scholarly journals Effects of Microwave Sintering Temperature and Holding Time on Mechanical Properties and Microstructure of Si3N4/n-SiC ceramics

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3837 ◽  
Author(s):  
Li Qiao ◽  
Zhenhua Wang ◽  
Taiyi Lu ◽  
Juntang Yuan
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Formation ◽  
Mechanical Performance ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Holding Time ◽  
Sic Ceramics ◽  
Si3n4 Ceramics

The n-SiC (nanometer SiC) is added to be the additive in order to improve the mechanical performance of Si3N4 ceramics. A microwave sintered the ceramics at different temperature and holding times. The results shows that the Si3N4/n-SiC ceramics (85 wt% Si3N4 + 5 wt% n-SiC + 5 wt% Al2O3 + 5 wt% Y2O3) have the best mechanical properties at 1600 °C, which is beneficial to the densification and β-Si3N4 phase formation for 10 min: the density, hardness, and fracture toughness were 97.1%, 14.44 GPa, and 7.77 MPa·m1/2, which increased by 2.8%, 7.0%, and 13.1%, respectively, when compared with the ceramics (90 wt% Si3N4 + 5 wt% Al2O3 + 5 wt% Y2O3).

Microwave Sintering of Si3N4 Ceramics

1992 ◽  
Vol 269 ◽  
Author(s):  
Jinsong Zhang ◽  
Lihua Cao ◽  
Fei Xia
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Pressureless Sintering ◽  
Transformation Rate ◽  
Sintering Time ◽  
Si3n4 Ceramics ◽  
Room Temperature Strength ◽  
Better Than

ABSTRACTThe Si3N4 ceramics(91wt%Si3N4+5wt%Y2O3+4wt%Al2O3) of room temperature strength 620--760 MPa and fracture toughness 7 MPa-m½ were prepared by microwave sintering and their microstructure and mechanical properties were studied.The experiment results show that the higher N2 pressure (>4atm) is very necessary for microwave sintering of Si3N4 ceramics; microwave sintering can greatly decrease the sintering temperature to 1500* C, and increase the transformation rate of α to β-Si3N4,and reduce the total sintering time to about 1 hour. The mechanical properties of the Si3N4 ceramics sintered by microwave are better than that by conventional pressureless sintering.

Mechanical Properties of La2O3-Al2O3 Ceramics Prepared by Microwave Sintering

2012 ◽  
Vol 519 ◽  
pp. 265-268 ◽  
Author(s):  
Yun Long Ai ◽  
Fei He ◽  
Bing Liang Liang ◽  
Wen He ◽  
Wei Hua Chen
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Draw Ratio ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Microwave Energy ◽  
Pure Alumina ◽  
Sintering Time ◽  
Microstructure Evaluation ◽  
Columnar Grains

The influence of La2O3 on the phase and microstructure evaluation and mechanical properties of La2O3-Al2O3 ceramics sintered with 2.45 GHz microwave energy was investigated. The results showed that La2O3 could densify the pure alumina with a lower sintering temperature and a short sintering time. La2O3 reacted with Al2O3 to form LaAl11O18 completely and the amount of LaAl11O18 increased with the increasing content of La2O3, distributing at the Al2O3 grain boundaries. The specimen doped with 10 vol.% and 15 vol.% La2O3 sintered at 1500 °C exhibited plenty of columnar grains with draw ratio about 1:4. The existence of columnar grains enhanced the microhardness and fracture toughness of La2O3-Al2O3 ceramics.

Mechanical Properties of Al2O3-TiN Nanocomposite Ceramic Tool Materials

2012 ◽  
Vol 499 ◽  
pp. 108-113
Author(s):  
Yu Huan Fei ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Vickers Hardness ◽  
Sintering Temperature ◽  
Holding Time ◽  
Bending Test ◽  
Ceramic Tool ◽  
Tool Materials ◽  
Nano Scale

Al2O3-TiN nanocomposite ceramic tool materials were fabricated by hot-pressing technique and the mechanical properties were measured. Mechanical properties such as room temperature flexural strength, Vickers hardness and fracture toughness were measured through three-point bending test and Vickers indentation. The effects of the content of nano-scale TiN, sintering temperature and holding time on the mechanical properties were investigated. The results shows that the addition of nano-scale TiN can improve the mechanical properties of alumina ceramics. Both the flexural strength and the fracture toughness first increased then decreased with an increment in the content of nano-scale TiN. Both the Vickers hardness and the fracture toughness increased with an increment in the sintering temperature. The flexural strength increased with an increment in the holding time, while the fracture toughness decreased with an increment in the holding time. The composites with only nano-scale TiN have the highest Vickers hardness for the holding time of 30min, while the hardness of the composites with nano-scale TiN and micro-scale TiN decreased with an increment in the holding time.

Effect of Temperature and Holding Time on Zirconia Toughened Alumina (ZTA) Prepared by Two-Stage Sintering

2021 ◽  
Vol 1030 ◽  
pp. 11-18
Author(s):  
Teow Hsien Loong ◽  
Ananthan Soosai ◽  
Suresh Muniandy
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Young’S Modulus ◽  
Sintering Temperature ◽  
Young's Modulus ◽  
Holding Time ◽  
Effect Of Temperature ◽  
Two Stage ◽  
Pinning Effect ◽  
Zirconia Toughened Alumina

The microstructure and mechanical properties of Zirconia Toughened Alumina (ZTA) produced via two-stage sintering at various sintering temperature of T1 and T2 in addition to effect of various holding time were investigated. T1 temperature was set between the range of 1400°C to 1500°C with a heating rate of 20°C/min. The samples were then sintered at T2 ranging from 1350°C to 1400°C followed by various holding time between 2 hours to 12 hours. The sintered samples’ microstructural properties, bulk density, hardness (Vickers hardness), elastic modulus (Young’s modulus) and fracture toughness (K1C) were then determined. Compared to standard holding time of two-stage sintering which is 12 hours, results show that ZTA produced via two-stage sintering with shorter holding time of 4 hours with T1 set at 1500°C and T2 of 1450°C are capable of achieving full densification. In addition, the same sample were also able to achieve hardness up to 19 GPa, Young’s modulus of 390 GPa and fracture toughness of 6.1 MPam1/2. The improvement in mechanical properties can be mainly attributed to the absent of surface diffusion at T2 above 1400°C and also presence of Y-TZP which contributed to lower grain growth due to the pinning effect.

Sinterability and Mechanical Properties of MnO2-Doped Y-TZP: The Effects of Holding Time Variations

2011 ◽  
Vol 110-116 ◽  
pp. 1284-1288 ◽  
Author(s):  
Mahdi Amiriyan ◽  
Meenaloshini Satgunam ◽  
Sivanesan Sivakumar ◽  
Singh Ramesh ◽  
Ranna Tolouei
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Beneficial Effect ◽  
Bulk Density ◽  
Vickers Hardness ◽  
Time Variation ◽  
Sintering Temperature ◽  
Tetragonal Zirconia ◽  
Holding Time ◽  
Time Variations

The effect of holding time variation and sintering temperature on the mechanical properties and sinterability of yttria stabilized tetragonal zirconia doped with 1 wt. % MnO2 was investigated. Samples were sintered at 1150-1500 °C with holding times varying from 12 and 120 minutes. Comparing to the MnO2-doped Y-TZP, longer holding time resulted in enhanced densification of the undoped Y-TZP samples. In the case of MnO2-doped Y-TZP however, Bulk density, Young’s modulus, Vickers hardness and fracture toughness results show the beneficial effect of MnO2 in enhancing the densification of Y-TZP ceramics.

scholarly journals Microstructure and Properties of Ultrafine Cemented Carbides Prepared by Microwave Sintering of Nanocomposites

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 507
Author(s):  
Yanju Qian ◽  
Zhiwei Zhao
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Vickers Hardness ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Raw Material ◽  
Cemented Carbides ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size

Ultrafine cemented carbides were prepared by microwave sintering, using WC-V8C7-Cr3C2-Co nanocomposites as a raw material. The effects of sintering temperature and holding time on the microstructure and mechanical properties of cemented carbides were studied. The results show that the ultrafine cemented carbides prepared at 1300 °C for 60 min have good mechanical properties and a good microstructure. The relative density, Vickers hardness, and fracture toughness of the specimen reach the maximum values of 99.79%, 1842 kg/mm2 and 12.6 MPa·m1/2, respectively. Tungsten carbide (WC) grains are fine and uniformly distributed, with an average grain size of 300–500 nm. The combination of nanocomposites, secondary pressing, and microwave sintering can significantly reduce the sintering temperature and inhibit the growth of WC grains, thus producing superfine cemented carbides with good microstructure and mechanical properties.

scholarly journals C0.3N0.7Ti-SiC Toughed Silicon Nitride Hybrids with Non-Oxide Additives Ti3SiC2

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1428
Author(s):  
Heng Luo ◽  
Chen Li ◽  
Lianwen Deng ◽  
Yang Li ◽  
Peng Xiao ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Silicon Nitride ◽  
Flexural Strength ◽  
Mechanical Performance ◽  
Sintering Temperature ◽  
Hot Press ◽  
Pull Out ◽  
Hot Press Sintering ◽  
Si3n4 Ceramics

In situ grown C0.3N0.7Ti and SiC, which derived from non-oxide additives Ti3SiC2, are proposed to densify silicon nitride (Si3N4) ceramics with enhanced mechanical performance via hot-press sintering. Remarkable increase of density from 79.20% to 95.48% could be achieved for Si3N4 ceramics with 5 vol.% Ti3SiC2 when sintered at 1600 °C. As expected, higher sintering temperature 1700 °C could further promote densification of Si3N4 ceramics filled with Ti3SiC2. The capillarity of decomposed Si from Ti3SiC2, and in situ reaction between nonstoichiometric TiCx and Si3N4 were believed to be responsible for densification of Si3N4 ceramics. An obvious enhancement of flexural strength and fracture toughness for Si3N4 with x vol.% Ti3SiC2 (x = 1~20) ceramics was observed. The maximum flexural strength of 795 MPa for Si3N4 composites with 5 vol.% Ti3SiC2 and maximum fracture toughness of 6.97 MPa·m1/2 for Si3N4 composites with 20 vol.% Ti3SiC2 are achieved via hot-press sintering at 1700 °C. Pull out of elongated Si3N4 grains, crack bridging, crack branching and crack deflection were demonstrated to dominate enhance fracture toughness of Si3N4 composites.

Mechanical Properties and Microstructure of Reaction Sintering B4C/SiC Ceramics

2011 ◽  
Vol 66-68 ◽  
pp. 510-515
Author(s):  
Wen Song Lin ◽  
Ning Xiang Fang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Carbon Content ◽  
Sintering Temperature ◽  
Reaction Sintering ◽  
Sic Ceramics ◽  
Compact Pressure ◽  
Optimal Value ◽  
Major Factors

Reaction sintering B4C/SiC ceramics with high density were manufactured. The effect of the carbon content in green bodies on the microstructure and mechanical properties of the ceramics has been studied. Results showed that the carbon content and the value of carbon relative density (ρCRD) in the green bodies were the major factors affected the composition, that is, the free silicon and carbon contents and mechanical behaviors of sintered specimens. The optimal value of ρCRD was gotten at 0.85 g/cm3. The fracture toughness, flexural strength, and hardness of the composites increased with increasing carbon content up to 20 wt.%. The maximum values of fracture toughness of 3.8 MPa∙m1/2, flexural strength of 475 MPa, and hardness of 32.0 GPa were obtained under the following process parameters: value of ρCRD in the green bodies was about 0.85 g/cm3; carbon, B4C and SiC contents in green bodies were 20 wt.%, 30 wt.% and 50 wt.%, respectively; compact pressure was 75 MPa and sintering temperature was 1600°C.

Mechanical Properties of Nb2O5-Al2O3 Ceramics Prepared by Microwave Sintering

2011 ◽  
Vol 338 ◽  
pp. 120-123 ◽  
Author(s):  
Yun Long Ai ◽  
Fei He ◽  
Bing Liang Liang ◽  
Wen He ◽  
Wei Hua Chen
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Draw Ratio ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Microwave Energy ◽  
Pure Alumina ◽  
Sintering Time ◽  
Microstructure Evaluation ◽  
Columnar Grains

The influence of Nb2O5 on the phase and microstructure evaluation and mechanical properties of Nb2O5-Al2O3 ceramics sintered with 2.45 GHz microwave energy was investigated. The results showed that Nb2O5 could densify the pure alumina with a lower sintering temperature and a short sintering time. Nb2O5 reacted with Al2O3 to form AlNbO4 completely and the amount of AlNbO4 increased with the increasing content of Nb2O5, distributing at the Al2O3 grain boundaries. The specimen doped with 10 vol.% Nb2O5 sintered at 1500 °C exhibited plenty of columnar grains with draw ratio about 1:3. The existence of columnar grains enhanced the microhardness and fracture toughness of Nb2O5-Al2O3 ceramics.

Effect of toughened polyamide-coated carbon fiber fabric on the mechanical performance and fracture toughness of CFRP

2021 ◽  
pp. 002199832199945
Author(s):  
Jong H Eun ◽  
Bo K Choi ◽  
Sun M Sung ◽  
Min S Kim ◽  
Joon S Lee
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Photoelectron Spectroscopy ◽  
Mechanical Performance ◽  
Epoxy Composites ◽  
Scanning Calorimetry ◽  
Internal Damage ◽  
Impact Tests ◽  
Flexural Tests ◽  
The Impact

In this study, carbon/epoxy composites were manufactured by coating with a polyamide at different weight percentages (5 wt.%, 10 wt.%, 15 wt.%, and 20 wt.%) to improve their impact resistance and fracture toughness. The chemical reaction between the polyamide and epoxy resin were examined by fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray photoelectron spectroscopy. The mechanical properties and fracture toughness of the carbon/epoxy composites were analyzed. The mechanical properties of the carbon/epoxy composites, such as transverse flexural tests, longitudinal flexural tests, and impact tests, were investigated. After the impact tests, an ultrasonic C-scan was performed to reveal the internal damage area. The interlaminar fracture toughness of the carbon/epoxy composites was measured using a mode I test. The critical energy release rates were increased by 77% compared to the virgin carbon/epoxy composites. The surface morphology of the fractured surface was observed. The toughening mechanism of the carbon/epoxy composites was suggested based on the confirmed experimental data.

Sign in / Sign up

Export Citation Format

Share Document