scholarly journals Microstructure and Mechanical Properties of TiN–TiB2–hBN Composites Fabricated by Reactive Hot Pressing Using TiN–B Mixture

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7198
Author(s):  
Qianglong He ◽  
Tian Tian ◽  
Shi Tian ◽  
Wenchao Guo ◽  
Yunwei Shi ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Hot Pressing ◽  
Bending Strength ◽  
Raw Materials ◽  
Ceramic Composites ◽  
Structural Defects ◽  
Highly Active ◽  
Pull Out ◽  
Uniform Dispersion ◽  
Reactive Hot Pressing

In this study, TiN–TiB2–hBN composite ceramics were prepared via reactive hot pressing using TiN and amorphous B powders as raw materials. Different sintering temperatures and composition ratios were studied. The results show that the 70 vol% TiN–17.6 vol% TiB2–12.4 vol% hBN ceramic composites obtained ideal comprehensive properties at 1600 °C. The relative density, Vickers hardness, bending strength, and fracture toughness were 99%, 11 GPa, 521 MPa, and 4.22 MPa·m1/2, respectively. Densification was promoted by the highly active reaction product TiB2, and the structural defects formed in the grains. Meanwhile, the good interfacial bonding between TiN and TiB2 grains and the uniform dispersion of ultrafine hBN in the matrix contributed to the excellent bending strength. Moreover, the toughening mechanism of crack deflection and grain pull-out improved the fracture toughness.

Reactive Synthesis and Mechanical Properties of ZrB2-SiC-ZrC Composites

2008 ◽  
Vol 368-372 ◽  
pp. 1758-1760 ◽  
Author(s):  
Wen Wen Wu ◽  
Guo Jun Zhang ◽  
Yan Mei Kan ◽  
Pei Ling Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Raw Materials ◽  
Reactive Synthesis ◽  
Reactive Hot Pressing

ZrB2-SiC based composites with 0,5 and 15 vol% addition of ZrC were synthesized via reactive hot pressing at 1800°C using Zr, Si and B4C as raw materials. The mechanical properties of the composites were investigated. The composite of ZSC15 that contained 15 vol% of ZrC has the highest hardness. ZSC5 with 5 vol% of ZrC owns a most homogenous microstructure and the highest fracture toughness and flexural strength.

The Mechanical Properties of AlN/BN Laminated Ceramic Composites

2008 ◽  
Vol 569 ◽  
pp. 97-100 ◽  
Author(s):  
Tao Zhang ◽  
Hai Yun Jin ◽  
Yong Ian Wang ◽  
Zhi Hao Jin
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Hot Pressing ◽  
Bending Strength ◽  
Tape Casting ◽  
Ceramic Composites ◽  
Crack Deflection ◽  
Weak Interface ◽  
Parallel Propagation ◽  
Monolithic Ceramics

AlN/BN laminated ceramic composites were fabricated using tape-casting and hot-pressing by optimizing the designs of the structure and geometry of AlN/BN laminated ceramic composites. The results showed that the fracture toughness and bending strength for AlN/BN laminated ceramics reached 9.1MPa.m1/2 and 378MPa respectively. The fracture toughness is two times higher than that of AlN monolithic ceramics. The excellent fracture toughness of AlN/BN laminated ceramics could be mainly attributed to crack deflection, delaminating, branching, parallel propagation and crack laminate pilling out at the AlN/BN weak interface.

scholarly journals Fabrication and mechanical properties of self-toughening ZrB2–SiC composites from in-situ reaction

2019 ◽  
Vol 8 (4) ◽  
pp. 527-536 ◽  
Author(s):  
Zhaofu Zhang ◽  
Jianjun Sha ◽  
Yufei Zu ◽  
Jixiang Dai ◽  
Yingjun Liu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Hot Pressing ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Microstructure Observation ◽  
Pull Out ◽  
Sic Composites ◽  
Reactive Hot Pressing

AbstractSelf-toughening ZrB2–SiC based composites are fabricated by in-situ reactive hot pressing. The effect of sintering additive content on the microstructure and mechanical properties of the composites is investigated. Microstructure observation found that the in-situ reactive hot pressing could promote the anisotropic growth of ZrB2 grains and the formation of interlocking microstructure. Such microstructure could improve the mechanical properties, especially, for the fracture toughness. The improved mechanical properties could be attributed to the self-toughening structure related to the ZrB2 platelets and the formed interlocking microstructure, which could trigger various toughening mechanisms such as grain pull-out, crack bridging, crack deflection, and crack branching, providing the main contribution to the high fracture toughness.

Effect of Sintering Pressure on Mechanical Properties of BN-Si3N4 Ceramic Composites Prepared by Spark Plasma Sintering

2016 ◽  
Vol 697 ◽  
pp. 188-192
Author(s):  
Jia Xin An ◽  
Wen Dong Xue ◽  
Feng Rui Zhai ◽  
Ruo Meng Xu ◽  
Jia Lin Sun
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
Raw Materials ◽  
Ceramic Composites ◽  
Composite Ceramics ◽  
Plasma Sintering ◽  
Spark Plasma

BN-Si3N4 composite ceramic wave-transparent materials with excellent mechanical properties were prepared by spark plasma sintering (SPS) using h-BN and α-Si3N4 powders as raw materials, Al2O3 and Y2O3 as sintering aids. The influence of sintering pressure on density and mechanical properties of BN-Si3N4 composite ceramics were studied. The phases were observed by X-ray diffraction (XRD), and the microstructures were identified by scanning electron microscopy (SEM). The results showed that with the sintering pressure increases, the relative density, bending strength and fracture toughness of the composite ceramics were significantly increased, and the porosity decreased rapidly. The effects of pressure on the properties of the composite ceramics was not significant at >40MPa, so 40MPa is optimal for the composite ceramics to gain good overall performance, i.e. the relative density was 89.1%, the porosity was 2.3%, the bending strength reached 215.4 MPa, and the fracture toughness was 3.1/MPa·m1/2.

Microstructure and Properties of Graphite Embedded SiC Composite by Coating Method

2010 ◽  
Vol 105-106 ◽  
pp. 855-858 ◽  
Author(s):  
Liang Yu ◽  
Jing Zhao ◽  
Xin Yan Yue ◽  
Jing Yang Li ◽  
Hong Qiang Ru
Keyword(s):  
Fracture Toughness ◽  
Hot Pressing ◽  
Graphite Particle ◽  
Bending Strength ◽  
Raw Materials ◽  
Electron Energy Spectrum ◽  
Apparent Porosity ◽  
Particle Content ◽  
Coating Method ◽  
Hot Pressing Sintering

Gp/SiC composite was prepared with electrode graphite particle and SiC powders as the raw materials, using coating process and hot-pressing sintering technology. The microstructure and phase constitution was measured by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron energy spectrum (EDS). It was found that the graphite cores are embedded in the SiC matrix as the islands. The apparent porosity increased, density decreased, with graphite particle content increasing, the bending strength decreased, however, fracture toughness increased with the graphite particle content increasing. Increasing hot-pressing sintering temperature imparted Gp/SiC composite characteristic behaviors of better mechanical strength. The apparent porosity, bulk density, bending strength, fracture toughness were 4.0%, 2.58 g•cm-3, 50 MPa, 6.3 MPa•m1/2, respectively, with the size 200 μm graphite core at 2050 °C, while the volume rate of SiC and graphite was 6:4.

In Situ Preparation and Mechanical Properties of (ZrB2+ZrC)/Zr3[Al(Si)]4C6 Composites

2014 ◽  
Vol 602-603 ◽  
pp. 438-442
Author(s):  
Lei Yu ◽  
Jian Yang ◽  
Tai Qiu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
Raw Materials ◽  
Linear Increase ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Uniform Microstructure

Fully dense (ZrB2+ZrC)/Zr3[Al (Si)]4C6 composites with ZrB2 content varying from 0 to 15 vol.% and fixed ZrC content of 10 vol.% were successfully prepared by in situ hot-pressing in Ar atmosphere using ZrH2, Al, Si, C and B4C as raw materials. With the increase of ZrB2 content, both the bending strength and fracture toughness of the composites increase and then decrease. The synergistic action of ZrB2 and ZrC as reinforcements shows significant strengthening and toughing effect to the Zr3[Al (Si)]4C6 matrix. The composite with 10 vol.% ZrB2 shows the optimal mechanical properties: 516 MPa for bending strength and 6.52 MPa·m1/2 for fracture toughness. With the increase of ZrB2 content, the Vickers hardness of the composites shows a near-linear increase from 15.3 GPa to 16.7 GPa. The strengthening and toughening effect can be ascribed to the unique mechanical properties of ZrB2 and ZrC reinforcements, the differences in coefficient of thermal expansion and modulus between them and Zr3[Al (Si)]4C6 matrix, fine grain strengthening and uniform microstructure derived by the in situ synthesis reaction.

scholarly journals Fabrication of Ti3AlC2/Al2O3 nanocomposite by a novel method

2011 ◽  
Vol 43 (3) ◽  
pp. 289-294 ◽  
Author(s):  
J. Zhu ◽  
L. Ye ◽  
F. Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Hot Pressing ◽  
Reaction Path ◽  
Raw Materials ◽  
High Energy ◽  
Good Combination ◽  
High Energy Milling ◽  
Al2o3 Composite ◽  
Novel Method

A Ti3AlC2/Al2O3 nanocomposite was synthesized using Ti, Al, C and TiO2 as raw materials by a novel combination of high-energy milling and hot pressing. The reaction path of the 3Ti-8C-16Al-9TiO2 mixture of powders was investigated, and the results show that the transitional phases TiC, TixAly and Al2O3 are formed in high-energy milling first, and then TixAly is transformed to the TiAl phase during the hot pressing. Finally, a reaction between TiC and TiAl occurs to produce Ti3AlC2 and the nanosized Ti3AlC2/Al2O3 composite is synthesized. The Ti3AlC2/Al2O3 composite possessed a good combination of mechanical properties with a hardness of 6.0 GPa, a flexural strength of 600 MPa, and a fracture toughness (K1C) of 5.8 MPa?m1/2. The strengthening and toughening mechanisms were also discussed.

Fabrication of Carbon Nanotube Reinforced Boron Carbide Composite by Hot-Pressing Following Extrusion Molding

2014 ◽  
Vol 616 ◽  
pp. 27-31 ◽  
Author(s):  
Tomohiro Kobayashi ◽  
Katsumi Yoshida ◽  
Toyohiko Yano
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Boron Carbide ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Bending Strength ◽  
Extrusion Direction ◽  
Sem Observation

The CNT/B4C composite with Al2O3 additive was fabricated by hot-pressing following extrusion molding of a CNT/B4C paste, and mechanical properties of the obtained composite were investigated. Many CNTs in the composite aligned along the extrusion direction from SEM observation. 3-points bending strength of the composite was slightly lower than that of the monolithic B4C. Elastic modulus and Vickers hardness of the composite drastically decreased with CNT addition. Fracture toughness of the composite was higher than that of the monolithic B4C.

Effect of BN Short Fiber Content on Mechanical Properties of ZrB2-SiC UHTCs

2012 ◽  
Vol 512-515 ◽  
pp. 706-709 ◽  
Author(s):  
Chang Ling Zhou ◽  
Yan Yan Wang ◽  
Zhi Qiang Cheng ◽  
Chong Hai Wang ◽  
Rui Xiang Liu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Ceramic Composites ◽  
Short Fiber ◽  
Hot Pressing Sintering ◽  
Scanning Electron

ZrB2-20%volSiC ceramic composites with different volume of BN short fiber were fabricated by the hot-pressing sintering under 2000°C. The content of BN short fiber changed from 0 to 15vol%. The density, flexural strength, fracture toughness and thermal expansions coefficient were studied. The microstructures of the samples were observed by scanning electron microscopy. The results show that the introducing of BN short fiber into the ZrB2-20%volSiC lead to a serious of change to the mechanical properties of the ceramic. When the content of the BN short fiber is 10vol%, the flexural strength and fracture toughness reach 422.1MPa and 6.15 MPa•m 1/2 respectively. And the mechanism of the increasing toughness was studied.

scholarly journals The effect of various Co contents on the microstructure and properties of Ti(C,N)-TiB2-Co cermets prepared in situ via reactive hot pressing

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402092571
Author(s):  
Xianrui Zhao ◽  
Ze Yu ◽  
Dunwen Zuo ◽  
Qintao Li ◽  
Mengxian Zhang ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Relative Density ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Hardness Test ◽  
Reactive Hot Pressing ◽  
Compacting Pressure ◽  
Vickers Hardness Test ◽  
Scanning Electron

Ti(C,N)-TiB2-Co cermets were in situ synthesized, via reactive hot pressing from the Co-Ti-C-BN system, with a Co content ranging from 6 to 22 wt%. The microstructure, relative density, hardness, and fracture toughness of the sintered compacts was investigated by light microscopy, scanning electron microscopy, ceramic densitometry, and Vickers hardness test. The investigations indicate that during hot pressing (compacting pressure = 30 MPa), when the Co content is 14–22 wt%, the metal binder is extruded. Co and Ti are included in the extrudate, breaking the original ratio and deteriorating the properties of the sintered products. As the Co content increases from 6 wt% to 12 wt%, the porosity increases, and the relative density increases from 97.2% to 99.5%. The fracture toughness increases from 6.1 to 6.8 MPa m1/2. The Vickers hardness first increases from 1897 HV10 to the maximum 1960 HV10 and then decreases slightly to 1945 HV10.

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