The Effects of Codoping Y2O3 on MgO Doped Spark Plasma Sintered Al2O3

2010 ◽  
Vol 63 ◽  
pp. 74-78
Author(s):  
Burcu Apak ◽  
Gültekin Göller ◽  
Yücel Onüralp ◽  
Filiz Çinar Şahin
Keyword(s):  
Fracture Toughness ◽  
High Pressure ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Vacuum Atmosphere ◽  
Spark Plasma ◽  
Scanning Electron ◽  
Nanocrystalline Alumina

Nanocrystalline alumina (Al2O3) powders were sintered by Spark Plasma Sintering (SPS) method in a vacuum atmosphere to obtain highly dense and fine grained final ceramic products. In the first section of experiments, 0.4 % wt MgO doped and 0.4 wt % Y2O3 doped Al2O3 were sintered at high temperatures and under high pressure with a SPS system. Later sintering procedures were carried out with codoping Y2O3 with the cathodic ratio of 0.4 wt % in order to investigate dopant effects on spark plasma sintered alumina. The microstructures of all samples were observed using scanning electron microscope and the properties such as density, hardness and fracture toughness were examined.

Processing of ZrC-TiC Composites by SPS

2016 ◽  
Vol 674 ◽  
pp. 94-99 ◽  
Author(s):  
Der Liang Yung ◽  
Irina Hussainova ◽  
M.A. Rodriguez ◽  
Rainer Traksmaa
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Vickers Hardness ◽  
Free Carbon ◽  
Sem Images ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Scanning Electron

ZrC – TiC composites containing 20 wt.% TiC, along with and without 0.2 wt.% graphite were prepared by spark plasma sintering (SPS) at temperatures between 1600 - 1900 °C for 10 min under pressure up to 100 MPa. The addition of free carbon tends to reduce the appearance of tertiary phases in the microstructure according to scanning electron microscope (SEM) images. However, free carbon also reduced the mechanical properties of Vickers’ hardness and fracture toughness of the composites. SPS data showed when pressure was increased to 100 MPa, evident grain growth started to occur at a temperature as low as 1600 °C resulting in relative density > 100%. Samples produced at 1600 °C, but with maximum allowable pressure according to the SPS machine, yielded samples with greater hardness and fracture toughness compared to samples produced at 1900 °C.

scholarly journals X-ray spectral microanalysis of W-Ni-Fe pseudoalloy obtained from electroerosive powders

2021 ◽  
Vol 344 ◽  
pp. 01001
Author(s):  
Evgeny V. Ageev ◽  
Oxana G. Loktionova ◽  
Sergey V. Pikalov ◽  
Valeryi I. Kolmykov
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Spark Plasma Sintering ◽  
Transverse Section ◽  
Sample Surface ◽  
Sintered Sample ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Scanning Electron

The results of X-ray spectral microanalysis of W-Ni-Fe pseudo-alloy, obtained from electroerosive powders, are presented. Consolidation of the obtained electroerosive powders was carried out by the method of spark plasma sintering using the SPS 25-10 spark plasma sintering system. Using an EDAX energy-dispersive X-ray analyzer built into a Quanta 600 FEG scanning electron microscope, characteristic X-ray spectra were obtained at various points on the sample surface and along a transverse section. As a result of the study, it was found that on the surface of the investigated sintered sample, tungsten, nickel and iron are contained as the main elements, and oxygen, copper and chromium are also present in small amounts.

Scanning acoustic microscopy investigation of melted collagen in thermoplastic leather

1999 ◽  
Vol 14 (6) ◽  
pp. 2446-2448
Author(s):  
A. Wyler ◽  
G. Golan
Keyword(s):  
High Pressure ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
Acoustic Microscope ◽  
Microscopy Investigation ◽  
The Matrix ◽  
Scanning Acoustic Microscope ◽  
Scanning Electron

A scanning acoustic microscope (SAM) has been used to investigate the structure of thermoplastic leather. This material is formed by pressing fibers of leather under high pressure and moderate temperature. The result is a matrix from transformed, melted fibers in which leftover fibers act as reinforcement. Unlike the scanning electron microscope (SEM), the SAM is able to distinguish between completely and incompletely transformed fibers and also to penetrate the material beneath the surface. The results show that the matrix is built as a domain structure. The advantages of the SAM over the SEM for organic materials are indicated.

RESEARCH OF THE NANOMETER HELICOIDAL LAYUP OF RUFESCENS SHELL

2005 ◽  
Vol 19 (01n03) ◽  
pp. 577-579
Author(s):  
BIN CHEN ◽  
XIANG-HE PENG ◽  
JING-HONG FAN ◽  
WAN-LU WANG
Keyword(s):  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Ceramic Composite ◽  
Organic Matrix ◽  
Nanometer Scale ◽  
Pullout Force ◽  
Sem Observation ◽  
Scanning Electron

A scanning electron microscope (SEM) observation on a Rufescens shell shows that the shell is a bio-ceramic composite consisting of aragonite sheets with nanometer scale and organic matrix. These nano-aragonite sheets are arranged in the shell in the form of helicoidal layup. The reason of the excellent fracture toughness of the shell is analyzed based on the maximal pullout force of the helicoidal layup of the aragonite sheets in the shell.

Microstructures, Tensile Properties and Forming Process of AZ31 Alloy Sheets

2007 ◽  
Vol 546-549 ◽  
pp. 241-244 ◽  
Author(s):  
Yun Qi Yan ◽  
H. Zhang ◽  
Q. Chen ◽  
H. Zhong ◽  
W.P. Weng
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Tensile Properties ◽  
Cell Phone ◽  
Az31 Alloy ◽  
Forming Process ◽  
Fine Grained ◽  
Forming Temperature ◽  
Scanning Electron

Rolling and punching techniques of AZ31 alloy were investigated in this paper. Various rolling experiments were carried out to make fine-grained Mg sheets. Punching tests were conducted at the temperatures range from 70 to 300 oC. The analysis revealed that there existed an excellent warm forming temperature for as-rolled AZ31 alloy. A warm deep punching tool setup using heating elements was designed and manufactured to produce the cell phone. Microstructures were observed using optical and scanning electron microscope equipped with EBSD. The textures in as-rolled and as-annealed specimens attribute to different mechanical properties along the various direction.

Effects of Nano-ZrO2 on the Microstructure and Mechanical Properties of Ti(C,N)-Based Cermet Die Materials

2010 ◽  
Vol 154-155 ◽  
pp. 1319-1323 ◽  
Author(s):  
Xing Hai Wang ◽  
Chong Hai Xu ◽  
Ming Dong Yi ◽  
Hui Fa Zhang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Flexural Strength ◽  
Weight Percent ◽  
Environmental Scanning ◽  
Microstructure And Mechanical Properties ◽  
Vacuum Atmosphere ◽  
Die Materials ◽  
Scanning Electron

In recent, the development of new die materials is one of the important topics in the field of die research. In this paper, effects of nano-ZrO2 addition on the microstructure and mechanical properties of Ti(C,N)-based cermets were studied. The newly developed Ti(C,N)-based cermet die materials with different contents of nano-ZrO2 of 0~25wt% were prepared by hot pressing technique under vacuum atmosphere at 1450°C for 30min. Moreover, the microstructure of this Ti(C,N)-based cermet die materials was observed by environmental scanning electron microscope. It indicates that the comprehensive mechanical properties can reach the optimum when the weight percent of the nano-ZrO2 is 10%. The corresponding flexural strength and fracture toughness is 967 MPa and 13.62 MPa•m1/2, respectively which is approximately 65% and 110% higher than that of the cermet without nano-ZrO2 addition. It suggests that the addition of nano-ZrO2 can improve the mechanical properties especially the fracture toughness and flexural strength of Ti(C,N)-based cermet die materials.

Helicoidal-Rounded-Hole Microstructure of Mature Shankbone

2011 ◽  
Vol 460-461 ◽  
pp. 652-655
Author(s):  
Bin Chen ◽  
Ji Luo ◽  
Quan Yuan
Keyword(s):  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Protein Matrix ◽  
Pullout Force ◽  
Sem Observation ◽  
Collagen Protein ◽  
Scanning Electron

Scanning electron microscope (SEM) observation on a mature shankbone shows that the bone is a kind of bioceramic composite consisting of hydroxyapatite sheets and collagen protein matrix. The observation also shows that there are many holes in the bone and that the hydroxyapatite sheets near by these holes helicoidally round these holes forming a kind of helicoidally-rounded-hole microstructure (HRHM). The maximum pullout force of the HRHM is investigated and compared with that of non-helicoidally-rounded-hole microstructure (NHRHM). It shows that the HRHM could markedly increase the maximum pullout force of the hydroxyapatite sheets compared to the NHRHM and therefore enhance the fracture toughness of the bone.

scholarly journals Occurrence of Sesquioxide in a Mid-Low Grade Collophane-Sedimentary Apatite Ore from Guizhou, China

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1038
Author(s):  
Jie Deng ◽  
Kecheng Zhang ◽  
Dongsheng He ◽  
Hengqin Zhao ◽  
Rachid Hakkou ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Low Grade ◽  
Carbonate Apatite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fine Grained ◽  
Mineral Liberation ◽  
Fine Grain ◽  
Scanning Electron

Checking the presence of sesquioxide (Fe2O3, Al2O3) is helpful for its removal in advance. Therefore, the occurrence of sesquioxide in a mid-low grade calcareous-siliceous collophane ore (massive carbonate-apatite, also known as francolite) from Guizhou, China was determined by X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), field emission scanning electron microscope-energy dispersive X-ray spectrometry (FESEM-EDX) and Mineral Liberation Analyzer (MLA). The results show that iron mainly occurs as pyrite FeS2, goethite FeO(OH) and as substitution within dolomite Ca(Mg,Fe)(CO3)2, while aluminum is enriched in muscovite KAl2(AlSi3O10)(OH)2 and also found in apatite (F,CO3)CaPO4 and calcite CaCO3 due to isomorphism or adsorption. All these minerals are fine-grained, among which pyrite and goethite tend to be enriched in larger particles. Intergrowth is predominant in the six minerals’ locking. Pyrite is mainly intergrown with calcite, biotite and also included in apatite and muscovite, while the monomer pyrite appears as semi-automorphic fine grain with the liberation of 56.1%. Apatite particles are mainly intergrown with quartz and calcite. Most of goethite, dolomite, muscovite and calcite form intergrowth with apatite, with contents of 21.7%, 11.1%, 19.5% and 41%, respectively. The removal of pyrite, goethite, dolomite, muscovite and calcite in the ore is the key to reduce the contents of Fe2O3 and Al2O3. In the subsequent beneficiation, the ore must be fully ground. In addition to flotation, magnetic separation can also be considered to remove part of iron in ore. For the removal of aluminum from apatite, leaching method can be considered.

Influence of SiC on the Properties of PcBN Cutting Tools Fabricated by High Pressure and High Temperature Sintering

2016 ◽  
Vol 697 ◽  
pp. 526-529 ◽  
Author(s):  
Shi Xun Zhang ◽  
Jian Li ◽  
Yao Ma ◽  
Hai Long Wang ◽  
Rui Zhang
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Electron Microscope ◽  
High Temperature ◽  
Scanning Electron Microscope ◽  
Cutting Tools ◽  
X Ray Diffraction ◽  
Micro Structure ◽  
X Ray ◽  
Scanning Electron

SiC-Al3BC3-cBN composites with different contents of cBN were fabricated by high pressure and high temperature sintering (HPHT) at 1450 °C for 3 min under a pressure of 5.0 GPa using SiC, Al, B4C and C as additives. The effect of SiC content on the density and mechanical properties of SiC-Al3BC3-cBN composites was investigated. X-ray diffraction (XRD) and Scanning electron microscope (SEM) were used to analyze phases and micro-structure of the sintered samples. The hardness of SiC-Al3BC3-cBN composites decreased with the increasing of SiC content, However, the fracture strength of SiC-Al3BC3-cBN composites increased with the increasing of SiC content.

Microstructure and Toughness Mechanism of Tooth

2011 ◽  
Vol 467-469 ◽  
pp. 567-570
Author(s):  
Bin Chen ◽  
Ji Luo ◽  
Quan Yuan ◽  
Jing Hong Fan
Keyword(s):  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Protein Matrix ◽  
Collagen Protein ◽  
Fine Microstructure ◽  
Representative Model ◽  
Toughness Mechanism ◽  
Parallel Distribution ◽  
Scanning Electron

Tooth is a kind of biomaterial in nature. It behaves favorable strength, stiffness and fracture toughness, which are closely related to its fine microstructure. The observation of scanning electron microscope (SEM) on a mature tooth shows that the tooth is a kind of natural bioceramic composite consisting of hydroxyapatite layers and collagen protein matrix. The observation also shows that the hydroxyapatite layers consist of long and thin hydroxyapatite sheets and that all the hydroxyapatite sheets are arranged in a kind of parallel distribution. The maximum pullout energy of the hydroxyapatite sheets, which is closely related to the fracture toughness of the tooth, is investigated based on the representative model of the parallel distribution. It shows that the long and thin shape as well as the parallel distribution of the hydroxyapatite sheets increase the maximum pullout energy and enhance the fracture toughness of the tooth.

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