材料期刊网

THE BASIC CONSIDERATIONS OF SELF-SReM AND SELF-BoSS MODELS

G.C. Jiang , K. Tang , X.B. Zhang and K.D. Xu Shanghai Enhanced Laboratory of Ferrometallurgy , Shanghai University , 149 Yanchang Road , Shanghai 200072 , China

金属学报(英文版)

Model Investigation is the only feasible way to solve the problem about the component activities in concentrated multicomponent alloys and molten slags at present. The basic characteristic of SELF-SReM model is briefly introduced in this paper. It intends to give out the systematical value of component activities in the whole homogeneous region of a concentrated multicomponent melt, then to provide a reliable database for the description of the equilibrium conditions associated with metallurgy processes. For molten slags, the key issue is to distinguish the accuracy of thermodynamic properties in binary systems. The fundamental approach for this task is to link the microscopic bond structure and macroscopic activity based on both of the measurement of high tem- perature Raman spectroscopy and the corresponding computation simulation according to molecular dynamics and quantum chemistry.

关键词: activity , null , null , null

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

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

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

SYNTHESIS OF TiN FILM WITH ION BEAM ENHANCED DEPOSITION AND ITS PROPERTIES

ZHOU Jiankun LIU Xianghuai CHEN Youshan WANG Xi ZHENG Zhihong HUANG Wei ZOU Shichang Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , China

金属学报(英文版)

The TiN films were synthesized with an alternate process of depositing titanium from a E-gun evaporation source and 40 keV N~+ bombarding onto the target.It is shown from the composi- tion analysis and structure investigations using RBS,AES,TEM,XPS and X-ray diffraction spectrum that the formed fihns are mainly composed of TiN phase with grain size of 30—40 nm and without preferred orientation,the nitrogen content in the film is much less than that in case without N~+ bombarding,and an intermixed region about 40 nm thick exists between the film and the substrate.The films exhibt high microhardness and low friction. ZHOU Jiankun,Ion Beam Laboratory,Shanghai Institute of Metallurgy,Academia Sinica, Shanghai 200050,China

关键词: TiN film , null

Deformation-enhanced thermal stability of an amorphous Fe80B20 alloy

Journal of Applied Physics

By means of differential scanning calorimeter (DSC) measurements, the thermal stability of an amorphous Fe80B20 alloy after various periods of low-energy ball milling has been studied. The results indicate that the thermal stability of the amorphous Fe80B20 ribbons can be enhanced upon mechanical deformation with a low milling intensity. The crystallization temperature T-p, the crystallization enthalpy Delta H, and the crystallization activation energy E(x) increase with milling time. The above observations will be compared with our previous findings that extensive mechanical deformation with a high milling intensity can otherwise induce a structural relaxation in an amorphous Fe80B20 alloy. Based on conventional thermodynamic and kinetic arguments, a reasonable interpretation will be made to explain the enhanced thermal stability of the amorphous Fe80B20 alloy after mechanical deformation. (C) 1996 American Institute of Physics.

关键词:

Enhanced ferroelectricity in orthorhombic manganites Gd(1-x)Ho(x)MnO(3)

Journal of Applied Physics

A series of orthorhombic manganites Gd(1-x)Ho(x)MnO(3) (0 <= x <= 0.5) are synthesized. The Ho doping leads to a transition of paraelectric phase into ferroelectric one, making Gd(1-x)Ho(x)MnO(3) multiferroic. It is argued that the enhanced electric polarization originates from the transition of the A-type Mn(3+) anti-ferromagnetic state into the spiral spin order driven by the reduction of Mn-O-Mn bond angle due to the doping. The noncollinear spin order of the A-site Ho(3+) spins at high doping level may also make contribution to the polarization. (c) 2011 American Institute of Physics. [doi: 10.1063/1.3535543]

关键词: polarization;perovskite

Enhanced multiferroicity in Mg-doped Ca(3)Co(2-x)Mn(x)O(6)

Applied Physics Letters

Polycrystalline Ca(3-x)Mg(x)Co(2-y)Mn(y)O(6) (y similar to 1.0) samples are prepared in order to investigate the A-site doping effect of Ca(3)Co(2-y)Mn(y)O(6) (y similar to 1.0). Compared with Ca(3)Co(2-y)Mn(y)O(6) (y similar to 1.0), the ferroelectric polarization and Curie point of Ca(3-x)Mg(x)Co(2-y)Mn(y)O(6) (y similar to 1.0) at the maximal doping x similar to 0.3 are significantly enhanced. The magnetic order of Ca(3-x)Mg(x)Co(2-y)Mn(y)O(6) (x similar to 0.3, y similar to 1.0) and thus ferroelectric order are more robust than the undoped compound. The slight lattice shrinking as a result of Mg substitution may contribute to the enhancement of exchange striction, leading to the changes in magnetic and ferroelectric properties.

关键词: calcium compounds;cobalt compounds;Curie temperature;dielectric;polarisation;doping;ferroelectric materials;magnesium compounds;multiferroics;one-dimensional oxides;ca3co1+xmn1-xo6

Enhanced remanence and high product energy of Fe3B-based nanocrystalline magnetic materials

Nanostructured Materials

This paper presents new results of an investigation of a commercial rapidly quenched Nd4.5Fe77B18.5 alloy that was studied previously. The enhanced remanence Jr = 13.2 KGs and high product energy (BH)max = 16.2 MGOe are shown to be due to ultrafine grain. The microstructure, consisting of no alpha-Fe that results in optimum magnetic properties, occurs in the amorphous Nd4.5Fe77B18.5 alloy after crystallization. The coexistence of Fe3B, Nd2Fe14B and residual amorphous phase play dominant roles in the achievement of the hard magnetic properties, and hence, the amorphous phase seems to act as an effective magnetic exchange-coupled medium.

关键词: alloys

AN UNIDENTIFIED MAGNETIC TRANSITION IN R2FE14X COMPOUNDS (R = SM, TB, DY, HO, ER, AND TM - X = B OR C)

Journal of Applied Physics

In Ho2Fe14B and Ho2Fe14C the temperature dependence of the ac initial susceptibility between 4.2 and 300 K shows two peaks. The peak at the lower temperature can be explained by a well-known spin reorientation transition (at 62 K for Ho2Fe14B and at 40 K for Ho2Fe14C). The peak at the higher temperature (at 245 K for Ho2Fe14B and at 265 K for Ho2Fe14C) disappears when the external field is applied parallel or perpendicular to the preferential direction of a magnetically aligned sample. The similar peak was also traced for R2Fe14X compounds (R = Sm, Tb, Dy, Ho, Er, and Tm; X = B or C). Searching for the nature of this peak traced by measuring the temperature dependence of the ac susceptibility for 3d-4f compounds is still under progress.

关键词:

FeMoB Enhanced Sintering of P/M 316L Stainless Steel

YANG Xia , GUO Shiju

钢铁研究学报(英文版)

Liquidphase enhanced sintering of powder metallurgy (P/M) 316L stainless steel by addition of sintering aids was studied. 2%-8% of prealloyed FeMoB powder with two different particle sizes was added as sintering aids, and the specimens were sintered in vacuum at 1 200-1 350 ℃. The results show that the fine FeMoB powder (5-10 μm) has stronger activated effect. The sintered density increases with the increase in sintering aid content or sintering temperature. Warm compaction has a better effect on the control of dimensional precision of compacts. The prealloyed FeMoB powder deviated from Mo2FeB2 component can also be sintering aid of P/M 316L stainless steel.

关键词: P/M 316L stainless steel;liquidphase sintering;activated sintering;FeMoB;sintering aid