Yulei ZHANG
,
Hejun LI
,
Qiangang FU
,
Kezhi LI
,
Dangshe HOU
,
null
材料科学技术（英文）
In order to improve the anti-oxidation property of carbon/carbon (C/C) composites, a novel SiC-Si-ZrSiO4 multiphase oxidation protective coating was produced on the surface of C/SiC coated carbon/carbon composites by a pack cementation technique. The phase composition and microstructure of the as-prepared coatings were characterized by XRD (X-ray diffraction), SEM (scanning electron microscopy) and EDS (energy dispersive spectroscopy). Oxidation behavior of the multiphase coated C/C composites was also investigated. It showed that the as-prepared coating characterized by excellent oxidation resistance and thermal shock resistance could effectively protect C/C composites from oxidation at 1773 K for 57 h in air and endure the thermal cycle between 1773 K and room temperature for 12 times, whereas the corresponding weight loss is only 1.47%. The excellent oxidation protective ability of the SiC-Si-ZrSiO4 coating could be attributed to the C/SiC gradient inner layer and the multiphase microstructure of the coating.
关键词:
Carbon/carbon composites
,
null
,
null
Scripta Materialia
A recent comment on a previously published paper addressed the invalid explanation of the off diagonal interdiflusion coefficients of the beta-Ni(Al,Cr) phase in the Ni-Cr-Al system according to the symmetric property of the thermodynamic matrix. In this paper, the experimental data presented by Hou et al. was reanalyzed and the interdiffusion coefficient matrix was estimated again. The results of the analysis have been discussed in terms of a brief reply to the comments of Liu and Liang. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
关键词:
Diffusion;Intermetallic compound;Ni-Cr-Al
张春路
,
丁国良
,
李灏
工程热物理学报
准确、快速、稳定地计算制冷剂热力性质是计算机辅助设计和工程计算的
要求。本文将隐式拟合方法与MartinHou方程相结合，提出制冷剂过热气体热力
性质的隐式拟合方法，该方法不仅具有形式统一、精度高、速度快、外推性和
稳定性好的优点，而且保证了过热区与两相区之间热力性质的连续性
关键词:
制冷剂
,
过热气体
,
热力性质
,
拟合
曾东
,
燕瑛
,
王立朋
,
刘兵山
复合材料学报
doi:10.3321/j.issn:1000-3851.2005.06.022
通过三维动力学有限元法,采用空间杆单元来描述缝线,结合试验系统地研究了缝合复合材料的低速冲击损伤问题.采用修正的赫兹接触定律计算冲击接触力,NewMark直接积分法求解运动方程,求解冲击过程中的应力应变;在Chang和Hou等的分层扩展准则基础上,提出一修正的分层扩展准则并考虑纤维断裂,建立了分析低速冲击损伤面积的方法;对相同铺层的缝合与未缝合复合材料层板进行了低速冲击试验.分析结果与实验结果具有良好的一致性,证明本文中提出的修正的分层扩展准则是正确的.计算及试验结果均表明,在相同冲击能量作用下,缝合使冲击损伤面积明显减小.
关键词:
缝合复合材料
,
低速冲击
,
三维有限元
,
损伤面积
