Progress in Silicon Nitride Ceramics in Japan

1992 ◽  
Vol 287 ◽  
Author(s):  
K. Komeya
Keyword(s):  
Silicon Nitride ◽  
Cost Reduction ◽  
Industrial Applications ◽  
Powder Synthesis ◽  
Materials Development ◽  
Nitride Ceramics ◽  
Government Project ◽  
Three Stages ◽  
The Government ◽  
Fine Ceramics

ABSTRACTProgress in silicon nitride ceramics in Japan is reviewed. It is historically divided into three stages. Through these stages, basic experimental research and innovations have progressed along with industrial applications, and the government project on fine ceramics in 1981-1992 has contributed much to the acceleration in the development of silicon nitride ceramics. Focus in this paper is mainly on materials development including raw powder synthesis and exploration for applications. The future prospect of utilizing silicon nitride as an engineering material, however, is seen to depend on cost reduction and reliability improvement.

scholarly journals Influence of the substitution of Y2O3 for CeO2 on the mechanical and microstructural properties of silicon nitride

Cerâmica ◽  
2005 ◽  
Vol 51 (319) ◽  
pp. 285-288
Author(s):  
J. V. C. de Souza ◽  
C. A. Kelly ◽  
M. R. V. Moreira ◽  
M. V. Ribeiro ◽  
C. dos Santos ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Cost Reduction ◽  
Nitrogen Atmosphere ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
X Ray ◽  
Nitride Ceramics ◽  
Mechanical And Microstructural Properties ◽  
Sintered Silicon

This work investigated the substitution of Y2O3 for CeO2 in liquid-phase sintered silicon nitride ceramics. Cost reduction as well as good physical, mechanical and microstructural properties are the main objectives of the present study. Two powder mixtures were prepared, varying the contents of alpha-Si3N4, Al2O3, AlN, Y2O3 and CeO2. The mixtures were homogenized in ethanol, dried in a rotating evaporator and kiln, respectively, and then uniaxially (100 MPa) and cold isostatically pressed (300 MPa). The samples were sintered at 1850ºC for 1 h in a graphite resistive furnace under nitrogen atmosphere. After sintering the density of the samples was higher than 97% of the theoretical value. The fracture toughness and hardness were higher than 5.28 MPa.m½ and 17.12 GPa, respectively. Phase analysis by X-ray diffraction and scanning electron microscopy revealed the presence of alpha-SiAlON and beta-Si3N4.

Thermal Modeling for Laser-Assisted Machining of Silicon Nitride Ceramics with Complex Features

2005 ◽  
Vol 128 (2) ◽  
pp. 425-434 ◽  
Author(s):  
Yinggang Tian ◽  
Yung C. Shin
Keyword(s):  
Silicon Nitride ◽  
Thermal Model ◽  
Three Dimensional ◽  
Infrared Camera ◽  
Ceramic Materials ◽  
Industrial Applications ◽  
Laser Assisted Machining ◽  
Nitride Ceramics ◽  
Complex Features ◽  
Fabrication Costs

The feasibility of laser-assisted machining (LAM) and its potential to significantly reduce fabrication costs and improve product quality have been shown experimentally for various ceramic materials. However, no systematical investigation has been performed to expand LAMs capability to parts with complex features, although such capability is essential for industrial applications. This paper presents a transient, three-dimensional thermal model developed for LAM of workpieces with complex geometric features and its validation by in-process surface temperature measurements with an infrared camera. It is shown that the LAM experiments designed based on the predictions by the thermal model successfully produced silicon nitride parts with complex features, thus demonstrating the capabilities of LAM in fabricating ceramic parts suitable for industrial implementation.

Seeds Innovation and Bearing Applications of Silicon Nitride Ceramics

2007 ◽  
Vol 352 ◽  
pp. 147-152 ◽  
Author(s):  
Katsutoshi Komeya ◽  
Junichi Tatami
Keyword(s):  
Silicon Nitride ◽  
Grain Boundary ◽  
Powder Processing ◽  
Flaw Detection ◽  
High Strength ◽  
Production Volume ◽  
Materials Development ◽  
Nitride Ceramics ◽  
National University ◽  
New Applications

Silicon nitride (Si3N4) is one of the most attractive materials for wear applications because it has excellent wear resistance and offers advantages such as light weight, higher strength and toughness, and good corrosion resistance. In 1984, Materials Div., Toshiba Corp. (today, Toshiba Materials Co., Ltd.) and Koyo Seiko Co. Ltd. (today JTEKT Corp.) successfully utilized high-strength silicon nitride for anti-friction bearings for the first time in the world.1-3 This ceramic bearing was a most successful product and has expanded in area and volume through key innovations such as pioneered compositions, further improvement of durability against a steel ball and the development of a conventional fabrication process. Since 1989, Yokohama National University group has investigated new materials development in silicon nitride ceramics, densification/strengthening mechanisms in an optimized sintering aids system, powder processing for reliable components and tribological evaluation for bearing applications. Subsequently it was confirmed that the addition of TiO2 and AlN to an Si3N4-Y2O3-Al2O3 system promoted densification at low temperatures.4 During firing, the TiO2 changed into TiN at the grain boundary, causing grain boundary strengthening.5,6 Most recently, it has developed a carbon nanotube (CNT) dispersed silicon nitride with high strength and high electrical conductivity that is expected to open up new applications as a new functional silicon nitride.7 However, there are many items to be overcome toward the future, which are the development of cost reduction processes with higher material reliability, and the opening up of new applications supported by validated evaluation techniques including tribology, flaw detection and life prediction, raw powder problems related to cost and production volume, and the classification of silicon nitride bearings for various graded applications.

Status and Standards in ISO/TC206 'Fine Ceramics'

2016 ◽  
Vol 690 ◽  
pp. 57-64
Author(s):  
Shuji Sakaguchi
Keyword(s):  
Ceramic Materials ◽  
Industrial Applications ◽  
Technical Committee ◽  
International Organization ◽  
Wide Field ◽  
Testing Methods ◽  
Fundamental Properties ◽  
Bearing Materials ◽  
Working Groups ◽  
Fine Ceramics

ISO/TC206 'Fine ceramics' is one of a technical committee (TC) in the International Organization for Standardization (ISO), established in 1992. The first plenary meeting for this TC was held in 1994, and the latest meeting was held in August 2015, in Jeju, Republic of Korea. The scope of this TC covers very wide field concerning the ceramic materials for industrial applications, in forms of powders, monoliths, coatings and composites, and in functions of mechanical, thermal, chemical, electrical, magnetic, optical and their combinations. This TC consists of 18 participating member (P-member) countries and 13 observing member (O-member) countries. We already have 81 published standards from this TC. About 30 new work items are under discussion, about 15 items are waiting for starting the discussion, and about 10 items are in the process for revision of the published standards. In this TC, we have 12 working groups. More than twenty years have passed since starting this TC, generally speaking, the categories of the discussed items tends to shift, from some testing methods for fundamental properties (strength, density, thermal properties etc.), to some properties for specified applications, such as ceramic bearing materials, photocatalytic materials and electrical applications.

Microstructure, toughness and flexural strength of self-reinforced silicon nitride ceramics doped with yttrium oxide and ytterbium oxide

2001 ◽  
Vol 201 (2) ◽  
pp. 238-249 ◽  
Author(s):  
Y. S. Zheng ◽  
K. M. Knowles ◽  
J. M. Vieira ◽  
A. B. Lopes ◽  
F. J. Oliveira
Keyword(s):  
Silicon Nitride ◽  
Flexural Strength ◽  
Yttrium Oxide ◽  
Ytterbium Oxide ◽  
Nitride Ceramics
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