable substrate have drawn extensive attention for wearable electronics and electronic skins. Printable inks that contain liquid metal are strong candidates for these applications, but the insulating oxide skin that forms around the liquid metal particles limits their conductivity. This study reveals that hydrogen doping introduced by ultrasonication in the presence of aliphatic polymers makes the oxide skin highly conductive and deformable.

Superior Strength and Multiple Strengthening Mechanisms in Nanocrystalline TWIP Steel.

The strengthening mechanism of the metallic material is related to the hindrance of the dislocation motion, and it is possible to achieve superior strength by maximizing these obstacles. In this study, the multiple strengthening mechanism-based nanostructured steel with high density of defects was fabricated using high-pressure torsion at room and elevated temperatures. By combining multiple strengthening mechanisms, we enhanced the strength of Fe-15 Mn-0.

A new method for mapping the three-dimensional atomic distribution within nanoparticles by atom probe tomography (APT).

We present a new method of preparing needle-shaped specimens for atom probe tomography from freestanding Pd and C-supported Pt nanoparticles. The method consists of two steps, namely electrophoresis of nanoparticles on a flat Cu substrate followed by electrodeposition of a Ni film acting as an embedding matrix for the nanoparticles. Atom probe specimen preparation can be subsequently carried out by means of focused-ion-beam milling.

Nanometer-Scale Phase Transformation Determines Threshold and Memory Switching Mechanism.

Creation of nanometer-scale conductive filaments in resistive switching devices makes them appealing for advanced electrical applications. While in situ electrical probing transmission electron microscopy promotes fundamental investigations of how the conductive filament comes into existence, it does not provide proof-of-principle observations for the filament growth. Here, using advanced microscopy techniques, electrical, 3D compositional, and structural information of the switching-induced conductive filament are described.

Understanding of Capping Effects on the Tip Shape Evolution and on the Atom Probe Data of Bulk LaAlO3 Using Transmission Electron Microscopy.

Two challenges exist in laser-assisted atom probe tomography (APT). First, a drastic decline in mass-resolving power is caused, not only by laser-induced thermal effects on the APT tips of bulk oxide materials, but also the associated asymmetric evaporation behavior; second, the field evaporation mechanisms of bulk oxide tips under laser illumination are still unclear due to the complex relations between laser pulse and oxide materials. In this study, both phenomena were investigated by depositing Ni- and Co-capping layers onto the bulk LaAlO3 tips, and using stepwise APT analysis with transmission electron microscopy (TEM) observation of the tip shapes.

Correlation of Controllable Aggregation with Light-Emitting Property in Polymer Blend Optoelectronic Devices.

The control of solution-processed emitting layers in organic-based optoelectronic devices enables cost-effective processing and highly efficient properties. However, a solution-based protocol for emitter fabrication is highly complex, and the link between the device performance and internal nanoscale features as well as three associated fabricating parameters (e.g.

Temperature-dependent nanomorphology-performance relations in binary iridium complex blend films for organic light emitting diodes.

Understanding the mechanism responsible for the temperature-dependent performances of emitting layers is essential for developing advanced phosphorescent organic light emitting diodes. We described the morphological evolution occurring in PVK:Ir(ppy)3 binary blend films, with respect to thermal annealing up to 300 °C, by coupling atomic force microscopy and transmission electron microscopy. In particular, in situ temperature-dependent experimental characterization was performed to directly determine the overall sequence of morphological evolution occurring in the films.

Combined nano-SIMS/AFM/EBSD analysis and atom probe tomography, of carbon distribution in austenite/ε-martensite high-Mn steels.

We introduce a new experimental approach for the identification of the atomistic position of interstitial carbon in a high-Mn binary alloy consisting of austenite and ε-martensite. Using combined nano-beam secondary ion mass spectroscopy, atomic force microscopy and electron backscatter diffraction analyses, we clearly observe carbon partitioning to austenite. Nano-beam secondary ion mass spectroscopy and atom probe tomography studies also reveal carbon trapping at crystal imperfections as identified by transmission electron microscopy.

Atomic scale investigation on the distribution of boron in medium carbon steels by atom probe tomography and EELS.

The medium carbon (0.5 wt% C) steels containing various boron contents were studied to observe the distribution of boron using atom probe tomography and electron energy loss spectroscopy. APT revealed the segregation of boron atoms at retained austenite for 100 ppm boron added steels and the trapped carbon atoms at micro-twins for 50 ppm boron treated steels.