Mechanical Properties and Microstructure of PMMA-ZrO2 Nanocomposites for Dental CAD/CAM

2013 ◽  
Vol 785-786 ◽  
pp. 533-536 ◽  
Author(s):  
Shi Bao Li ◽  
Yi Min Zhao ◽  
Jian Feng Zhang ◽  
Cheng Xie ◽  
Dong Mei Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
In Situ Polymerization ◽  
Zirconia Ceramics ◽  
Sem Images ◽  
The Matrix ◽  
Cad Cam ◽  
Organic Resin

A novel PMMA-ZrO2 composite (PZC) was prepared by resin infiltrated to ceramic method. The composite mechanical properties were evaluated and correlated to its microstructure. Partially sintered zirconia ceramics (PSZC) were made by isostatic pressing and partially sintering. Subsequently, the PZC was prepared by vacuum infiltrating prepolymerized MMA into PSZC, followed by in-situ polymerization. When PSZC-70% was used as the matrix, the bending strength, elastic modulus, and fracture toughness of the prepared composite i.e PZC-70% were 202.56±12.09 MPa, 58.71±3.98 GPa, and 4.60±0.26 MPa·m1/2, corresponding to 25.69%, 23.31%, and 169.01% improvement, respectively, in comparison with the control matrix. Among them, the fracture toughness improvement was the most prominent. According to SEM images of the fracture surfaces, each pore of zirconia skeleton was filled by organic resin contributing to the bending strength improvement. These weak interfaces between zirconia skeleton and organic resin absorbed energy and terminated the growth of microcracks which might be responsible for significant improvement in fracture toughness. This PZC material is anticipated to be a new member of the dental CAD/CAM family.

Mechanical Properties and Microstructure of Partially Sintered Zirconia Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 1252-1254 ◽  
Author(s):  
Shi Bao Li ◽  
Zhao Hui Chen ◽  
Yi Min Zhao ◽  
Zhong Yi Wang ◽  
Li Hui Tang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Bending Strength ◽  
Target Material ◽  
Dental Restoration ◽  
Diameter Distribution ◽  
Zirconia Ceramics ◽  
Grain Sizes ◽  
Cad Cam

Partially sintered zirconia ceramics (PSZCs) for dental uses were prepared from zirconia nanopowder via isostatic pressing and partially sintering. The open porosities, pore diameters, grain sizes and mechanical properties of the ceramics with different densities were studied. The results show that the pores formed in the PSZCs are all open pores, with a diameter distribution of 60nm~130nm and a grain size distribution of 120~170nm. The machinability becomes worse when the density of PSZC is higher than 75% of the theoretical density, so a ceramic named PSZC-70% with density of 70%TD was selected as the target material. Its bending strength is 168 MPa and fracture toughness is 1.8 MPa·m1/2. A dental restoration framework can be obtained via machining the PSZC-70% on a dental CAD/CAM system.

In Situ Preparation and Mechanical Properties of (ZrB2+ZrC)/Zr3[Al(Si)]4C6 Composites

2014 ◽  
Vol 602-603 ◽  
pp. 438-442
Author(s):  
Lei Yu ◽  
Jian Yang ◽  
Tai Qiu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
Raw Materials ◽  
Linear Increase ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Uniform Microstructure

Fully dense (ZrB2+ZrC)/Zr3[Al (Si)]4C6 composites with ZrB2 content varying from 0 to 15 vol.% and fixed ZrC content of 10 vol.% were successfully prepared by in situ hot-pressing in Ar atmosphere using ZrH2, Al, Si, C and B4C as raw materials. With the increase of ZrB2 content, both the bending strength and fracture toughness of the composites increase and then decrease. The synergistic action of ZrB2 and ZrC as reinforcements shows significant strengthening and toughing effect to the Zr3[Al (Si)]4C6 matrix. The composite with 10 vol.% ZrB2 shows the optimal mechanical properties: 516 MPa for bending strength and 6.52 MPa·m1/2 for fracture toughness. With the increase of ZrB2 content, the Vickers hardness of the composites shows a near-linear increase from 15.3 GPa to 16.7 GPa. The strengthening and toughening effect can be ascribed to the unique mechanical properties of ZrB2 and ZrC reinforcements, the differences in coefficient of thermal expansion and modulus between them and Zr3[Al (Si)]4C6 matrix, fine grain strengthening and uniform microstructure derived by the in situ synthesis reaction.

Preparation and Study of PMMA/TiO2 Nanocomposites

2011 ◽  
Vol 233-235 ◽  
pp. 1830-1833 ◽  
Author(s):  
Yong Chen ◽  
Hui Xu ◽  
Tao Sun
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Thermal Stability ◽  
In Situ Polymerization ◽  
The Matrix ◽  
Thermal Stability Of

The PMMA/TiO2 nanocomposites were prepared by in situ polymerization，the dissolution, thermal stability and the mechanical property of the nanocomposites were studied. The results indicated that nano-TiO2 may be crosslinking points in the matrix and the thermal stability of the nanocomposites became higher. As the content of nano-TiO2 increased, the mechanical properties of the nanocomposites had great changes.

Fabrication and Mechanical Properties of Alumina—CNTs Composites

2011 ◽  
Vol 66-68 ◽  
pp. 1390-1396
Author(s):  
Jing Song Zhao ◽  
Yi Feng ◽  
Nan Nan Chen ◽  
Fan Yan Chen ◽  
Jie Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Powder Metallurgy ◽  
Nuclear Waste ◽  
Mass Fraction ◽  
Bending Strength ◽  
Waste Material ◽  
Powder Metallurgy Method ◽  
The Matrix

The transmutation target of nuclear waste material has been fabrication by a powder metallurgy method by using Alumina as the matrix and CNTs as reinforcement. The effect of different nanotube contents on the fracture toughness and the bending strength was investigation. The results showed the fracture toughness and the bending strength of composites increased with increasing CNTs mass fraction when the content of CNTs was less than 1.5%. However, when the contents of CNTs greater than 1.5%, the fracture toughness and the bending strength of composites decreased as the content of CNTs increased. Possible mechanisms are discussed in detail in the paper.

Properties of Nanostructured 3Y-TZP Blocks Used for CAD/CAM Dental Restoration

2008 ◽  
Vol 396-398 ◽  
pp. 603-606 ◽  
Author(s):  
Claudinei dos Santos ◽  
Felipe Antunes Santos ◽  
Carlos Nelson Elias
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Weibull Modulus ◽  
Bending Strength ◽  
Dental Restoration ◽  
Tetragonal Zro2 ◽  
All Ceramic ◽  
Cad Cam ◽  
Ceramic Blocks ◽  
Xrd Patterns

Several CAD/CAM systems are available to dental prosthesis laboratories which can be used to fabricate all-ceramic copings and frameworks. The use of these systems presents low demand, due principally the high blocks ceramics cost used for theses systems. Usually, these ceramic blocks are sintered at high temperatures, between 1450 and 15500C, resulting in micrometric ZrO2 microstructure. A considerable innovation in these ceramics systems used in CAD/CAM applications was introduced by the use of nanometric-tetragonal ZrO2 blocks, which are sintered at low sintering temperatures resulting in nanometric grains morphology and improved mechanical properties. The purpose of the present work is to characterize the mechanical properties of nanoparticled zirconium oxide blocks comparing with commercial micrometric ceramic parts. XRD patterns showed that the blocks have only the tetragonal-ZrO2 as crystalline phase. The tetragonal-monoclinic transformation phase was responsible for the excellent mechanical properties. Nanometric blocks presented hardness of 13GPa, fracture toughness of 11MPam1/2 , bending strength of 1020MPa and Weibull modulus, m=14, while micrometric ZrO2 blocks similar hardness, fracture toughness 8.5MPam1/2, bending strength of 850MPa and Weibull modulus of 10.

Synthesis of Biodegradable β-TCP/PLGA Composites Using Microwave Energy

2006 ◽  
Vol 510-511 ◽  
pp. 758-761 ◽  
Author(s):  
Hyeong Ho Jin ◽  
Sang Ho Min ◽  
Kyu Hong Hwang ◽  
Ik Min Park ◽  
Hong Chae Park ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Young’S Modulus ◽  
Tricalcium Phosphate ◽  
Bending Strength ◽  
In Situ Polymerization ◽  
Young's Modulus ◽  
Microwave Energy ◽  
Microstructure And Mechanical Properties

Biodegradable β-tricalcium phosphate (β-TCP)/poly (lactide-co-glycolide) (PLGA) composites were synthesized by in situ polymerization with microwave energy. The influence of the β-TCP content in β-TCP/PLGA composites on the molecular weight, crystallinity, microstructure, and mechanical properties was investigated. As the molecular weight of composites decreased, the β-TCP content increased up to 10 wt%, while further raising of the β-TCP content above 10%, the molecular weight increased with increasing β-TCP content. This behavior may be ascribed to the superheating effect or nonthermal effect induced by microwave energy. It was found that the bending strength and Young’s modulus of the β-TCP/PLGA composites were proportional to the molecular weight of PLGA. The bending strength of the β-TCP/PLGA composites ranged from 18 to 38 MPa, while Young’s modulus was in the range from 2 to 6 GPa.

Influence of Cr2O3 Addition on the Properties of TiAl Composites

2011 ◽  
Vol 230-232 ◽  
pp. 789-792
Author(s):  
Jian Feng Zhu ◽  
Wen Wen Yang ◽  
Fang Ni Du
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Synthesis Method ◽  
Strengthening Mechanism ◽  
Reaction Synthesis ◽  
The Matrix ◽  
Method Effects ◽  
Particulate Reinforced

Using Ti, Al and Cr2O3 as starting materials, Al2O3 particulate reinforced TiAl composites have been fabricated by in-situ reaction synthesis method. Effects of the Cr2O3 addition on the microstructures and mechanical properties of the TiAl/Al2O3 composites were investigated in detail. The results show that the composites have a matrix of TiAl, Ti3Al, and minor Cr containing phases, and a second reinforcement Al2O3. The addition of Cr2O3 effectively refined the structure of the matrix, and as a result, the mechanical properties of TiAl composites are improved. At Cr2O3 7.36 wt%, the flexural strength and fracture toughness reach the maximum values of 634.62 MPa and 9.79 MPa·m1/2, which are increased by 80% and 30%, respectively. The strengthening mechanism is also discussed.

Effects of Rapid Heat Treatment on Microstructure and Mechanical Properties of Ti2AlC/TiAl Composite

2007 ◽  
Vol 336-338 ◽  
pp. 1164-1167
Author(s):  
Yun Long Yue ◽  
Hai Tao Wu ◽  
Wei Bing Wu ◽  
Hai Yan Yin
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Duplex Microstructure ◽  
Microstructure And Mechanical Properties ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Rapid Heat Treatment

In this paper Ti2AlC/TiAl composites were in-situ fabricated by spark plasma sintering (SPS) and then the effects of rapid heat-treatment on microstructure and mechanical properties of Ti2AlC/TiAl composites were investigated. After rapid heat-treatment the microstructure of TiAl matrix was significantly transformed from the near γ microstructure to duplex microstructure. Ti2AlC particles effectively refined the γ phase grains and the α2/γ lamellar colony microstructure. For the Ti2AlC/TiAl composite after rapid heat-treatment at 1200°C, the bending strength and fracture toughness reached 956.8MPa and 22.8MPa·m1/2, respectively.

Study on Dental Colored Zirconia Restoration

2008 ◽  
Vol 368-372 ◽  
pp. 1255-1257 ◽  
Author(s):  
Ning Wen ◽  
Yuan Fu Yi ◽  
Wei Wei Zhang ◽  
Hong Chen Liu ◽  
Long Quan Shao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Erbium Oxide ◽  
Zirconia Ceramics ◽  
Three Point Bending ◽  
Dental Application ◽  
Porous Microstructure ◽  
L Value ◽  
Dental Zirconia Ceramics

This paper explored the color and mechanical properties of CeO2 and Er2O3 shaded zirconia ceramics for dental application. Twelve kinds of colored dental ZrO2 powders were prepared. Experimental results showed that the hue of the materials shift from yellow-green to yellow-red with the increasing concentration of the CeO2 and Er2O3, while reducing of the brightness( L* ) value was little. Three-point bending strength decreased form 1209MPa to 845MPa after coloring, which was lower than the uncolored materials (1301MPa). The fracture toughness decrease slightly. SEM observation revealed more porous microstructure in specimen containing both two additives. Cerium oxide and erbium oxide are candidates of color additives for shading dental zirconia ceramics.

Effect of Pressure on TiB2-Cu Composite via In-Situ Reaction Synthesis

2007 ◽  
Vol 280-283 ◽  
pp. 1437-1440
Author(s):  
Yue Feng Sun ◽  
Qiang Xu ◽  
Xing Hong Zhang ◽  
Jie Cai Han ◽  
Jin Huai Liu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Exothermic Reaction ◽  
Applied Pressure ◽  
Reaction Synthesis ◽  
Matrix Composites ◽  
Copper Powders ◽  
Fine Microstructure

TiB2-Cu matrix composites from titanium, boron and copper powders were in-situ fabricated by exothermic reaction. The effect of the applied pressure on the mechanical properties of the composite was investigated. The results showed that when the applied pressure increasing, the relative density, bending strength, fracture toughness and hardness of the composites were on the increase due to the formation of fine microstructure and the improvement of densification with the pressure increasing. The high pressure is beneficial to the better mechanical properties.

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