Influence of Additives on Mechanical Properties in Liquid-Phase Sintered Silicon Carbide Ceramics

2008 ◽  
Vol 403 ◽  
pp. 185-188 ◽  
Author(s):  
Young Wook Kim ◽  
Toshiyuki Nishimura ◽  
Mamoru Mitomo
Keyword(s):  
Mechanical Properties ◽  
Liquid Phase ◽  
Room Temperature ◽  
Trade Off ◽  
Molar Ratios ◽  
Sic Ceramics ◽  
Cationic Radius ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics ◽  
Sintered Silicon

The effect of sintering additives comprising AlN and RE2O3 (RE=Lu, Yb, Er and Y) in 2:3 and 3:2 molar ratios on mechanical properties of liquid-phase-sintered (LPS) and subsequently annealed SiC ceramics was investigated. The toughness vs cationic radius curve had a maximum in both 2:3 and 3:2 molar ratios; Yb-doped specimens showed maximal toughness of 5.8 and 6.6 MPa..m1/2 in 2:3 and 3:2 molar ratios, respectively. There was no correlation between room temperature (RT) strength and cationic radius. In contrast, the high temperature (HT) strength vs cationic radius curve had a minimum in both 2:3 and 3:2 molar ratios; Yb-doped specimens showed minimal strength of 520 MPa and 550 MPa in 2:3 and 3:2 molar ratios, respectively. The present results suggest that there is a trade-off in improving both RT toughness and HT strength in LPS-SiC ceramics.

Effects of Vickers Cracks on the Mechanical Properties of Solid-phase-sintered Silicon Carbide Ceramics

2012 ◽  
Vol 27 (9) ◽  
pp. 965-969
Author(s):  
Xiao YANG ◽  
Xue-Jian LIU ◽  
Zheng-Ren HUANG ◽  
Gui-Ling LIU ◽  
Xiu-Min YAO
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Solid Phase ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics ◽  
Sintered Silicon

Effect of aluminum nitride-scandia content on the microstructural and mechanical properties of sintered silicon carbide ceramics

2009 ◽  
Vol 15 (6) ◽  
pp. 937-941 ◽  
Author(s):  
Myong-Hoon Roh ◽  
Young-Wook Kim ◽  
Wonjoong Kim ◽  
Toshiyuki Nishimura ◽  
Won-Seon Seo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Aluminum Nitride ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics ◽  
Sintered Silicon

Phase Transformation and Texture in Hot-Forged or Annealed Liquid-Phase-Sintered Silicon Carbide Ceramics

2004 ◽  
Vol 85 (2) ◽  
pp. 459-465 ◽  
Author(s):  
Rong-Jun Xie ◽  
Mamoru Mitomo ◽  
Wonjoong Kim ◽  
Young-Wook Kim ◽  
Guo-Dong Zhan ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Phase Transformation ◽  
Liquid Phase ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics ◽  
Sintered Silicon

Microstructure and Mechanical Properties of Heat-Resistant Silicon Carbide Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 1409-1413 ◽  
Author(s):  
Young Wook Kim ◽  
Yong Seong Chun ◽  
Sung Hee Lee ◽  
Ji Yeon Park ◽  
Toshiyuki Nishimura ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Silicon Carbide ◽  
Intergranular Phase ◽  
Sintering Additives ◽  
Heat Resistant ◽  
Sic Ceramics ◽  
Microstructure And Mechanical Properties ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics

There has been a great progress in the development of heat-resistant silicon carbide ceramics, owing to the better understanding of composition-microstructure-properties relations. Based on the progress, it has been possible to fabricate heat-resistant SiC ceramics with improved fracture toughness. In this paper, three rare-earth oxides (Re2O3, Re=Er, Lu, and Sc) in combination with AlN were used as sintering additives for a β-SiC containing 1 vol% α-SiC seeds. The effect of intergranular phase, using Re2O3 and AlN as sintering additives, on the microstructure and mechanical properties of liquid-phasesintered, and subsequently annealed SiC ceramics were investigated. The microstructure and mechanical properties were strongly influenced by the sintering additive composition, which determines the chemistry and structure of IGP. The strength and fracture toughness of the Lu2O3-doped SiC were ∼700 MPa at 1400oC and ∼6 MPa.m1/2 at room temperature, respectively. The beneficial effect of the new additive compositions on high-temperature strength was attributed to the crystallization of the intergranular phase.

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