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

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.

2012 ◽  
Vol 512-515 ◽  
pp. 706-709 ◽  
Author(s):  
Chang Ling Zhou ◽  
Yan Yan Wang ◽  
Zhi Qiang Cheng ◽  
Chong Hai Wang ◽  
Rui Xiang Liu

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.


2012 ◽  
Vol 05 ◽  
pp. 551-558 ◽  
Author(s):  
A. RAHIMNEZHAD YAZDI ◽  
H.R. BAHARVANDI ◽  
H. ABDIZADEH ◽  
N. EHSANI

In this study Al 2 O 3- SiC nanocomposites have been fabricated by mixing of alumina and silicon carbide nano powders, followed by hot pressing at 1700°C. The mechanical properties and fracture mode of Al 2 O 3- SiC nanocomposites containing different volume fractions (5, 10 and 15%) of nano scale SiC particles were investigated and compared with those of alumina. Al 2 O 3- SiC powders were prepared by planetary milling in isopropanol. Fracture mode of specimens was investigated by means of scanning electron microscopy. Nanocomposites were tougher than alumina when they were hot pressed at the same temperature, and the values of nanocomposite's flexural strength and hardness were higher than those of alumina. Flexural strength, hardness and fracture toughness of the nanocomposites increase by increasing the volume percent of SiC up to 10% and then decrease slightly. The Scanning electron microscopy observations showed that fracture mode changes from intergranular for alumina to transgranular for nanocomposites. Finally X-ray diffraction analysis couldn't detect any chemical reactions between Al 2 O 3 and SiC particles.


2015 ◽  
Vol 655 ◽  
pp. 68-71
Author(s):  
Yuan Yuan Zhu ◽  
Jin Jia ◽  
Ai Guo Zhou ◽  
Li Bo Wang ◽  
Qing Feng Zan

Layered ternary compounds Ti3SiC2combines attractive properties of both ceramics and metals, and has been suggested for potential engineering applications. Near-fully dense Ti3SiC2bulks were sintered from commercial Ti3SiC2powders by hot press at 1350°C-1600°C for 60-120min under Ar atmosphere in this paper. The phase compositions and morphology of the as-prepared samples were evaluated by X-Ray diffraction (XRD) and scanning electron microscopy (SEM). And the mechanical properties were measured by Three-Point bending method. It was found that the Ti3SiC2had only a little of decomposition at sintering temperature above 1350°C. And effects of sintering temperature and holding time on the morphology of the bulk Ti3SiC2are not obvious. Relative density of 98% and flexural strength of 480MPa were obtained for the Ti3SiC2samples sintered at 30MPa and 1400°C for 90min.


2012 ◽  
Vol 512-515 ◽  
pp. 932-935
Author(s):  
Ying Peng ◽  
Zhi Jian Peng ◽  
Xiao Yong Ren ◽  
Hui Yong Rong ◽  
Cheng Biao Wang ◽  
...  

TiCN-based cermets with different amounts of SiC nano-whiskers were prepared by spark plasma sintering. The microstructure and mechanical properties of the as-prepared cermets were investigated. X-ray diffraction revealed that there were no SiC peaks detected, turning out some peaks of new carbide and silicate hard phases. Scanning electron microscopy indicated that there were more and more pores in the cermets with increasing amount of SiC whisker added, and the fracture mechanism of the cermets was mainly inter-granular fracture. With increasing addition amount of nano-SiC whisker, the hardness and flexural strength of the cermets increased first and decreased then, presenting the highest hardness (2170 HV) and flexural strength (750 MPa), respectively, when the addition content of nano-whiskers is 2.5 wt%.


2013 ◽  
Vol 745-746 ◽  
pp. 652-656
Author(s):  
Yang Miao ◽  
Wen Liu ◽  
Lei Zhuang ◽  
Hui Ling Cheng ◽  
Qing Sen Meng

In this paper, Mechanical alloying (MA) and field activated and pressure assisted synthesis (FAPAS) were used for preparing the ultra-hard, super-abrasive AlMgB14-xTiB2 composite ceramic. The samples were fabricated at 1500 under a pressure of 60 MPa. The microstructures and compositions of samples were observed and determined by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD). It was indicated that addition of TiB2 was effective for increasing both quantities. A maximum Vichers hardness of 38.5GPa and a fracture toughness of 3.85MPam½ of AlMgB14 reinforced with 70 wt.% of TiB2 were achieved. Abrasion wear tests showed that adding TiB2 would improve the wearability obviously.


2018 ◽  
Vol 912 ◽  
pp. 124-129
Author(s):  
Caio Marcelo Felbinger Azevedo Cossu ◽  
Manuel Fellipe Rodrigues Pais Alves ◽  
Luiz Cláudio Lemos de Assis ◽  
Roberto de Oliveira Magnago ◽  
José Vitor Candido de Souza ◽  
...  

The objective of this work was the development of Al2O3-ZrO2 ceramic composites using recycled-source of ZrO2(Y2O3). Al2O3 powder was mixed with different proportions of ZrO2(Y2O3) arising from pre-sintered blocks used in dental prostheses manufacturing. The mixtures containing 3wt% to 15wt% ZrO2(Y2O3) were uniaxially pressed at 80MPa and sintered at 1600°C-2h. Raw materials and sintered samples were characterized by X-ray diffraction, scanning electron microscopy (SEM), relative density, hardness and fracture toughness. The results of X-ray diffraction showed α-Al2O3 and tetragonal-ZrO2 as crystalline phases after sintering. Furthermore, the relative density in all compositions was higher than 95%. The samples presented Vickers hardness and fracture toughness higher than 1300HV and 3.5MPa. m1/2, respectively.


2006 ◽  
Vol 309-311 ◽  
pp. 45-48 ◽  
Author(s):  
Faik N. Oktar ◽  
H. Aydin ◽  
Gültekin Göller ◽  
Simeon Agathopoulos ◽  
G. Rocha ◽  
...  

The properties of sintered hydroxyapatite (HA), obtained from bovine femoral shafts via calcination method, were investigated utilizing scanning electron microscopy (SEM) and X-ray diffraction analysis together with measurements of microhardness, density, and compression strength. The production of HA from natural sources is preferred due to money and time saving reasons. The results indicate the new HA materials as promissing in biomedicine, since similar mechanical behaviour was obtained with previous studies.


2019 ◽  
Vol 51 (2) ◽  
pp. 175-187
Author(s):  
Gabriela Téllez-Arias ◽  
José Miranda-Hernández ◽  
Oscar Olea-Mejía ◽  
J. Lemus-Ruiz ◽  
Eduardo Terrés

The objective of this work was to study the influence of the addition of silver nanoparticles in the microstructure of mullite at two different temperatures of sintering (1500 and 1600?C), in order to decrease the porosity and increase the density as well better the hardness and fracture toughness. The microstructural characteristics were studied by scanning electron microscopy, confocal scanning microscopy and X-ray diffraction. Mullite/Ag cermets with homogenous microstructure were and a fracture toughness of 2.42 MP??m1/2.


2010 ◽  
Vol 658 ◽  
pp. 428-431
Author(s):  
Bhupendra Joshi ◽  
Hyun Hwi Lee ◽  
Seung Ho Kim ◽  
Zheng Yi Fu ◽  
Koichi Niihara ◽  
...  

The addition of h- BN to a polycrystalline Si3N4 was to increase the fracture toughness and other mechanical properties such as flexural strength and hardness of the material. The hot pressed samples were prepared from the mixture of α-Si3N4, AlN, MgO and h-BN. The composite contained from 0 to 2 wt.% BN powder with sintering aids (9% AlN + 3% MgO). The transparency, mechanical properties and microstructure of hot pressed polycrystalline Si3N4-BN composite materials were investigated by UV/VIS spectrophotometer, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The transparency decreased with increasing the content of h-BN into Si3N4.


2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.


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