Effect of B4C on the Mechanical Properties and Microstructure of ZrB2-SiC Based Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 218-221 ◽  
Author(s):  
Xuan Liu ◽  
Qiang Xu ◽  
Shi Zhen Zhu

ZrB2-SiC-B4C is sintered at 1700°C by spark plasma sintering process. The effect of B4C content on the mechanical properties and microstructure of ZrB2-SiC based ceramics is studied. The results show that, with the content of B4C increases, the relative density and room-temperature strength decrease in the ZrB2-SiC-B4C composite. The fracture toughness rises at first and then falls down. The high temperature strength increases.

1985 ◽  
Vol 58 ◽  
Author(s):  
A. Brown ◽  
D. Raybould

ABSTRACTIn recent years, interest in high temperature aluminum alloys has increased. However, nearly all the data available is for simple extrusions. This paper looks at the properties of sheet made from a rapidly solidified Al-10Fe-2.5V-2Si alloy. The sheet is made by direct forging followed by hot rolling, this is readily scalable, so allowing the production of large sheet. The room temperature strength and fracture toughness of the sheet are comparable to those of 2014-T6. The high temperature strength, specific stiffness and corrosion resistance are excellent. Recently, improved thermomechanical processing and new alloys have allowed higher strengths and fracture toughness values to be obtained.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5221
Author(s):  
Jaroslaw Wozniak ◽  
Mateusz Petrus ◽  
Tomasz Cygan ◽  
Artur Lachowski ◽  
Bogusława Adamczyk-Cieślak ◽  
...  

This paper discusses the influence of Ti3C2 (MXene) addition on silicon nitride and its impact on the microstructure and mechanical properties of the latter. Composites were prepared through powder processing and sintered using the spark plasma sintering (SPS) technic. Relative density, hardness and fracture toughness, were analyzed. The highest fracture toughness at 5.3 MPa·m1/2 and the highest hardness at HV5 2217 were achieved for 0.7 and 2 wt.% Ti3C2, respectively. Moreover, the formation of the Si2N2O phase was observed as a result of both the MXene addition and the preservation of the α-Si3N4→β-Si3N4 phase transformation during the sintering process.


2014 ◽  
Vol 602-603 ◽  
pp. 380-383
Author(s):  
Chao He ◽  
Xiao Fei Shi ◽  
Xin Yan Yue ◽  
Jiang Jun Wang ◽  
Hong Qiang Ru

SiAlON-cBN composites with different contents of cBN were consolidated by spark plasma sintering (SPS) at 1450°C using Y2O3, B2O3 and Al as additives. The effect of cBN content on the density, phase compositions, microstructures and mechanical properties of β-SiAlON-cBN composites was investigated. With increasing the cBN content, the density and hardness of β-SiAlON-cBN composites decreased. Fracture toughness could increase thanks to the crack deflection resulted from the cBN particles. For β-SiAlON-10 wt% cBN composites, the optimum hardness and highest relative density were 13 GPa and 96.4 %, respectively. For β-SiAlON-40 wt% cBN composites, the highest fracture toughness was KIC = 5.3 MPa∙m1/2.


2006 ◽  
Vol 21 (6) ◽  
pp. 1460-1466 ◽  
Author(s):  
Diletta Sciti ◽  
Laura Silvestroni ◽  
Alida Bellosi

HfB2–15 vol% MoSi2 composites were produced from powder mixtures and densified through different techniques, namely hot pressing and spark plasma sintering. Dense materials were obtained at 1900 °C by hot pressing and at 1750 °C by spark plasma sintering. Microstructure and mechanical properties were compared. The most relevant result was for high-temperature strength: independent of the processing technique, the flexural strength in air at 1500 °C was higher than 500 MPa.


2009 ◽  
Vol 620-622 ◽  
pp. 395-398 ◽  
Author(s):  
Fan Zhang ◽  
Zheng Yi Fu ◽  
Jin Yong Zhang ◽  
Hao Wang ◽  
Wei Min Wang ◽  
...  

The densification behavior and mechanical properties of B4C by SPS at 1900°C for 2 min with additions of Al2O3 up to 10 wt.% were investigated. When the additional of 10 wt.%, the relative density was 99% and the hardness went to 33GPa. Sinterability was greatly improved by the addition of a small amount of Al2O3, and the SPS technology with high hearing rate is particularly attractive for prepare of poorly sinterable materials. The improvement was attributed to the enhanced mobility of elements through the Al2O3 near the melting temperature. As a result of this improvement in the density, mechanical properties, such as hardness, fracture toughness, increased remarkably.


Author(s):  
Shufeng Li ◽  
Hiroshi Izui ◽  
Michiharu Okano

This paper discusses the dependence of the mechanical properties and microstructure of sintered hydroxyapatite (HA) on the sintering temperature and pressure. A set of specimens was prepared from as-received HA powder and sintered by using a spark plasma sintering (SPS) process. The sintering pressures were set at 22.3MPa, 44.6MPa, and 66.9MPa, and sintering was performed in the temperature range from 800°Cto1000°C at each pressure. Mechanisms underlying the interrelated temperature-mechanical and pressure-mechanical properties of dense HA were investigated. The effects of temperature and pressure on the flexural strength, Young’s modulus, fracture toughness, relative density, activation energy, phase stability, and microstructure were assessed. The relative density and grain size increased with an increase in the temperature. The flexural strength and Young’s modulus increased with an increase in the temperature, giving maximum values of 131.5MPa and 75.6GPa, respectively, at a critical temperature of 950°C and 44.6MPa, and the fracture toughness was 1.4MPam1∕2 at 1000°C at 44.6MPa. Increasing the sintering pressure led to acceleration of the densification of HA.


2010 ◽  
Vol 163-167 ◽  
pp. 2949-2952
Author(s):  
Jian Qing Qian ◽  
Ji Ping Chen ◽  
Bao Qiao Wu ◽  
Jie Ca Wu

The fire-resistant hot-rolled H-beam steel is the newly developed structure material. The development situation of the fire-resistant H-beam steel is briefly introduced. The chemical composition, microstructure, room temperature and high temperature mechanical properties and weldability of several batches of the developed domestic fire-resistant hot-rolled H-beam steels are comprehensively analyzed. The results show that the newly developed hot-rolled fire-resistant H-beam steel has very high room temperature strength, certain high temperature strength, good welding performance, but the toughness needs to be further improved. The performance of web and flange of H-beam steel has large gap.


2016 ◽  
Vol 697 ◽  
pp. 188-192
Author(s):  
Jia Xin An ◽  
Wen Dong Xue ◽  
Feng Rui Zhai ◽  
Ruo Meng Xu ◽  
Jia Lin Sun

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.


2006 ◽  
Vol 306-308 ◽  
pp. 941-946
Author(s):  
Sheng Wu Wang ◽  
Tatsuo Tabaru ◽  
Hisatoshi Hirai ◽  
Hideto Ueno

Nb-base in-situ composites with the base composition of Nb-18Si-2HfC were prepared by conventional arc-melting. Their microstructures and mechanical properties, such as high-temperature strength and room temperature fracture toughness, were investigated to elucidate the effects of Re alloying. The in-situ composites predominantly have eutectic microstructures consisting of an Nb solid solution (NbSS) and Nb5Si3. The compressive strength increased with the increasing Re contents at 1470K and not at 1670 K. The strengthening effect observed at 1470 K is higher than that by W and Mo. Re alloying of about 2 % is valuable for improving both the high temperature strength and room temperature fracture toughness of Nb-18Si-2HfC base materials.


2010 ◽  
Vol 434-435 ◽  
pp. 165-168 ◽  
Author(s):  
Chun Feng Hu ◽  
Yoshio Sakka ◽  
Tetsuo Uchikoshi ◽  
Tohru Suzuki ◽  
Byung Koog Jang ◽  
...  

Dense bulk ZrB2 ceramic was synthesized by mechanical alloying (MA) and followed spark plasma sintering (SPS) using zirconium and boron as initial materials. It was found that MA process was effective to fragment the coarse metal zirconium particles from 45 m to less than 1 m within 20 hours. In comparison with the commercial ZrB2 powder, the as-obtained zirconium and boron mixture powders showed higher sinterability. When the sintering was carried out at 1800oC, the relative density of synthesized ZrB2 samples using mixture powder was above 95%, higher than that of ZrB2 sample prepared using commercial powder (73%). Vickers hardness of those ZrB2 samples was at the same level of 15 GPa. However, the fracture toughness of ZrB2 samples seemed to depend on the heating rate of the SPS process. Corresponding to the heating rates of 10, 50, and 100oC/min, the fracture toughness of as-prepared ZrB2 samples were 3.83, 3.19, and 2.74 MPa•m1/2, respectively.


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