Effect of B4C Content on Densification Behavior of SiC-B4C Ceramics

2014 ◽  
Vol 997 ◽  
pp. 454-456
Author(s):  
Yun Long Zhang ◽  
Yu Min Zhang ◽  
Ming Hu ◽  
Xiao Gang Song
Keyword(s):  
Rare Earth ◽  
Rare Earth Oxide ◽  
Gas Pressure ◽  
Volume Shrinkage ◽  
Densification Behavior ◽  
Sintering Aids ◽  
Phase Constitution ◽  
Sintering Additives ◽  
Multi Phase ◽  
Gas Pressure Sintering

The SiC-B4C multi-phase ceramics was fabricated by gas-pressure sintering technology. The rare-earth oxide Al2O3combined with Er2O3/SiO2was served as sintering aids. The results were shown that the combination of Al2O3/Er2O3/SiO2sintering additives were effective for densification of SiC-B4C multi-phase ceramics. The influence of B4C content on the phase constitution, microstructure and densification behavior of the SiC-B4C multi-phase ceramics were detailed. The lose weight and volume shrinkage rate of SiC-B4C multi-phase ceramics had similar evolvement trend when B4C content increased. Keywords: Gas-Pressure Sintering, SiC-B4C multi-phase ceramics, densification behavior.

Influence of Reaction Temperature on the Densification Behavior of the SiC/B4C Composites

2015 ◽  
Vol 727-728 ◽  
pp. 11-14
Author(s):  
Yun Long Zhang ◽  
Yu Min Zhang ◽  
Cheng Hai Li ◽  
Jin Ping Li
Keyword(s):  
Rare Earth ◽  
Sinter Temperature ◽  
Reaction Temperature ◽  
Rare Earth Oxide ◽  
Pressureless Sintering ◽  
Densification Behavior ◽  
Micro Structure ◽  
Phase Constitution ◽  
Sintering Additives ◽  
The Rare Earth

In this investigation, the rare-earth oxide La2O3 combined with Al2O3 served as sintering additives and commercial α-SiC and B4C powder were applied to fabricate SiC/B4C composites by pressureless sintering. The results proved that combination of Al2O3 and La2O3 sinter additives were effective for densification of SiC/B4C composites. The influence of sinter temperature on the phase constitution, micro-structure and densification behavior of SiC/B4C composites was investigated.

Influence of Additives Content on the Sintering Behavior of SiC Ceramics with Al2O3/La2O3 Aids

2014 ◽  
Vol 997 ◽  
pp. 457-460 ◽  
Author(s):  
Yun Long Zhang ◽  
Yu Min Zhang ◽  
Ming Hu
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Relative Density ◽  
Rare Earth Oxide ◽  
Volume Shrinkage ◽  
Shrinkage Rate ◽  
Sintering Behavior ◽  
Phase Constitution ◽  
Sintering Additives ◽  
Sic Ceramics

In this paper, the rare-earth oxide Al2O3 combined with La2O3 served as sintering additives and commercial α-SiC powder were applied to fabricate SiC ceramics by pressure-less sintering technology. The results proved that combination of Al2O3 and La2O3 sintering additives was effective for densification of SiC ceramics. The influence of sintered additives content on the phase constitution, microstructure and sintering behavior of the SiC ceramics was detailed. The relative density, lose weight and volume shrinkage rate of SiC ceramics had similar evolvement trend with the increase of sintered aids content. Keywords: Pressure-less Sintering, Mechanical Properties, Sintering Behavior

Oxidation Behavior Research of the SiC/B4C Multiphase Ceramics

2015 ◽  
Vol 727-728 ◽  
pp. 288-291 ◽  
Author(s):  
Yun Long Zhang ◽  
Xiao Gang Song ◽  
Guo Jing Li ◽  
Yu Min Zhang
Keyword(s):  
Rare Earth ◽  
Oxidation Behavior ◽  
Rare Earth Oxide ◽  
Eutectic Phase ◽  
Oxidation Time ◽  
Pressureless Sintering ◽  
Micro Structure ◽  
Phase Constitution ◽  
Sintering Additives ◽  
Multiphase Ceramics

Inthis investigation, the rare-earth oxide Yb2O3 combined with Al2O3served as sintering additives and SiC and B4C powder were applied to fabricate SiC/B4C multiphase ceramics composites by pressureless sintering. The results proved thatcombination of Al2O3 and Yb2O3 sinter additives were effective fordensification of SiC/B4C composites. The influence of oxidation time onthe phase constitution, micro-structure and oxidation behavior of SiC/B4C composites was investigated.Theformation of eutectic phase Yb2Si2O7 phase waswrapped on the SiC surface and it reduced further oxidation of SiC particles.The oxidation kineticcurves followed a parabolic rule.

Silicon Nitride Containing Rare Earth Silicate Intergranular Phases

1992 ◽  
Vol 287 ◽  
Author(s):  
Stephen D. Nunn ◽  
Terry N. Tiegs ◽  
Kristin L. Ploetz ◽  
Claudia A. Walls ◽  
Nelson Bell
Keyword(s):  
Rare Earth ◽  
Ternary Phase ◽  
Gas Pressure ◽  
Trivalent Cation ◽  
Processing Conditions ◽  
Microstructure Development ◽  
Sintering Aids ◽  
Conventional Sintering ◽  
Compositional Variations ◽  
Gas Pressure Sintering

ABSTRACTSi3N4 ceramics prepared with refractory grain boundary phases to improve high temperature properties are difficult to densify by conventional sintering methods. Gas-pressure sintering may be used to promote densification and development of acicular grains for improved fracture toughness. The current study examined rare earth silicate sintering aids with the composition M2Si2O7, where M is a trivalent cation (Y, La, Nd). M2O3 and Si02 additions were varied to develop a number of compositions in the Si3N4—Si2N2O—M2Si2O7 ternary phase field. Pressureless sintering and gas-pressure sintering were used to densify the samples. Densification, microstructure development, oxidation resistance, and mechanical properties were evaluated and compared with respect to compositional variations and processing conditions.

Effect of rare-earth species on the wear properties of α sialon and β silicon nitride ceramics under tribochemical type conditions

2004 ◽  
Vol 19 (9) ◽  
pp. 2750-2758 ◽  
Author(s):  
Mark I. Jones ◽  
Kiyoshi Hirao ◽  
Hideki Hyuga ◽  
Yukihiko Yamauchi
Keyword(s):  
Rare Earth ◽  
Grain Boundary ◽  
Wear Behavior ◽  
Rare Earth Oxide ◽  
Lower Amount ◽  
Boundary Phase ◽  
Wear Properties ◽  
Sintering Additives ◽  
Nitride Ceramics ◽  
Worn Surfaces

The wear properties under low loads of β Si3N4 and α sialon materials sintered with different rare-earth oxide sintering additives have been studied under dry sliding conditions using block-on-ring wear tests. All the worn surfaces showed an absence of fracture and smooth surfaces with the presence of an oxygen-rich filmlike debris indicating tribochemically induced oxidation of the surfaces. Extensive grain boundary removal was observed on the worn surfaces thought to be due to adhesion between this silicate phase and the tribochemically oxidized surfaces. The resistance to such oxidation and the properties of the residual grain boundary phase are thought to be important parameters affecting the wear behavior under the present testing conditions. For both the β Si3N4 and α sialon materials, there was an increase in wear resistance with decreasing cationic radius of the rare earth, thought to be due to improved oxidation resistance, and this was more remarkable in the case of the sialon materials where the incorporation of the sintering additives into the Si3N4 structure results in a lower amount of residual boundary phase.

Thermal shock resistance of Si3N4 and Si3N4–SiC ceramics with rare-earth oxide sintering additives

2014 ◽  
Vol 34 (14) ◽  
pp. 3301-3308 ◽  
Author(s):  
Monika Kašiarová ◽  
Peter Tatarko ◽  
Peter Burik ◽  
Ján Dusza ◽  
Pavol Šajgalík
Keyword(s):  
Rare Earth ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Rare Earth Oxide ◽  
Sintering Additives ◽  
Sic Ceramics ◽  
Shock Resistance

The Effect of Different Doping Methods of Sintering Aids on the Barium Titanate Based X7R Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 83-86 ◽  
Author(s):  
C. Ma ◽  
X.H. Wang ◽  
R.Z. Chen ◽  
Long Tu Li ◽  
Zhi Lun Gui
Keyword(s):  
Rare Earth ◽  
Dielectric Loss ◽  
Barium Titanate ◽  
Low Temperature ◽  
Rare Earth Oxide ◽  
Sintering Aids ◽  
Sintering Properties ◽  
Relationship Of ◽  
The Relationship

The barium titanate based X7R ceramics, which are doped with rare earth oxide, Nb2O5, Co3O4 and ZnO-B2O3, could be sintered at a rather low temperature to satisfy the X7R requirements with good permittivity and dielectric loss. In this paper, different doping methods of sintering aids have been used to prepare X7R BaTiO3 ceramics. Samples were sintered at a low temperature and the relationship of doping methods and sintering properties has been concluded.

Effect of Powder Characteristics on Gas-Pressure Sintering of Si3N4 With Rare Earth Additives

1994 ◽  
pp. 871-874
Author(s):  
T.N. Tiegs ◽  
S.D. Nunn ◽  
C.A. Walls ◽  
D. Barker ◽  
C. Davisson ◽  
...  
Keyword(s):  
Rare Earth ◽  
Gas Pressure ◽  
Powder Characteristics ◽  
Gas Pressure Sintering
Sign in / Sign up

Export Citation Format

Share Document