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.

A Study on the Effect of Grain Size on the Bioactivity of Nano-Titania Ceramics

2007 ◽  
Vol 342-343 ◽  
pp. 565-568
Author(s):  
Qi Feng Yu ◽  
Zhen Sheng Li ◽  
Bang Cheng Yang ◽  
Y. Huang ◽  
L. Gan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Grain Growth ◽  
Growth Inhibitor ◽  
Grain Growth Inhibitor ◽  
Different Grain Size

Nano-titania ceramics is a potential biomaterial for orthopaedic application. In our previous studies, a bioactive nano-titania ceramics was prepared by using alkali-heat treatment. In this paper, hydroxyapatite was used as a grain growth inhibitor additive to get nano-titania ceramics with different grain size, and the effect of grain size on the bioactivity was studied in vitro.

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

2007 ◽  
pp. 1237-1240
Author(s):  
Dong Kyu Park ◽  
Kwang Chul Jung ◽  
Jin Chun Kim ◽  
Sung Yeal Bae ◽  
In Sup Ahn
Keyword(s):  
Grain Growth ◽  
Growth Inhibitor ◽  
Nanocrystalline Powders ◽  
Grain Growth Inhibitor

Wear Property of Superfine Grained Si2N2O-Si3N4 Composites

2008 ◽  
Vol 368-372 ◽  
pp. 917-919
Author(s):  
Jun Ting Luo ◽  
Qing Zhang ◽  
Hong Bo Li
Keyword(s):  
Grain Size ◽  
Wear Resistance ◽  
Silicon Nitride ◽  
Liquid Phase ◽  
Sintering Temperature ◽  
High Hardness ◽  
Liquid Phase Sintering ◽  
Wear Property ◽  
Average Grain Size ◽  
Bearing Ball

Si3N4-Si2N2O composites were fabricated with amorphous nano-sized silicon nitride powders by the liquid phase sintering. The mass loss, relative density and average grain size increase with increasing sintering temperature. The average grain size is less than 500nm when the sintering temperature is lower than 1700°C. Friction coefficient is from 0.35 for sintering temperature 1650°C to 0.74 for 1600°C when the composites were worn by silicon nitride bearing ball. High hardness of 21.5GPa and relative wear resistance of 32 were observed at a sintering temperature of 1600°C. The wear surface are very smooth and no grooving and subsurface fracture, which indicates that they are worn slightly.

Measurement of WC Grain Size in Nanocrystalline WC-10Co Hardmetal

2007 ◽  
Vol 534-536 ◽  
pp. 1205-1208 ◽  
Author(s):  
Chen Guang Lin ◽  
Guan Sen Yuan
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Quantitative Measurement ◽  
Growth Inhibitor ◽  
Grain Growth Inhibitor ◽  
Mean Grain Size ◽  
The Mean ◽  
Good Contrast

Nano-grained WC-10Co hardmetal can be made by doping a new invented VC-based multi-grain-growth-inhibitor and suitable technical processing. The specifications for quantitative measurement of the grain size of WC in the alloy were investigated. It is very important to obtain the SE images of the alloy with good contrast and clear profile of WC grains by FESEM; then the linear intercept (LI) method was used to quantitatively measure the intercepts of WC grains. When the surveyed intercept numbers of WC grain exceeded 200, the statistic data for the mean grain size of WC were reproduced. The discriminative minimal grain size of used LI method was 12 nm; the maximum intercept of WC grain was 109 nm; the average intercept of WC grains was 45 nm and the corresponding 3D mean grain size of WC was 70 nm which is agreeable with the XRD outcome.

Effect of Ti(C0.7N0.3) Content on the Microstructure and Mechanical Properties of Ni Bonded NbC-Ti(C0.7N0.3) Based Cermets

2018 ◽  
Vol 274 ◽  
pp. 43-52
Author(s):  
S.G. Huang ◽  
J. Vleugels ◽  
H. Mohrbacher ◽  
M. Woydt
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Grain Size ◽  
Liquid Phase ◽  
Grain Growth ◽  
Xrd Analysis ◽  
Liquid Phase Sintering ◽  
Partial Replacement ◽  
Microstructural Investigation

NbC-xTi (C0.7N0.3)-10Ni-7.5VC (vol%) based cermets with 0, 5, 10, 15 or 25 vol% Ti (C0.7N0.3) were prepared by conventional pressureles liquid phase sintering at 1420°C in vacuum. Detailed microstructural investigation was performed by SEM, EPMA and XRD analysis. Sintering results indicated that the partial replacement of NbC by Ti (C0.7N0.3) had a significant effect on the carbide grain growth, microstructure, hardness as well as fracture toughness of the fully densified NbC-based cermets. The Ti (C0.7N0.3)-free NbC cermet was composed of homogeneous cubic (Nb,V)C solid solution grains, whereas core-rim structured NbC grains were observed in cermets with Ti (C0.7N0.3) addition. All sintered cermets with  15 vol% Ti (C0.7N0.3) were composed of a fcc solid solution Ni binder and a cubic core-rim solid solution (Nb,V,Ti)C phase with a Nb-rich core and a Ti-rich rim. 3.8 vol% of residual pristine Ti (C0.7N0.3) was present in the cermets with 25 vol% Ti (C0.7N0.3) addition. The 15 vol% Ti (C0.7N0.3) starting powder based cermet exhibited the finest average NbC grain size of 1.48 μm, with a core-rim structure and an interesting combination of hardness (1486 kg/mm2) and fracture toughness (8.7 MPa.m1/2).

Low temperature sintering of nano-SiC using a novel Al8B4C7 additive

2010 ◽  
Vol 25 (3) ◽  
pp. 471-475 ◽  
Author(s):  
Sea-Hoon Lee ◽  
Byung-Nam Kim ◽  
Hidehiko Tanaka
Keyword(s):  
Grain Size ◽  
Liquid Phase ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Applied Pressure ◽  
Liquid Phase Sintering ◽  
Low Temperature Sintering ◽  
Densification Rate ◽  
Sintering Additive ◽  
Average Grain Size

Al8B4C7 was used as a sintering additive for the densification of nano-SiC powder. The average grain size was approximately 70 nm after sintering SiC-12.5wt% Al8B4C7 at 1550 °C. The densification rate strongly depended on the sintering temperature and the applied pressure. The rearrangement of SiC particles occurred at the initial shrinkage, while viscous flow and liquid phase sintering became important at the middle and final stage of densification.

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.

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