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-potential value of the powders is down to 5.376 mV from 48.28 mV after coating. Generally, the surface of ZrC is consistently, firmly and uniformly coated by a nano-structured La2O3 layer. Key words...文章编号:1004-0609(2012)04-1102-05 非均相沉淀-煅烧法制备La2O3包覆ZrC纳米复合粉末 袁晓虹1,范景莲1,成会朝1,银锐明2 (1. 中南大学 粉末冶金国家重点实验室,长沙 410083; 2. 湖南工业大学 焊接研究所,株洲 412008) 摘 要:以La(NO3)3·6H2O,氨水和ZrC为原料,采用非均相沉淀-煅烧法制备La2O3包覆ZrC复合粉......
ZrC涂层的表面形貌 Fig. 3 Surface morphologies of ZrC coating prepared at different deposition temperatures: (a) 1 400 ℃; (b) 1 450 ℃; (c) 1 500 ℃; (d) 1 550 ℃; (e) 1 600 ℃ 2.3 断面结构及生长机制 图4所示...; 不同沉积温度下ZrC涂层断面的组织结构 Fig. 4 Micrographs of fracture surface of ZrC coating prepared at different deposition temperatures: (a) 1 400 ℃; (b) 1 450 ℃; (c) 1 500 ℃; (d) 1 550 ℃; (e) 1 600 ℃ 在涂层......
为强烈的(220)择优取向,晶粒形貌变为纳米针状. 关键词:ZrC涂层;常压化学气相沉积;H2浓度;择优取向 中图分类号:TQ134.1 文献标志码:A Effect of hydrogen concentration on preparation of ZrC coating by APCVD LI Guo-dong, ZHENG... that the coating phase composition, preferential growth and structure morphology change significantly as the hydrogen concentration increasing. With pure argon or less hydrogen, ZrC coating is porous, which......
temperature increasing. At 1 400 and 1 500 ℃, the preferred orientation of the ZrC coating is (200), but it changes to (220) and (200) at 1 600 ℃. As temperature increasing, the grain size increases... are deposited in the reactor scale from -100 mm to -230 mm.Key words:ZrC coating; low pressure chemical vapor deposition; phase composition; microstructure; homogeneity......
:A dense ZrC coating with the thickness of 130 μm is prepared on graphite by reactive melt infiltration. XRD and SEM analyses show that the phase composition of the coating is ZrC and it adheres well with the substrate. The influence of ZrC coating on mechanical properties of the graphite was investigated by compression tests and the results show that after the coating process, the compression strength......
Vapor pressure and thermochemical properties of ZrCl4 for ZrC coating of coated fuel particles LIU Chao(刘 超), LIU Bing(刘 兵), SHAO You-lin(邵友林), LI Zi-qiang(李自强), TANG Chun-he(唐春和) Institute... for ZrC coating of coated fuel particles. ZrCl4 sample is hydrolyzed to some extent to give ZrO2 and HCl, which however, has little influence on vapor pressure of ZrCl4 at high temperature. No ZrCl3......
of the coating. Key words: chemical vapor deposition; ZrC coating; formation mechanism; defect control 碳化锆(ZrC)是一种过渡金属碳化物,具有较为优异的物理和化学性能,如高硬度,高熔点,良好的导电性,较好的耐化学腐蚀和抗热冲击性能等.在各应用领域中,ZrC陶瓷多以涂层或薄膜的形式存在并发挥... protective coating for carbon/carbon composites[J]. Carbon, 2009, 47(14): 3368-3371. [5] 郑湘林, 李国栋, 熊 翔, 孙 威. 常压化学气相沉积ZrC涂层动力学与组织结构[J]. 中南大学学报: 自然科学版, 2011, 42(7): 1912-1917.ZHENG Xiang-lin, LI Guo-dong......
ZrC质量分数对C/C-ZrC复合材料力学性能的影响 杨鑫1, 2,苏哲安1,黄启忠1,涂川俊1,柴立元2 (1. 中南大学 粉末冶金国家重点实验室,湖南 长沙,410083; 2. 中南大学 冶金科学与工程学院,湖南 长沙,4130083) 摘要:采用基体改性技术将ZrC引入C/C复合材料中,制备一种新型的C/C-ZrC复合材料.利用X线衍射仪,扫描电镜及能谱等分析手段,研究材料的形貌和结构,并采用三点弯曲试验研究材料的力学性能,讨论ZrC质量分数对复合材料断裂行为的影响.研究结果表明:引入的ZrC主要以纳米颗粒的形式分布在材料中;随着ZrC质量分数的升高,C/C-ZrC复合材料抗弯强度逐渐降低,当ZrC质量分数为36.64%时,C/C-ZrC复合材料断裂过程中发生脆性断裂,材料断裂模式转变的原因主要与ZrC质量分数升高引起的纤维损伤及石墨化度提高综合作用有关;经2 000 ℃的石墨化......
method is the use of oxidation resistant coating [5,6] or matrix modification [7-9]. ZrC not only has higher melting point (>3000 °C) and better compatibility with carbon, but also the oxide itself...] SHI X H, HUO J H, ZHU J L, LIU L, LI H J, HU X J, LI M Y L. GUO L J, FU Q G. Ablation resistance of SiC-ZrC coating prepared by a simple two-step method on carbon fiber reinforced composites [J......
; 文章编号:1672-7207(2011)07-1912-06 Deposition kinetics and microstructure of APCVD ZrC coating ZHENG Xiang-lin, LI Guo-dong, XIONG Xiang, SUN Wei (State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China) Abstract: ZrC coating was prepared by atmospheric pressure chemical vapor deposition (APCVD) with ZrCl4-CH4-H2-Ar chemical system at different......