XU Huibin TAN Shusong Technische Universitat Berlin
,
FRG XU Huibin Dipl.-Ing
,
FB9
,
Physikalische Ingenieurwissenschaft
,
HF1
,
TU Berlin
,
1000 Berlin 12
,
FRG
金属学报(英文版)
The radiation of material surface by high intensity laser beams is used to produce the uhrafine powder of pure Fe and ZrO_2.The morphology,size and phases of the powder were examined by X-ray diffraetometer,scanning electron microscopy as well as transmission electron microscopy.In pure Fe a considerable quantity of γ-phase was found in the powder.In ZrO_2 powder,instead of stable phase,two metastable phases appeared.
关键词:
laser beam
,
null
,
null
Journal of the American Ceramic Society
In this work, we have fabricated a novel ternary aluminum nitride, Hf(3)AlN, via a reactive hot pressing method using hafnium and aluminum nitride as starting materials. The crystal structure of Hf(3)AlN was established by a combination of ab initio calculation, X-ray diffraction, and electron diffraction analyses. The point group and space group of Hf(3)AlN were determined as mmm and Cmcm, respectively. The lattice constants are a=0.3298 nm, b=1.135 nm, c=0.8842 nm and the atomic positions are Hf1 at 4c (0, 0.0441, 0.2500), Hf2 at 8f (0, 0.3701, 0.0437), Al at 4c (0, 0.7469, 0.2500), and N at 4a (0, 0, 0). Electronic structure analysis demonstrated that Hf(3)AlN should possess metallic conductivity and intrinsic damage tolerance. We hope that this work will inspire future experimental research on this Hf-based ternary ceramic.
关键词:
magnetron sputtering method;fusion-reactor materials;zr-al-n;films;oxidation;hafnium
徐世友
,
张溪文
,
韩高荣
功能材料
以光学石英片为衬底,采用热丝-等离子体辅助化学气相沉积方法(HF-PECVD)沉积了BN1-xPx薄膜.通过X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、X射线能谱(EDAX)、紫外-可见(UV-VIS)等测试手段研究了薄膜的化学组成、结构以及P元素掺杂量对BN1-xPx薄膜材料光学带隙的调制规律.结果表明所沉积薄膜为B、P、N组成的三元化合物,没有相偏析,定向生长,与石英衬底结合牢固.BN1-xPx薄膜中随着磷元素相对含量的增加,其光学带隙相应窄化,即通过控制磷的掺杂量可以有效调整该薄膜材料的光学带隙.
关键词:
BN1-xPx薄膜
,
磷掺杂
,
光学带隙
徐春梅
,
郭建亭
,
杨福宝
金属学报
研究了NiAl-28Cr-5Mo--1Hf合金在1000--1200℃空气中的氧化行为X射线结构分析表明,氧化膜主要由α-Al2O3构成,并含有Cr2O3和少量HfO2.采用扫描电镜和能谱分析研究了氧化产物的微观组织及成分,并从合金相组成探讨了NiAl-28Cr-5Mo--1Hf合金的氧化机制.
关键词:
金属间化合物
,
null
,
null
徐春梅
,
郭建亭
金属学报
研究了定向凝固NiAl-28Cr-5Mo-1Hf合金的显微组织和高温拉伸蠕变行为. 该合金由NiAl相、Cr(Mo)相和少量聚集在NiAl和Cr(Mo)相界处Ni2AlHf（Heusler）相组成。 蠕变曲线表现为较短的减速度蠕变阶阶段和较长的稳态蠕变阶段及较高的蠕变应变，且蠕变后显微组织的变化不大. 该合金的蠕变由晶格自扩散引起的位错攀移所控制. 蠕变断裂数据符合Monkman-Grant关系.
关键词:
NiAl基金属间化合物
,
null
Oxidation of Metals
The effect of an NiAl microcrystalline coating prepared by magnetron sputtering on the high-temperature oxidation behavior of NiAl-28Cr-5Mo-1Hf was investigated in static air at 1000-1150degreesC. The additions of Cr, Mo, and Hf changed the single beta-phase structure into a multiphase structure [beta-NiAl, alpha-Cr(Mo), and Heusler phase]. The NiAl-28Cr-5Mo-1Hf alloy formed a nonprotective mixed scale of Al2O3 + Cr2O3 + HfO2 and exhibited relatively large weight gains. The large weight gains were attributed to extensive internal oxidation. The sputtered NiAl microcrystalline coating remarkably improved the oxidation resistance of NiAl-28Cr-5Mo-1Hf due to the formation of a compact and adherent Al2O3 scale at all test temperatures. It was found that the theta- alpha-Al2O3 transformation caused the anomalous behavior of the oxidation-kinetics cures of the NiAl microcrystalline coating in the temperature range 1000-1150degreesC. A change in the morphology of scales occurred with the transformation.
关键词:
beta-NiAl;multiphase alloy;NiAl microcrystallne coating;oxidation;rod-plate transition;in-situ composites;mechanical-properties;matrix;composites;cr alloys;resistance;additions;superalloy;compound;systems
谷月
,
张艳辉
,
尹丽娟
,
晁月盛
稀有金属材料与工程
采用熔体单辊急冷法制备了非晶(Fe1-xCo)86Hf7B6Cu1(x=0.4～0.6)合金,使用穆斯堡尔谱仪、透射电镜(TEM)和振动样品磁强计(VSM)对其进行了表征,穆斯堡尔谱和TEM结果表明所制样品均为非晶态.然后借助于固体与分子经验电子理论(EET理论),计算了非晶(Fe1-xCox)86Hf7B6Cu1合金的价电子结构和磁矩,磁矩的理论计算值与实验测定值的误差小于10％,满足一级近似要求,实现了从价电子层次上计算非晶(Fe1-xCox)86Hf7B6Cu1合金的磁矩,这对于优化非晶合金(Fe1-xCox)86Hf7B6Cu1的软磁性能将具有理论指导意义.
关键词:
(Fe1-xCox)86Hf7B6Cu1
,
价电子结构
,
EET
,
磁矩
谭心
,
李瑜庆
,
刘学杰
,
信振洋
,
李智
,
张安萍
材料导报
采用基于密度泛函理论的第一性原理方法研究了二元的fcc-HfN和三元分散相fcc-Hf1-xSi,N及fcc-HfSixN1-x的原子结构、电子结构与弹性性质.计算提供了HfN和置换固溶体Hf1-xSi,N及 HfSixN1-x的晶格常数、内聚能、弹性常数和电子态密度.结果表明,HfN及其固溶体Hf1-xSixN、HfSix N1-x都呈现出金属性,并且其加Si后更具金属性,HfSix N1-x的力学性能有所改善,Hf1-xSixN的综合性能(除G44基本不变外)有所下降,随着x的增大这种趋势越发明显,这些是由于电子结构的改变引起的.
关键词:
Hf-Si-N
,
第一性原理
,
力学性能
,
态密度
