Y.Umakoshi
,
T. Nakano and H .Y. Yasuda (Department of Materials Science and Engineering
,
Faculty of Engineering
,
Osaka University
,
2-1
,
Yamada-Oka
,
Suita
,
Osaka 565 Japan)
金属学报(英文版)
Plastic behaviour of TiAl polysynthetically twinned (PST) crystals is reviewed to show our knowledge and understanding for receiving a good combination of strength and ductility of two phase TiAl alloys under monotonic and cyclic loading conditions. Anisotropy and mechanism of strength, ductility, toughness. cyclic hardening and fatigue life are described focusing on the effect of lamellar structure.
关键词:
:Fatigue. Deformation
,
null
,
null
陈敬超
,
郭学鹏
,
杜焰
,
周晓龙
,
李玉华
,
甘国友
稀有金属
doi:10.3969/j.issn.0258-7076.2004.01.005
通过真空自耗电极炉熔炼得到硅锆比为1/2的Ti-Zr-Si 合金材料, 对合金材料进行了1200 ℃, 3.5 h的固溶处理和850 ℃不同时间的时效处理, 通过时效析出反应制备Ti/(Ti, Zr)2Si复合材料. 利用光学显微镜、扫描电镜、 X射线衍射、 EDX分析了Ti-Zr-Si 合金的铸造、固溶和不同时效阶段的显微组织及其相组成. 分析结果表明, 硅锆比为1/2(重量百分比)的Ti-Zr-Si合金, 铸造组织为块状β-Ti、晶界由块状β-Ti 和条状的5-3型硅化物组成; Ti-Zr-Si合金经过850 ℃, 480 min的时效处理, 5-3型硅化物转变为2-1型硅化物; 尺寸细小、分布均匀的2-1型硅化物使制备高性能的Ti/(Ti, Zr)2Si复合材料成为可能.
关键词:
Ti/(Ti,Zr)2Si复合材料
,
析出反应
,
时效处理
,
相变
,
硅化物
吴崇试
,
潘奕
原子核物理评论
doi:10.3969/j.issn.1007-4627.2002.01.001
系统分析了A≈170区正常形变带[521]1/2-中的ΔI=1颤动现象. 根据旋称伙伴带的跃迁能量提取Δ2 Eγ (I)=[Eγ(I)+Eγ(I-2)]/2-Eγ(I-1)值, 表现出旋称相关的规则上下颤动. 其颤动幅度在低自旋端约为50 keV, 而后随自旋而增大或减小, 大体呈抛物线形. 利用改进的ab公式, 提取了相关的脱耦合系数. 运用Nilsson波函数, 探讨了原子核集体哈密顿量中高阶微扰项的可能形式.
关键词:
正常形变带
,
旋称伙伴带
,
ΔI = 1颤动
,
脱耦合效应
,
改进的ab拟合
Chinese Physics Letters
The magnetic properties of 1 T-TaS2 and 1 T-Fe-0.07 Ta-0.93 S-2 have been studied, Experimental results show that the phase transition temperature of 1 T-TaS2 is a function of the magnetic field, At low temperatures, both compounds are in a mixed state of charge density wave -spin density wave due to the coherent superposition of antiferromagnetic coupling.
关键词:
density
季路成
工程热物理学报
为理清1+1/2对转涡轮及1+3/2对转涡轮使用范围和效能,从而帮助设计决策,本文采用Stewart方法,从速度三角形基本分析入手,以速功比为主要变量,考察、对比1+3/2和1+1/2对转涡轮性能特点.研究表明:各转速比下,1+3/2对转涡轮高效率范围都比1+1/2对转涡轮窄,但其高效区发生在更小的总速功比区域;随转速比绝对值增加,两种涡轮高效率区都增加,高效率区位置都偏向大的总速功比区域;相比于1+1/2对转涡轮,1+3/2对转涡轮具有较低出功比,且偏向于低速功比区域;随转速比绝对值增加,两种对转涡轮出功比范围均拓展.这些结果为未来先进航空发动机涡轮选型提供了重要借鉴.
关键词:
航空发动机
,
对转涡轮
,
无导叶对转涡轮
,
效率
,
出功比
张昌
,
段远源
,
史琳
,
朱明善
,
韩礼钟
工程热物理学报
析了气相声速与理想气体比定压热容的热力学关系，用超声变程干涉仪测定了1,1,1,2,3,3,3-七氟丙烷(HFC-227ea)的72组气相声速值，温度范围273-333 K，压力范围26-315 kPa，测量不确定度小于0.05%。根据这些实验数据，确定了HFC-227ea的理想气体比定压热容和声速第二维里系数，并分别拟合得到了与温度的函数，理想气体比定压热容的不确定度小于0.5%。使用方阱势能模型导出了HFC-227ea的第二维里系数，并与文献值进行了比较。
关键词:
HFC-227ea
,
声速
,
理想气体比定压热容
,
第二维里系数
Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers
The structures and dielectric properties of Pb(Fe1/2Nb1/2)(1-x)TixO3 (PFNT, x = 0.07 and 0.48) single crystals were investigated using a combination of temperature-dependent dielectric, X-ray diffraction (XRD), Raman, and X-ray absorption fine structure (XAFS) spectra. Detailed structure analyses reveal that the crystal structure of PFNT (x = 0.48) is single-phase tetragonal perovskite, whereas that of PFNT (x = 0.07) is a mixture of rhombohedral and tetragonal phases. The structural differences are found to have significant connections with the dielectric properties in the temperature range of 90-300 K. Both samples exhibit a frequency-dependent dielectric anomaly, arising primarily from the 3d electrons hopping between Fe2+ and Fe3+. The second dielectric anomaly, which is a weak frequency dispersion and observable only for PFNT (x = 0.07), was probably caused by a dipole glass behavior near the morphotropic phase boundary. (C) 2012 The Japan Society of Applied Physics
关键词:
iron;fe;ceramics;region;xanes
