scholarly journals Fabrication of Cu Based Metallic Binder for Diamond Tools by Microwave Pressureless Sintering

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1453 ◽  
Author(s):  
Shenghui Guo ◽  
Xiaolei Ye ◽  
Liang Wang ◽  
Sivasankar Koppala ◽  
Li Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Relative Density ◽  
Metallic Matrix ◽  
Strength Increase ◽  
Pressureless Sintering ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Mps Method ◽  
Diamond Tools

Microwave pressureless sintering (MPS) method is successfully applied in the fabrication of Cu based metallic matrix for diamond tools. The main purpose of this work is to obtain better mechanical properties when the metal binder of the diamond tools was prepared by the MPS method. The orthogonal experimental method is adopted to design the sintering process parameters. The optimized experimental conditions are suggested as 880 °C of sintering temperature, 375 MPa of cold pressure, and 35 min of withholding time. The contrastive investigation of the MPS and conventional pressureless sintering (CPS) are performed under optimized conditions. The microstructures information are obtained by scanning electron microscopy (SEM), X-ray diffraction (XRD), electron probe microanalysis (EPMA), and the necessary mechanical properties, such as relative density, hardness, and flexural strength are tested. Experimental results show that the MPS method, compared with CPS, can significantly improve the mechanical properties of the metallic matrix. The factors of relative density, hardness, and flexural strength increase 1.25%, 3.86%, and 6.28%, respectively. The possible sintering mechanism of the MPS method is also discussed. This work may provide a reference for the fabrication of metal-based diamond tools by microwave heating method.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3-TiC-ZrO2 Ceramic Composites

2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Al2O3-TiC-ZrO2ceramic composites (ATZ) were fabricated by hot-pressed sintering. The phases and microstructure of the composites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relative density and mechanical properties (flexural strength, fracture toughness and Vicker’s hardness) of the composites were tested. The results show that the microstructure of the composites was the gray core-white rim. With the increase of sintering temperature, the relative density and mechanical properties of the composites increased first and then decreased. The composite sintered at 1705°C has the highest synthetical properties, and its relative density, flexural strength, fracture toughness and Vickers hardness are 98.3%,970MPa,6.0 MPa•m1/2and 20.5GPa, respectively.

Preparation of 10B Enriched B4C Ceramics by Pressureless Sintering

2014 ◽  
Vol 602-603 ◽  
pp. 540-543
Author(s):  
Yu Jun Zhang ◽  
Sha Li Tan ◽  
Ru Bin Wei ◽  
Shu He Ai ◽  
Hai Bin Sun
Keyword(s):  
Flexural Strength ◽  
Boron Carbide ◽  
Relative Density ◽  
Sintering Temperature ◽  
Raw Material ◽  
Carbide Powder ◽  
Average Particle ◽  
Strength Increase ◽  
Pressureless Sintering ◽  
Water Reactors

Boron carbide is an attractive neutron absorbing material used both in Fast Breeder Reactors (FBR) and in Pressurised Water Reactors (PWR) owing to its very high absorption cross section for thermal neutrons, chemical stability and refractory character. In the present paper, 10B enriched B4C ceramics are prepared by pressureless sintering at 19602160°C, under argon, using 10B boron carbide powder as raw material, 18 wt% phenolic resin as sintering aid. In the sintering temperature range, with the increasing of sintering temperature, both the relative density and flexural strength increase linearly, the average particle sizes increase from about 3μm at 1960°C to more than 30μm at 2160°C. The sample sintered at 1960°C has a 91.7% of relative density and 192 MPa of flexural strength and a homogeneous texture with 3-4μm particle size, which are enough for pellet application of reactors.

scholarly journals Improvement of mechanical properties of HfB2-based composites by incorporating in situ SiC reinforcement through pressureless sintering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Ghadami ◽  
E. Taheri-Nassaj ◽  
H. R. Baharvandi ◽  
F. Ghadami
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Relative Density ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Vacuum Atmosphere ◽  
Sic Reinforcement ◽  
Microstructural Studies ◽  
Composite Samples

AbstractHfB2, Si, and activated carbon powders were selected to fabricate 0–30 vol% SiC reinforced HfB2-based composite. Pressureless sintering process was performed at 2050 °C for 4 h under a vacuum atmosphere. Microstructural studies revealed that in situ SiC reinforcement was formed and distributed in the composite according to the following reaction: Si + C = SiC. A maximum relative density of 98% was measured for the 20 vol% SiC containing HfB2 composite. Mechanical investigations showed that the hardness and the fracture toughness of these composites were increased and reached up to 21.2 GPa for HfB2-30 vol% SiC and 4.9 MPa.m1/2 for HfB2-20 vol% SiC, respectively. Results showed that alpha-SiC reinforcements were created jagged, irregular, and elongated in shape which were in situ formed between HfB2 grains and filled the porosities. Formation of alpha-SiC contributed to improving the relative density and mechanical properties of the composite samples. By increasing SiC content, an enhanced trend of thermal conductivity was observed as well as a reduced trend for electrical conductivity.

Effects of Sintering Additives on the Microstructure and Mechanical Properties of Silicon Nitride Ceramics by GPS

2010 ◽  
Vol 105-106 ◽  
pp. 27-30 ◽  
Author(s):  
Wei Ru Zhang ◽  
Feng Sun ◽  
Ting Yan Tian ◽  
Xiang Hong Teng ◽  
Min Chao Ru ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Transformation ◽  
Silicon Nitride ◽  
Porous Silicon ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Additives ◽  
Microstructure And Mechanical Properties ◽  
Nitride Ceramics

Silicon nitride ceramics were prepared by gas pressure sintering (GPS) with different sintering additives, including La2O3, Sm2O3 and Al2O3. Effect of sintering additives on the phase-transformation, microstructure and mechanical properties of porous silicon nitride ceramics was investigated. The results show that the reaction of sintering additives each other and with SiO2 had key effects on the phase-transformation, grain growing and grain boundaries. With 9MPa N2 atmosphere pressure, holding 1h at 1850°C, adding 10wt% one of the La2O3, Sm2O3, Al2O3, porous silicon nitride was prepared and the relative density was 78%, 72%, 85% respectively. The flexural strength was less than 500MPa, and the fracture toughness was less than 4.8MPam1/2. Dropping compounds sintering additives, such as La2O3+Al2O3, Sm2O3+Al2O3 effectively improves the sintering and mechanical properties. The relative density was 99.2% and 98.7% with 10wt% compounds sintering additives. The grain ratio of length to diameter was up to 1:8. The flexural strength was more than 900MPa, and the fracture toughness was more than 8.9MPam1/2.

Mechanical Behavior of the Cr3C2 Compound at High Pressure and High Temperature

2015 ◽  
Vol 1120-1121 ◽  
pp. 1187-1193 ◽  
Author(s):  
Bin Li Jiang ◽  
Zi Li Kou ◽  
De Jiang Ma ◽  
Yong Kun Wang ◽  
Chun Xia Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Pressure ◽  
Relative Density ◽  
X Ray Diffraction ◽  
Density Measurements ◽  
X Ray ◽  
Hardness Tests ◽  
Novel Method ◽  
Heat Preservation

In the present study, we present a novel method to sinter Cr3C2 powders under high pressure without any addittives. The sintering Cr3C2 samples were charaterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), relative density measurements, Vicker’s hardness tests and Fracture toughness tests. The reasults show that Cr3C2 powders could be sintered to be bulk under the conditions of 3-5 GPa, 800-1200 °C and the heat preservation for 15 min. Moreover, the sintering body of Cr3C2 compound with the relative density of 99.84% by simultaneously tuning the pressure-temperature conditions exhibited excellent mechanical properties: a Vickers hardness of 20.3 GPa and a fracture toughness of ~8.9 MPam1/2. These properties were much higher than that by using the previous methods. The temperature condition obtained good mechanical properties in the experiment was about 1/3 lower than that using any other methods owing to the high pressure.

Microstructures and Mechanical Properties of B4C-TiB2 Composite Prepared by Hot Pressure Sintering

2010 ◽  
Vol 434-435 ◽  
pp. 50-53 ◽  
Author(s):  
Xin Yan Yue ◽  
Shu Mao Zhao ◽  
Liang Yu ◽  
Hong Qiang Ru
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Microstructural Analysis ◽  
Crack Deflection ◽  
Second Phase ◽  
Fine Grain ◽  
Pull Out ◽  
Microstructures And Mechanical Properties

B4C-TiB2 composite was prepared using hot pressure sintering. The microstructures and mechanical properties of the B4C-TiB2 composite were investigated. The B4C-TiB2 composite with 43 mass % TiB2 showed the optimized properties. The relative density, hardness, flexural strength and fracture toughness of that were 98.2 %, 25.9 GPa, 458 MPa and 8.7 MPa•m1/2, respectively. A number of toughening mechanisms, including fine grain, crack deflection and grain pull-out, were observed during microstructural analysis of the composite. The fracture mode of the B4C-TiB2 composite was greatly affected by the existence of the second phase of TiB2.

Effect of Iron Additive on the Sintering Behavior of Hot-Pressed ZrC-W Composites

2008 ◽  
Vol 368-372 ◽  
pp. 1764-1766 ◽  
Author(s):  
Yu Jin Wang ◽  
Lei Chen ◽  
Tai Quan Zhang ◽  
Yu Zhou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Sintering Behavior ◽  
Hot Press ◽  
Sintering Additive ◽  
Microstructure And Mechanical Properties ◽  
Hot Press Sintering

The ZrC-W composites with iron as sintering additive were fabricated by hot-press sintering. The densification, microstructure and mechanical properties of the composites were investigated. The incorporation of Fe beneficially promotes the densification of ZrC-W composites. The relative density of the composite sintered at 1900°C can attain 95.3%. W2C phase is also found in the ZrC-W composite sintered at 1700°C. The content of W2C decreases with the increase of sintering temperature. However, W2C phase is not identified in the composite sintered at 1900°C. The flexural strength and fracture toughness of the composites are strongly dependent on sintering temperature. The flexural strength and fracture toughness of ZrC-W composite sintered at optimized temperature of 1800°C are 438 MPa and 3.99 MPa·m1/2, respectively.

Mechanical Properties and Machinability of Si3N4/hBN Composites Prepared by Pressureless Sintering

2006 ◽  
Vol 510-511 ◽  
pp. 1014-1017 ◽  
Author(s):  
Won Seung Cho ◽  
Ki Ju Lee ◽  
Myeong Woo Cho ◽  
Jae Hyung Lee ◽  
Woon Suk Hwang
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Ceramic Composites ◽  
Pressureless Sintering ◽  
Si3n4 Ceramic ◽  
Cutting Resistance ◽  
Axis Parallel ◽  
Si3n4 Ceramics

The effects of hBN content on microstructure, mechanical properties, and machinability of the pressureless-sintered Si3N4 ceramics were investigated. Flexural strength, Young’s modulus, and hardness decreased with increasing h-BN content. The mechanical properties are decreased mainly because of increased porosity of composite, and the much lower Young's modulus of BN compared to that of Si3N4. Pressureless-sintered Si3N4/hBN composites exhibit strong texture of BN grains oriented with the c-axis parallel to the cold-pressing direction. Cutting resistance of Si3N4 ceramic composites with more than 10 vol% hBN decreased with increasing hBN content, demonstrating a good machinability of the composites. The residual pores can be attributed to improved machinability of pessureless-sintered Si3N4-BN composite.

Microstructure and Mechanical Properties of MoSi2 Coating Deposited on Mo Substrate by Hot Dipping Processes

2019 ◽  
Vol 14 (12) ◽  
pp. 1680-1685 ◽  
Author(s):  
Yingyi Zhang ◽  
Shahid Hussain ◽  
Kun Cui ◽  
Tao Fu ◽  
Jie Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Important Influence ◽  
Strength Increase ◽  
Average Hardness ◽  
Microstructure And Mechanical Properties ◽  
Dipping Temperature ◽  
Mosi2 Coating ◽  
Dipping Process ◽  
Dipping Time

MoSi2 coating was deposited on Mo substrate by a hot dipping process within the silicon bath. The effects of the hot dipping temperature and time on the thickness and mechanical properties of MoSi2 coating have been investigated. The results indicated that the average hardness of MoSi2 coating is only 209.15 MPa, and the average flexural strength is 873.63 MPa. Therefore, the MoSi2 coating deposited on Mo substrate exhibit better mechanical properties than monolithic MoSi2 and MoSi2 -based composites. In addition, the hot dipping processes have an important influence on mechanical properties. The hardness and flexural strength decrease sharply with increasing hot dipping temperature, then increases slightly on increasing hot dipping temperature. Meanwhile, the hardness and flexural strength increase sharply with increasing hot-dipping time.

Microstructure and properties of pressureless sintered ZrC-based materials

2008 ◽  
Vol 23 (7) ◽  
pp. 1882-1889 ◽  
Author(s):  
Laura Silvestroni ◽  
Diletta Sciti
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Flexural Strength ◽  
Room Temperature ◽  
Pressureless Sintering ◽  
Secondary Phases ◽  
Sintering Aid ◽  
Mean Particle Size ◽  
Dense Bodies ◽  
Similar Materials

ZrC-based composites were produced by pressureless sintering thanks to the addition of MoSi2 as sintering aid. After preliminary tests, a baseline ZrC material and two mixed ZrC–HfC and ZrC–ZrB2 composites with 20 vol% MoSi2 were densified at 1900 to 1950 °C reaching final relative densities of 96%–98%. Mean particle size of the dense bodies ranged from 5 to 9 μm. Secondary phases were found to form during sintering, such as SiC and Zr–Mo–Si-based compounds. Room-temperature mechanical properties were in the range of the values reported in the literature for similar materials densified by pressure-assisted techniques. The flexural strength was tested at room temperature, 1200 and 1500 °C.

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