Effect of VC, TaC and NbC Additions on Microstructure and Properties of Ultrafine WC-10%Co Cemented Carbides

2013 ◽  
Vol 320 ◽  
pp. 281-286 ◽  
Author(s):  
Hao Yu ◽  
Wan Ni Li ◽  
Xian Quan Jiang ◽  
Peng He Jiao
Keyword(s):  
Mechanical Properties ◽  
Grain Growth ◽  
Growth Inhibitor ◽  
Cemented Carbides ◽  
Testing Methods ◽  
Vacuum Sintering ◽  
Microstructure And Properties ◽  
Grain Growth Inhibitor

The ultrafine WC-10%Co cemented carbides were prepared by vacuum sintering processing. To inhibit the growth of WC grains during sintering, single VC, TaC and NbC were used as inhibitors. Effects of VC, TaC and NbC as grain growth inhibitor on the microstructure and properties of ultrafine WC-10%Co cemented carbides were investigated with different kinds of testing methods. With the transformation of doped inhibitors content, the results show that VC, TaC and NbC additions can refine the WC grains, and increase the mechanical properties of the WC-10%Co cemented carbides, respectively. And the efficiency of these three kinds of inhibitors to limit gain size has been compared after sintering for 1.5h at 1 400 °C.

Effects of Combined Addition of Cr3C2 and NbC on Microstructure and Properties of Cemented Carbides Prepared by WС-Co Composite Powder

2016 ◽  
Vol 849 ◽  
pp. 794-800 ◽  
Author(s):  
Ai Min Jiang ◽  
Quan Li ◽  
Feng Jie Yang
Keyword(s):  
Grain Growth ◽  
Composite Powder ◽  
Rupture Strength ◽  
Growth Inhibitor ◽  
Interface Energy ◽  
Grain Structure ◽  
Ultrafine Grain ◽  
Binder Phase ◽  
Microstructure And Properties ◽  
Grain Growth Inhibitor

With addition various contents of combined grain growth inhibitors Cr3C2 and NbC into the ultrafine WC-Co6% composite powder, and the effects of codoped Cr3C2 and NbC addition on microstructure and properties of the alloys have been investigated by X-ray diffraction, scanning electron microscopy. The results showed that increasing the content of inhibitors in the composite powder, the abnormal grain growth disappeared and homogeneous ultrafine grain structure formed, i.e., the grain growth inhibitor promoted sintering densification process. WC grains were refined by the comprehensive effects of the Cr3C2/NbC dissolving in the Co phase to alter the interface energy and interfere the WC solution in the binder phase, which prevents the structure of cobalt change from the face-center-cubic into dense-hexagonal crystal, and to increases the transverse rupture strength.

Effect of Grain Growth Inhibitor on the Microstructure and Mechanical Properties of Ti(C,N)-Based Cermet

2007 ◽  
Vol 280-283 ◽  
pp. 1413-1416 ◽  
Author(s):  
Yong Zheng ◽  
Wen Jun Liu ◽  
Quan Yuan ◽  
Lei Wen ◽  
Wei Hao Xiong
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Liquid Metal ◽  
Grain Growth ◽  
Vanadium Carbide ◽  
Growth Inhibitor ◽  
Grain Growth Inhibitor ◽  
Microstructure And Mechanical Properties ◽  
Transmission Electron ◽  
Lower Extent

Several Ti(C,N)-based cermets with different grain growth inhibitor were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX). The microstructure and mechanical properties of a cermet as a function of the content of the typical grain growth inhibitors, such as vanadium carbide (VC) and chromium carbide (Cr3C2), was revealed. VC addition could remarkably refine the grains, but it reduced the wetting of the ceramic grains by liquid metal during sintering. Thus it still reduced the performances of the cermet. Cr3C2 addition was found to inhibit grains from growing to lower extent during sintering. However it reduced the wetting of the ceramic grains by liquid metal slightly. Most of chromium element congregated in the rim phase and improved the plasticity of the rim. With Cr3C2 added properly, the performances of the cermets were improved remarkably.

Physical and Mechanical Properties of WC-Co Submicron Powders Using P/M Technique

2014 ◽  
Vol 879 ◽  
pp. 12-15 ◽  
Author(s):  
Ahmad Aswad Mahaidin ◽  
Mohd Asri Selamat ◽  
Samsiah Abdul Manaf ◽  
Talib Ria Jaafar
Keyword(s):  
Mechanical Properties ◽  
Grain Growth ◽  
Vanadium Carbide ◽  
Physical And Mechanical Properties ◽  
Growth Inhibitor ◽  
Cold Isostatic Pressing ◽  
Mixing Process ◽  
Sintering Process ◽  
Grain Growth Inhibitor ◽  
Work Done

The properties of WC-Co are greatly improved with the use of submicron powders. However, grain growth tends to occur during the sintering process which causes the properties to deteriorate to some extent. Free carbon and vanadium carbide are added in this study to serve as grain growth inhibitor. The effect of these two materials is evaluated based on WC-Co properties. In this work, the powders are mixed together via wet mixing process, compacted and undergo cold-isostatic pressing (CIP) before the samples are sintered in the temperature range of 1350-1450°C under nitrogen-based atmosphere. The physical and mechanical properties of the WC-Co sintered powders were analysed. Based on the work done, the WC-Co-C has a better properties compared to WC-Co-VC.

Analysis of Microgram Tungsten Carbide-Cobalt Cemented Carbides

1976 ◽  
Vol 34 ◽  
pp. 624-625
Author(s):  
T.A. Emma
Keyword(s):  
Grain Growth ◽  
High Hardness ◽  
Growth Inhibitor ◽  
High Strength ◽  
Cemented Carbides ◽  
Grain Growth Inhibitor ◽  
Concentrated Sulfuric Acid ◽  
Grain Size And Shape ◽  
Co Alloys ◽  
Sintered Product

When small quantities of a grain growth inhibitor are added to starting powders containing submicron WC and Co, the sintered product is a high strength, high hardness alloy. The microstructure of the carbide is quite similar to that of the macrograin variety. For the purposes of this study WC with 10-20% Co alloys containing small amounts of a grain growth inhibitor were examined with the electron microscope to determine grain size and shape, general composition, identification of possible undesirable species, and the disposition of the grain growth inhibitor.During the initial stages of the investigation, fractured surfaces were examined using an RCA-3F microscope converted to operate as a high resolution diffraction instrument with 50 cm camera. Reflection patterns from fractured surfaces showed that the major phase was cobalt with a weaker pattern from WC, indicating that fracture took place inside the cobalt cement. These same surfaces were then treated electrolytically in concentrated sulfuric acid at a temperature in the range between 3 and 8°C to remove the cobalt binder.

Effect of Ta, Nb and V Additions on the Microstructure and Mechanical Properties of (W,Ti)C-Co

2012 ◽  
Vol 535-537 ◽  
pp. 783-786
Author(s):  
Yan Wu ◽  
Hai Xia Xin ◽  
Yu Chun Zhai
Keyword(s):  
Mechanical Properties ◽  
Grain Growth ◽  
Growth Inhibitor ◽  
Grain Growth Inhibitor ◽  
Microstructure And Mechanical Properties ◽  
Nb Addition

(W,Ti)C-10%Co system cermets doped with Ta, Nb or V grain growth inhibitor were prepared in this work. The effect of Ta, Nb and V on the microstructure and mechanical properties of (W0.8783Ti0.0976VB0.0242)C-10%Co systems was investigated. The results show that the three elements play an important role on the WC grain growth and shape; the cermets appeared uniformly distributed as whiskers or thin platelets. V results in the hardest material, Ta causes the material to become harder compared with (W0.9Ti0.1)C-10%Co cermets. But the hardness of cermets with Nb addition decrease because of the increasing of porosity.

Effects of NbC/VC Addition on Mechanical Properties of Ultrafine Grained Cemented Carbides

2014 ◽  
Vol 602-605 ◽  
pp. 420-423
Author(s):  
Ai Min Jiang ◽  
Xian Quan Jiang ◽  
Zi Peng Zhao ◽  
Jin Yang ◽  
Rong Yu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Grain Growth ◽  
Sintered Sample ◽  
Cemented Carbides ◽  
Vacuum Sintering ◽  
Ultrafine Grained ◽  
Effective Reduction ◽  
Co Alloys ◽  
Co Doped

The samples are prepared by vacuum sintering technology, and the effects of VC/NbC combined addition on the mechanical properties of the WC-8% Co alloys with superfine grain are investigated. The results show that: with the transformation of Co-doped inhibitors content, the grain growth is inhibited and the grain size 460nm at 0.4%NbC/0.4%VC. The mechanism that Co-doped NbC/VC on the effective reduction of ultrafine WC-8%Co cemented carbides was analyzed. The 0.4%NbC/0.4%VC addition equipped with the best integrated properties was obtained in this study. And sintered sample were investigated with SEM.

Effects of Sintering Temperature on Microstructure and Properties of Ultrafine WC-VC-NbC-Co Cemented Carbides

2014 ◽  
Vol 926-930 ◽  
pp. 93-97
Author(s):  
Ai Min Jiang ◽  
Xian Quan Jiang ◽  
Zi Peng Zhao ◽  
Rong Yu ◽  
Rong Jie Yang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Sintering Temperature ◽  
Optical Microscope ◽  
Cemented Carbides ◽  
Vacuum Sintering ◽  
Microstructure And Properties ◽  
Microstructure And Mechanical Properties ◽  
Overall Performance

In this study, Ultrafine WC-VC-NbC-Co was sintered by vacuum sintering at the different sintering temperature. The microstructure and mechanical properties of alloy were analysed by Zeiss optical microscope, SEM-EDS. The results demonstrated that with the increasing sintering temperature, porosity first decreases and then increases, WC grain size enlarges content of η phase decreases. In addition, results reveal the best overall performance was abstained at 1440°C: Density, Vikers hardness, bening were: 14.30g/cm3, 1950HV30, 1787Mpa.

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