High-strain rate superplasticity of nanocrystalline silicon nitride

纳米晶氮化硅的高应变率超塑性

• 批准号: 14350348
• 负责人: WAKAI Fumihiro
• 金额: $ 9.34万
• 依托单位: TOKYO INSTITUTE OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14350348/
• 关键词: superplasiticy; silicon nitride; covalent ceramics; high-strain-rate; grain boundary

Superplasticity is phenomenologically defined as the ability of a polycrystalline material to exhibit extraordinarily large elongation at elelvated temperatures and at relatively low stresses. Silicon nitride is a hard, strong and stiff material. It is brittle, and lacks the ductility of metals at ambient temperatures. The application of superplasticity makes it possible to fabricate ceramic components just like superplastic metals. High-strain-rate superplasticity of covalent ceramics, such as silicon nitride, renders the superplastic forming an attractive technology for shaping components efficiently.1)High-strain-rate superplasticity was achieved in Si_3N_4-TiN-Si_2N_2O nanocomposite. The nanocomposite could be deformed at 1 X 10^<-2> s^<-1> at 1600℃ which was 10 to 100 times higher than strain rate of conventional superplastic Si_3N_4. The nanocomposite could be deformed also at 1300℃, which was 300 degree lower than the forming temperature of Si_3N_4.2)The effect of viscosity of i … More ntergranular glass on deformation was studied by using Si_3N_4 containing Y_2O_3-Al_2O_3-SiO_2 glass at grain boundaries. The relation between flow stress and glass composition corresponded to the effect of chemical composition on viscosity of the glass qualitatively. However, the flow stress was not proportion to the viscosity of the glass, because the composition of intergranular glass phase had changed by dissolving Si_3aN_4.3)The stability of grain boundary glass film was used by using spatially resolved electron energy-loss spectroscopy(EELS) analysis in liquid-phase-sintered ultrafine silicon carbide material. The YAG phase was crystallized from the intergranular glass during deformation at elevated temperatures. The crystallized YAG phase prohibited grain boundary sliding, and brought about fracture.4)The effect of dopant on deformation of covalent ceramic materials was studied by using fine-grained SiC. The small amount of boron doping enhanced superplastic deformation of SiC significantly. The contribution of grain-boundary diffusion to the accommodation process of grain boundary sliding decreased as the amount of boron doping decreased. The apparent contribution of the dislocation glide increased with boron doping Less

超塑性在现象学上被定义为多晶材料在高温和相对较低的应力下表现出异常大的伸长率的能力。氮化硅是一种坚硬、坚固且坚硬的材料，在环境温度下缺乏金属的延展性。超塑性的应用使得制造像超塑性金属一样的陶瓷部件成为可能。共价陶瓷（例如硅）的高应变率超塑性。 1)Si_3N_4-TiN-Si_2N_2O纳米复合材料实现了高应变率超塑性，该纳米复合材料可以在1 X 10^<-2> s^<-下变形。 1>在1600℃下，应变速率比传统超塑性Si_3N_4高10至100倍。纳米复合材料在1300℃下也能变形，比Si_3N_4的成型温度低300度。2)以晶界含Y_2O_3-Al_2O_3-SiO_2的Si_3N_4玻璃为研究对象，研究了晶间玻璃的粘度对变形的影响。流动应力与玻璃成分之间的关​​系对应于化学成分对玻璃粘度的影响。但从定性上看，流动应力与玻璃的粘度不成正比，因为Si_3aN_4的溶解改变了晶间玻璃相的组成。3)通过空间分辨电子能量损失谱分析了晶界玻璃膜的稳定性。 (EELS) 分析液相烧结超细碳化硅材料，YAG 相在高温变形过程中从晶间玻璃中结晶出来。 4)利用细晶SiC研究了掺杂剂对共价陶瓷材料变形的影响,少量硼掺杂显着增强了SiC的晶界扩散对超塑性变形的贡献。随着硼掺杂量的减少，晶界滑移的调节过程减弱。位错滑移的表观贡献随着硼掺杂量的减少而增加。

项目成果

Effect of chemical composition of intergranular glass on superplastic compressive deformation of β-silicon nitride

晶间玻璃化学成分对β-氮化硅超塑性压缩变形的影响

• 期刊: Journal of the European Ceramic Society (in press)
• 作者: E.Narimatsu;Y.Shinoda;T.Akatsu;F.Wakai
• 通讯作者: F.Wakai

High temperature plastic anisotropy of YTZ-single crystals

YTZ-单晶的高温塑性各向异性

• 发表时间: 2002
• 期刊: Journal of the European Ceramic Society 22
• 作者: A Munos;D.Gomez-Garcia;A.Dominguez-Rodriguez;F.Wakai
• 通讯作者: F.Wakai

ナノ粒子セラミックスの超塑性

纳米颗粒陶瓷的超塑性

• 发表时间: 2005
• 期刊: 粉体工学会誌 42
• 作者: 若井史博

Sintering forces in equilibrium and non-equilibrium states during sintering of two particles

两个颗粒烧结过程中平衡和非平衡状态下的烧结力

• 发表时间: 2004
• 期刊: Science and Technology of Advanced Materials 5
• 作者: F.Wakai;F.Aldinger
• 通讯作者: F.Aldinger

超塑性の粒界ネットワークダイナミクス

超塑性晶界网络动力学

• 发表时间: 2003
• 期刊: セラミックス 38
• 作者: 若井史博;赤津隆;篠田豊
• 通讯作者: 篠田豊