scholarly journals Densification Behaviour and Mechanical Properties of Aluminium Oxide and Cerium Oxide-Doped Yttria Tetragonal Zirconia Polycrystal Ceramics Using Two-Step Sintering

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
M. Golieskardi ◽  
M. Satgunam ◽  
D. Ragurajan
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Young’S Modulus ◽  
Vickers Hardness ◽  
Young's Modulus ◽  
Tetragonal Zirconia ◽  
Sintering Process ◽  
Weight Percentage ◽  
Densification Behaviour ◽  
Phase Arrangement

The densification behaviour, mechanical properties, and microstructure of high-purity Al2O3 and CeO2-doped Y-TZP with different weight percentage varied from 0.3 to 1 wt% were investigated. The samples were pressed uniaxially at 200 MPa into rectangular bars and discs and pressureless-sintered at temperature ranging between 1250°C and 1450°C for 2 h while the microstructure was characterized with a scanning electron microscope (SEM). Two-step sintering process works well for temperature higher than 1400°C and it created most tetragonal phase arrangement for stable structure to delay ageing through phase transformation. The mechanical properties in terms of bulk density, Young’s modulus, Vickers hardness, and fracture toughness were also measured. The results indicate that the addition of dopants accelerated the densification parameters and reinforced and toughened the obtained bodies. The maximum values for the mechanical properties of the Al2O3 and CeO2-doped Y-TZP ceramics were 6.01, 220 GPa, 13.8 GPa, and 7 MPa for density, Young’s modulus, Vickers hardness, and fracture toughness, respectively, which are higher than those of the doped samples.

Densification Behaviour and Mechanical Properties on MgO Doped Zirconia Toughened Alumina (ZTA) Prepared by Two-Stage Sintering

2021 ◽  
Vol 1030 ◽  
pp. 3-10
Author(s):  
Teow Hsien Loong ◽  
Ananthan Soosai ◽  
Suresh Muniandy
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Total Hip Arthroplasty ◽  
Young’S Modulus ◽  
Vickers Hardness ◽  
Young's Modulus ◽  
Two Stage ◽  
Positive Effect ◽  
Zirconia Toughened Alumina

The effect of doping small amounts of Magnesium Oxide ranging between 0 to 1 vol% on Zirconia Toughened Alumina (ZTA) composites which is one of main biomaterial used for production of total hip arthroplasty were investigated. The samples were produced via conventional two-stage sintering with T1 varies between 1450°C and 1550°C with heating rate of 20°C/min. The samples were then rapid cooled to T2 set at 1400°C with holding time of 12 hours. The microstructural and mechanical properties of the two-stage sintered ZTA are then investigated to determine the feasibility of MgO addition. Combination of two-stage sintering at T1 above 1500 and also small amount of MgO up to 0.5 vol% were shown to have positive effect on ZTA which exhibited improvement on its grain size, mechanical properties such as Vickers hardness, Young’s modulus and fracture toughness compared to undoped ZTA composites. The sample with 0.5 vol% MgO addition sintered at T1 of 1500°C and T2 1400°C was able to achieve Vickers hardness of 19.6 GPa, Young’s modulus of 408 GPa and fracture toughness of 6.8 MPam1/2 without significant grain growth compared to undoped ZTA composites.

Sintering Behaviour and Properties of Flyash-Doped Zirconia

2017 ◽  
Vol 894 ◽  
pp. 85-88
Author(s):  
Singh Ramesh ◽  
Wai Jin Kelvin Chew ◽  
H.C. Alexender Chee ◽  
C.Y. Tan
Keyword(s):  
Fracture Toughness ◽  
Young’S Modulus ◽  
Vickers Hardness ◽  
Monoclinic Phase ◽  
Sintering Temperature ◽  
Young's Modulus ◽  
Tetragonal Zirconia ◽  
Lower Amount ◽  
Common Trend ◽  
Sintering Behaviour

The effect of flyash (FA) additions of 0.05 wt% to 1 wt% on yttria-stabilized tetragonal zirconia polycrystals (Y-TZP), sintered in air at temperatures ranging from 1250°C to 1500°C, was examined. The bulk density, Young’s modulus, Vickers hardness and fracture toughness for each addition were determined while ageing behaviour were observed by subjecting them to superheated steam at 180°C/10 bar in an autoclave for 24 hours. Additions of FA, particularly of 0.05 wt% and 0.1 wt%, were found to be beneficial in aiding densification and increasing Young’s modulus beyond 200 GPa for sintering temperatures up to 1350°C. A common trend was observed for the Vickers hardness of all additions including undoped; hardness continues to rise from 1250°C and peaked at 1350°C before gradually decreasing as the sintering temperature increases further. No pronounced effect of flyash was seen on the fracture toughness of all samples. The ageing resistance of Y-TZP improved with addition of FA resulting in relatively lower amount of ageing-induced tetragonal to monoclinic phase transformation exhibited by doped samples compared to the undoped.

Influence of Material Composition on Mechanical Properties and Fracture Behavior of Ceramic-Metal Composites

2005 ◽  
Vol 297-300 ◽  
pp. 1516-1521 ◽  
Author(s):  
Keiichiro Tohgo ◽  
Takayuki Kawaguchi
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Young’S Modulus ◽  
Fracture Strength ◽  
Vickers Hardness ◽  
Fracture Behavior ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Metal Phase ◽  
Metal Composites

In order to estimate distribution of mechanical properties and fracture toughness in ceramic-metal functionally graded materials (FGMs), mechanical properties and fracture behavior have been investigated on non-graded ceramics-metal composites which correspond to each region of FGMs. The materials are fabricated by powder metallurgy using partially stabilized zirconia (PSZ) and stainless steel (SUS 304). Vickers hardness, Young’s modulus and bending fracture strength were examined on smooth specimens. The Vickers hardness of the composites continuously decreases with an increase in a volume fraction of SUS 304 metal phase, while the Young’s modulus and fracture strength exhibit low values in the composites with balanced composition of each phase. This suggests that the interfacial strength between the ceramic and metal phases is very low. Fracture toughness tests are conducted by three-point-bending on rectangular specimens with a sharp edgenotch. In contrast with the Young’s modulus and fracture strength, the fracture toughness obtained for the composites increases with an increase in a volume fraction of SUS 304 metal phase. The fracture toughness of the composites is slightly lower than that obtained previously by stable crack growth in a PSZ-SUS 304 FGM. The difference in fracture toughness between the composites and FGM seems to be attributed to the residual stress created during fabrication of the FGM.

Effect of Added Cr3C2 on the Microstructure and Mechanical Properties of WC–SiC Ceramics

2015 ◽  
Vol 656-657 ◽  
pp. 33-38 ◽  
Author(s):  
Akihiro Nino ◽  
Takashi Sekine ◽  
Kazuhisa Sugawara ◽  
Shigeaki Sugiyama ◽  
Hitoshi Taimatsu
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Grain Size ◽  
Young’S Modulus ◽  
Vickers Hardness ◽  
Young's Modulus ◽  
Sic Ceramics ◽  
Phase Type ◽  
Binder Free

WC–20 mol% SiC ceramics with added Cr3C2 were sintered at 1600°C with a resistance-heated hot-pressing machine. Dense WC–SiC ceramics containing 0.1–0.9 mol% Cr3C2 were obtained. Above 1.2 mol% Cr3C2, the relative density decreased with increasing Cr3C2 content. A small amount of a Nowotny-phase type (Mo5Si3C-type) product was formed by the addition of Cr3C2, and no Cr3C2-based solid solution was found. The WC–20 mol% SiC–Cr3C2 ceramics had very fine equiaxed granular WC grains because of inhibited grain growth of WC. The Young’s modulus of the WC–20 mol% SiC–Cr3C2 ceramics decreased with increasing Cr3C2 content because Cr3C2 has a much lower Young’s modulus than WC. Cr3C2 addition below 0.9 mol% increased the Vickers hardness from 20.9 to 23.0 GPa, but a larger added amount reduced the Vickers hardness. The hardness of the WC–20 mol% SiC–Cr3C2 ceramics and the WC grain size obeyed a Hall–Petch-like relationship, suggesting that the hardness was strongly controlled by the WC grain size. A higher fracture toughness, 6.4 MPa m1/2, was obtained for the ceramics containing a small amount of Cr3C2 than for the binder-free WC. The addition of 0.1–0.3 mol% Cr3C2 improved the fracture toughness without reducing the hardness.

The Effect of Sintering Profiles on Zirconia Toughened Alumina (ZTA) Prepared by Two-Stage Sintering

2021 ◽  
Vol 904 ◽  
pp. 174-180
Author(s):  
Teow Hsien Loong ◽  
Sivakumar Sivanesan ◽  
Se Yong Eh Noum
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bulk Density ◽  
Young’S Modulus ◽  
Heating Rate ◽  
Vickers Hardness ◽  
Young's Modulus ◽  
Holding Time ◽  
Two Stage ◽  
Zirconia Toughened Alumina

The effects of sintering profiles on the Zirconia Toughened Alumina (ZTA) composite containing 0 vol% Y-TZP (pure alumina) to 20 vol% Y-TZP content prepared by a sintering method known as two-stage sintering were investigated. The heating rate was set between 10°C/min to 20°C/min, T1 set between 1400°C to 1500°C, T2 at 1350°C and holding time was set at 12 hours. The samples’ microstructural properties and mechanical properties, including bulk density, Vickers hardness, Young’s modulus and fracture toughness, were evaluated. Based on the data obtained, the ZTA composites with 10 vol% Y-TZP sintered at a heating rate of 10°C/min and holding time of 12 hours were able to achieve mechanical properties requirements set by the industry standard. In addition, the maximum ZTA composite’s bulk density was recorded to be above 90% T.D, while the Vickers hardness of the composite was recorded to be exceeding 17 GPa. The ZTA composite also recorded maximum Young’s modulus exceeding 380 GPa and fracture toughness above 6 MPam1/2.

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

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.

Two-Stage Sintering of Alumina-Y-TZP (Al2O3/Y-TZP) Composites

2019 ◽  
Vol 814 ◽  
pp. 12-18 ◽  
Author(s):  
Sivakumar Sivanesan ◽  
Teow Hsien Loong ◽  
Satesh Namasivayam ◽  
Mohammad Hosseini Fouladi
Keyword(s):  
Fracture Toughness ◽  
Young’S Modulus ◽  
Heating Rate ◽  
Vickers Hardness ◽  
Young's Modulus ◽  
Two Stage ◽  
Dwelling Time ◽  
Microstructure Density

Alumina-Y-TZP composites between 0 to 25 vol% Y-TZP content produced via conventional two-stage sintering with T1 ranging between 1400°C and 1550°C, heating rate of 20°C/min, followed by T2 of 1350°C and 12 hours dwelling time. The microstructure, density, Vickers hardness (HV), Young’s modulus (E) and fracture toughness (KIC) of the sintered samples were then evaluated. It is observed that all samples up to 10 vol% Y-TZP achieved > 98% T.D. as the T1 increases. Samples with Y-TZP content above 10 vol% resulted in a significant decrease in density and hardness. Samples with ≤ 10 vol% Y-TZP sintered at T1 of 1450°C was able to achieve density > 98% T.D., Vickers hardness > 18 GPa and Young’s modulus > 380 GPa and fracture toughness > 6 MPam1/2 when compared to pure Al2O3 ceramics.

Mechanical Properties of Transparent Polycrystalline Silicon Nitride

2006 ◽  
Vol 317-318 ◽  
pp. 305-308 ◽  
Author(s):  
Rak Joo Sung ◽  
Takafumi Kusunose ◽  
Tadachika Nakayama ◽  
Yoon Ho Kim ◽  
Tohru Sekino ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Silicon Nitride ◽  
Young’S Modulus ◽  
Fracture Strength ◽  
Polycrystalline Silicon ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Β Phase ◽  
Α Phase

A novel transparent polycrystalline silicon nitride was fabricated by hot-press sintering with MgO and AlN as additives. The mixed powder with 3 wt.% MgO and 9 wt.% AlN was sintered at 1900oC for 1 hour under 30 MPa pressure in a nitrogen gas atmosphere. Transparent polycrystalline silicon nitride was successfully fabricated. The mechanical properties such as density, hardness, young’s modulus, fracture strength and fracture toughness were evaluated. The effect of α/β phase on the mechanical properties of transparent polycrystalline silicon nitride was investigated. The properties were changed depending on the amount of α/β phase. The hardness and Young's modulus increased with increasing the volume fraction of α-phase fraction as a reflection of the higher hardness of α-phase Si3N4. The fracture toughness and fracture strength decreased with decreasing the volume fraction of β-phase Si3N4.

Mechanical Properties of Carboxymethyl Cellulose-Oleic Acid Solid Biopolymer Electrolyte

2018 ◽  
Vol 929 ◽  
pp. 186-190 ◽  
Author(s):  
M.N. Chai ◽  
M.M. Chai ◽  
M.I.N. Isa
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Oleic Acid ◽  
Young’S Modulus ◽  
Carboxymethyl Cellulose ◽  
Young's Modulus ◽  
Testing Machine ◽  
Strain Curve ◽  
Weight Percentage ◽  
Universal Material Testing Machine

In this paper, the mechanical properties of carboxymethyl cellulose-oleic acid (CMC-OA) solid bio-polymer electrolyte (SBE) were examined. The host, CMC was doped with different weight percentage (wt. %) of OA in the CMC-OA solution. The SBEs were tested by using the Universal Material Testing Machine where the readings of tensile strength and Young’s modulus can be obtained from the stress-strain curve produced by the software during the tension test. The sample of CMC doped with 20% wt. of OA was found to obtain the highest value of tensile strength and Young’s modulus which is 0.2069 MPa and 4.615 MPa respectively.

Thermal Cycling Effect on Mechanical Properties, Grain Size and Residual Stress in Alumina and Yttria-Stabilized Tetragonal Zirconia

2014 ◽  
Vol 875-877 ◽  
pp. 1642-1646
Author(s):  
Jing Zhang
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Grain Size ◽  
Thermal Cycling ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Tetragonal Zirconia ◽  
Thermal Cycles ◽  
Optical Applications ◽  
Increasing Temperature

Alumina and zirconia are important materials for energy and optical applications. In this study, the effect of thermal cycling on grain size and residual stress was reported. Residual stress was measured using X-ray diffraction (XRD) sin2ψ method for the as-received and the samples after thermal cycling up to 900 cycles. For alumina, the measured residual stress is approximately 96 MPa in tensile for the as-received material, and increases to its highest value of 480 MPa after 650 thermal cycles. The residual stress decreases from 480 MPa to 96 MPa in tensile with increased thermal cycling from 650 to 900 cycles. The crystallized grain size calculated from the diffraction pattern shows that the mean crystallized grain size is about 93 nm for the as-received and increases to 232 nm after 650 thermal cycles. This result is consistent with the enlarged grain size observed by scanning electron microscopy for the alumina after 650 thermal cycles reported earlier. With continued thermal cycling up to 900 cycles, the crystallized grain size is greatly reduced to 104 nm. It suggests that evolution of the crystallized grain size is correlated with the residual stress. For yttria-stabilized tetragonal zirconia (Y-TZP), the mechanical properties at room temperature, are consistent with the property values provided by the manufacturer. The Young’s modulus of shows a non-linear inverse relationship with increasing temperature. The degradation of the Young’s modulus mostly occurs prior to 400 °C and to a less extent in the temperature range of 400 °C up to 850 °C. The Vickers hardness number for the as-received Y-TZP material decreases to a very small extent after 560 thermal cycles and increases approximately 2%, after 1200 thermal cycles. This is consistent with the trend of the Young’s modulus for thermal-cycled specimens.

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