Ostwald ripening and grain growth in Ti(C,N)-based cermets during liquid phase sintering

2016 ◽  
Vol 58 ◽  
pp. 1-7 ◽  
Author(s):  
Qi Zheng ◽  
Wen-Xin Yao ◽  
Leong-Chew Lim
Keyword(s):  
Liquid Phase ◽  
Grain Growth ◽  
Ostwald Ripening ◽  
Liquid Phase Sintering

scholarly journals A mathematical approach to Ostwald ripening due to diffusion and deformation in liquid bridge

2013 ◽  
Vol 45 (3) ◽  
pp. 261-271 ◽  
Author(s):  
B. Randjelovic ◽  
K. Shinagawa ◽  
Z.S. Nikolic
Keyword(s):  
Liquid Phase ◽  
Liquid Bridge ◽  
Ostwald Ripening ◽  
Solid Phase ◽  
Liquid Phase Sintering ◽  
Solute Diffusion ◽  
Deformation Analysis ◽  
Mathematical Approach ◽  
Fe Method ◽  
Grain Coarsening

From many experiments with mixtures of small and large grains, it can be concluded that during liquid phase sintering, smaller grains partially dissolve and a solid phase precipitates on the larger grains and grain coarsening occurs. The growth rate can be controlled either by the solid-liquid phase boundary reaction or by diffusion through the liquid phase. The microstructure may change either by larger grains growing during the Ostwald ripening process or by shape accommodation. In this study, two-dimensional mathematical approach for simulation of grain coarsening by grain boundary migration based on a physical and corresponding numerical modeling of liquid phase sintering will be considered. A combined mathematical method of analyzing viscous deformation and solute diffusion in liquid bridge between two grains with different sizes will be proposed. The viscous FE method will be used for calculating meniscus of the liquid bridge, with the interfacial tensions taken into consideration. The FE method for diffusion will be also implemented by using the same mesh as the deformation analysis.

Liquid Phase Sintering of (Ti,W)C-Ni-Co-Cr Cermets: Microstructure and Abrasive Wear Behavior

2018 ◽  
Vol 274 ◽  
pp. 1-8 ◽  
Author(s):  
I. Iparraguirre ◽  
L. Lozada ◽  
F. Ibarreta ◽  
R. Martinez ◽  
J.M. Sanchez
Keyword(s):  
Liquid Phase ◽  
Grain Growth ◽  
Abrasion Resistance ◽  
Wear Behavior ◽  
Liquid Phase Sintering ◽  
Point Of View ◽  
Cemented Carbides ◽  
Microstructural Refinement ◽  
Abrasive Wear Behavior ◽  
High Degree

TiC-WC-(Ni,Co,Cr) cermets are potential candidates for the substitution of straight cemented carbides in certain wear applications. This work analyses the effect of Ti/W and Co/Ni ratios on the microstructure and abrasion resistance of this type of cermets. From a microstructural point of view, cermets in the (Ti,W)C-(Ni,Co,Cr) pseudo-binary region show uncontrolled (Ti,W)C grain growth and a high degree of contiguity of the carbide phase. A microstructural refinement is observed as the Ti/W ratio decreases, especially when WC precipitation occurs. Abrasion resistance in these materials is dominated by hardness.

Synthesis of WC-10wt.%Co Nanocrystalline Powders with Grain Growth Inhibitor by MTP

2007 ◽  
Vol 534-536 ◽  
pp. 1237-1240 ◽  
Author(s):  
Dong Kyu Park ◽  
Kwang Chul Jung ◽  
Jin Chun Kim ◽  
Sung Yeal Bae ◽  
In Sup Ahn
Keyword(s):  
Grain Size ◽  
Wear Resistance ◽  
Liquid Phase ◽  
Grain Growth ◽  
Growth Inhibitor ◽  
Liquid Phase Sintering ◽  
Nanocrystalline Powders ◽  
Grain Growth Inhibitor ◽  
Nano Crystalline ◽  
Carburizing Process

To improve the fracture strength and wear resistance of WC-Co cemented carbide, various technologies have been developed related producing the nano crystalline. There have been extensive studied conducted to retard grain growth during liquid phase sintering. However, when this inhibitor is added by simple mixing, a micro-pores forms during sintering In this study, WC-Co nanocrystalline powders with grain growth inhibitor in the site were prepared by MTP (Mechano-Thermic carburizing Process) to minimize this formation of micro pores and to retard grain growth effectively during sintering. In addition, then the phase and grain size of WC-Co nanocrystalline powders were evaluated according to the condition of MTP.

Microstructure of TiB2 liquid phase sintered with Ni3Al

1983 ◽  
Vol 41 ◽  
pp. 62-63
Author(s):  
P. Angelini ◽  
J. Bentley ◽  
C. B. Finch ◽  
P. S. Sklad
Keyword(s):  
Solid Solution ◽  
Thermal Expansion ◽  
Liquid Phase ◽  
Electrical Properties ◽  
Grain Growth ◽  
Hot Pressing ◽  
Liquid Phase Sintering ◽  
Intergranular Phase ◽  
Phase Development ◽  
Al Powder

TiB2 is a ceramic material which possesses exceptional thermal, chemical, and electrical properties. Commercial powders can be formed into bulk pieces by hot pressing at temperatures near 2000°C. However, this produces excessive grain growth which can lead to cracking and low mechanical integrity due to the relatively large anisotropic thermal expansion of the TiB2 grains. Liquid phase sintering can be used to produce structural forms of TiB2 by hot pressing at temperatures near 1450°C. This process limits the TiB2 grain growth but introduces an intergranular phase. Previous work used Ni as a binder and under most hot-pressing conditions this resulted in the formation of a Ni3B intergranular phase. Additional binders are being considered to understand the phase development during liquid-phase sintering and to improve the properties of the bonded TiB2 forms.The present research concerns the use of Ni3Al as a binder for TiB2. The Ni3Al powder was a physical mixture of 32 wt % NiAl and 68 wt % of a solid solution of 95 at. % Ni with 5 at. % Al powders.

Three Dimensional Monte Carlo Simulation of Isotropic Coarsening of Particles in Liquid Phase

2007 ◽  
Vol 558-559 ◽  
pp. 1115-1120
Author(s):  
Suk Bin Lee ◽  
Anthony D. Rollett
Keyword(s):  
Particle Size ◽  
Monte Carlo ◽  
Liquid Phase ◽  
Ostwald Ripening ◽  
Monte Carlo Model ◽  
Liquid Phase Sintering ◽  
Three Dimensions ◽  
Average Particle ◽  
Size Distributions ◽  
Particle Size Distributions

Coarsening of particles during liquid phase sintering is known to be an example of Ostwald ripening. This coarsening process, in a fully wetting system, is simulated in three dimensions with a kinetic Monte Carlo model. The results from the simulation for microstructures, kinetics and particle size distributions are compared to available experimental findings. It is found that the average particle volume increases linearly with time and that the particle size distributions are consistent with those obtained experimentally, as in the W-Ni-Fe and Sn-Pb systems.

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