scholarly journals Microstructure and Properties of Ultrafine Cemented Carbides Prepared by Microwave Sintering of Nanocomposites

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 507
Author(s):  
Yanju Qian ◽  
Zhiwei Zhao
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Vickers Hardness ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Raw Material ◽  
Cemented Carbides ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size

Ultrafine cemented carbides were prepared by microwave sintering, using WC-V8C7-Cr3C2-Co nanocomposites as a raw material. The effects of sintering temperature and holding time on the microstructure and mechanical properties of cemented carbides were studied. The results show that the ultrafine cemented carbides prepared at 1300 °C for 60 min have good mechanical properties and a good microstructure. The relative density, Vickers hardness, and fracture toughness of the specimen reach the maximum values of 99.79%, 1842 kg/mm2 and 12.6 MPa·m1/2, respectively. Tungsten carbide (WC) grains are fine and uniformly distributed, with an average grain size of 300–500 nm. The combination of nanocomposites, secondary pressing, and microwave sintering can significantly reduce the sintering temperature and inhibit the growth of WC grains, thus producing superfine cemented carbides with good microstructure and mechanical properties.

Effect of (Ni,Mo) and (W,Ti)C on the Microstructure and Mechanical Properties of TiB2 Ceramic Tool Materials

2012 ◽  
Vol 723 ◽  
pp. 233-237 ◽  
Author(s):  
Tong Chun Yang ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou ◽  
Hong Tao Zhu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Flexural Strength ◽  
Grain Growth ◽  
Vickers Hardness ◽  
Ceramic Tool ◽  
Tool Materials ◽  
Sintering Additive ◽  
Microstructure And Mechanical Properties

TiB2-(W,Ti)C composites with (Ni,Mo) as sintering additive have been fabricated by hot-pressing technique, and the microstructure and mechanical properties of the composites have been investigated. (Ni,Mo) promotes grain growth of the composites. In the case of 7vol.% (Ni,Mo), the grain size decreases consistently with an increase in the content of (W,Ti)C. When the proper content of (W,Ti)C is added to TiB2 composites, the growth of matrix grains is inhibited and the mechanical properties of the composites are improved. The best mechanical properties of the composites are 1084.13MPa for three-point flexural strength, 7.80MPa•m 1/2 for fracture toughness and 17.92GPa for Vickers hardness.

Influence of Al2O3 Addition on the Microstructure and Mechanical Properties of Pressureless Sintered Ce-TZP

2005 ◽  
Vol 492-493 ◽  
pp. 783-0 ◽  
Author(s):  
Shui Gen Huang ◽  
Lin Li ◽  
Jef Vleugels ◽  
Pei Ling Wang ◽  
Omer Van der Biest
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Grain Growth ◽  
Vickers Hardness ◽  
Good Combination ◽  
Al2o3 Content ◽  
Pressureless Sintering ◽  
Sintering Time ◽  
Microstructure And Mechanical Properties

Mixtures of 12 mol% CeO2-stabilised ZrO2 with 5 to 20 wt % Al2O3 were prepared and densified through pressureless sintering in air at 1450° C for 1 to 4 h. The influence of the Al2O3 content and sintering time on the phase constitution, microstructure and mechanical properties of the as-sintered composites were investigated. Fully dense Ce-TZP/Al2O3 ceramics with a good combination of hardness and fracture toughness can be obtained by pressureless sintering in air for only 1 h. The addition of Al2O3 to Ce-TZP improves the mechanical properties and suppresses ZrO2 grain growth. The average ZrO2 grain size increases with increasing sintering time and decreasing Al2O3 content. This leads to an increase in toughness. An excellent fracture toughness of 14.3 MPam1/2 in combination with a Vickers hardness of 9.14 GPa was obtained for 12 mol % CeO2-TZP with 5 wt % Al2O3, sintered for 4 h.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of WC-16TiC-xTaC-9Co Cemented Carbides

2012 ◽  
Vol 268-270 ◽  
pp. 340-343
Author(s):  
Chong Cai Zhang ◽  
Quan Wang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Sintering Temperature ◽  
Rupture Strength ◽  
High Energy ◽  
Cemented Carbides ◽  
Average Grain Size ◽  
Comprehensive Performance ◽  
Energy Ball ◽  
Average Size

In this paper, the WC-16TiC-xTaC-9Co and Co are mixed together preparing for WC, (W, Ti, Ta) C. By high-energy ball milling, the powder is cold isostatic pressed and vacuum sintered by 1410°C, 1430°Cand 1450°C.The physical properties and the micrographs of samples are detected. The main conclusions are as following: sintered samples have the best comprehensive performance at 1450°C, the density of the sample is 99.7% and the actual density is 10.91g/cm3. The hardness is 92.8 HRA and the transverse rupture strength (TRS) is 1100MPa. The grain size grows up obviously with the high temperature. The average grain size of WC is 0.7μm and the average size of (W, Ti, Ta)C is 3μm.

Ultrafine WC-10Co cemented carbides fabricated by electric-discharge compaction

2004 ◽  
Vol 19 (8) ◽  
pp. 2240-2244 ◽  
Author(s):  
X.Y. Wu ◽  
W. Zhang ◽  
W. Wang ◽  
F. Yang ◽  
J.Y. Min ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Electric Discharge ◽  
Holding Time ◽  
Conversion Process ◽  
Cemented Carbides ◽  
Microstructure And Mechanical Properties ◽  
Spray Conversion

This research investigates the microstructure and mechanical properties of ultrafine WC-10Co cemented carbides fabricated by an electric-discharge compaction (EDC) process, from powder synthesized by a spray-conversion process (SCP). Due to a short holding time during EDC, a grain size as small as 120 nm can be achieved. We also found that dispersion of pores in WC-Co cemented carbides may contribute to fracture toughness, besides the bridging ligament mechanism.

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.

Preparation of Industrial Watchcase of 5Y-Tetragonal ZrO2 by Microwave Sintering

2014 ◽  
Vol 602-603 ◽  
pp. 323-326
Author(s):  
Xiao Xuan Pian ◽  
Bing Bing Fan ◽  
Xin Zhang ◽  
Hao Chen ◽  
Chen Yang Wang ◽  
...  
Keyword(s):  
Grain Size ◽  
Phase Change ◽  
Vickers Hardness ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Resonant Mode ◽  
Homogeneous Microstructure ◽  
Average Grain Size ◽  
Conventional Sintering ◽  
Lower Temperature

The industrial watchcases of 5Y-Tetragonal ZrO2were prepared by microwave sintering. Samples were sintered in a microwave chamber with TE666 resonant mode at 2.45GHz. The sintering temperature was from 1250°C to 1400°C. XRD and SEM techniques were used to characterize the samples. It is found that microwave sintering improved the phase change from t-ZrO2to m-ZrO2. Dense and homogeneous microstructure was obtained within the microwave-sintered samples and the average grain size was about 500nm. Compared to conventional sintering, microwave-sintered samples show higher density and hardness. And microwave-sintered samples were performed 130°C lower temperature. Optimized sample with the density of 6.1 g/cm3and Vickers Hardness of 16.2MPa is microwave-sintered at 1350°C for 30min.

Preparation and Properties of 3Y-TZP Ceramic Tools

2010 ◽  
Vol 177 ◽  
pp. 373-377
Author(s):  
Zhi Wei Chen ◽  
Liu Feng ◽  
Jin Ye Niu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Theoretical Density ◽  
Ceramic Tools ◽  
Average Value ◽  
Obvious Change ◽  
Microstructure And Mechanical Properties

Fully densitified 3Y-TZP (>98% of theoretical density) ceramic tools have been prepared by gelcasting and sintered with conventional pressureless at 1500 ~ 1600°C. The microstructure and mechanical properties as a function of sintering temperature were investigated. The experiment results indicate that the samples with a range of grain size from 300nm to700nm have high mechanical properties. With the sintering temperature rising, the hardness show no obvious change, the average value is 13.2GPa; while the bending strength have a trend of first increasing then decreasing. The optimal sintering temperature is 1550°C, the bending strength and the fracture toughness all reach the maximum, which is 947 MPa and 8.9MPa.M1/2.

scholarly journals Microstructure and mechanical properties of Ti3SiC2 MAX phases sintered by hot pressing

2021 ◽  
Vol 1 (4) ◽  
pp. 216-222
Author(s):  
Sheida Haji Amiri ◽  
Nasser Pourmohammadie Vafa
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Sintering Temperature ◽  
Sintered Sample ◽  
Max Phases ◽  
Microstructure And Mechanical Properties ◽  
Fine Grained Structure

The Ti3SiC2 used in this project has been purchased ready-made. This study aimed to investigate the effect of sintering temperature on samples' microstructure and mechanical properties, including three-point flexural strength, Vickers hardness, and fracture toughness. Therefore, Ti3SiC2 samples were sintered under a vacuum atmosphere at a pressure of 35 MPa for 30 minutes at two temperatures of 1500 °C and 1550 °C by hot pressing. The microstructure obtained from the fracture cross-section of the samples shows that by increasing the sintering temperature to 1550 °C, the microstructure of this sample becomes larger than the sintered sample at 1500 °C. Also, increasing the sintering temperature to 1550 °C causes the decomposition of Ti3SiC2 to TiC, which can be seen in the X-ray diffraction pattern (XRD). In addition, the relative density of the sintered sample at 1550 °C is 98.08% which is higher than that of the sintered sample at 1500 °C with the result of 89%. On the other hand, the three-point flexural strength (227.5 MPa), the Vickers hardness (~9 GPa), and the fracture toughness (8.6 MPa.m1/2) of the sintered sample at 1500 °C are higher due to the fine-grained structure.

scholarly journals Improvement of the mechanical properties of spark plasma sintered hap bioceramics by decreasing the grain size and by adding multi-walled carbon nanotubes

2013 ◽  
Vol 45 (2) ◽  
pp. 233-243 ◽  
Author(s):  
Dj. Veljovic ◽  
G. Vukovic ◽  
I. Steins ◽  
E. Palcevskis ◽  
P.S. Uskokovic ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Grain Size ◽  
Sintering Temperature ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Multi Walled Carbon Nanotubes ◽  
Spark Plasma ◽  
Walled Carbon Nanotubes

Composites based on HAP and oxidized multi-walled carbon nanotubes (o-MWCNT) and monophase HAP materials were processed by spark plasma sintering. Starting from stoichiometric nano-sized HAP powder, monophase bioceramics were obtained with a density close to the theoretical one and with an average grain size of several hundred nanometers to micron dimensions. It was shown that decreasing the sintering temperature resulted in a decrease of the grain size, which affected an increase in the fracture toughness and hardness. The fracture toughness of an HAP/ o-MWCNT bioceramic processed at 900?C for only 5 min was 30 % higher than that of monophase HAP materials obtained under the same conditions. The addition of MWCNT during SPS processing of HAP materials caused a decrease in the grain size to the nano-dimension, which was one of the reasons for the improved mechanical properties.

Effects of TiN Content on Mechanical Properties and Microstructure of ATN Materials

2013 ◽  
Vol 589-590 ◽  
pp. 590-593 ◽  
Author(s):  
Min Wang ◽  
Jun Zhao
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Fracture Toughness ◽  
Vickers Hardness ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Ceramic Materials ◽  
Hot Press ◽  
Hot Press Sintering ◽  
Tin Content

In order to investigate the effects of TiN content on Al2O3/TiN ceramic material (ATN), the ATN ceramic materials were prepared of TiN content in 30%, 40%, 50%, 60% in the condition of hot press sintering. The sintering temperature is 1700°C, the sintering press is 32MPa, and the holding time are 5min, 10min, 15min. The effects of TiN content on mechanical properties and microstructure of ATN ceramic materials were investigated by analyzing the bending strength, hardness, fracture toughness. The results show that ATN50 has the best mechanical property, its bending strength is 659.41MPa, vickers hardness is 13.79GPa, fracture toughness is 7.06MPa·m1/2. It is indicated that the TiN content has important effect on microstructure and mechanical properties of ATN ceramic materials.

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