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Isothermal section of Fe-Gd-Pd ternary system at 873 K has been established by means of x-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscope (SEM) with energy disperse x-ray spectroscopy (EDS) in backscattered electron imaging modes. The isothermal section consists of 14 single-phase regions, 25 two-phase regions, and 12 three-phase regions. At 873 K, no ternary compound was found and the binary inermetallic compounds Gd 3 Pd and Fe 23 Gd 6 are not stable, whereas the compound Fe 23 Gd 6 decomposes into compounds Fe 17 Gd 2 and Fe 3 Gd. The XRD and the SEM/EDS analysis show that there is almost no solubility of Gd in the FePd and FePd 3 phases, and the solubilities of Pd in Fe 17 Gd 2 , Fe 3 Gd and Fe 2 Gd and Fe in GdPd 2 , α-Gd 3 Pd 4 and Gd 3 Pd 2 are all less than 1 at.%. Meanwhile, the solubilities of Fe in GdPd 3 , α-GdPd and Gd 7 Pd 3 are determined to be as high as 1.37, 5.31, and 4.18 at.% Fe, respectively.

We recently proposed a theory of mechanism-based strain gradient (MSG) plasticity to account for the size dependence of plastic deformation at micron- and submicronlength scales. The MSG plasticity theory connects micron-scale plasticity to dislocation theories via a multiscale, hierarchical framework linking Taylor's dislocation hardening model to strain gradient plasticity. Here we show that the theory of MSG plasticity, when used to study micro-indentation, indeed reproduces the linear dependence observed in experiments, thus providing an important self-consistent check of the theory. The effects of pileup, sink-in, and the radius of indenter tip have been taken into account in the indentation model. In accomplishing this objective, we have generalized the MSG plasticity theory to include the elastic deformation in the hierarchical framework.

Since April 2008 the Wuhan High Magnetic Field Center (WHMFC) has been under development at the Huazhong University of Science and Technology (HUST) at Wuhan, China. It is funded by the Chinese National Development and Reformation Committee. Magnets with bore sizes from 12 to 34 mm and peak fields in the range of 50 to 80 T have been designed. The power supplies for these magnets are a capacitor bank with 12 modules of 1 MJ, 25 kV each and a 100 MVA/100 MJ flywheel pulse generator. The objective of the facility is to accommodate external users for extensive experiments in pulsed high magnetic fields. Up to seven measurement stations will be available at temperatures in the range from 50 mK to 400 K. The first prototype 1 MJ, 25 kV capacitor bank with thyristors, crowbar diodes and a mechanical switch has been developed and successfully tested. For the protection of the thyristor switch, a toroidal inductor is developed to limit the current at 40 kA. Five magnets have been wound with CuNb and copper wires and internal reinforcement by Zylon fiber; external reinforcement is a stainless steel shell encased by carbon fiber composite. Two Helium flow cryostats have been successfully tested and reached temperatures down to 4.2 K. Measurement stations for magneto-transport and magnetization are in operation. The design, construction and testing of the prototype system are presented.

Nanometer scale is introduced in the well-known Haldane system Y 2 BaNiO 5 ( S = 1 ) . Magnetization and pulsed-field electron spin resonance (ESR) measurements were performed. As a result, the magnetization of nanoparticles is much enhanced as compared with that of the bulk material. The Haldane gap in the bulk form tends to be suppressed as the grain size is reduced down to the nanometer scale. The chain-end S - 1 / 2 spins have an important contribution to the magnetism of nanoparticles. The high-field ESR data demonstrated a paramagnetic-like resonance. The frequency–field (f–H) relationship is linear and passes through the origin. The g value is about 2.16, in good agreement with the typical value of paramagnetic Ni 2 + . It is concluded that the nanometer scale is a new degree of freedom for controlling the ground state of quantum magnets.

The magnetization properties of (Tb 0.2 Pr 0.8 )(Fe 0.4 Co 0.6 ) 1.9− x C x ( –0.5) were investigated in a pulsed high magnetic field. Obvious unsymmetry magnetic hysteresis loops were observed, in which the magnetization measured in the second(negative) magnetic field route was larger than that measured in the first(positive) one. Meanwhile, the unsymmetry of the hysteresis loops was C doping levels, magnetic fields and temperatures dependent. The experimental results suggest that the unusual hysteresis phenomenon result mainly from the collapse of the pinning center and the formation of ferromagnetic(FM) pseudo-domain.

. We report the breaking of one-dimensional (1D) magnetism in a spin-1 chain antiferromagnet Ni 2 V 2 O 7 . First, basic structure and magnetization data are presented, showing that the compound is ordered at K and a field-induced spin-flop transition occurs at T. Second, high-field electronic spin resonance (ESR) data demonstrate antiferromagnetic (AFM) resonance modes below T N , which can be well understood by conventional AFM resonance theory with uniaxial anisotropy. Third, the first-principles calculations based on density function theory reveal a much larger interchain AFM interaction than the intrachain couplings. Combining with all these results, we can see that Ni 2 V 2 O 7 is not a 1D antiferromagnet, although it is a skew chain from the viewpoint of crystallographic structure.

High-frequency electron spin resonance (ESR) measurements were carried out on a single crystal β -Cu 2 V 2 O 7 , where Cu–O edge-sharing chains are connected by non-magnetic VO 4 tetrahedrons. Due to sizable anisotropies, analyses of bulk magnetic properties alone have not yielded any definite conclusion and the modeling of the magnetic lattice is controversial. By means of high-frequency ESR with operating frequencies of 135–405 GHz and at a temperature range of 4.2–50 K, the large g value anisotropy is determined, which removes the ambiguity of susceptibility fitting. Moreover, non-negligible exchange anisotropy is evaluated by analyzing high-field magnetization and antiferromagnetic resonance in antiferromagnetic state appearing below T N  = 26 K. Based on these microscopic information, we found that alternating-chain model is the most reasonable candidate for explaining properties of the crystal. The present study shows the importance of combining macroscopic and microscopic probes in analyzing magnetic network of complex magnetic materials.

Compared with the conventional steels, \"shear fracture\" is one of the main issues for advanced high strength steels (AHSS). Due to rolling, anisotropy is an intrinsic property for sheet metals. Not only the plastic responses of sheet metals but also the fracture strengths are orientation dependent. In the small radius forming process, for example, the stretch-bending deformation of sheet metals under small radius condition, the normal stress cannot be neglected. Three-dimensional loading condition constructs complex shear stress states of sheet metals especially the out-of-plane shear stress. The out-of-plane performance must be considered in order to better understand the \"shear fracture\" phenomenon of AHSS. Compared to in-plane shear test, the out-of-plane shear test is more difficult to carry out due to the severe restriction of the dimensions in the thickness direction. In this paper, a new specimen is presented for out-of-plane shear test. Failure of the specimen occurs in shear between two centrally located notches machined halfway through its thickness from opposing sides. Meanwhile, the finite element (FE) model and possible failure modes of this specimen are investigated in detail. At last, brief experimental results between out-of-plane shear fracture strength and the in-plane shear fracture strength are compared for DP980 sheets.

Waterjet propulsion system is widely used in high speed vessels with advantages of simple transmission mechanism, low noise underwater and good manoeuvrability. Compared with the propeller, waterjet propulsion can be used flow stamping to increasing cavitation resistance at high speed. But under certain conditions, such as low ship speed or high ship speed, cavitation problem still exists. If water-jet propulsion pump is run in cavitation condition for a long time, then the cavitation will cause a great deal of noise CFD is applied to analysis and predict the process of production and development of cavitation in waterjet propulsion pump. Based on the cavitation model of Zwart-Gerber-Belamri and a mixture of homogeneous flow model, commercial CFD software CFX was taken for characteristics of cavitation under the three operating conditions. Commercial software ANSYS 14.0 is used to build entity model, mesh and numerical simulation. The grid independence analysis determine the grid number of mixed flow pump model is about 1.6 million and the grid number of water-jet pump system unit is about 2.7 million. The cavitation characteristics of waterjet pump under three operating conditions are studied. The results show that the cavitation development trend is similar design and small rate of flow condition .Under the design conditions Cavitation bubbles are mainly gathered in suction surface of blade near the inlet side of the hub under the primary stage, and gradually extended to the water side in the direction of the rim with the loss of the inlet total pressure. Cavitation appears in hub before the blade rim, but the maximum value of gas content in blade rim is bigger than that in hub. Under large flow conditions, bubble along the direction of wheel hub extends to the rim gradually. Cavitation is found in the pressure surface of blade near the hub region under the critical point of cavitation nearby. When NPSHa is lower than critical point, the area covering by bubbles is about 40% in the suction surface of blade. It means that the critical point of cavitation of pump system is not the accrue point of install cavitation but cavitation has been developed to a certain stage.

The present paper concentrates on the factors inducing cracking near the Cu/Al vacuum brazing interface using Al-Si brazing alloy. Various analysis and test methods were adopted to analyse the cause of the cracking. Experiment results indicated that two intermetallic compounds layers - δ phase and θ phase - were formed near the interface of Cu and brazing seam region. The microhardness of both the two intermetallic compounds phases reached 720 and 510 HM respectively. The brazing seam region consisted mainly of θ phase and α-Al (Cu) solid solution. Si presence had led to obvious zone liquation in the brazing seam region. Stress concentration appeared on the margin and edge region of the joint. The crack initiated on the θ phase layer, and then extended towards the brazing seam region and δ phase layer. The separation in the θ phase had an obviously brittle fracture surface.