Characterization and Mechanical Properties of TiN/O′-Sialon Ceramics Prepared from High Titania Slag

2011 ◽  
Vol 284-286 ◽  
pp. 1353-1357
Author(s):  
Tao Jiang ◽  
Xiang Xin Xue ◽  
Pei Ning Duan
Keyword(s):  
Mechanical Properties ◽  
Bulk Density ◽  
Raw Materials ◽  
Pressureless Sintering ◽  
Particle Sizes ◽  
Densification Behavior ◽  
Flexure Strength ◽  
Titania Slag ◽  
Granular Morphology ◽  
Lower Size

TiN/O′-Sialon ceramics were prepared by pressureless sintering using high titania slag, silicon fume and bauxite chalmette as the starting materials. Phase compositions and microstructure were analyzed by XRD and SEM. The effect of TiO2 content in the staring materials on densification behavior and mechanical properties was studied. The results showed that the sintered samples consisted of O′-Sialon and TiN. O′-Sialon exhibited equiaxied morphology and the particle sizes were about 1-3μm. TiN showed fine granular morphology and most of the particle have lower size than 0.5μm. For the samples sintered at 1500°C using raw materials containing 30wt%TiO2, bulk density, hardness and flexure strength are 3.1g/cm3, 9.2GPa and 169MPa, respectively.

Fabrication of Electroconductive Si3N4–TiN Ceramic from Iron Ore Tailing

2011 ◽  
Vol 284-286 ◽  
pp. 1067-1070
Author(s):  
Shu Hui Zhang ◽  
Zhi Qiang Kang ◽  
Qing Lü ◽  
Jie Li ◽  
Xiao Jie Liu
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Iron Ore ◽  
Raw Materials ◽  
Pressureless Sintering ◽  
Flexure Strength ◽  
Titanium Slag ◽  
Grain Sizes ◽  
Iron Ore Tailing ◽  
Granular Morphology

Electroconductive Si3N4–TiN ceramic was fabricated by pressureless sintering from the chief materials containing high titanium slag and Si3N4powder synthesized by carbonthermal reduction nitridation method using iron ore tailing as raw materials. Phase constitutes and microstructure were analyzed by XRD and SEM. The densification, mechanical properties and electrical conductivity of Si3N4–TiN ceramic were also measured. Results show that the sintered samples mainly consist of Si3N4and TiN. Si3N4exhibits rod morphology and the grain sizes are about 1-3mm.TiN shows fine granular morphology with most of grain size being lower than 0.5mm. The electroconductive Si3N4–TiN ceramic has optimal properties when it is sintered at 1550°C for 2h using initial raw materials containing 20wt% TiO2. The sintered sample’s bulk density, hardness, flexure strength and room electrical resistivity are 2.79 g·cm-3, 8.23GPa, 66 MPa and 7.1×10-2W·cm, respectively.

Preparation and Mechanical Properties of ReAl11O18 Ceramics

2014 ◽  
Vol 602-603 ◽  
pp. 345-348
Author(s):  
Jun Dong Zhang ◽  
Ming Hao Fang ◽  
Zhao Hui Huang ◽  
Yan Gai Liu ◽  
Xin Min ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Bulk Density ◽  
Room Temperature ◽  
Pressureless Sintering ◽  
Optimal Temperature ◽  
Flexure Strength ◽  
The Real

In this paper, plate-like ReAl11O18 (Re = La, Pr, Nd) toughened ceramics were prepared by pressureless sintering at 1650 °C for 5 h in air. The bulk densities of the sintered samples were between 4.7 to 5.3g/cm3. The mechanical properties of the ReAl11O18 ceramics were studied systematically at room temperature. The flexure strength and fracture toughness of ReAl11O18 ceramics were 97.5 to 102.7 Mpa and 3.8 to 4.2Mpa.m1/2. The results show that: The optimal temperature to synthesis ReAl11O18 ceramics was 1650 °C; The flexural strength and fracture toughness of the ReAl11O18 ceramics increase with the increasing of its bulk density.

Room-Temperature Electrical Conductivity Property of TiN/O′-Sialon Multiphase Ceramics

2011 ◽  
Vol 239-242 ◽  
pp. 2072-2075
Author(s):  
Tao Jiang ◽  
Xiang Xin Xue ◽  
Jun Bin Wu ◽  
Pei Ning Duan
Keyword(s):  
Electrical Conductivity ◽  
Electrical Discharge Machining ◽  
Raw Materials ◽  
Raw Material ◽  
Conductivity Property ◽  
Electro Discharge Machining ◽  
Titania Slag ◽  
Granular Morphology ◽  
Lower Size ◽  
Multiphase Ceramics

Electroconductive TiN/O′-Sialon multiphase ceramics were prepared by pressureless sintering from TiN/O′-Sialon powders as the chief raw material which were synthesized by the carbothermal reduction nitridation method using high titania slag, silicon fume and bauxite chalmette. Phase compositions and were analyzed. The effect of microstructure and TiO2content in initial raw materials on electrical conductivity were studied by SEM and TEM. The electro-discharge machining (EDM) of the materials was carried out. The results show that the sintered samples consist of O′-Sialon and TiN. O′-Sialon grains exhibit equiaxied morphology and the particle sizes are about 1-3μm. TiN grains exhibit fine granular morphology and most of grains have lower size than 0.5μm. The minimum amount of TiO2in initial raw materials is 25wt% for the formation of electroconductive network in the multiphase ceramics, of which the electrical resistivity is 1.8×10-2Ω·cm and meets the requirement of electrical discharge machining.

scholarly journals Pressureless Sintering of YIG Ceramics from Coprecipitated Nanopowders

2021 ◽  
Vol 7 (5) ◽  
pp. 56
Author(s):  
Yimin Yang ◽  
Xiaoying Li ◽  
Ziyu Liu ◽  
Dianjun Hu ◽  
Xin Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Calcination Temperature ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Secondary Phase ◽  
Coprecipitation Method ◽  
Pressureless Sintering ◽  
Densification Behavior ◽  
Sintering Process

Nanoparticles prepared by the coprecipitation method were used as raw materials to fabricate Y3Fe5O12 (YIG) ceramics by air pressureless sintering. The synthesized YIG precursor was calcinated at 900–1100 °C for 4 h in air. The influences of the calcination temperature on the phase and morphology of the nanopowders were investigated in detail. The powders calcined at 1000–1100 °C retained the pure YIG phase. YIG ceramics were fabricated by sintering at 1200–1400 °C for 10 h, and its densification behavior was studied. YIG ceramics prepared by air sintering at 1250 °C from powders calcinated at 1000 °C have the highest in-line transmittance in the range of 1000-3000 nm. When the sintering temperature exceeds 1300 °C, the secondary phase appears in the YIG ceramics, which may be due to the loss of oxygen during the high-temperature sintering process, resulting in the conversion of Fe3+ into Fe2+.

scholarly journals Effect of Different Sintering Additives on the Microstructure, Phase Compositions and Mechanical Properties of Si3N4/SiC Ceramics

2020 ◽  
Author(s):  
Ying Qin ◽  
Hailing Yang ◽  
Qinggang Li ◽  
Zhi Wang ◽  
Hao Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Glass Phase ◽  
Secondary Recrystallization ◽  
Pressureless Sintering ◽  
Composite Ceramics ◽  
Flexure Strength ◽  
Sic Ceramics ◽  
Liquid Phases ◽  
Sic Ceramic

Abstract Y2O3 and CeO2 were chosen as additives to investigate the effect of different additives on the microstructure, composition of phases and mechanical properties of Si3N4/SiC ceramics using pressureless sintering. Si3N4/SiC ceramic without additives had a high density, while after adding Y2O3 and CeO2, the density and flexural strength of Si3N4/SiC ceramics were significantly decreased due to the increase of porosity. The main phase compositions of samples were β-Si3N4 and SiC. Moreover, the liquid phases Y-Si-O-N and Ce-Si-O-N were observed after adding Y2O3 and CeO2 respectively. It also indicated that for Si3N4/SiC composite ceramics, the high aspect ratio β-Si3N4 overlapped with each other and closely bonded with glass phase could improve flexure strength effectively. Besides, the SiC crystal grains mainly existed in grain boundary, which could inhibit the secondary recrystallization to avoid that the decrease of flexural strength caused by the overgrowth of β-Si3N4 grains.

scholarly journals Sintering and mechanical properties of porcelains prepared from algerian raw materials

Cerâmica ◽  
2011 ◽  
Vol 57 (344) ◽  
pp. 453-460 ◽  
Author(s):  
S. Kitouni ◽  
A. Harabi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flexural Strength ◽  
Bulk Density ◽  
Phase Diagrams ◽  
Heating Rate ◽  
Ternary Phase ◽  
Raw Materials ◽  
Micro Hardness ◽  
Ternary Phase Diagrams

Porcelain is a type of ceramics highly valued for its beauty and strength. The overall goal of this work is to utilize local raw materials within the following fractions: 37 wt.% kaolin, 35 wt.% feldspar and 28 wt.% quartz. This composition has been selected on the basis of the ternary phase diagrams (kaolin-feldspar-quartz). The densification behaviour indicated that specimens sintered at 1200 °C for 2 h with a heating rate of 5 °C/min, have a bulk density of about 2.50 g/cm³. This value is slightly higher than that reported for the conventional porcelain products (2.45 g/cm³). Porcelain specimens with and without calcination sintered at 1200 °C for 2 h have tensile strength values of about 45 and 73 MPa, respectively (equivalent flexural strength values of about 122 and 197 MPa, respectively). The flexural strength values of both specimens are much higher than those reported for conventional porcelains (ranged between 60 and 80 MPa). Furthermore, the value of micro-hardness of the fired samples without calcination at 1200 °C is 9.3 ± 0.2 GPa which is higher than the commercial porcelain products (5.5 GPa).

Formation of tough interlocking microstructure in ZrB2–SiC-based ultrahigh-temperature ceramics by pressureless sintering

2009 ◽  
Vol 24 (7) ◽  
pp. 2428-2434 ◽  
Author(s):  
Ji Zou ◽  
Guo-Jun Zhang ◽  
Yan-Mei Kan
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Raw Materials ◽  
Pressureless Sintering ◽  
Sic Ceramics ◽  
Microstructure And Mechanical Properties ◽  
Ultrahigh Temperature

A self-reinforced ultrahigh-temperature ceramic (UHTC) with elongated ZrB2 grains has been successfully densified by pressureless sintering using commercially available ZrB2, SiC, and WC powders as raw materials. Benefiting from the unique interlocking microstructure, this material had improved strength (518 ± 10 MPa) and higher fracture toughness (6.5 ± 0.2 MPa m1/2) compared to ZrB2–SiC ceramics prepared by pressureless sintering. This work provides a new route for tailoring the microstructure and mechanical properties of UHTCs.

Effect of Z Values on the Microstructure and Mechanical Properties of Post-sintered Reaction Bonded β-SiAlON

2017 ◽  
Vol 36 (5) ◽  
pp. 453-458 ◽  
Author(s):  
Yanjun Li ◽  
Donghua Liu ◽  
Han Jin ◽  
Donghai Ding ◽  
Guoqing Xiao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Bulk Density ◽  
Grain Growth ◽  
Bending Strength ◽  
Raw Materials ◽  
Apparent Porosity ◽  
Reaction Bonding ◽  
Microstructure And Mechanical Properties ◽  
Before And After

Abstractβ-SiAlON materials with different Z values (Z=0.5–3) were fabricated by a reaction bonding combining post-sintering route using raw materials of Si, Al2O3, AlN, etc. The reaction bonded β-SiAlON (RB-β-SiAlON) were post-sintered at 1,750 °C for 6 h. Apparent porosity, bulk density, bending strength and Vicker’s hardness of the samples before and after post-sintering were tested. XRD results showed that the phase composition of both RB-β-SiAlON and post-sintered RB-β-SiAlON (PSRB-β-SiAlON) were β-SiAlON. For RB-β-SiAlON, the apparent porosity was decreased with the increase of Z values, while the strength and hardness was increased accordingly. After the post-sintering procedure, nearly full densified PSRB-β-SiAlON was obtained and the mechanical properties were significantly improved. The bending strength and Vicker’s hardness of the PSRB-β-SiAlON (Z=0.5) achieved 510 MPa and 16.5 GPa, respectively, which were as 2.7 and 6.7 times high as those of the corresponding RB-β-SiAlON. However, the strength and hardness of PSRB-β-SiAlON decreased with the increase of Z value due to the grain growth.

Physical and mechanical properties of polyurethane thermoset matrices reinforced with green coconut fibres

2020 ◽  
Vol 54 (30) ◽  
pp. 4841-4852 ◽  
Author(s):  
Douglas Lamounier Faria ◽  
Laércio Mesquita Júnior ◽  
Ana Angélica Resende ◽  
Daiane Erika Lopes ◽  
Lourival Marin Mendes ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bulk Density ◽  
Raw Materials ◽  
Chemical Constituents ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Tensile Tests ◽  
Sem Images ◽  
The Matrix ◽  
Coconut Fibre

Currently, the use of composites to replace parts made only with plastics has been gradually employed. The advantages of these composites are low cost, high availability of raw materials and good physical and mechanical properties. Thus, this work aimed at producing and characterizing composites produced with coconut fibre reinforced polyurethane matrices. The coconut fibres were studied as to their chemical constituents, aspect ratio, bulk density, pH, tensile properties, and surface SEM images. The composites were prepared using the hand lay-up process and four different concentrations of coconut fibre were evaluated: 30, 40, 50, and 60%. The composites were assessed as for water absorption after 20 days of immersion, bulk density, impact IZOD, tensile tests, and visualize the matrix-reinforcement interface using SEM. The electron micrographs showed a great deal of impurities on the surface of coconut fibres, such as greases, waxes, and gums, due to the high amount of extraction material (19.78%), which damages the adherence of the polymer onto the coconut fibre and, as observed, cause detachment between the reinforcement and the matrix. The tensile strength of the composites tended to increase as greater amounts of coconut fibres were added to the matrix. The averages were around 6.51 to 6.72 MPa for composites with 30 and 60% fibres, respectively. Therefore, coconut fibres can be considered as an alternative to synthetic fibres commonly used in composites, and they can be used at a ratio of 60% without prejudicing the properties of the composites, making them lighter and cheaper.

Microstructure and Mechanical Properties of In Situ Al2O3- Ti(C,N) Composites

2011 ◽  
Vol 239-242 ◽  
pp. 1243-1247
Author(s):  
Xiu Mei Feng ◽  
Xiao Qing Lian ◽  
Ming Xue Jiang ◽  
Yi Ner He
Keyword(s):  
Mechanical Properties ◽  
Bulk Density ◽  
Raw Materials ◽  
In Situ Synthesis ◽  
Apparent Porosity ◽  
Composite Ceramics ◽  
Comprehensive Properties ◽  
Microstructure And Mechanical Properties ◽  
Metal Aluminum

Al2O3-Ti(C,N)composite ceramics were prepared by in situ aluminothermic reduction and pressureless sintering. The effects of different Ti(C,N) contents and sintering temperatures on microstructure and mechanical properties (bulk density ,apparent porosity and blending strength)of samples were investigated through experiments.The results show that Al2O3-Ti(C,N) composite ceramics with 10 wt.% Ti(C,N) prepared using titanium dioxide and metal aluminum powder as raw materials and sintered at 1300 °C for 3h under a flowing nitrigen stream have good properties ,with bulk density 2.94g/cm3,apparent porosity 26.4%, and blending strength reaches to 28.04 MPa. According to the microstructure analysis,the fine in situ synthesis Ti(C,N) particles are uniformly dispersed in tabular alundum matrix. Ti(C,N) and tabular alundum phases are closely combined and can inhibit grain growth each other,which is benefical in improving the comprehensive properties of composite ceramics.

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