Thermodynamic Assessment of Co-Y System

ＴｈｅｒｍｏｄｙｎａｍｉｃＡｓｓｅｓｓｍｅｎｔｏｆＣｏ－ＹＳｙｓｔｅｍＤｕＺｈｅｎｍｉｎ；ＺｈａｎｇＷｅｉｊｉｎｇａｎｄＺｈａｏＬｉａｎｇ（杜振民）（张维敬）（赵亮）（ＤｅｐｏｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｅｒｉｎ...     

Thermodynamic Assessment of Dy-Co System

ＴｈｅｒｍｏｄｙｎａｍｉｃＡｓｓｅｓｓｍｅｎｔｏｆＤｙ－ＣｏＳｙｓｔｅｍＳｕＸｕｐｉｎｇ；ＺｈａｎｇＷｅｉｊｉｎｇａｎｄＤｕＺｈｅｎｍｉｎ（苏旭平）（张维敬）（杜振民）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｅｒｉ...     

Thermodynamic Assessment of the Fe-Y System

ＴｈｅｒｍｏｄｙｎａｍｉｃＡｓｅｓｍｅｎｔｏｆｔｈｅＦｅＹＳｙｓｔｅｍＤｕＺｈｅｎｍｉｎ，ＺｈａｎｇＷｅｉｊｉｎｇ（杜振民）（张维敬）ＵｎｉｖｅｒｓｉｔｙｏｆＳｃｉｅｎｃｅａｎｄＴｅｃｈｎｏｌｏｇｙＢｅｉｊｉｎｇ，Ｂｅｉｊｉｎｇ１０００８３，Ｃｈ...     

Thermodynamic Assessment of Fe-Dy System

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅａｌｏｙｓｙｓｔｅｍｓｏｒｉｎｔｅｒｍｅｔａｌｉｃｃｏｍｐｏｕｎｄｓｃｏｍｐｏｓｅｄｏｆ３ｄｔｒａｎｓｉｔｉｏｎｍｅｔａｌｓａｎｄｒａｒｅｅａｒｔｈｓｈａｖｅａｔｒａｃｔｅｄｍｕｃｈａｔｔｅｎｔｉｏｎａｓａｃｌａ...     

Co-Nb-W三元系相图的热力学计算

基于Co-Nb-W三元体系的相平衡和热力学的实验信息,采用Calphad方法修改了Co-W二元体系的部分相模型,以评估Co-Nb-W三元体系1273、1373、1473 K的等温截面相图。Co-Nb-W三元体系热力学评估过程中,αCo和BCC相采用溶体相模型; λ、χ、Co3Nb相采用双亚点阵模型;Co7W6、Co7Nb6相描述在同一四亚点阵模型 (Co, Nb)1(Co, Nb, W)2(Co, Nb, W)4(Co)6中。结果表明,计算所得相图较好的符合实验数据。     

Magnetic properties and large magnetocaloric effect in Gd-Ni amorphous ribbons for magnetic refrigeration applications in intermediate temperature range

Amorphous Gd_68−xNi_32+x (x = −3, 0, 3) ribbons were prepared by melt-spinning method. The crystallization onset temperatures T_x1 for Gd_68−xNi_32+x amorphous ribbons with x = −3, 0, and 3 are 561, 568, and 562 K, respectively. All the samples undergo the second-order magnetic transition at temperatures between ∼122 (x = −3 and 3) and 124 K (x = 0). The Curie temperature T_C does not change with the composition significantly. The maximum isothermal magnetic entropy changes (−ΔS_M)_max of Gd₇₁Ni₂₉, Gd₆₈Ni₃₂, and Gd₆₅Ni₃₅ amorphous ribbons for a magnetic field change of 0-5 T were 9.0, 8.0, and 6.9 J kg⁻¹ K⁻¹, respectively. Large values of the refrigerant capacity (RC) were obtained in these ribbons. For example, Gd₇₁Ni₂₉ amorphous ribbon has a maximum RC value of 724 J kg⁻¹. Large magnetic entropy change and RC values together with high stability enable the Gd₇₁Ni₂₉ amorphous alloy a competitive candidate among the magnetic refrigeration materials working at temperatures near 120 K.     

Thermodynamic modeling of the Al–Cr system

By means of calculation of phase diagram (CALPHAD) technique, the Al–Cr system was critically assessed. Three solution phases (liquid, body-centered cubic, face-centered cubic) were modeled with the Redlich–Kister equation. The intermetallic compounds Al₇Cr, Al₁₁Cr₂, Al₄Cr, Al₈Cr₅, AlCr₂, which have a homogeneity range, were treated as the formulae Al₇(Al,Cr), Al₁₁(Al,Cr)₂, Al₄(Al,Cr), (Al,Cr)₈(Al,Cr)₅, (Al,Cr)(Al,Cr)₂ using two-sublattice model, respectively. A set of self-consistent thermodynamic parameters describing the Gibbs energy of each individual phase as a function of composition and temperature for the Al–Cr system was obtained.     

Thermodynamic properties of liquid glass-forming Ca–Mg alloys

The complex formation model was used to investigate the thermodynamic properties of liquid Ca–Mg glassy alloys. Our expressions reproduce the thermodynamic functions such as free energy of mixing, enthalpy of mixing, entropy of mixing and activity ratio. The study of long wavelength concentration–concentration fluctuations (S_CC(0)) provides structural information about liquid glass-forming Ca–Mg alloys. Chemical short range order parameter (₁) was obtained from S_CC(0) to quantify the degree of order. The study reveals that the formation of more than one type of complex may be related to the process of glass formation.     

Thermodynamic Description of Ni-Co-Gd System

ＴｈｅｒｍｏｄｙｎａｍｉｃＤｅｓｃｒｉｐｔｉｏｎｏｆＮｉＣｏＧｄＳｙｓｔｅｍ①ＳｕＸｕｐｉｎｇ，ＺｈａｎｇＷｅｉｊｉｎｇａｎｄＤｕＺｈｅｎｍｉｎ（苏旭平）（张维敬）（杜振民）ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎ...     

辉银矿在硫脲体系中浸出银的热力学分析

对辉银矿在硫脲体系中浸出银进行热力学分析,建立硫化银在酸性硫脲体系中的溶解腐蚀电化学机理模型－原电池反应模型。推导出其氧化溶解过程,主要分两步,第一步是硫化银在酸性铁离子的作用下溶解。第二步是分解后银离子的络合。计算了反应过程中形成原电池的电动势Ｅ、反应吉布斯自由能△Ｇ等。对浸出反应过程ＰＨ值对硫脲浸出体系的影响也进行了分析讨论,该研究为硫脲法从辉银矿中浸出银的实际生产工艺研究提供相应的理论基础。     

Thermodynamic modeling of the Ru–Zr system

The Ru–Zr system has been critically assessed by means of the CALPHAD technique. Based on the experimental data, the solution phases (liquid, body-centered cubic, hexagonal close-packed) were initially modeled with the Redlich–Kister equation. It was shown that this model had a definite temperature range beyond which the liquid became unstable. To tackle the problem, the solution phases were modeled with a new semi-empirical equation, which was recommended by Kaptay. A two-sublattice model (Ru, Zr)_0.5(Ru, Zr)_0.5 is applied to describe the compound RuZr in order to deal with the order–disorder transition between body-centered cubic solution (A2) and RuZr with CsCl-type structure (B2). Another two-sublattice model (Ru, Zr)_0.6667(Ru, Zr)_0.3333 is applied to describe the compound Ru₂Zr in order to cope with the order–disorder transition between hexagonal close-packed (A3) and Ru₂Zr with MgZn₂-type structure (C14). A set of self-consistent thermodynamic parameters of the Ru–Zr system was obtained.     

基于AMESim的闭式液压系统热力学建模与仿真

以两行式甘蔗联合收割机液压闭式系统为对象,建立了基于AMESim热力学仿真模型,分析了影响系统温度的因素。结果表明:油箱的散热面积和冲洗阀压力影响温升的权重较低;散热器散热面积、风扇转速、负载和内泄漏量影响温升的权重较高,为闭式液压系统温升校核和元件选型提供参考。     

Thermodynamic analysis of the Re–Si system

The Re–Si system is assessed thermodynamically, using the CALPHAD method. The calculated phase diagram and thermodynamic properties are in good agreement with available experimental data. Calculated enthalpies and entropies of fusion are compared with available data for other transition metal silicides, against melting points, showing good agreement with the general trends. This is a useful approach for thermodynamic assessment of alloy systems, where experimentally measured thermodynamic data are limited. The stability of the amorphous phase in this system has also been discussed.     

Thermodynamic assessment of the Cu–Dy binary system

The Cu–Dy binary system has been thermodynamically assessed with CALPHAD approach. The solution phases including liquid, Bcc, Fcc and Hcp were treated as substitutional solution phases, of which the excess Gibbs energies were formulated with Redlich–Kister polynomial functions. The binary intermetallic compounds were treated as stoichiometric phases. A set of self-consistent thermodynamic parameters for describing various phases in this system has been obtained, which can well reproduce the corresponding experimental data.     

热力系统热损耗的红外热像诊断技术

针对火电、冶金及石油化工等热力系统因热漏造成能源浪费的现象,在评述传统测量热损耗方法,如热流测试法、导热传热法、对流传热法及焓降法不足的基础上,提出了利用红外热像诊断技术测量热损耗,评价热力设备保温效果的方法。通过对吉林石化某厂圆柱型热反应器设备进行实测与计算,得到了热漏超标部分导致的直接经济损失。结果表明,红外热像诊断与保温评价方法具有广泛的应用价值。     

Thermodynamic assessment of the Mo–Re binary system

The existing Mo–Re phase diagrams are reviewed and a thermodynamic calculation of the Mo–Re binary system is undertaken. The Gibbs energies are estimated for liquid, bcc (Mo), hcp (Re), σ and χ phases. The liquid, bcc (Mo) and hcp (Re) phases are described by a regular solution model, whereas the σ and χ phases are described respectively by three-sublattice models. For the σ phase, two thermodynamic models are used for calculations and the results are compared. The models take into account the crystallographic structure and similarity between the σ and χ phases. The calculated results remove the ambiguity of the existing phase diagram data and are compared with the experimental data in the literature.     

Thermodynamic Assessment of the Ru-Zr Binary System

The Ru-Zr system has been assessed by means of the Calphad approach. The solution phases (Liquid, (Ru), and were modeled with the sublattice formalism and the excess term of the Gibbs energy with the Redlich-Kister equation. The intermetallic compounds and RuZr, which have homogeneity ranges, were treated as the formula and by a two-sublattice model with a mutual substitution of Ru and Zr on both sublattices. The calculated phase diagram and the thermodynamic properties of the system are in satisfactory agreement with the experimental data.     

Experimental and Thermodynamic Analysis on Phase Equilibria of Ni-rich Region in Ni-Al-Ti System

1ＩｎｔｒｏｄｕｃｔｉｏｎＮｉｂａｓｅｓｕｐｅｒａｌｌｏｙｓｈａｖｅｃｏｍｐｌｅｘｍｉｃｒｏｓｔｒｕｃｔｕｒｅｓｃｏｎｓｉｓｔｉｎｇｏｆγａｎｄγ′(ｃｏｍｐｏｎｅｎｔｉｓＮｉ3Ａｌ,ｓｔｒｕｃｔｕｒｅＬｌ2)ａｓｍａｊｏｒｐｈａｓｅｓａｎｄｔｈｅｃａｒｂｉｄｅｓａｎｄｂｏｒｉｄｅｓａｓｍｉｎｏｒｐｈａｓｅｔｅｎｄｉｎｇｔｏｐｏｐｕｌａｔｅｔｈｅｇｒａｉｎｂｏｕｎｄａｒｉｅｓ[1～3].Ｂｅｓｉｄｅｓｔｈｅｓｅｐｈａｓｅｓ,ｕｎｄｅｓｉｒａｂｌｅｃｏｍｐｏｕｎｄｓｓｕｃｈａｓη,μ,σａｎｄＬａｖｅｓｃａｎａ…