Effect of α/β phase ratio on microstructure and mechanical properties of silicon nitride ceramics

2001 ◽  
Vol 16 (8) ◽  
pp. 2264-2270 ◽  
Author(s):  
Hirokazu Kawaoka ◽  
Tomohiko Adachi ◽  
Tohru Sekino ◽  
Yong-Ho Choa ◽  
Lian Gao ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Silicon Nitride ◽  
Phase Ratio ◽  
Phase Content ◽  
Sintering Process ◽  
Β Phase ◽  
Nitride Ceramics ◽  
Pulse Electric ◽  
Sintering Condition ◽  
Sintered Materials

Highly densed silicon nitride ceramics with various α/β phase ratios were produced by pulse electric current sintering process. The β-phase content of Si3N4 in sintered materials varied from 20 to 100 wt% depending on the sintering condition. The microstructure was observed by scanning electron microscopy and investigated by image analysis. Young's modulus, hardness, fracture toughness, and strength were strongly dependent on the α/β phase ratio. The fracture toughness increased from 4.6 MPa m1/2 for 20-wt% b-phase content to 8.2 MPa m1/2 for 95-wt% β-phase content, and the fracture strength showed a maximum value of about 1.6 GPa at 60-to-80-wt% β-phase content.

scholarly journals Influence of MXene (Ti3C2) Phase Addition on the Microstructure and Mechanical Properties of Silicon Nitride Ceramics

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5221
Author(s):  
Jaroslaw Wozniak ◽  
Mateusz Petrus ◽  
Tomasz Cygan ◽  
Artur Lachowski ◽  
Bogusława Adamczyk-Cieślak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Transformation ◽  
Silicon Nitride ◽  
Powder Processing ◽  
Sintering Process ◽  
Microstructure And Mechanical Properties ◽  
Plasma Sintering ◽  
Nitride Ceramics ◽  
Spark Plasma

This paper discusses the influence of Ti3C2 (MXene) addition on silicon nitride and its impact on the microstructure and mechanical properties of the latter. Composites were prepared through powder processing and sintered using the spark plasma sintering (SPS) technic. Relative density, hardness and fracture toughness, were analyzed. The highest fracture toughness at 5.3 MPa·m1/2 and the highest hardness at HV5 2217 were achieved for 0.7 and 2 wt.% Ti3C2, respectively. Moreover, the formation of the Si2N2O phase was observed as a result of both the MXene addition and the preservation of the α-Si3N4→β-Si3N4 phase transformation during the sintering process.

Correlation between fracture toughness and microstructure of seeded silicon nitride ceramics

2007 ◽  
Vol 42 (18) ◽  
pp. 7920-7926 ◽  
Author(s):  
D. Bučevac ◽  
S. Bošković ◽  
B. Matović ◽  
Lj. Živković ◽  
M. Vlajić ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Silicon Nitride ◽  
Nitride Ceramics

scholarly journals Comparison of fracture toughness measuring methods applied on silicon nitride ceramics

1993 ◽  
Vol 03 (C7) ◽  
pp. C7-1273-C7-1276 ◽  
Author(s):  
E. RUDNAYOVÁ ◽  
J. DUSZA ◽  
M. KUPKOVÁ
Keyword(s):  
Fracture Toughness ◽  
Silicon Nitride ◽  
Measuring Methods ◽  
Nitride Ceramics

Effects of Sintering Additives on the Microstructure and Mechanical Properties of Silicon Nitride Ceramics by GPS

2010 ◽  
Vol 105-106 ◽  
pp. 27-30 ◽  
Author(s):  
Wei Ru Zhang ◽  
Feng Sun ◽  
Ting Yan Tian ◽  
Xiang Hong Teng ◽  
Min Chao Ru ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Transformation ◽  
Silicon Nitride ◽  
Porous Silicon ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Additives ◽  
Microstructure And Mechanical Properties ◽  
Nitride Ceramics

Silicon nitride ceramics were prepared by gas pressure sintering (GPS) with different sintering additives, including La2O3, Sm2O3 and Al2O3. Effect of sintering additives on the phase-transformation, microstructure and mechanical properties of porous silicon nitride ceramics was investigated. The results show that the reaction of sintering additives each other and with SiO2 had key effects on the phase-transformation, grain growing and grain boundaries. With 9MPa N2 atmosphere pressure, holding 1h at 1850°C, adding 10wt% one of the La2O3, Sm2O3, Al2O3, porous silicon nitride was prepared and the relative density was 78%, 72%, 85% respectively. The flexural strength was less than 500MPa, and the fracture toughness was less than 4.8MPam1/2. Dropping compounds sintering additives, such as La2O3+Al2O3, Sm2O3+Al2O3 effectively improves the sintering and mechanical properties. The relative density was 99.2% and 98.7% with 10wt% compounds sintering additives. The grain ratio of length to diameter was up to 1:8. The flexural strength was more than 900MPa, and the fracture toughness was more than 8.9MPam1/2.

Development of High Performance Silicon Nitride Ceramics and their Applications

1992 ◽  
Vol 287 ◽  
Author(s):  
Yo Tajima
Keyword(s):  
Mechanical Properties ◽  
Silicon Nitride ◽  
High Performance ◽  
Future Prospect ◽  
Cutting Tools ◽  
Sintering Process ◽  
Sintering Additives ◽  
Nitride Ceramics ◽  
Engine Components

ABSTRACTProgress in sintering process and improvement of mechanical properties of silicon nitride ceramics are reviewed. Emphases are placed on contributions of advanced sintering techniques and better understanding of sintering additives and microstructure-properties relations. Current applications as engine components and cutting tools are described, and future prospect is considered.

scholarly journals Comparison between Pulse Electric Current Sintering and Hot Pressing of Silicon Nitride Ceramics.

1999 ◽  
Vol 107 (1250) ◽  
pp. 887-890 ◽  
Author(s):  
Shigetaka WADA ◽  
Motohiro SUGANUMA ◽  
Yasunori KITAGAWA ◽  
Norimitsu MURAYAMA
Keyword(s):  
Silicon Nitride ◽  
Electric Current ◽  
Hot Pressing ◽  
Pulse Electric Current ◽  
Nitride Ceramics ◽  
Pulse Electric

scholarly journals Errata: Sintering Condition and Microstructure of Translucent Silicon Nitride Ceramics

2015 ◽  
Vol 62 (4) ◽  
pp. 216_1
Author(s):  
Junichi HOJO ◽  
Wenwu YANG ◽  
Miki INADA ◽  
Yumi TANAKA ◽  
Naoya ENOMOTO
Keyword(s):  
Silicon Nitride ◽  
Nitride Ceramics ◽  
Sintering Condition

Si3N4/BN Composite Ceramics with Nd2O3-Al2O3-Y2O3 Ternary Additives by Pressureless Sintering

2010 ◽  
Vol 434-435 ◽  
pp. 106-108
Author(s):  
Ping Liu ◽  
Yong Feng Li ◽  
Xiang Dong Wang ◽  
Hai Yun Jin ◽  
Guan Jun Qiao
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Transformation ◽  
Flexural Strength ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Composite Ceramics ◽  
Fracture Toughness Testing ◽  
Β Phase ◽  
Toughness Testing

Si3N4/BN composite ceramics with 25vol% h-BN were prepared by pressure-less sintering process with Nd2O3/Al2O3/Y2O3 as sintering additives. The effects of these ternary additives on the densification behaviors and mechanical properties were investigated. XRD and FESEM were used to investigate the α-β phase transformation and microstructure. The XRD results showed that α-Si3N4 has transformed to β-Si3N4 completely in all the samples during the pressureless sintering process. The line shrinkage increased with the Nd2O3 contents increasing, and the highest line shrinkage (7.75%) was observed when 4wt% Nd2O3 was added, then decreased. The same trends were observed in flexural strength and fracture toughness testing. The ternary additives of Y2O3-Al2O3-Nd2O3 could improve the density, strength and fracture toughness of the material effectively.

Sign in / Sign up

Export Citation Format

Share Document