Fabrication and mechanical properties of boron nitride nanotube reinforced silicon 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.

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Development of High Performance Silicon Nitride Ceramics and their Applications

MRS Proceedings ◽

10.1557/proc-287-189 ◽

1992 ◽

Vol 287 ◽

Cited By ~ 22

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.

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Microstructure and Mechanical Properties of Hot-pressed Silicon Nitride Ceramics

Advanced Materials '93 ◽

10.1016/b978-0-444-81991-8.50212-0 ◽

1994 ◽

pp. 883-886

Author(s):

Yutaka Sato ◽

Masaaki Mishima ◽

Masanori Ueki

Keyword(s):

Mechanical Properties ◽

Silicon Nitride ◽

Microstructure And Mechanical Properties ◽

Nitride Ceramics

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Effect of rare earth oxides addition on the mechanical properties and coloration of silicon nitride ceramics

Journal of the European Ceramic Society ◽

10.1016/j.jeurceramsoc.2019.11.058 ◽

2020 ◽

Vol 40 (4) ◽

pp. 1132-1138 ◽

Cited By ~ 2

Author(s):

Ning Liu ◽

Jingxian Zhang ◽

Yusen Duan ◽

Xingbang Li ◽

Shaoming Dong

Keyword(s):

Mechanical Properties ◽

Rare Earth ◽

Silicon Nitride ◽

Rare Earth Oxides ◽

Nitride Ceramics

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Mechanical Properties and Oxidation Behavior of Si3N4/BN Laminated Ceramics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.280-283.1869 ◽

2007 ◽

Vol 280-283 ◽

pp. 1869-1872

Author(s):

Cui Wei Li ◽

Chang An Wang ◽

Yong Huang

Keyword(s):

Mechanical Properties ◽

High Temperature ◽

Silicon Nitride ◽

Boron Nitride ◽

Oxidation Behavior ◽

Elevated Temperatures ◽

Testing Procedure ◽

No Oxidation ◽

Temperature Oxidation ◽

High Temperature Oxidation Behavior

Laminated ceramics with high mechanical properties were fabricated in the Si3N4/BN system. The mechanical properties at elevated temperatures were tested, and the oxidation behavior during tested procedure was studied at the same time. The flexure strength of the Si3N4/BN laminated ceramics changed a little below 1000°C. The displacement-load curves appeared non-linear characteristic even at high temperature. During testing procedure at high temperature, oxidation behavior of silicon nitride and silicon carbide happened, and no oxidation product of boron nitride was found. The silicon nitride layers were oxidized to form a protective silicate scale, which prevented oxidation of the boron nitride interlayers. The stability of boron nitride was beneficial to the boron nitride interlayer to partition the silicon nitride matrix layers at high temperature.

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