Statistical Mechanics Model of Liquid Binary Ailoy

ＳｔａｔｉｓｔｉｃａｌＭｅｃｈａｎｉｃｓＭｏｄｅｌｏｆＬｉｑｕｉｄＢｉｎａｒｙＡｉｌｏｙＦａｎＣｈｅｎｇｃａｉ，ＷａｎｇＪｉａｎａｎｄＬｉＷｅｎｃｈａｏ（樊成才）（王俭）（ＵｎｉｖｅｒｓｉｔｙｏｆＳｃｉｅｎｃｅａｎｄＴｅｃｈｎｏｌｏｇｙＢｅｉｊｉｎｇ...     

Statistical Mechanics Model of Liquid Binary Alloy（Ⅱ）─Parameters of Liquid Binary Alloy

ＳｔａｔｉｓｔｉｃａｌＭｅｃｈａｎｉｃｓＭｏｄｅｌｏｆＬｉｑｕｉｄＢｉｎａｒｙＡｌｌｏｙ（Ⅱ）─ＰａｒａｍｅｔｅｒｓｏｆＬｉｑｕｉｄＢｉｎａｒｙＡｌｌｏｙＦａｎＣｈｅｎｇｃａｉ，ＷａｎｇＪｉａｎａｎｄＬｉＷｅｎｃｈａｏ（樊成才）（王俭）（李文超）（Ｕ...     

Numerical model of solidification process in binary Al-Fe alloy under centrifugal casting

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｏｌｉｄｉｆｉｃａｔｉｏｎｐｒｏｃｅｓｓｏｆｂｉｎａｒｙＡｌ Ｆｅａｌｌｏｙｕｎｄｅｒｃｅｎｔｒｉｆｕｇａｌｃａｓｔｉｎｇｉｓｃｏｎｔｒｏｌｌｅｄｂｙｔｈｅｍａｓｓ,ｍｏｍｅｎｔｕｍ ,ｈｅａｔａｎｄｃｈｅｍｉｃａｌｓｐｅｃｉｅｓｔｒａｎｓｐｏｒｔａ ｔｉｏｎ .Ｔｈｅｒｅｆｏｒｅ,ｉｔｉｓａｎｉｍｐｏｒｔａｎｔｍｅａｎｓｔｏｋｎｏｗｔｈｅｍｉｃｒｏｓｔｒｕｃｔｕｒｅａｎｄｔｈｅｓｅｇｒｅｇａｔｉｏｎｏｆｂｉｎａｒｙＡｌ Ｆｅａｌｌｏｙｕｎｄｅｒｃｅｎｔｒｉｆｕｇａｌｃ…     

Fe-Al系金属间化合物中的微观缺陷和电子密度

对二元Fe-Al合金，含Cr和Si的Fe3Al合金的正电子寿命谱测量表明：随着二元Fe-Al合金中Al含量的增加，空位浓度增加，微孔洞的开空间增大。在Al含量高于40％原子分数）的B2－FeAl合金中存在着较高的空位浓度和开空间相当于Fe中的10－15个空位聚集体的微空洞。在B2－FeAl和D03－Fe3Al合金中，晶格中最邻近的Fe-Al原子对之间发生Fe-d-Alp杂化使用。Al的3p电子与Fe的3d电子被局域化并形成共价键。导致合金中的自由电子密度降低。二元Fe-Al合金中的平均电子密度随着Al含量的增加而下降。用Cr元素对Fe3Al进行合金化。合金基体和晶界处的自由电子密度均增加；而加入Si元素，合金基体和晶界处的自由电子密度均减小。讨论了Fe-Al合金的微结构对其力学性能的影响。     

A model for work of solid–liquid adhesion in multicomponent melts

The thermodynamic work of solid–liquid adhesion in multicomponent melts is important in many fields. Quantitative calculation of the work of solid–liquid adhesion has not, however, been well developed. A model for quantitative calculation of the work of solid–liquid adhesion in a multicomponent melt has been proposed based on the expansion of the Maclaurin infinite series in the neighborhood of each pure component of the binary alloy. The parameters used in this model are assessed through the statistical thermodynamic model of surface and interface tensions, which is based on the monolayer approximation for metal–vapor and metal–solid interfaces and Bragg–Williams statistics. According to the present model, the work of adhesion–concentration dependency over the whole concentration range for binary alloy can be theoretically determined from only the physical parameters of the pure components. The model has been successfully applied to calculate the work of adhesion for various solid–liquid systems.     

化学镀Fe—Mo—W—B非晶态合金的晶化

利用化学镀获得非晶态Ｆｅ－Ｍｏ－Ｗ－Ｂ四元合金镀层。用Ｘ射线衍射方法研究了镀层的结构和晶化过程。结果表明;Ｂ含量在９．８ａｔ％－２７．３ａｔ％范围内镀层为非晶态结构,该区域大于Ｆｅ－Ｂ二元合金镀层,但不如Ｆｅ－Ｍｏ－Ｂ三元合金镀层。观察到两步晶化过程：首先析出的晶化相为α－Ｆｅ,Ｆｅ３Ｂ和（Ｍｏ,Ｗ）２Ｂ;然后在较高温度出现Ｆｅ２Ｂ,（Ｍｏ,Ｗ）Ｂ和Ｆｅ（Ｍｏ,Ｗ）的衍射峰。     

Structures of bulk amorphous Zr_(41) Ti_(14) Ni_(10) Cu_(12.5) Be_(22.5)alloy in amorphous, crystalline, supercooled liquid and liquid states

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｂｕｌｋａｍｏｒｐｈｏｕｓａｌｌｏｙｓｏｆＭｇ ＴＭ Ｌｎ ,Ｌｎ Ａｌ ＴＭ ,Ｚｒ Ａｌ ＴＭ ,Ｈｆ Ａｌ ＴＭａｎｄＴｉ Ｚｒ ＴＭｗｅｒｅｐｒｅｐａｒｅｄｂｙＩｎｏｕｅａｎｄｈｉｓｃｏ ｗｏｒｋｅｒｓｓｉｎｃｅ 1990 [1] .Ｔｈｅｃ     

On the impact toughness of Fe-40Al-based B2 aluminides

Charpy impact tests were conducted in the temperature range 300–973 K on polycrystalline, large-grained Fe–40Al, Fe–40Al-0.6C, and Fe–40Al–0.7C–0.5B alloys that were in the extruded and low-temperature annealed condition. For purpose of comparison, wrought 1045 steel was also similarly tested. At room temperature, the alloy containing carbon and boron exhibited twice the impact resistance of binary Fe–40Al. Impact resistance for all three FeAl-based alloys increased with temperature initially but then exhibited a substantial decrease with further increases in temperature. Fracture mode in the binary FeAl alloy was intergranular at all temperatures whereas in the C-containing alloy, and the C+B alloy, there was some evidence of transgranular cleavage at room temperature; at 973 K a substantial amount of transgranular cleavage was evident. Tensile tests were conducted at a variety of strain rates at room temperature and at 973 K to help understand the impact response observed.     

Theoretical calculation of the mixing enthalpies of 21 IIIB-IVB, IIIB-VB and IVB-VB binary alloy systems

The calculation of the formation/mixing enthalpies of binary alloys is an important problem. There have been no systematic theoretical calculations of the mixing enthalpies for group B alloy systems using the famous Miedema theory or from the theoretical methods of first principle. Therefore such calculations for the 21 binary group IIIB-IVB, IIIB-VB and IVB-VB metal alloy systems are performed systematically for the first time using a subregular model. The results show that the agreement between the calculations and experimental data is pretty good and could be accepted from the theoretical or experimental points of view. From the present results and those in other two papers by the authors, it also can be concluded that the subregular model can be used for calculating the mixing enthalpies for all the 36 alloy systems combined with the 9 group B metals of Zn, Cd, Ga, In, Tl, Sn, Pb, Sb and Bi.     

Nd-Fe-B合金的腐蚀及防蚀表面处理

研究了在环境腐蚀试验条件下Ｎｄ－Ｆｅ－Ｂ合金的腐蚀行为及腐蚀对其磁性能的影响,并提出了防止腐蚀的表面处理方法。试验结果表明,Ｎｄ－Ｆｅ－Ｂ合金有较高的腐蚀速率,腐蚀后Ｎｄ－Ｆｅ－Ｂ合金的磁性能降低。化学镀Ｎｉ－Ｐ及电泳涂装的复合表面处理方法,具有良好的防蚀效果。     

Cluster Model of Formation of an Incommensurate ω-Phase in Alloys of the Titanium – Iron System

The structural model of formation of the ω-phase in titanium alloys is refined by considering coordination polyhedra of the matrix b.c.c. phase. It is established that fragments of the crystal lattice of the ω-phase can unite with fragments of the lattice of the intermediate Ti₂Fe phase in Ti – 20 at.% Fe alloy after quenching from the liquid state. The structural model makes it possible to explain the anomalies of diffusion scattering on electron diffraction patterns of quenched alloys of the Ti – Fe system.     

液态合金深过滤的机理

论述了铸造合金的液态结构、表面张力、流动产生的扰动及真空对铸造合金深过滤的影响，并从流体力学的角度提出了过滤器设计的基本要求     

Fe-1C-xSi合金的液态结构

利用高温液态X射线衍射研究了纯铁，Fe-1C和Fe-1Si合金在约1550℃及Fe-1C-xSi(质量分数，％）合金从熔点附近至1560℃的液态结构。结果表明：与纯铁的最近邻距离r1=0.259nm和配位数N1＝10.5相比，液态Fe-1C合金的r1和N1略有增加。而液态Fe-1Si合金的r1和N1却略微减小。在1560－1470℃，液态Fe-1C-1Si合金的r1=0.254-0.250nm，明显低于液态Fe-1C合金和Fe-1Si合金的r1值。从1560℃降温至1530℃时，Fe-1C-1Si合金的r1值减少，而N1由10.3剧增至118.8，并且在熔点以上不高的温度保持12.0不变，分析表明：在液态二元系中，C和Si以不同形式存在；而在三元系中，C和Si对纯铁的液态结构具有复杂的影响。Fe-1C-1Si合金在1560－1530℃范围内存在由δ相向γ相的转变，而这种相变随Si含量的增加向低温区域扩展，在Si含量为4％时熔体为单一的δ相，这主要是Si元素抑制γ相区而扩展δ相区产生的。     

Fe-Mo-B-CSINTERED STE ELS PRODUCED BY ADDITI ON OF MASTER ALLOY POWDERS

１．ＩｎｔｒｏｄｕｃｔｉｏｎＢｏｒｏｎｉｓａｖｅｒｙｅｆｆｅｃｔｉｖｅｌｉｑｕｉｄｐｈａｓｅｓｉｎｔｅｒｉｎｇａｄｄｉｔｉｖｅｔｏｉｒｏｎ〔１－２〕．ＴｈｅＦｅＢＣｐｈａｓｅｄｉａｇｒａｍｓｈｏｗｓａｔｅｒｎａｒｙｅｕｔｅｃｔｉｃｒｅａｃｔｉｏｎｏｃｃｕｒｒｉｎｇａｔ１０９７℃〔３〕．ＡｄｄｉｔｉｏｎｏｆＦｅＢａｎｄＦｅＣｍａｓｔｅｒａｌｌｏｙｐｏｗｄｅｒｓｔｏＦｅＭｏＢＣｓｉｎｔｅｒｅｄｓｔｅｅｌｓｃａｎａｃｔｉｖａｔｅｔｈｅｓｉｎｔｅｒｉｎｇｐｒｏｃｅｓｓｂｙｌｉｑｕｉｄｐｈａ…     

Effect of chromium on the mechanical properties of powder-processed Fe–0.45 wt.% P alloys

The present investigation shows the role of chromium in Fe–P binary and Fe–P–Cr ternary alloys. The compositions are characterized in terms of microstructure, porosity content, hardness and tensile properties. The alloys were made using a hot powder forging technique. In this process mild steel encapsulated powders were hot forged into slabs. Then the slabs were hot rolled and annealed to relieve the residual stresses. Densifications as high as 98.9% of theoretical density have been realized. Microstructures of these alloys consist of single-phase ferrite only. Both Fe–0.45P and Fe–0.45P–3Cr alloys showed very high strength. As forged and hot rolled Fe–0.45P alloy showed low elongation. It was observed that, the addition of Cr to Fe–P based alloys caused an increase in strength associated with the reduction in ductility. Alloys developed in the present investigation were capable of hot working to very thin gage of sheets and wires.     

Influence of chemical composition and alloying elements on microdefects and electron density in Ni—Al alloys

1　ＩＮＴＲＯＤＵＣＴＩＯＮＬｌ2 Ｎｉ3ＡｌａｎｄＢ2 ＮｉＡｌａｒｅｉｍｐｏｒｔａｎｔｉｎｔｅｒｍｅｔａｌ ｌｉｃｃｏｍｐｏｕｎｄｓｉｎＮｉＡｌａｌｌｏｙｓ .ＡＮｉ3Ａｌａｌｌｏｙｈａｓｒｅｌａ ｔｉｖｅｌｙｈｉｇｈｓｔｒｅｎｇｔｈａｎｄｐｒｅｓｅｎｔｓｒｅ     

烧结NdFeB磁体热压变形后富Nd相的显微组织

采用热压变形法对NdFeB磁体晶间富Nd相的显微组织进行了研究,实验结果表明,NdFeB磁体经真空热压变形后,富Nd相不再平均地分布在磁体晶间,而是聚集成团块状或从磁体边缘渗出,显微组织分析表明,富Nd相主要是由α-Dd和Nd2Fe17两相组成,与Nd-Fe合金的共晶组织成分接近,对于晶间添加Al元素的磁体,Al溶入晶间形成Nd2Fe15Al2相弥散地分布在晶界上,这有益于磁体矫顽力的提高;对于晶间添加Cu元素的磁体,晶间没有发现有新相产生。     

Phase equilibria in the Fe–Al–Mo system – Part I: Stability of the Laves phase Fe2Mo and isothermal section at 800 °C

Phase equilibria in the Fe–Al–Mo system were experimentally determined at 800 °C. From metallography, X-ray diffraction and electron probe microanalysis on equilibrated alloys and diffusion couples a complete isothermal section has been established. It is shown that the Laves phase Fe₂Mo is a stable phase. The phase Al₄Mo, which only becomes stable above 942 °C in the binary system, is the only ternary compound found at 800 °C. For all binary phases the solid solubility ranges for the third component have been established. The D0₃/B2 and B2/A2 transition temperatures have been determined for a selected alloy by differential thermal analysis and transmission electron microscopy. The results confirm that the D0₃/B2 transition temperature substantially increases by the addition of Mo, while the B2/A2 transition temperature is about that for a binary alloy with the same Al content.     

铜模吸铸法制备的Fe74Al4Sn2P10Si4B4C2非晶合金圆棒及圆管块体

利用铜模吸铸法制备了直径1．0mm,1．5mm和2．0mm的Fe74Al4Sn2P10Si4B4C2块体非晶合金圆棒,利用振动样品磁强计测试了圆棒的磁性能,其饱和磁感应强度较高,矫顽力较低。利用铜模吸铸法制备了Ф5mm×庐7mm×15mm的Fe74Al4Sn2P10Si4B4C2块体非晶合金圆管,并测试了其DSC曲线,块体非晶合金圆管与块体非晶合金圆棒的热性质一致。Fe74Al4Sn2P10Si4B4C2块体非晶合金显示出优良的铸造性能。     

Thermodynamic optimization of the boron-cobalt-iron system

A thermodynamic optimization of the boron-cobalt-iron ternary system is performed based on thermodynamic models of the three constitutional binary systems and the experimental data on phase diagrams and thermodynamic properties of the ternary system. The liquid, fcc_A1, bcc_A2 and hcp_A3 solution phases are described by the substitutional solution model. The three intermediate line compounds, (Co,Fe)B, (Co,Fe)₂B and (Co,Fe)₃B, are described by the two sublattice model. A set of thermodynamic parameters are obtained. The calculated phase diagram and thermodynamic properties are in reasonable agreement with most of the experimental data.