3C–, 4H–, and 6H–SiC crystal habitus and interfacial behaviours in high temperature Si-based solvents

CrystEngComm ◽  
2020 ◽  
Vol 22 (20) ◽  
pp. 3489-3496 ◽  
Author(s):  
Taka Narumi ◽  
Didier Chaussende ◽  
Takeshi Yoshikawa
Keyword(s):  
High Temperature ◽  
Ostwald Ripening ◽  
Particle Growth ◽  
Growth Behaviour ◽  
Sic Particles ◽  
Habit Planes

We investigated the stable habit planes of 3C–, 4H– and 6H–SiC in Si and Si–Cr-based solvents using Ostwald ripening of SiC particles, and found that particle-growth behaviour varied significantly with both SiC polytypes and solvent compositions.

Solidification Behaviour of 357 Al-Alloy under Intensive Forced Convection

2006 ◽  
Vol 519-521 ◽  
pp. 1747-1752 ◽  
Author(s):  
Michael Hitchcock ◽  
Zhong Yun Fan
Keyword(s):  
Forced Convection ◽  
Ostwald Ripening ◽  
Particle Growth ◽  
Primary Phase ◽  
Al Alloy ◽  
Growth Behaviour ◽  
Entire Volume ◽  
Solidification Behaviour ◽  
Primary Particles ◽  
Fast Growth Rate

Solidification behaviour of 357 Al-alloy under intensive forced convection in the rheo-die-casting (RDC) process, was investigated experimentally to understand the effects of the intensity of forced convection and shearing time on the nucleation and growth behaviour. It was found that under intensive forced convection, heterogeneous nucleation occurred continuously throughout the entire volume of the solidifying melt. All the nuclei could survive due to the uniform temperature and composition fields created by the forced convection. This has been named as ‘effective and continuous nucleation’. It is also found that the nuclei grow spherically with an extremely fast growth rate. This makes the primary solidification essentially a slow coarsening process, in which Ostwald ripening takes place by dissolution of the smaller particles. In addition, it was found that intensive forced convection suppresses partially the formation of the primary phase, promote nucleation of the primary particles, and hinders the particle growth.

Precise Quantitative Evaluation of Nano-Ordered Intermetallic Compounds in Sn-3.0Ag-0.5Cu Lead-Free Solder Bump by Using TEM

2008 ◽  
Vol 47-50 ◽  
pp. 907-911
Author(s):  
Chang Woo Lee ◽  
Y.S. Shin ◽  
J.H. Kim
Keyword(s):  
Intermetallic Compounds ◽  
Flip Chip ◽  
Solder Bump ◽  
Lead Free Solder ◽  
Growth Behaviour ◽  
Sic Particles ◽  
Imcs Growth ◽  
Ordered Intermetallic ◽  
Free Solder ◽  
The One

The growth behaviour of the intermetallic compounds (IMCs) in Pb-free solder bump is investigated. The Pb-free micro-bump, Sn-50%Bi, was fabricated by binary electroplating for flip-chip bond. The diameter of the bump is about 506m and the height is about 60 6m. In order to increase the reliability of the bonding, it is necessary to protect the growth of the IMCs in interface between Cu pad and the solder bump. For control of IMCs growth, SiC particles were distributed in the micro-solder bump during electroplating. The thickness of the IMCs in the interface was estimated by FE-SEM, EDS, XRF and TEM. From the results, The IMCs were found as Cu6Sn5 and Cu3Sn. The thickness of the IMCs decreases with increase the amount of SiC particles until 4 g/cm2. The one candidate of the reasons is that the SiC particles could decrease the area which be reacted between the solder and Cu layer. And another candidate is that the particle can make to difficult inter-diffusion within the interface.

scholarly journals Improvement of High Temperature Strength of Mullite by Dispersion of SiC Particles.

1996 ◽  
Vol 43 (12) ◽  
pp. 1429-1434
Author(s):  
Shigemi Sato ◽  
Min-Cheol Chu ◽  
Yasuyoshi Kobayashi ◽  
Kotoji Ando
Keyword(s):  
High Temperature ◽  
High Temperature Strength ◽  
Sic Particles

scholarly journals Theoretical analysis of particle size re-distribution due to Ostwald ripening in the fuel cell catalyst layer

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 779-789 ◽  
Author(s):  
Ambrož Kregar ◽  
Tomaž Katrašnik
Keyword(s):  
Particle Size ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Electric Potential ◽  
Ostwald Ripening ◽  
Particle Growth ◽  
Mean Particle Size ◽  
Fuel Cell Catalyst

Abstract The limited durability of hydrogen fuel cells is one of the main obstacles in their wider adoption as a clean alternative technology for small scale electricity production. The Ostwald ripening of catalyst material is recognized as one of the main unavoidable degradation processes deteriorating the fuel cell performance and shortening its lifetime. The paper systematically studies how the modeling approach towards the electrochemically driven Ostwald ripening in the fuel cell catalyst differs from the classical diffusion driven models and highlights how these differences affect the resulting evolution of particle size distribution. At moderately low electric potential, root-law growth of mean particle size is observed with linear relation between mean particle size and standard deviation of particle size distribution, similar to Lifshitz-Slyozov-Wagner theory, but with broader and less skewed distribution. In case of high electric potential, rapid particle growth regime is observed and qualitatively described by redeposition of platinum from a highly oversaturated solution, revealing the deficiencies of the existing platinum degradation models at describing the Ostwald ripening in the fuel cells at high electric potentials. Several improvements to the established models of platinum degradation in fuel cell catalysts are proposed, aimed at better description of the diffusion processes involved in particle growth due to Ostwald ripening.

scholarly journals Fatigue crack growth behaviour of Inconel 718 – the concept of a damaged zone caused by high temperature hold times

2011 ◽  
Vol 10 ◽  
pp. 2821-2826 ◽  
Author(s):  
David Gustafsson ◽  
Johan Moverare ◽  
Kjell Simonsson ◽  
Sten Johansson ◽  
Magnus Hörnqvist ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
High Temperature ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Inconel 718 ◽  
Growth Behaviour ◽  
Crack Growth Behaviour ◽  
Damaged Zone

An In Situ XRD Technique For Annealing Investigations

1994 ◽  
Vol 38 ◽  
pp. 757-762
Author(s):  
D.E. Koylman ◽  
S.C. Axtel ◽  
B.W. Robertson
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
Copper Powder ◽  
Diffraction Data ◽  
Particle Growth ◽  
Annealing Behavior ◽  
In Situ Xrd ◽  
Analysis Technique ◽  
Fourier Analysis Technique

Abstract An in situ XRD technique employing a diffractometer equipped with a high temperature camera was used to investigate the annealing behavior of nanoerystalline copper powder produced by mechanical milling. Specimens were annealed isothermally for 12 h at temperatures between 480 and 770 K. The diffraction data was analyzed using a single-profile Fourier analysis technique. The activation energy for diffracting particle growth was determined to be 0.45 eV/atom.

Friction and Wear Properties of α-Al2O3-Coated SiC Particle Reinforced Nickel Matrix Composites Sliding against Bearing Steel

2017 ◽  
Vol 266 ◽  
pp. 155-164
Author(s):  
Chao Feng ◽  
Yi Xie ◽  
Zhong Wu
Keyword(s):  
High Temperature ◽  
Friction And Wear ◽  
Sol Gel ◽  
Bearing Steel ◽  
Wear Behaviour ◽  
Nickel Matrix ◽  
Wear Properties ◽  
Sic Particles ◽  
Friction And Wear Properties ◽  
Sic Composites

In this study, attempt has been made to investigate the effect of SiC particles on the friction and wear properties of Ni/SiC composites manufactured by electrodeposition, especially for the composites with high-temperature treatment.For this purpose, α-Al2O3 was coated on the surfaces of SiC particles by sol-gel technology to inhibit interfacial reaction of SiC and nickel at high temperature. Both of the Ni/α-Al2O3-coated SiC (Ni/CSp) and Ni/uncoated SiC (Ni/UCSp) composites were treated at 600 °C to study the resulting wear behaviour. The results indicated that with heat treatment at 600 °C, the Ni/CSp composite had better tribological properties than the Ni/UCSp composite. It was proved that the uncoated SiC particles have reacted completely with nickel leaving many defects, while the coated SiC particles still remained in the Ni/CSp composite hardening the nickel matrix and supporting the counterpart, thus improving the wear resistance of Ni/CSp composite with relatively low friction coefficient and wear mass loss compared to the Ni/UCSp composite.

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