Influence of Additives and Hot-Press Sintering on Lipophilic Properties of Silicon Nitride Ceramics

Silicon nitride nanoceramics were prepared by hot press sintering amorphous Si3N4and α-Si3N4nanopowders. The microstructures as well as the effect of starting powders size on the mechanical properties and thermal fatigue properties were investigated. The results show that microstructure of sintered materials consists of spherical grains with approximate size of 100 nm. The mechanical properties and thermal fatigue resistance vary with the addition of α–Si3N4powders. The maximum flexural strength and fracture toughness are obtained when the α–Si3N4powders amount is 40wt.%. And the Si3N4nanoceramic added 40wt.% α–Si3N4powders has the best capability to suppress crack propagation and the highest critical temperature difference.

Download Full-text

Influence of Component Exerted and Hot Press Sintered on Lipophulic Property of Silicon Nitride Ceramics

Journal of the Japan Institute of Metals and Materials ◽

10.2320/jinstmet.68.475 ◽

2004 ◽

Vol 68 (7) ◽

pp. 475-481 ◽

Cited By ~ 2

Author(s):

Koji Kato ◽

Kouji Mukai ◽

Tarou Tokuda ◽

Syouzou Nakamura ◽

Mitsuo Kido

Keyword(s):

Silicon Nitride ◽

Hot Press ◽

Nitride Ceramics

Download Full-text

Sintering of β-Si3N4 Powder Prepared by Self-Propagating High-Temperature Synthesis (SHS)

Materials Science Forum ◽

10.4028/www.scientific.net/msf.546-549.2179 ◽

2007 ◽

Vol 546-549 ◽

pp. 2179-2182 ◽

Cited By ~ 2

Author(s):

Ling Bai ◽

Xing Yu Zhao ◽

Chang Chun Ge

Keyword(s):

High Temperature ◽

Silicon Nitride ◽

Bending Strength ◽

Sintering Process ◽

Hot Press ◽

Temperature Synthesis ◽

High Temperature Synthesis ◽

Good Sinter ◽

The Cost ◽

Hot Press Sintering

Sintering of the Self-Propagating High-Temperature Synthesis (SHS) of β-Si3N4 powder with 6.67 wt.% Y2O3 and 3.33 wt.% Al2O3 as sintering additives has been emphatically investigated using hot-press sintering process. The relative density of hot-pressed β-Si3N4 reached near to the full densification (99.43%) at 1700°C. The similar micrographs with self-reinforcing rod-like β-Si3N4 grains forming an interlocking structure were observed. The better mechanical properties of hot-pressed Si3N4, such as the hardness (16.73GPa), fracture toughness (5.72 MPa·m1/2) and bending strength (611.72MPa) values, were obtained at 1700°C. The results indicate that good sinter ability can be obtained with the cheaply SHS of silicon nitride powder for preparing silicon nitride materials, which will make the cost of silicon nitride materials lowered.

Download Full-text

Electrically Conductive Aluminum Nitride Ceramics Containing In-Situ Synthesized Boron Carbonitride

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.317-318.653 ◽

2006 ◽

Vol 317-318 ◽

pp. 653-656 ◽

Cited By ~ 3

Author(s):

Jun Yoshikawa ◽

Yuji Katsuda ◽

Naohito Yamada ◽

Hiroaki Sakai

Keyword(s):

Three Dimensional ◽

Nitrogen Atmosphere ◽

Hot Press ◽

Boron Carbonitride ◽

Electrically Conductive ◽

Sintering Aid ◽

Nitride Ceramics ◽

Hot Press Sintering ◽

Treatment Step

Electrically conductive AlN ceramics were fabricated by the addition of a small amount of B4C and sintering aid, and hot-press sintering in a nitrogen atmosphere. The electrical resistivity of AlN ceramics decreased remarkably from 1014 cm to the range of 100 to 102 cm by a minimum of 2.3 wt% of B4C addition. This resistivity decrease was caused by forming three-dimensional networks composed of boron carbonitride (B-C-N) platelets synthesized during sintering. To produce the networks of B-C-N platelets, two-step sintering with a heat-treatment step at 1600°C before the densification step at 2000°C was needed.

Download Full-text

Effect of Starting Powders on Microstructure and Properties of Silicon Nitride Nanoceramics

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.217-219.239 ◽

2012 ◽

Vol 217-219 ◽

pp. 239-244

Author(s):

Hai Jiang ◽

Chun Yan Tian

Keyword(s):

Mechanical Properties ◽

Silicon Nitride ◽

Thermal Shock ◽

Thermal Shock Resistance ◽

Grain Morphology ◽

Hot Press ◽

Shock Resistance ◽

Hot Press Sintering ◽

Spherical Grains ◽

Hardness Values

Silicon nitride nanoceramics were fabricated by hot press sintering two kinds of Si3N4nano-sized powders. The effect of starting powders on microstructure, mechanical properties and thermal shock resistance were investigated. The microstructure of sintered materials consists of spherical grains and the addition of α–Si3N4to starting powders does not affect the grain morphology. The flexural strength, fracture toughness and thermal shock resistance increase with the increase in amount of α–Si3N4starting powders, and the maximum mechanical properties are obtained when the amount of α–Si3N4 powders is 40wt.%. The hardness values decrease with the increase of α–Si3N4amount.

Download Full-text

Scratch Resistance of the Si3N4-Graphene Nanoplatelets Composites

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.662.165 ◽

2015 ◽

Vol 662 ◽

pp. 165-168

Author(s):

Monika Kašiarová ◽

Monika Michalková ◽

Ján Dusza ◽

Pavol Šajgalík

Keyword(s):

Silicon Nitride ◽

Crack Propagation ◽

Coefficient Of Friction ◽

Applied Load ◽

Scratch Test ◽

Scratch Resistance ◽

Graphene Nanoplatelets ◽

Hot Press ◽

The Coefficient Of Friction ◽

Hot Press Sintering

The scratch resistance of the silicon nitride with the addition of 1 and 7 wt% of graphene multiplatelets prepared by hot press sintering has been studied. The scratch resistance behaviour of Si3N4-GNP composites were investigated using a Rockwell indenter for normal applied loads ranging from 1-150 N. Si3N4-7-wt%GNP composite behaved differently during the scratch test depending on the normal applied load. The coefficient of friction changed dramatically at higher load and extensive crack propagation resulting in the chipping is observed.

Download Full-text

Hot-press sintering studies of amorphous silicon nitride powders

Journal of Materials Science ◽

10.1007/bf01151839 ◽

1992 ◽

Vol 27 (13) ◽

pp. 3599-3604 ◽

Cited By ~ 6

Author(s):

G. T. Burns ◽

J. A. Ewald ◽

K. Mukherjee

Keyword(s):

Silicon Nitride ◽

Amorphous Silicon ◽

Hot Press ◽

Amorphous Silicon Nitride ◽

Hot Press Sintering

Download Full-text

Mechanical and wear properties of Si3N4–W composites using tungsten boride powder

Journal of Materials Research ◽

10.1557/jmr.2003.0315 ◽

2003 ◽

Vol 18 (9) ◽

pp. 2262-2267 ◽

Cited By ~ 2

Author(s):

Hideki Hyuga ◽

Mark I. Jones ◽

Kiyoshi Hirao ◽

Yukihiko Yamauchi

Keyword(s):

Silicon Nitride ◽

Sliding Wear ◽

Nitrogen Atmosphere ◽

Hot Press ◽

Wear Properties ◽

Tungsten Boride ◽

Sintering Conditions ◽

Hot Press Sintering ◽

Boride Powder ◽

Composite Disk

Silicon nitride–tungsten (Si3N4–W) composites were fabricated by reduction of tungsten boride under hot-press sintering in a nitrogen atmosphere. The fabricated composite consisted of mainly β–Si3N4 and W. The Si3N4 matrix grains were composed of an elongated and bimodal structure similar to conventional Si3N4. The mechanical properties of the composites in terms of fracture toughness and strength were almost the same as those of a monolithic Si3N4 produced under the same sintering conditions. The sliding wear properties of the composites were evaluated using a ball-on-disk machine under unlubricated sliding conditions against a commercial Si3N4 ceramic ball. The tungsten (W) content had a significant effect on the composite wear properties. In particular, for a composite disk with a W content of 8 vol% the specific wear rate of the opposing ball was decreased around ten times compared to the monolithic Si3N4. The composites had higher wear resistance compared with the conventional silicon nitride, which was attributed to the formation of debris consisting of W, Si, and O. The debris restricted the adhesion of the two surfaces.

Download Full-text