Hu Zhuangqi

Structure features in binary liquid Li–Tl alloys

With the help of potential mapping techniques, molecular dynamics simulations have been performed to study the local structure features in binary liquid Li–Tl alloys. The generalized nonlocal model pseudopotentials have been chosen as the bases for our calculations. Both the bond orientational order and pair analysis approach have been adopted as the basic structural functions to examine the structure features in binary liquid Li–Tl alloys. In addition, bonded pairs with various symmetries, icosahedra, defective icosahedra, Frank–Kasper polyhedra, etc., formed in the Li–Tl alloys are examined in detail, and the relationship between the structure features and composition has been established. The results show that the distribution of attractive parts of the potentials play an important role in characterizing the liquid structure. Finally, the results are discussed in detail.

Influence of Laserglaze on The Microstructure and Wear Resistance Of A Cast Nickel-Base Superalloy

Influence of laserglaze on the microstructure and wear resistance of a cast nickel-base superalloy has been studied, which contains very high contents of refractory metals (Mo 33 wt%, W 17 wt%). After surface treatment by laserglaze the alloy structure changes extraordinarily. This change of microstructure enhances the alloy properties. Hardness of the laser melted region is evidently increased, and wear resistance and and corrosion resistance are also improved.

A NEW PHASE IN RAPIDLY SOLIDIFIED TI3AL-BASED ALLOYS

Abstract The martensite with a P2221 space group has been found in Ti3Al-Nb alloys containing Nb below 5-at% via rapid solidification in the cooling rate of 105 ~ 106K/s. The ordering for the martensite α″0 in the alloys inherited that of the β0 phase. Enormous twins with (111) crystallographic planes were observed in the martensite α″0. The orientation relationships between the α″0 and β0 were derived from the SAED patterns as [110]α″o//[111]βo, (001) α″o //(1 1 0) βo .

Alloying Effect on the Microstructure and Property of Single Crystal Ni3Al Alloys

The alloying effects of Cr, Zr, Ta, Nb and B on the microstructure and properties of single crystal Ni 3 Al alloys have been studied. The strength of the alloys has been improved markedly with promising plasticity. The 0.2% yield stress of some of these alloys is higher than that of IN713C, a typical cast nickel-base superalloy, in the temperature range from 25 to 950°C and some of them reach the strength level of advanced cast nickel-base alloys such as IN100 in the high temperature range. The creep strength of these alloys is also improved markedly. The single crystal Ni 3 Al alloy with a high Cr content ( 7 at-%) obviously shows an intermediate temperature low plasticity behavior. Although heat treatment can only slightly improve the strength, it can double the elongation of the alloy from 25% to 50%. In the Ni 3 Al monocrystal containing 1.2at%Zr there exist great amounts of the low melting point Ni 5 Zr-γ eutectics around the ordinary γ/γ′ eutectics. This makes it difficult to homogenize the coarse casting structures completely.

Electrical Resistivity of Nanocrystalline Fe-Cu-Si-B Alloys

We have studied the room temperature and low-temperature electrical resistivities of nanocrystalline Fe-Cu-Si-B alloys with various grain sizes prepared by crystallization of amorphous material. Experimental results showed that with the reduction of grain size both room temperature resistivity rho(RT) and residual resistivity rho0 of the nanostructured alloys studied increased significantly. Based on the scattering effects from interfaces and lattice distortion, the above results were qualitatively discussed.

A novel preparation method for continuous BiSrCaCuO / Ag high-density superconducting tape

Continuous 2212 Bi-Sr-Ca-Cu-O / Ag superconducting composite tapes were prepared by a novel technique called Current Heat Melt-Painting (CHMP) method. The composite tapes exhibit excellent flexibility, and no microcrack can be found even at 2-3 mm curvature radius. The superconducting layer is very dense and very even in thickness and binds very well with Ag substrate observed by SEM.