J. Zhang
,
J.B. Li
,
Q.Heng and X.H.Zhang Shenyang University
,
Shenyang 110044
,
China L.Q.Qi LiMing Aeroengine Manufacfruing Corperation
,
Shenyang 110043
,
China
金属学报(英文版)
NCoCrAlSiYHf and CoNiCrAlTaY coatings which belong to protective Al 2O 3 scale forming type were deposited by multi arc ion plating technique . The effect of deposition process parameters on qualities of the coatings was discussed. The high temperature oxidation performances isothermal oxidation with 950℃ / 500h and 1100℃ / 100h were studied. And also, the hot corrosion performances at 700℃ and 800℃, with molten mixed salt composed of 75%wt Na 2SO 4 and 25%wt NaCl were investigated. Then the high temperature protection decaying mechanisms were proposed.
关键词:
multi arc ion plating
,
null
,
null
,
null
J. Zhang
金属学报(英文版)
Based on the atomicity and molecularity as well as the consistency of thermodynamicproperties and activities of metallic melts with their structures, the coexistence the-ory of metallic melts structure involving compound has been suggested. According tothis theory, the calculating models of mass action concentrations for different binarymetallic melts have been formulated. The calculated mass action concentrations agreewell with corresponding measured activities, which confirms that the suggested theorycan reflect the structural characteristics of metallic melts involving compound and thatthe mass action law is widely applicable to this kind of metallic melts.
关键词:
metallic melts
,
null
,
null
,
null
J. Zhang
金属学报(英文版)
After investigation on the thermodynamic
properties of a small number of binary metallic melts, the
structural units of which cannot be wholly determined by the
corresponding phase diagrams, it was found that they can be
determined by the principle of annexation of two kinds of
solutions in binary metallic melts. According to the principle of
annexation, calculating models of mass action concentrations for
several binary metallic melts have been formulated. The calculated
results agree well with practice, showing that this principle is a
reliable basis for determination of the structural units for some
binary metallic melts.
关键词:
metallic melt
,
null
,
null
J. Zhang
金属学报(英文版)
It is shown by the the law of mass action in combination with the coexistence theory of slag structure that K'Mn=NMnO/(NFeO[%Mn]) does not change with basicities and maintains constant at constant temperature; the oxidizing capabilities of multicomponent slag systems containing CaO, MgO etc., can be expressed by NretO=NFeO+6NFe2O3+8NFe3O4; the desulfurizing capabilities of various basic oxides for multicomponent slag systems can be calculated by Ls=8(KCasNCaO +KMgsNMgO +KFesNFeO)∑ n/[%O]; the dephosphorizing capabilities of CaO-MgO-FeO-Fe2O3-P2O5 as well as CaO-FeO-Fe2O3-Al2O3-P2O5 molten slags expressed respectively by LpO=(%P2O5)/[P]2 = 141.g4[%O] ∑nK00(1 +4 2 3 3 4KsN2CaO + K6N3CaO + K7N4CaO + KsNMgO + K9N3MgO + K10NFeO + K11NFeO);2 3 4LpO=(%P2O5)/[P]2 = 141.94[%O ∑nK00(1 + K10N2CO + K11NcaO + K12N4CaO+ K13N3FeO + 14N4FeO) have good agreement with practical values.
关键词:
coexistence theory
,
null
,
null
J. Zhang
金属学报(英文版)
Based on the phase diagrams, measured activities and the annexation principle, the calculating models of mass action concentrations for Cd-Pb, Pb-Sb and Cd-Sb binary as well as Cd-Pb-Sb ternary metallic melts have been formulated. The results of calculation both agree with practice and obey the mass action law. This in turn testifies that the models formulated can reflect the structural reality of corresponding melts and the annexation principle is applicable to these melts.
关键词:
activity
,
null
,
null
,
null
J. Zhang
,
D. Feng
,
Z.Y. Zhong
金属学报(英文版)
The application advances of TiAl, Ti3Al and Ni3Al base alloys were demonstrated by Central Iron and Steel Research Institute, China. The recent research progresses on improving the reliability of cast TiAl were mainly presented and discussed. The characteristics of the self-oriented lamellar microstructure in cast TiAl were investigated in both as cast and as HIPed states. Based on the mechanical anisotropy of the cast lamellar microstructure, the component specific microstructure design was proposed for a better performance and reliability of cast TiAl.
关键词:
intermetallic
,
null
,
null
Journal of Materials Research
The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.
关键词:
room-temperature
Journal of Physics-Condensed Matter
The temperature dependences of the magnetization, internal energy and specific heat in a three-sublattice ferrimagnet or ferromagnet with /J(ab)/ = /J(bc)/ not equal /J(ca)/ are calculated within the framework of the linear spin-wave approximation, by employing retarded Green's functions. For both the ferromagnet and the ferrimagnet, the internal energy and the specific heat decrease with increasing J ' /J and/or the value of the spins. For fixed values of S,, Sb, S, and J ' /J, the internal energy and the specific heat increase, whereas the sublattice magnetization decreases with increasing temperature theta. The three-sublattice ferrimagnet has some particular characteristics which are not shown by the systems with two sublattices. For ferrimagnets, the antiferromagnetism of the system becomes weaker with increasing J ' /J. The sublattice magnetization at low temperatures (also the magnetization M(0) at 0 K) of a ferrimagnet increases with increasing J ' /J for fixed values of S(a), S(b) and S(c). The effects of the spins S(a) (S,) and Sb On the magnetizations of other sublattices differ. The characteristics of the a-sublattice are the same as those of the c-sublattice, due to their similarity as well as the symmetry of the system. The behaviours of the b-sublattice are different from those of the a- and c-sublattices, due to the asymmetry of the three-sublattice system. The spin-value dependences of the spin deviation Deltam per spin land also the energy for the zero-point quantum fluctuation) of the system are different for different sublattices. These differences are ascribed to the asymmetry of the three-sublattice systems, which leads to the new intrinsic properties of the systems.
关键词:
layered heisenberg ferrimagnets;spin-wave theory;elementary;excitations;superlattices;systems;magnetoresistance;antiferromagnet;interfaces
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