李诗卓
,
姜晓霞
,
尹付成
,
M.B.Peterson
,
S.J.Calabrese
材料研究学报
用真空电弧炉熔制了六种成分的Ni-Cu-Re 合金,当Re 量(?)5at.-%时,除了Ni(Cu,Re)固溶相外还出现Re(Ni,Cu)相。用旋转式销盘高温摩擦试验机测定了这几种合金的摩擦系数随温度变化规律,证实高温摩擦系数降低至0.2—0.3。通过摩擦系数转变温度及磨损系数与Re 量关系找出了合金的合适含Re 量(7.5at.-%)。用SEM 观察了室温到700℃下的磨痕,确认了氧化膜层的减摩作用。
关键词:
摩擦
,
oxide film
,
rhenium
,
nickel
姜晓霞
,
李诗卓
,
M.B.Peterson
,
S.J.Calabrese
材料研究学报
冶炼了五种Co-Cu-Re 合金样品。当Cu 和Re 含量较低时,只有两种结构的Co 固溶体相,Cu 和Re 量达12.5at.-%,出现Cu 及Re 的固溶相。用往复式高温销盘摩擦试验机测定摩擦系数随温度变化,并与Co,Co-Re,Cu-Re 对比,用X 射线及能谱测定磨屑、表层氧化物及Co-Cu-Re 550℃挥发物结构,测定磨屑及近表层成分。试验结果表明,Co-Cu-Re 合金高温摩擦系数低至0.15—0.20的原因是,Re 抑制了Co 的相变及形成易挥发的含Re 氧化物膜起润滑作用。设计了自生氧化膜减摩作用模型。
关键词:
摩擦
,
cobalt
,
rhenium
,
oxide film
李诗卓
,
姜晓霞
,
M.B.Peterson
,
S.J.Calabrese
材料研究学报
用旋转式高温销盘摩擦试验机测定了Ni、Ni-Re,Ni-Cu、Cu-Re 及Ni-Cu-Re 等合金摩擦系数随温度的变化;用X 射线测定了磨屑及氧化层、Ni-Cu-Re 550℃的挥发物结构;能谱测定了磨屑、氧化膜及近表层成分,还进行了静态氧化实验,试验发现高温摩擦实验后样品近表层有富Re 层,它不利于氧化膜的形成,但降低了合金的氧化速度,提高了耐磨性,试验结果还表明了Ni-Cu-Re 系高温摩擦系数较低(0.2-0.3),原因是Cu,Re 共同作用形成易挥发性氧化物起的润滑作用,提出了氧化膜的减摩模型。
关键词:
润滑
,
Cu
,
Re
,
soft oxide film
Journal of the Less-Common Metals
High-field magnetization measurements were performed on magnetically aligned samples of quasi-ternary compounds of the Pr2(Fe,M)14B series with M = Al, Ga and Si at 4.2 K in magnetic fields up to 35 T. The saturation magnetization and anisotropy constants were derived as functions of composition. The results suggest that the transition in the magnetization curves of these series is probably not a first-order magnetization process (FOMP).
关键词:
crystal;anisotropy;pr2fe14b
Journal of Applied Physics
The magnetic properties of nanocomposite multilayer magnets of the (Nd,Dy)(Fe,Co,Nb,B)(5.5)/M (M=Co,FeCo) on Ti-buffered Si substrates have been investigated. X-ray diffraction results reveal that the Nd2Fe14B-type phase in almost all the films is randomly oriented. Different thickness x (nm) for Co layers and y (nm) for FeCo layers were adopted in the multilayers. It is found that high remanence is achieved in the nanocomposite multilayer films consisting of the Nd2Fe14B-type phase and soft magnetic phase for Co with 6greater than or equal toxgreater than or equal to4 and for FeCo with 10greater than or equal toygreater than or equal to6. The enhancement of the remanence in the nanocomposite multilayer films is attributed to the exchange coupling between the magnetically soft and hard phases. Increasing the soft magnetic components results in a continuously decreasing coercivity. (C) 2002 American Institute of Physics.
关键词:
remanence enhancement;fe;films
Journal of Magnetism and Magnetic Materials
Phase constitution and magnetic properties of Nd10Fe76B4M10 and Nd10Fe76B2M12 (M = Fe,Ti,V,Cr, Mn,Co and Al) alloys prepared by mechanical alloying and subsequent annealing have been systematically studied. It is found that the components of phases in the alloys critically depend on the additive transition metals M. In all the alloys, only the addition of Ti give significant enhancement to the permanent-magnetic properties. The increase of the Curie temperature in the Ti-doped alloys with an excessively low B content implies that part of the Ti atoms may occupy crystalline sites other than the Fe sites. In all the M additive alloys, with increasing content of the additive elements, the quantity of 1:7 phase increases and that of Nd2Fe14B-type phase decreases, (C) 2000 Elsevier Science B.V. All rights reserved.
关键词:
phase constitution;structure;magnetic properties;alloys;mechanical;alloying;nd;coercivity
SUN LilingInstitute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang
,
ChinaWU QiShenyang College of Technology
,
Shenyang
,
ChinaZHANG Zhiya
,
HU ZhuangqiInstitute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang
,
China
金属学报(英文版)
The effect of trace element B on microstructure of directionally solidified new type Co-base superalloy is studied systematically in this paper. It is found that the addition of B makes the incipient melting temperature of the alloy decline remarkably. Compared with the alloy having a boron content of 0.05 %, the incipient melting temperature of the alloy with 0.7 % B decreases by 197℃. The primary and secondary dendrite arm spacings increase and the volume fraction of interdendritic carbides with fine microstructure becomes bigger with the enhancement of boron content. When the alloy is with 0.7wt %B, M3B2 precipitates in the interdendrites.
关键词:
horon
,
null
,
null
,
null
邢峰
,
江潮
,
何文望
金属学报
本文研究了Nd_2(Fe_(1-x)M_x)_(14)B的磁性。少量类金属原子C和Si取代部分Fe,能形成四方结构,且具有单轴各向异性。碳取代Fe,使化合物的Curie温度降低,低温下粘结体样品的内禀矫顽力减少;而Si对Fe的取代可使Curie温度升高,并在x=0.15附近达到极大值。含Si样品在0≤x≤0.10范围内,矫顽力显著增加,室温下从x=0的62.7kA/m增加到x=0.06的138.7 kA/m,并且在x=0.06附近,剩磁有一个极值,饱和磁化强度减少不多。
关键词:
Nd-Fe-B合金
,
magnetic properties
,
Curie temperature
李玉清
金属学报
在NiFeCrWMoTiAl合金断口的萃取碳复型上,观察到:合金中的硼可以减少和消除能脆化合金晶界的Ti_4C_2S_2脆性薄片;硼含量为0.025—0.050％和0.075—0.100％时,M_3B_2分别呈薄片(或枝晶薄片)状和块状;在1200℃以下温度加热时,颗粒状M_3B_2沉淀,而且薄片状M_3B_2向颗粒状M_3B_2转变。
关键词:
