材料期刊网

3种高温合金的蠕变-疲劳交互作用行为及寿命预测

陈立佳 , 吴崴 , P.K.Liaw

金属学报

通过在816和927 ℃下进行总应变控制的不同拉伸应变保持时间的低周疲劳实验，研究了3种高温合金(HAYNES 188, HAYNES 230和HASTELLOY X)的蠕变-疲劳交互作用行为.结果表明，这3种高温合金的应变疲劳寿命主要取决于合金类型、应变保持周期及实验温度. 这些高温合金所表现出的不同应变疲劳寿命行为可归因于蠕变和氧化损伤方面的差异. 此外，应用频率修正的非弹性拉伸应变能作为损伤函数对这3种合金进行了应变疲劳寿命预测，结果显示该寿命预测方法对3种高温合金均表现出较好的寿命预测能力.

关键词: 高温合金 , creep-fatigue interaction , stress relaxation

3种高温合金的蠕变-疲劳交互作用行为及寿命预测

陈立佳 , 吴崴 , P.K.Liaw

金属学报 doi:10.3321/j.issn:0412-1961.2006.09.011

通过在816和927℃下进行总应变控制的不同拉伸应变保持时间的低周疲劳实验,研究了3种高温合金(HAYNES 188,HAYNES 230和HASTELLOY X)的蠕变-疲劳交互作用行为.结果表明,这3种高温合金的应变疲劳寿命主要取决于合金类型、应变保持周期及实验温度.这些高温合金所表现出的不同应变疲劳寿命行为可归因于蠕变和氧化损伤方面的差异.此外,应用频率修正的非弹性拉伸应变能作为损伤函数对这3种合金进行了应变疲劳寿命预测,结果显示该寿命预测方法对3种高温合金均表现出较好的寿命预测能力.

关键词: 高温合金 , 蠕变-疲劳交互作用 , 应力松弛 , 寿命预测

SNOEK-Ke-K■STER PEAK OF INTERNAL FRICTION IN Fe-P-N ALLOYS

Y.Y.Che , G. Y.Zeng , Y. C. Xu and J. W , Ji(College of Science , Northeastern University , Shenyang 110006 , China)

金属学报(英文版)

The internal friction and precipitate phases of the deformed Fe-P-N alloys have been investigated. It has been found that the ratio of depends on the content of P and the relation holds if the content of N is lower than 30wt.ppm and the content of P is lower than 640wt.ppm. It shows that the intercept K2 is related to the presence of the atomic pairs and clusters of P in the alloy matrix.

关键词: internal friction , null

关于K-p两体问题的相对论修正

王万章 , 张启仁 , 高春媛

原子核物理评论 doi:10.3969/j.issn.1007-4627.2005.04.033

从基本理论出发,导出并求解了含有相对论修正的K介子与质子的两体薛定谔方程.其解可看作有统计解释的波函数.计算了K p的散射长度,结果表明相对论效应是很明显的.

关键词: K-p系统 , 相对论修正 , 散射长度

Crystal structure and thermal properties of compound K(2)Zn(3)(P(2)O(7))(2)

Powder Diffraction

K(2)Zn(3)(P(2)O(7))(2) was synthesized by solid state reaction and its crystal structure was determined by ab initio method from powder X-ray diffraction (XRD) data. The title compound was determined to be orthorhombic with space group P2(1)2(1)2(1), Z=4, and lattice parameters a=12.901(8) angstrom, b=10.102(6) angstrom, and c=9.958(1) angstrom. Values of lattice parameters from 303 to 573 K were measured by temperature-dependent XRD. Thermal expansion coefficients alpha(0), lattice parameters, and cell volume at 0 K were determined to be alpha(0)(a)=1.62327X 10(-4)/K, a(0)=12.855(4) angstrom, alpha(0)(b) = 1.17921 X 10(-4)/K, b(0)=10.070(8) angstrom, alpha(0)(c)=2.62364X 10(-4)/K, c(0)=9.880(4) angstrom, and alpha(0)(V) = 6.599 X 10(-2) /K, V(0) = 1278.967(0) angstrom(3). The specific heat equation as a function of temperature was determined to be C(p)=0.77115 +0.00231 T-1241.60027T(-2)- 1.4133 X 10(-6)T(2) (J/K g), for temperatures from 198 to 710 K. The melting point estimated from the mu-DTA heating curve is 795 degrees C. (C) 2008 International Centre for Diffraction Data. [DOI: 10.1154/1.2992517]

关键词: K(2)Zn(3)(P(2)O(7))(2);structure determination;thermal expansion;coefficient;specific heat;powder-diffraction;refinement;zno

应力比对40CrMnSiMoVA钢P-da/dN-△k曲线 影响研究

李淑兰 , 杨玉芬

兵器材料科学与工程 doi:10.3969/j.issn.1004-244X.2008.03.016

在介绍40CrMnSiMoVA钢的力学性能和试验条件基础上,根据金属材料疲劳裂纹扩展的统计分析方法,求出Pa-N和P-da/dN-△k曲线,并对不同应力比条件下的试验数据进行可靠性分析和比较,探讨中值da/dN-△k曲线和99.9%可靠度dddN-△k曲线的变化规律.研究结果表明,P-da/dN-△k曲线与应力比有很强的相关性,随着应力比增强,裂纹扩展速率增加.当可靠度要求增加时,这种趋势更明显.根据研究结果,恰当地考虑40CrMnSiMoVA钢对于不同应力比的影响,便于进行概率断裂力学分析.

关键词: 断裂 , 40CrMnSiMOVA钢 , P-da/dN-△k曲线 , 应力比

KⅧ-TbLⅣ离子3s3p 3P1-3s2 1S0 的自旋禁戒跃迁

牟致栋 , 魏琦瑛

原子核物理评论 doi:10.3969/j.issn.1007-4627.2004.01.015

在对KⅧ-TbLⅣ离子3s3p 3P1能级结构的多组态相互作用理论HXR方法计算的基础上, 分析了各种效应对等电子序列离子能级结构的影响, 找出了能级沿等电子序列变化的规律性. 预测计算了K Ⅷ-Tb LⅣ离子3s3p 3P1的能级. 由此进一步计算了KⅧ-TbL Ⅳ离子自旋禁戒跃迁3s3p 3P1-3s2 1S0的谱线波长、振子强度和跃迁概率.

关键词: KⅧ-TbLⅣ离子 , 自旋禁戒跃迁 , 波长 , 振子强度和跃迁概率

La对Fe-P-N合金Snoek-Ke-K■ster峰的影响

戢景文 , 魏全金 , 张国福 , 赖祖涵 , 陈廷国

金属学报

研究了F? P—N合金加?对Snoek—Ke-Koster(SKK)峰的影响,发现与合金含La,P的原子浓度比(C_(La)/C_p)有关:对于C_(La)/C_p较大(例如4.56和2.6)的合金,La有明显增强SKK阻?效应:对于C_(La)/C_p=0.27的P过饱和合金,La对SKK峰无明显影响。

关键词: 内耗 , Snoek-Ke-Koster peak , Fe-P-La-N alloy

Phase relations and flux research for zinc oxide crystal growth in the ZnO-K(2)O-P(2)O(5) system

Journal of Alloys and Compounds

The subsolidus phase relations of the ternary system ZnO-K(2)O-P(2)O(5) were investigated by means of Xray diffraction (XRD). There are 7 binary compounds. 6 ternary compounds and 20 three-phase regions in this system. The phase diagram of the pseudo-binary system KZn(4)(PO(4))(3)-ZnO was also investigated by means of XRD and differential thermal analysis (DTA) methods. KZn(4)(PO(4))(3)-ZnO is a eutectic system with eutectic temperature about 952 degrees C and eutectic point at about 2 mol% ZnO. Only narrow composition range in the KZn(4)(PO(4))(3)-ZnO system is suitable for the growth of ZnO crystals. (C) 2008 Elsevier B.V. All rights reserved.

关键词: ZnO-K(2)O-P(2)O(5) system;ZnO semiconductor;Phase diagrams;X-ray;diffraction;single-crystals;potassium;zno;orthophosphates;monophosphate;equilibria;knowledge;(kpo3)x;na

Ga、K双掺杂P型Bi0.5Sb1.5Te3材料的制备及热电性能

段兴凯 , 胡孔刚 , 丁时锋 , 满达虎 , 张汪年 , 马明亮

稀有金属

采用真空熔炼和热压方法制备了Ga和K双掺杂Bi0.5Sb1.5Te3热电材料.XRD结果表明,Ga0.02Bi0.5Sb1.48-xKxTe3块体材料的XRD图谱与Bi0.5Sb1.5Te3的XRD图谱对应一致,但双掺杂样品的衍射峰略微向左偏移.热压块体材料中存在明显的(001)晶面择优取向.SEM形貌表明材料组织致密且有层状结构特征.Ga和K双掺杂可使Bi0.5Sb1.5Te3在室温附近的Seebeck系数有一定的提高,而双掺杂样品的电导率均得到了不同程度的提高,其中Ga0.02Bi0.5Sb1.42K0.06Te3样品的电导率得到较明显的改善.在300～500 K测量温度范围内,所有双掺杂样品的热导率高于Bi0.5Sb1.5Te3的热导率,在300 K附近双掺杂样品的ZT值得到提高,其中Ga0.02Bi0.5Sb1.42K0.06Te3样品在300 K时ZT值达到1.5.

关键词: 双掺杂 , 真空熔炼 , 热压 , 显微结构 , 热电性能