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RECRYSTALLIZATION IN A SPINODAL Cu Ni Fe ALLOY

S.M. Hao , X.J. Hao , G. Zhao and H.X. Li Schoolof Materials and Metallurgy , Northeastern University , Shenyang 110006 , China

金属学报(英文版)

Theinteraction ofspinodaldecomposition and recrystallization process,andthecharacteristic ofrecrystallizationin Cu Ni Fe alloy aged atdifferenttemperaturesaftersolution treatmentandcold rolling have been studied by structural analysis and Vickers hardnesstest. It has shownthat the recrystallization of spinodal Cu Ni Fe alloy might be divided into 2 types:spinodal decomposition, recovery and recrystallization oftwo phase microstructuretook placein the deformed alloy aged below thespinodaltemperature; whilerecrystallization ofsingle phase microstructureand growth offullyrecrystallized grainstook placeinthedeformed al loy aged abovethespinodaltemperature .The deformed alloyaged below thespinodaltemper aturerecrystallizedin cellular morphology.

关键词: spinodaldecomposition , null , null

J(τ_0γ_0/(x_1x_2))行列式与弹塑性J积分不守恒的理论与实验证明

刘叔仪

金属学报

<正> 作为固体脆性断裂判据的J积分,其数值与其积分路径无关,这在文献中叫“守恒性”。这个守恒性已被推广到塑性断裂,这到底有否根据?本文目的是作这个问题的证明。未用原作者的方法,但由两个旋度判据得到应力应变函数行列式给出的一些否定结论,希望这对J积分应用条件的了解有所助益。1.弹塑性J积分守恒的条件 J积分

关键词:

X70管线钢J1d和K1a与V型缺口Ak关系研究

朱杰武 , 柳永宁 , 许雁 , 冯耀荣

机械工程材料 doi:10.3969/j.issn.1000-3738.2005.06.007

在不同温度下测试了X70管线钢动态断裂韧度K1d、J1d和止裂韧度K1a以及夏氏V型缺口冲击韧度Ak,对三者的关系进行了分析.结果表明:温度和加载速率都对断裂韧度产生影响;加载速率变化引起的韧-脆断裂转变具有热激活特征,在热激活分析基础上,在应力强度因子速率K=15 MPa·m1/2s-1条件下,得出断裂韧度、止裂韧度和冲击韧度三者的关系:Ak=4.84×106T-2.8K1d(或K1a).可以用小试样Ak数据计算得到K1d和K1a.

关键词: 管线钢 , 断裂韧度 , 止裂韧度 , 韧-脆断裂转变

Spin waves in a four-sublattice Heisenberg ferrimagnet or ferromagnet with different exchange constants (J(ab)=J(cd)not equal J(bc)=J(da))

Physical Review B

The Hamiltonian for a four-sublattice Heisenberg ferrimagnet or ferromagnet with different exchange constants (J(ab) = J(cd) not equal J(bc) = J(da)) was established. An extended Bogoliubov transformation was developed by solving an equation group, consisting of 20 equations and 20 unknowns. The procedure for solving the equation group was carried out by introducing a simple way of reducing the numbers of the equations and the unknowns. The spin-wave spectra in the present system have been determined by performing the standard Holstein-Primakoff transformation and the Bogoliubov one. It has been found that the spin-wave spectra of the present system depend on the exchange constants and that the degeneracy of the spin-wave spectra remains. The results for a special case (J(ab) = J(bc)) i.e., an antiferromagnet are discussed briefly. The spin-wave spectra of the four-sublattice Heisenberg antiferromagnet are found to be degenerative also and they are linear in k for small k.

关键词: model

Spin waves in several Heisenberg systems: Three-sublattice with different exchange constants (J(ab)=J(bc)not equal J(ca)) and a superlattice with the elementary unit of four or three different layers

Physical Review B

The quadratic Holstein-Primakoff spin-wave Hamiltonian for three-sublattice Heisenberg systems with different exchange constants (J(ab)=J(bc)not equal J(ca)) was diagonalized by a three-step procedure. The classical ground state was examined and the effects of quantum fluctuation on the ground state were discussed. The 0 K spin reorientation angles due to quantum fluctuations were found to originate from the asymmetry of the system. As an extended application of the spin-wave study of the multisublattice systems, the spin-wave spectra of a Heisenberg superlattice, which has four or three magnetic atoms or spins, in each magnetic unit cell in the x direction, were solved analytically in terms of creation and annihilation operators. It has been found that the spin-wave spectra of the present superlattice systems depend on the exchange constants J and J(1), and that the degeneracy of the spin-wave spectra remains for the superlattice of four atomic layers and is partially removed for the superlattice of three atomic layers mainly due to the asymmetry of the system. Another type of splitting of the energy level occurs which differs for those levels with different degeneracies. The mixing of the interface and the bulk modes were found for the spin-wave dispersion of the superlattices. It was predicted that even for different superlattices having the same exchange constants (either J or J'), i.e., without the oscillation of the exchange coupling, the asymmetry can lead to the oscillation of magnetic properties, such as magnetization and giant magnetoresistance.

关键词: ferromagnetic superlattices;reorientation transitions;magnetic;superlattices;modes;temperatures;film

高分子专利j

高分子材料科学与工程

专利名称:具有改进的抗冲击性、尺寸稳定性和吹塑成形性能的热塑性ABS树脂组合物专利申请号:CN200580040787.3公开号:CN101065413申请日:2005.03.31公开日:2007.10.31申请人j韩国第一毛织株式会社根据本发明的热塑性ABS树脂组合物包括:(a)2

关键词: 专利名称 , 高分子 , 树脂组合物 , 专利申请号 , 尺寸稳定性 , 抗冲击性 , 株式会社 , 成形性能

Study on the Relationship Between J-Integral and COD

Y.G. Cao , X.Y. Sun

金属学报(英文版)

J-integral and crack opening displacement δ(COD) were important parameters for characterization of fractures in engineering materials. The relationship between J-integral and COD has been investigated for a long time and was enerally represented as J = m σyδ, where σy is the yield strength and m is a function of specimen geometry and material properties. To determine the value of m, extensive studies and experiments have been performed. The method that used the fracture-surface topography analysis (FRASTA) for determining J-integral from fracture surfaces of materials was introduced. On the basis of the relationship between COD and fracture surface average profile, the relationship between J-integral and COD was deduced and compared with the generally used equation. The method was experimentally confirmed to be able to provide a new way to determine the relationship between J-integral and COD.

关键词: FRASTA , null , null

浅析CTOD和J积分的关系

周峰峦 , 郭震

物理测试 doi:10.13228/j.boyuan.issn1001-0777.20160084

推导了CTOD和J积分的关系,并且从试验角度利用三点弯曲试样进行CTOD试验,根据ASTM E1820对GB/T 21143-2014中公式34进行了评价,研究表明,在小屈服范围内,采用裂纹嘴张开位移可以同时得到CTOD和J积分,从而可以简化J积分的试验装置.

关键词: J积分 , CTOD , 小屈服

悬臂弯曲方法测定J_(Ic)和J_(Iscc)的探讨

null , null

金属学报

在工程上,经常由于应力腐蚀开裂和氢脆引起中强度钢结构件发生滞后破坏。这类脆断往往从结构件中预先存在的疲劳或焊接裂纹处开始,因此,运用传统的光滑试样的检验方法不能反映这类破坏的特点。 本文将弹塑性断裂力学中的J积分概念用于滞后破坏的研究,提出用带预制疲劳裂纹的悬臂弯曲试样测定J积分的临界值J_(Ic)和应力腐蚀开裂阈值J_(Iscc)的方法。测定了40CrNiMo钢的J_(Ic)值及其在硫化氢水溶液中的J_(Iscc)值。通过和三点弯曲方法测定的J_(Ic)值的对比,以及和满足线弹性条件时直接测定的应力强度因子K_I值的对比,说明这种方法的可靠性。最后,对悬臂弯曲方法的特点进行了讨论。

关键词:

J/Ψ衰变的Roper共振态结构的研究

平荣刚

原子核物理评论 doi:10.3969/j.issn.1007-4627.2004.02.026

通过J/Ψ→pp-,pN-*,N*N-*衰变,研究了Roper共振态的混杂态结构对衰变角分布和分支比的影响.计算结果表明,如果Roper共振态为纯混杂态,那么J/Ψ→pN-*,N*N-*的角分布几乎相等,而J/Ψ衰变到混杂态的衰变宽度还不到J/Ψ→pp-的1%,给出了Γ(J/Ψ→ N*p-)/Γ(J/Ψ→pp-)和Γ(J/Ψ→ N*N-*)/Γ(J/Ψ→pp-)随混合参数的变化关系,并讨论了在J/Ψ衰变中研究Roper混杂态结构的可能性.

关键词: Roper共振态结构 , 混杂态 , J

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