scholarly journals Структура и механические свойства композиционной керамики CaO-ZrO-=SUB=-2-=/SUB=--Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- при малых концентрациях корунда

2019 ◽  
Vol 89 (1) ◽  
pp. 107 ◽  
Author(s):  
А.А. Дмитриевский ◽  
А.О. Жигачев ◽  
Д.Г. Жигачева ◽  
А.И. Тюрин
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Flexural Strength ◽  
Coefficient Of Friction ◽  
Zirconium Dioxide ◽  
Friction And Wear ◽  
Ceramic Composites ◽  
Porosity Coefficient

AbstractWe have studied the effect of the ratio between concentrations of zirconium dioxide (stabilized by CaO) and corundum on phase composition and mechanical properties of nanostructured CaO–ZrO_2–Al_2O_3 ceramic composites. The CaO–ZrO_2–Al_2O_3 composites sintered at temperatures typical of ZrO_2 are found to be characterized by the optimal microhardness/fracture toughness ratio at corundum content $${{C}_{{{\text{A}}{{{\text{l}}}_{2}}{{{\text{O}}}_{3}}}}}$$ = 5%. These composites have a high flexural strength; their porosity, coefficient of friction, and wear are typical of those for CaO–ZrO_2 ceramics.

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
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

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.

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.

Microstructure and Mechanical Properties of Hot Pressed ZrC-SiC-ZrB2 Composites

2010 ◽  
Vol 434-435 ◽  
pp. 173-177 ◽  
Author(s):  
Bao Xia Ma ◽  
Wen Bo Han ◽  
Xing Hong Zhang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Ceramic Composites ◽  
Strong Function ◽  
Slight Tendency ◽  
Microstructure And Mechanical Properties

Ternary ZrC-SiC-ZrB2 ceramic composites were prepared by hot pressing at 1900 °C for 60 min under a pressure of 30 MPa in argon. The influence of ZrB2 content on the microstructure and mechanical properties of ZrC-SiC-ZrB2 composites was investigated. Examination of SEM showed that the microstructure of the composites consisted of the equiaxed ZrB2, ZrC and SiC grains, and there was a slight tendency of reduction for grain size in ZrC with increasing ZrB2 content. The hardness increased considerably from 23.3 GPa for the ZS material to 26.4 GPa for the ZS20B material. Flexural strength was a strong function of ZrB2 content, increasing from 407 MPa without ZrB2 addition to 627 MPa when the ZrB2 content was 20vol.%. However, the addition of ZrB2 has little influence on the fracture toughness, ranging between 5.5 and 5.7 MPam1/2.

The Effects of MgO Content on the Mechanical Properties and Microstructures of Al2O3-TiN-TiC Ceramic Materials

2012 ◽  
Vol 500 ◽  
pp. 623-628 ◽  
Author(s):  
Yu Huan Fei ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Flexural Strength ◽  
Crack Path ◽  
Ceramic Materials ◽  
Optical Microscope ◽  
Volume Percent ◽  
Sintered Ceramic ◽  
Microstructure Morphology

Al2O3-TiN-TiC ceramic materials with different MgO content were fabricated by hot-pressing technique. The MgO volume percent was varied from 0vol% to 5vol%. The mechanical properties such as flexural strength, Vickers hardness and fracture toughness were tested. The phase composition of the sintered body was analyzed by XRD while the microstures of the sintering body were observed by OM (Optical Microscope) and SEM. The effects of MgO content on the mechanical properties and microstructures of Al2O3-TiN-TiC were investigated. The results shows that the addition of MgO can change the phase composition of the sintered ceramic materials which displayed with diverse solid solutions and intermetallic compounds. Meanwhile the new sintering products changed the the microstructure morphology which made the crack path complex and affected the mechanical properties.

Microstructure and Mechanical Properties of Hot-Pressed and Pressureless Sintered WC-Al2O3 Ceramic Composites

1993 ◽  
Vol 327 ◽  
Author(s):  
Hidehiro Endo ◽  
Masanori Ueki
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Composite System ◽  
Ceramic Composites ◽  
Pressureless Sintering ◽  
Sintering Aid ◽  
Al2o3 Ceramic ◽  
Remarkable Improvement

AbstractFully densified WC-A12O3 composites were successfully consolidated by both hot-pressing and pressureless sintering. The optimum hot-pressing condition for the composites was 1700°C for 2h under a pressure of 40MPa. A remarkable improvement in mechanical properties was achieved in the composite system, especially in WC-30 and -70vol%A12O3, compared to the monolithic WC and A12O3 ceramics. The addition of MgO as a sintering aid had a great effect on the properties of the composites. WC-30vol%A12O3 composite with 1.Owt% MgO addition exhibited flexural strength higher than 1000MPa up to 1200°C, fracture toughness; KIC≥7MPa√m, and hardness; HV ≥2450. In pressureless sintering with the addition of MgO as a sintering aid and subsequent HIP treatment, the WC-30vol%A12O3 composite exhibited the flexural strength higher than 900MPa up to 1200°C.

Effect of Al2O3 Addition on the Mechanical Properties of Biocompatible ZrO2-Al2O3 Composites

2006 ◽  
Vol 530-531 ◽  
pp. 575-580 ◽  
Author(s):  
Claudinei dos Santos ◽  
L.H.P. Teixeira ◽  
Kurt Strecker ◽  
Carlos Nelson Elias
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Relative Density ◽  
Room Temperature ◽  
Ceramic Composites ◽  
Linear Increase ◽  
Powder Mixtures ◽  
Al2o3 Ceramic ◽  
Sintering Conditions

In this work, the effects of alumina additions on the properties of the ZrO2-Al2O3 ceramic composites were investigated. Samples of ZrO2 with Al2O3 additions varying between 0 and 30wt-% were prepared. The powder mixtures were milled, compacted by uniaxial cold pressing and sintered at 16000C, in air, for 2 hours. The sintered samples were characterized by their relative density, phase composition and microstructure. As mechanical properties at room temperature, their Vickers hardness and fracture toughness were determined: In all sintering conditions and Al2O3 amounts, the samples presented relative density higher that 99%. The Al2O3 addition produces a linear increase of the hardness, reaching values between 1350 and 1610 HV for the addition of 0 and 30% of alumina, respectively. The fracture toughness was near to 8 MPam1/2 in all conditions. The phase composition, microstructure and relative density were correlated in order to interpret the mechanical properties obtained.

The Effects of MgO Addtion on the Mechanical Properties and the Phase Composition of Al2O3-TiC-TiN Ceramic Materials

2012 ◽  
Vol 457-458 ◽  
pp. 3-6
Author(s):  
Yu Huan Fei ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Flexural Strength ◽  
Ceramic Materials ◽  
Bending Test ◽  
Vickers Indentation ◽  
Volume Percent ◽  
Sintered Ceramic ◽  
Three Point Bending

Al2O3-TiN-TiC ceramic materials with different MgO content were fabricated by hot-pressing technique. The MgO volume percent was varied from 0vol% to 5vol%. Three point bending test was applied to get the flexural strength and the Vickers indentation was applied to get the Vickers hardness and the fracture toughness. The phase composition of the ceramics was analyzed by XRD. The effects of the content of MgO on the mechanical properties and the phase composition of Al2O3-TiN-TiC were investigated. The results shows that the addition of MgO can change the phase composition of the sintered ceramic materials which displayed with diverse solid solutions and intermetallic compounds. The convertion of the mechanical properties can also be explained by the XRD results.

Mechanical Properties of NanoSiC Reinforced ZrB2-Based Ceramic Composite

2013 ◽  
Vol 745-746 ◽  
pp. 560-564
Author(s):  
Wen Bo Han ◽  
Peng Wang ◽  
Yang Hou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Ceramic Composite ◽  
Ceramic Materials ◽  
Ceramic Composites

ZrB2-based ceramic composites were prepared through hot-pressing at a temperature of 1880°C. An intragranular microstructure was achieved because of the existence of nanoSiC. In this paper, the mechanical properties of ceramic materials of ZrB2-SiC-G were studied, and the influence of intragranular microstructure on the mechanical properties was analyzed. The values of flexural strength and fracture toughness of ZrB2-20vol%SiCnp-15vol%G reached 551.9MPa and 5.25MPa·m1/2, respectively. Compared to ZrB2-20vol%SiC-15vol%G with micro-SiC, the fracture toughness was improved.

Microstructures and Properties of B4C-Based Composites with Laminar Structure

2015 ◽  
Vol 655 ◽  
pp. 49-52
Author(s):  
Si Yang Fan ◽  
Qing Sen Ni ◽  
Zhen Nan Li ◽  
Jian Jun Wang ◽  
Xin Yan Yue ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Mixed Mode ◽  
Ceramic Composites ◽  
Good Combination ◽  
Transgranular Fracture ◽  
Laminar Structure ◽  
Comprehensive Performance ◽  
Hot Pressing Sintering

Three kinds of ceramic composites with laminar structure, B4C-B4C/Ti3SiC2, B4C-B4C/Ti2AlC and B4C-B4C/8%Si were synthesized by hot pressing sintering, respectively. The microstructures and properties of the composites were investigated in detail. The experimental results showed the two layers of each composite were in good combination and no spallation phenomenon was observed during the process of fracture. The fracture mechanism of three kinds of composites was similar with each other. The fracture mode of ceramic layers was mainly transgranular fracture. The ductile layers which showed good ductile fracture characteristic exhibited a mixed mode of intergranular and transgranular fracture. The results of mechanical properties showed the comprehensive performance of B4C-B4C/8%Si was the best, the flexural strength and fracture toughness of which were 524 MPa and 3.5 MPa∙m1/2 respectively.

scholarly journals Microstructure and mechanical properties of Zr3Al3C5-based ceramics synthesized by Al-Si melt infiltration

2021 ◽  
Vol 10 (3) ◽  
pp. 529-536
Author(s):  
Xiaomeng Fan ◽  
Yuzhao Ma ◽  
Yangfang Deng ◽  
Jinxue Ding ◽  
Laifei Cheng
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Flexural Strength ◽  
Boundary Energy ◽  
Zirconium Carbide ◽  
Formation Temperature ◽  
Abnormal Growth ◽  
Microstructure And Mechanical Properties ◽  
Melt Infiltration

AbstractIn this work, bulk Zr3Al3C5-based ceramics were synthesized by the infiltration of Al-Si melt into zirconium carbide (ZrC) perform. The phase composition, microstructure, and mechanical properties of as-fabricated ceramics were studied. The results demonstrate that Si is more effective to reduce the twin boundary energy of ZrC than Al, and thus promotes the decrease of formation temperature of Zr3Al3C5. With the infiltration temperatures increasing from 1200 to 1500 °C, the Zr3Al3C5 content increases from 10 to 49 vol%, which is contributed to the increase of flexural strength from 62±9 to 222±10 MPa, and fracture toughness (KIC) from 2.8±0.2 to 4.1±0.3 MPa·m1/2. The decrease of mechanical properties for the samples fabricated at 1600 °C is ascribed to the abnormal growth of Zr3Al3C5 grains.

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