Consider a substitutional solution of two metallic elements A and B. When the alloy is exposed to air at an elevated temperature, A oxidizes, but B does not. In the alloy, the two elements diffuse in opposite directions, but usually at different rates; the nonreciprocal diffusion is known as the Kirkendall effect. At the oxide-alloy interface, metallic atoms may either emit from or inject into ...

Fe-Ni system has been attracting broad attentions as an Invar alloy. Although the origin of the Invar effects has been explained based on the temperature variation of alignments and magnitudes of magnetic moments, two of the present authors (YC and TM) reported that the nonmonotonous temperature dependence of Coefficient of Thermal Expansion (CTE) were realized even without considering spin con...

The nucleation rate depends on the free-energy barrier and the kinetic factor. While the role of the free energy barrier is a text-book subject, the importance of the kinetic factor is frequently underestimated. In this study, we applied the mean first-passage time method, to obtain the free-energy landscape and kinetic factor directly from the molecular dynamics (MD) simulations of the nucleat...

Iron alloyed with Ni and Si has been suggested to be a major component of the Earth’s inner core. High-pressure results on the combined alloying effects of Ni and Si on seismic parameters of iron are thus essential for establishing satisfactory geophysical and geochemical models of the region. Here we have investigated the compressional (VP) and shear (Vs) wave velocity-density (ρ) relations, P...

in this study, cu50-ni50 alloy were synthesized by mechanical alloying. the alloy was then reinforced by dispersion of multiwalled carbon nanotubes using a planetary high energy ball mill. x-ray diffraction, scanning electron microscopy and vibrating sample magnetometer were used to evaluate the effects of cnt addition on the characteristics of the nanocomposites. xrd results of cu-ni sample sh...

Article history: Received 15 June 2016 Received in revised form 9 July 2016 Accepted 9 July 2016 Available online 20 July 2016 Multicomponent alloying can be utilized to enhance the thermal stability of nanocrystalline alloys. The grain boundary energy can be reduced significantly via both bulk and grain-boundary high-entropy effects with increasing temperature at/within the solid solubility li...

Ni nanoparticles supported on ZrO2 are a prototypical system for reforming catalysis converting methane to synthesis gas. Herein, we examine this catalyst on a fundamental level using a 2-fold approach employing industrial-grade catalysts as well as surface science based model catalysts. In both cases we examine the atomic (HRTEM/XRD/LEED) and electronic (XPS) structure, as well as the adsorpti...

High-strength low-carbon ferritic steels attaining a maximum yield strength of 1600 MPa by combined Cu and NiAl precipitationstrengthening were developed. The yield strength of the alloys increases monotonically with the total concentration of the principal alloying elements i.e. Mn, Cu, Ni and Al. At 12.40 at.%, a 1600 MPa yield strength is achieved after solution treatment at 950 C followed b...

Abstract. Pb/Ni(111) surface phases were investigated by synchrotron radiation photoemission, low-energy electron diffraction (LEED) and angular resolved ultraviolet photoelectron spectroscopy (ARUPS). For room temperature evaporation, two surface ordered layers, (3x3) and (4x4), were observed. The Pb 5d and Pb 4f core levels as well as valence band spectra indicated a weak chemical interaction...

In this work TiNi-based nanocrystalline alloys and composite were produced by mechanical alloying process with subsequent annealing at 750 ◦C for 0.5 h. Mechanical alloying was performed in a SPEX 8000 Mixer Mill. TiNi alloy was chemically modi ed by Ag elemental powder. Silver content equaled 5 wt%. X-ray di raction analyses revealed formation of TiNi main phase after annealing. Additionally, ...