Flexural Strength and Fracture Toughness of Dicor Glass-ceramic after Embedment Modification

A new nanomicro composite self-lubricating ceramic tool material was prepared with vacuum hot pressing technique. The effect of nanoAl2O3 powders on the microstructure and mechanical properties of nanomicro composite self-lubricating ceramic tool material was investigated. With the increase of nanoAl2O3 content, the hardness and fracture toughness first up then down. When the nanoAl2O3 content is 4 vol.%, the flexural strength, hardness and fracture toughness reaches 562 MPa, 8.46 MPa·m1/2 and 18.95 GPa, respectively. The microstructure and mechanical property of nanomicro composite self-lubricating ceramic tool material can be improved by the grain refinement strengthening of nanoAl2O3.

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Effect of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3-TiC-ZrO2 Ceramic Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.476-478.1031 ◽

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.

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A Study on Reaction Bonded Ceramics Fabricated by Silicon Infiltration to B4C Preforms

Materials Science Forum ◽

10.4028/www.scientific.net/msf.724.343 ◽

2012 ◽

Vol 724 ◽

pp. 343-346 ◽

Cited By ~ 1

Author(s):

Rong Zhen Liu ◽

Qing Wen Duan ◽

Wen Wei Gu ◽

Hai Yun Jin ◽

Shao Chun Xu ◽

...

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Flexural Strength ◽

Theoretical Result ◽

Boron Carbide ◽

Theoretical Calculation ◽

Vickers Hardness ◽

Volume Expansion ◽

Maximum Density ◽

Infiltration Process

Silicon was infiltrated into B4C preforms to fabricate B4C based composites ceramics at 1600 °C under vacuum circumstance. In this paper, silicon infiltration process was discussed by theoretical calculation. The volume expansion caused by reactions between silicon and boron carbide was about 89.1% from the calculation. In our study, the maximum density of B4C preform for the infiltration of silicon was about 1.5g/cm3 which was larger than theoretical result. The results of mechanical behavior showed that B4C based composites had excellent mechanical properties with a density lower than 2.6g/cm3, Vickers-hardness of this material was 27.2GPa, and this material showed a flexural strength of 349MPa and fracture toughness of 3.8 MPa*m1/2.

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Microstructure and Mechanical Properties of Multi-Scale Titanium Diboride Matrix Nanocomposite Ceramic Tool Materials

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.431-432.523 ◽

2010 ◽

Vol 431-432 ◽

pp. 523-526

Author(s):

Han Lian Liu ◽

Chuan Zhen Huang ◽

Shou Rong Xiao ◽

Hui Wang ◽

Ming Hong

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Flexural Strength ◽

Transgranular Fracture ◽

Ceramic Tool ◽

Tool Materials ◽

Micro Scale ◽

Multi Scale ◽

Nano Scale ◽

Matrix Nanocomposite

Under the liquid-phase hot-pressing technique, the multi-scale titanium diboride matrix nanocomposite ceramic tool materials were fabricated by adding both micro-scale and nano-scale TiN particles into TiB2 with Ni and Mo as sintering aids. The effect of content of nano-scale TiN and sintering temperature on the microstructure and mechanical properties was studied. The result showed that flexural strength and fracture toughness of the composites increased first, and then decreased with an increase of the content of nano-scale TiN, while the Vickers hardness decreased with an increase of the content of nano-scale TiN. The optimal mechanical properties were flexural strength 742 MPa, fracture toughness 6.5 MPa•m1/2 and Vickers hardness 17GPa respectively. The intergranular and transgranular fracture mode were observed in the composites. The metal phase can cause ductility toughening and crack bridging, while crack deflection and transgranular fracture mode could be brought by micro-scale TiN and nano-scale TiN respectively.

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Fabrication and Mechanical Properties of Homogenous and Graded Si3N4/(W, Ti)C Nano-Composite Ceramic Tool Materials

Materials Science Forum ◽

10.4028/www.scientific.net/msf.800-801.511 ◽

2014 ◽

Vol 800-801 ◽

pp. 511-515

Author(s):

Xian Hua Tian ◽

Jun Zhao ◽

Shuai Liu ◽

Zhao Chao Gong

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Flexural Strength ◽

Composite Ceramic ◽

Ceramic Tool ◽

Graded Materials ◽

Tool Materials ◽

Graded Structure ◽

Design Ideas ◽

Novel Design

Close attention has been paid to Functional graded materials (FGMs) worldwide for their novel design ideas and outstanding properties. To verify the advantage of FGMS in the design of ceramic tool materials, Si3N4/(W, Ti)C nanocomposite ceramic tool materials with homogenous and graded structure were fabricated by hot pressing and sintering technology. The flexural strength, fracture toughness and hardness of the sintered composites were tested and compared. The experimental results showed that the graded structure improved mechanical properties of the ceramic tool materials, especially the flexural strength and fracture toughness. The introduction of residual compressive stress in the surface layer contributes to the improvement of the properties .

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Evaluation of Mechanical Properties of Dental Feldsphatic Porcelains for Metal and Zirconia Core

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.1104 ◽

2012 ◽

Vol 727-728 ◽

pp. 1104-1107

Author(s):

Antonio Alves de Almeida-Junior ◽

Gelson Luis Adabo ◽

Beatriz Regalado Galvão ◽

Diogo Longhini ◽

Claudinei dos Santos

Keyword(s):

Fracture Toughness ◽

Flexural Strength ◽

Vickers Hardness ◽

High Hardness ◽

Hardness Test ◽

Dental Prostheses ◽

Significant Incidence ◽

Significant Difference ◽

Fixed Dental Prostheses ◽

Intermediate Value

Studies has been reported a significant incidence of chipping of the feldspathic porcelain veneer in zirconia-based restorations. The purpose of this study was to compare the three-point flexural strength (MPa), Weibull parameters, Vickers hardness (VHN) and Vickers indentation fracture toughness (MPa/mm1/2) in feldspatic porcelains for metal and for zirconia frameworks. Bar specimens were made with the porcelains e.MaxCeram (EM) and VitaVM9 (V9) for zirconia core, and Duceragold (DG) and VitaVMK95 (VK) for metal core (n= 15). Kruskal-Wallis and Dun test were used for statistical analysis. There was no significant difference (p=0.31) among the porcelains in the flexural strength (Median= 73.2; 74.6; 74.5; 74.4). Weibull calculation presented highest reliability for VK (10.8) followed by EM (7.1), V9 (5.7) and DG (5.6). Vickers hardness test showed that EM (536.3), V9 (579.9) and VK (522.1) had no difference and DG (489.6) had the lowest value (p.001). The highest fracture toughness was to VK (1.77), DG (1.58) had an intermediate value while V9 (1.33) and EM (1.18) had the lowest values (p.001). Despite of the suitable flexural strength, reliability and high hardness, the porcelains used to zirconia-based fixed dental prostheses showed lower fracture toughness values.

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Impact of Silane-containing Universal Adhesive on the Biaxial Flexural Strength of a Resin Cement/Glass-ceramic System

Operative Dentistry ◽

10.2341/17-356-l ◽

2019 ◽

Vol 44 (2) ◽

pp. 200-209 ◽

Cited By ~ 1

Author(s):

F Murillo-Gómez ◽

RB Wanderley ◽

MF De Goes

Keyword(s):

Flexural Strength ◽

Glass Ceramic ◽

Resin Cement ◽

Weibull Analysis ◽

Ceramic System ◽

Universal Adhesive ◽

Bonded Interface ◽

Biaxial Flexural Strength ◽

Digital Caliper ◽

One Way Anova

SUMMARY The aim of this study was to determine whether using a silane-containing universal adhesive as a silane primer in glass-ceramic/resin cement systems affects biaxial flexural strength (BFS) and bonded interface integrity after loading. Glass-ceramic (IPS e.max CAD, Ivoclar/Vivadent, Schaan, Liechtenstein) disc-shaped specimens (6.5±0.1mm in diameter, 0.5±0.1mm thick) were etched with 5% hydrofluoric acid (HF) for 20 seconds and divided into four groups of 30 specimens, to be treated as follows: 1) One bottle silane primer (RCP); 2) Separate application of silane and adhesive (RCP+SB); 3) Silane-containing universal adhesive (SBU); 4) No treatment (C). After silanization, all specimens were resin cement– coated and polymerized for 40 seconds. Each specimen layer was measured, as well as each assembly's thickness, using a digital caliper and scanning electron microscope (SEM). Specimens were stored for 24 hours and submitted to a BFS test (1.27 mm/min). BFS values were calculated using the bilayer disc-specimen solution. Bonded interfaces were analyzed on fractured fragments using SEM. One-way ANOVA and Tukey tests (α=0.05) were applied, as well as the Weibull analysis. Factor “silane treatment” was statistically significant (p<0.0001). RCP+SB (372.2±29.4 MPa) and RCP (364.2±29.5 MPa) produced significantly higher BFS than did the C (320.7±36.3 MPa) or SBU (338.0±27.1 MPa) groups. No differences were found in the Weibull modulus (m: RCP: 10.1-17.3; RCP+SB: 10.1-17.0; SBU: 12.3-22.4; C: 7.4-12.9). Bonded interface analysis exhibited ceramic-cement separation (SBU, C) and voids within the resin cement layer (all groups). Neither the ceramic/cement system's BFS nor its bonded interface stability were improved by SBU after loading.

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Effects of CNT Addition on Mechanical Properties, Electric Conductivity and Oxidation Resistance of Al2O3-TiC Composite

Materials Science Forum ◽

10.4028/www.scientific.net/msf.761.83 ◽

2013 ◽

Vol 761 ◽

pp. 83-86

Author(s):

Hideaki Sano ◽

Junichi Morisaki ◽

Guo Bin Zheng ◽

Yasuo Uchiyama

Keyword(s):

Mechanical Properties ◽

Carbon Nanotubes ◽

Fracture Toughness ◽

Flexural Strength ◽

Electric Conductivity ◽

Young’S Modulus ◽

Oxidation Resistance ◽

Young's Modulus ◽

Tic Particle

Effects of carbon nanotubes (CNT) addition on mechanical properties, electric conductivity and oxidation resistance of CNT/Al2O3-TiC composite were investigated. It was found that flexural strength, Young’s modulus and fracture toughness of the composites were improved by addition of more than 2 vol%-CNT. In the composites with more than 3 vol%-CNT, the oxidation resistance of the composite was degraded. In comparison with Al2O3-26vol%TiC sample as TiC particle-percolated sample, the Al2O3-12vol%TiC-3vol%CNT sample, which is not TiC particle-percolated sample, shows almost the same mechanical properties and electric conductivity, and also shows thinner oxidized region after oxidation at 1200°C due to less TiC in the composite.

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