ZHU Na-qiong
,
LU Li
,
HE Yan-lin
,
LI Lin
,
LU Xiao-gang
钢铁研究学报(英文版)
Coarsening of M23C6 precipitates in an Fe-12.4Cr-0.13C ternary alloy has been investigated ageing at 780 ℃ up to 200 h. Evolution of M23C6 carbides at different ageing times was determined experimentally using transmission electron microscopy. Particle size distribution was obtained with different measuring methods. Simulations of coarsening of M23C6 precipitates were carried out using computational thermodynamics and kinetics. Results showed low coarsening rates for M23C6 precipitates in the Fe-Cr-C ternary alloy. Interfacial energy of M23C6/ferrite interface is between 0.1 and 0.3 J·m-2 for the coarsening of M23C6 ageing at 780 ℃.
关键词:
M23C6
,
coarsening
,
PSD
,
interfacial energy
梁晓亮
,
王波
,
孙洵
,
顾庆天
,
丁建旭
,
许心光
人工晶体学报
本文利用传统的降温法和"点籽晶"快速生长法在不同Na+掺杂浓度的溶液中生长KDP晶体,定量研究了Na+对KDP晶体生长的影响.实验发现:Na+的存在降低了溶液的稳定性,致使KDP晶体柱面容易扩展.Na+的存在对KDP晶体的光学性能基本没有影响.
关键词:
KDP晶体
,
晶体生长
,
柱面扩展
MENG Liang ZHANG Baochang LIANG Ying ZHANG Weizhong TIAN Puke Northwestern Polytechnical University
,
Xi'an
,
China
金属学报(英文版)
The crack propagation resistance for alloy 8090 sheet decreases with the increase of content of Na and K impurities.An improvement over the fracture toughness and crack initiation resist- ance for the alloy containing Na and K within certain limit may be made by adding 0.05% Ce.This beneficial modification would not be manifested if the alloy contained more Na and K.One of the reasons why Na and K injure the toughness of the alloy might be due to that they cause the precipitation of T_1 phase along grain and subgrain boundaries and accelerate the abnormal growth of recystallized grains.
关键词:
alloy 8090
,
null
,
null
,
null
,
null
邵忠宝
,
赵敬棋
腐蚀学报（英文）
研究了Na2SO3的除氧效果，讨论了pH值、Ca和Mg 离 子浓度、催化剂Co(NO3)2的浓度对Na2SO3除氧效果的影响.实验结果表明：在无催 化剂存在的情况下，Na2SO3的除氧率最高仅达到90%.Ca、Mg离子浓度对Na2SO3的 除氧效果有一定的抑制作用，使除氧率降低约4%～6%.催化剂Co(NO3)2的引入，能够明 显地提高Na2SO3的除氧率，降低Na2SO3的用量，当Na2SO3加入量过剩约5.0 mg /L，催化剂Co(NO3)2的加入量为1.5 mg/L时，除氧率大于99.5%，且Ca、Mg离子浓度及p H值对其除氧率影响很小.
关键词:
Na2SO3
,
catalyst
,
Co(NO3)2
,
rate of deoxidation
邵忠宝
,
赵敬棋
腐蚀学报（英文）
doi:10.3969/j.issn.1002-6495.2002.01.013
研究了Na2SO3的除氧效果,讨论了pH值、Ca和Mg离子浓度、催化剂Co(NO3)2的浓度对Na2SO3除氧效果的影响.实验结果表明:在无催化剂存在的情况下,Na2SO3的除氧率最高仅达到90%.Ca、Mg离子浓度对Na2SCO3的除氧效果有一定的抑制作用,使除氧率降低约4%～6%.催化剂Co(N鸭)2的引入,能够明显地提高Na2SO3的除氧率,降低Na2SO3的用量,当Na2SO3加入量过剩约5.0 mg/L,催化剂Co(NO3)2的加入量为1.5 mg/L时,除氧率大于99.5%,且Ca、Mg离子浓度及pH值对其除氧率影响很小.
关键词:
Na2SOO3 催化剂 Co(NO3)2 除氧率
吕建国
,
陈学梅
,
朱剑博
,
黄凯
,
宋学萍
,
孙兆奇
人工晶体学报
采用溶胶-凝胶技术制备不同Na掺杂ZnO薄膜,用XRD、拉曼光谱仪、AFM、SEM和紫外可见分光光度计等表征方法研究了Na掺杂量对ZnO薄膜的表面形貌和光学性质的影响.XRD和Raman光谱分析表明:8.0 at%Na掺杂ZnO薄膜具有最佳c轴择优取向,内部残余张应力最大;表面形貌研究结果显示:薄膜的平均粒径和粗糙度均随Na含量的增加而增大.薄膜在可见光范围内的平均透射率大于80%,随着Na含量从0增加到10at%,薄膜的光学带宽由3.283 eV增大到 3.305 eV.
关键词:
Na掺杂
,
拉曼光谱
,
表面形貌
,
透射谱
罗劼
,
金宗哲
,
何欧里
材料研究学报
<正> 作为脆隆材料的Na-Ca-Si 玻璃,其纤维的应力应变曲线明显地偏离完全弹性,用Vickeis 金刚石尖压痕研究Na-Ca-Si 玻璃时,也发现许多偏离弹性的现象。如:压痕痕迹不消火,压痕丧丽上出现凸起~([1]),压痕下而出现位错线~([2])。本文设计了一种新的试验,用Vickers 压痕研究Na-Ca-Si 玻璃的微塑性。
关键词:
Journal of Physics-Condensed Matter
We present a detailed study of both the topological and the chemical short-range orders for liquid Na-Cd alloys using interatomic potentials derived from a non-local model pseudopotential theory. First, the mixing entropy is predicted using a hard-sphere Yukawa reference system, with the parameters being measured from the pseudopotential-calculated mean interatomic interactions and the ordering potentials. It is found that the ordering contribution to the entropy reaches its largest magnitude at around 30 to 50 at.% (atomic per cent) of Na, while above 70 at.% Na, the contribution is small. Then, the atomic structures are calculated using molecular dynamics simulations combined with an energy mapping technique. From the careful examination of the calculated structural distribution functions, the chemical shea-range-order parameters and the pair analysis results, we found that with increasing Na concentration, the Na-Cd alloy system exhibits a chemical ordering tendency from compound forming to phase separation, and a topological ordering tendency from a Cd-like structure characterized by 1311- and 1422-type atomic bonded pairs to a Na-like one characterized by 1551-type atomic bonded pairs.
关键词:
thermodynamic properties;binary-alloys;ga
Journal of Physics-Condensed Matter
Based on ab initio total energy calculations, Li, Na and Ag interstitials are found to be stable with at least a 1.56 eV energy barrier to transform to a zinc substitutional site in ZnO, whereas K interstitial has a relatively small energy barrier at 0.79 eV. The isolated dopant substitutional defects (LiZn, NaZn, KZn and AgZn) are found to be rather stable, with at least a 3.4 eV energy barrier to transform to an interstitial site. All of the dopant interstitials (Lii, Nai, Ki and Agi) are fast diffusers. The diffusion of Li interstitial is isotropic, whereas the diffusion of Na, K and Ag interstitials is highly anisotropic. Fundamental processes of the vacancy-assisted mechanisms are systematically investigated and specific values of the energy barriers are obtained.
关键词:
augmented-wave method
