Joining of Ti3SiC2 with Ti–6Al–4V Alloy

2002 ◽  
Vol 17 (1) ◽  
pp. 52-59 ◽  
Author(s):  
N.F. Gao ◽  
Y. Miyamoto
Keyword(s):  
Solid State ◽  
Rate Constant ◽  
Liquid State ◽  
Parabolic Rate Constant ◽  
Diffusion Path ◽  
Solid State Diffusion ◽  
Diffusion Controlled ◽  
State Diffusion ◽  
Rate Controlled ◽  
Higher Temperature

The joining of a Ti3SiC2 ceramic with a Ti–6Al–4V alloy was carried out at the temperature range of 1200–1400 °C for 15 min to 4 h in a vacuum. The total diffusion path of joining was determined to be Ti3SiC2/Ti5Si3Cx/Ti5Si3Cx + TiCx/TiCx/Ti. The reaction was rate controlled by the solid-state diffusion below 1350 °C and turned to the liquid-state diffusion controlled with a dramatic increase of parabolic rate constant Kp when the temperature exceeded 1350 °C. The TiCx tended to grow at the boundarywith the Ti–6Al–4V alloy at a higher temperature and longer holding time. TheTi3SiC2/Ti–6Al–4V joint is expected to be applied to implant materials.

Solid–state diffusion–controlled growth of the phases in the Au–Sn system

2017 ◽  
Vol 98 (1) ◽  
pp. 20-36 ◽  
Author(s):  
Varun A. Baheti ◽  
Sanjay Kashyap ◽  
Praveen Kumar ◽  
Kamanio Chattopadhyay ◽  
Aloke Paul
Keyword(s):  
Solid State ◽  
Solid State Diffusion ◽  
Controlled Growth ◽  
Diffusion Controlled ◽  
State Diffusion

Wagnerian Scaling Diffusion Kinetics

2008 ◽  
Vol 273-276 ◽  
pp. 594-601 ◽  
Author(s):  
César A.C. Sequeira
Keyword(s):  
Solid State ◽  
Point Defect ◽  
Parabolic Rate Constant ◽  
Scientific Basis ◽  
Lattice Diffusion ◽  
Solid State Diffusion ◽  
Protective Oxide ◽  
Oxidation Processes ◽  
Rate Limiting Step ◽  
State Diffusion

The reaction of a metal or alloy with an oxidising environment to form a scale often involves a diffusion process as the rate limiting step. The most protective oxide scales are slow growing, adherent to the substrate, and free of cracks or pores. The growth of these scales is typically by solid state diffusion of metal or oxygen ions that move via point defects in the oxide lattice. In 1933, C. Wagner established a scientific basis for oxidation processes controlled by solid state diffusion, with his celebrated derivation of the parabolic rate constant, which connects scaling rates, diffusion coefficients, point defect concentrations, point defect types, and effect of external parameters, e.g. pO2. These aspects are discussed in this paper. The importance of the Wagnerian theory is to provide a relatively simple model upon which more comprehensive models may be built. For many applications, the rate of degradation of the metal or alloy, owing to oxidation by lattice diffusion would be quite acceptable. Several examples of oxidation processes controlled by vacancy and/or interstitial diffusion will be discussed.

Kinetic mechanism of TiO2 nanocarving via reaction with hydrogen gas

2006 ◽  
Vol 21 (7) ◽  
pp. 1822-1829 ◽  
Author(s):  
Sehoon Yoo ◽  
Suliman A. Dregia ◽  
Sheikh A. Akbar ◽  
Helene Rick ◽  
Kenneth H. Sandhage
Keyword(s):  
Solid State ◽  
Inductively Coupled Plasma ◽  
Kinetic Mechanism ◽  
Hydrogen Gas ◽  
Solid State Diffusion ◽  
Appreciable Change ◽  
Inductively Coupled ◽  
Diffusion Controlled ◽  
State Diffusion ◽  
Oriented Parallel

Dense polycrystalline titania (TiO2, rutile) was converted into oriented arrays of single-crystal titania nanofibers by reaction with a noncombustible, hydrogen-bearing gas mixture at only 680–780 °C. Such nanofiber formation resulted from anisotropic etching (“nanocarving”) of the titania grains. The fibers possessed diameters of 20–50 nm and lengths of up to several microns, with the long fiber axes oriented parallel to the [001] crystallographic direction of rutile. Mass spectroscopy and inductively coupled plasma spectroscopy indicated that oxygen, but not titanium, was removed from the specimen during the reaction with hydrogen. The removal of substantial oxygen and solid volume from the reacting surfaces, without an appreciable change in the Ti:O ratio at such surfaces, was consistent with the solid-state diffusion of titanium cations from the surface into the bulk of the specimen. The reaction-induced weight loss followed a parabolic rate law, which was also consistent with a solid-state diffusion-controlled process.

Investigation of the diffusion behavior in Sn-xAg-yCu/Cu solid state diffusion couples

2016 ◽  
Vol 686 ◽  
pp. 794-802 ◽  
Author(s):  
Yuan Yuan ◽  
Dajian Li ◽  
Yuanyuan Guan ◽  
Hans J. Seifert ◽  
Nele Moelans
Keyword(s):  
Solid State ◽  
Solid State Diffusion ◽  
Diffusion Couples ◽  
Diffusion Behavior ◽  
State Diffusion
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