Mingwei LI
,
Jingchuan ZHU
,
Zhongda YIN
,
Gang ZENG
材料科学技术（英文）
This paper presents a new method to determine the equivalent oxygen diffusivities of particle dispersed composites. This method can be used to design FGM thermal barrier systems with the function of oxygen barrier. A qualitative explanation of the oxidation of nickel with the increment of zirconia contents in the composite samples can be accepted by this method. The values of equivalent oxygen diffusivities obtained with this method are in excellent agreement with those from the EMT method for the composites with ZrO2 particle dispersed phase when the volume fractions of dispersed phase are lower than 25%.
关键词:
Equivalent oxygen diffusivity
,
null
,
null
Yong LIU
,
Jingchuan ZHU
,
Zhongda YIN
,
Mingwei LI
材料科学技术（英文）
The effect of triple annealing on stress relaxation of Ti-6Al-4V alloy as well as the microstructure after stress relaxation were studied. The results showed that triple annealing treatment enhanced the resistance of stress relaxation performance, and when the temperature was rising, this effect became notable. The stress relaxation deformation mechanism is of dislocation creep at 400℃ and recovery creep at 600℃.
关键词:
Triple annealing
,
null
,
null
Mingwei LI
,
Jingchuan ZHU
,
Zhongda YIN
,
Xiaoqiang LI
,
Zuyan LIU
,
Jae-Ho Jeon
材料科学技术（英文）
The microstructure evolution of mechanical alloyed Mo-66.7%Si powder using the high-energy ball mill has been studied by X-ray diffraction and scanning electron microscopy. The results showed that MoSi2 can be synthesized by MA of Mo-66.7%Si powder mixtures. Cold welding behavior between Mo and Si powders plays an important role in the preparation of MoSi2 by the MA.
关键词:
Haitao FANG
,
Jingchuan ZHU
,
Zhongda YIN
,
Jae-Ho Jeon
,
Yoo-Dong Hahn
材料科学技术（英文）
A coating of composition Si-40Mo (wt pct) was prepared by fused slurry coating method on the two-dimensional carbon/carbon (2D-C/C) composite to improve oxidation resistance. In the procedure of the fabrication, pure St slurry inner layer in the pre-coating was necessary to apply because of infiltration of liquid Si into the substrate during the sintering. The coating consists of Si continuous phase and MoSi2 particles. In addition, the infiltration of Si into the substrate and the SiC reaction layer between the coating and the C/C composite were observed. Oxidation resistance and the thermal shock resistance of the Si-Mo fused sluury coating were quite excellent at 1730℃
关键词:
庄厚龙
,
彭平
,
周惦武
,
刘金水
稀有金属材料与工程
采用第一原理赝势平面波方法--CASTEP程序计算了4种B2型Y基金属间化合物YX(X=Ag,Cu,In,Rh)的部分弹性性质,计算结果与文献报道值基本一致.通过Pugh定律、Cauchy压力和泊松比等经验判据,分析并预测了它们的脆性/延性,其延性高低次序为:YRh＞YAg＞YCu＞YIn.电子结构分析表明:这4种金属间化合物良好的延性源于其较强的金属键,而不同程度的Y(d)-X(p)电子杂化则导致了其延性的差异.YIn中因In的p电子较多,杂化程度高,共价键方向性强,因而延展性最低,而YRh则由于存在Y(d)-Rh(d)电子间强的相互作用,增强了其金属键作用,因而延性最好.
关键词:
Y基金属间化合物
,
脆性/延性
,
第一原理
,
电子结构
