液态合金组元间相互作用系数模型

利用自由体积理论,Miedema半经验二元合金生成热模型和Toop几何模型建立了三元系液态合金组元间相互作用系数的计算模型,除N、H等气体元素外,计算结果与实验值符合良好。     

Activities of Phosphorus in Copper‐Iron Liquid Alloys Saturated with Copper‐Iron Solid Solutions

In order to determine the activities of phosphorus and iron in liquid {Cu‐Fe‐P} alloys, the two coexisting phases of liquid {Cu‐Fe‐P} alloys + <Cu‐Fe‐P> solid solutions were brought into equilibrium with a mixture of Al₂O₃ + AlPO₄ + Fe_xAl₂O₄ at temperatures of 1416K and 1526K. The oxygen partial pressures were measured with the aid of a solid‐oxide galvanic cell of the type: (+)Mo / Mo + MoO₂/ ZrO₂(MgO) / {Cu‐Fe‐P} + <Cu‐Fe‐P> + <Al₂O₃> + <AlPO₄> + <FeAl₂O₄> / Fe(‐) The equilibrium reactions underlying the experiments can be expressed by 2[P]_cu + (5/2) (O₂) + <Al₂O₃> = 2 <AlPO₄> and x[Fe]_Cu + (1/2) (O₂) + <Al₂O₃> = <Fe_xAl₂O₄> The Henrian activity coefficient referred to 1 wt pct solution in pure liquid copper could be well expressed by the formula log f_P° = (4.46±0.40) ‐ (8.67±0.59)/(T/K). The iron activities referred to pure solid iron could be formulated as log a_Fe =‐ (0.37 ± 0.12) + (500 ±200) /(T/K).     

基于遗传算法的MIVM预测合金溶液组元活度

在求解分子相互作用体积模型(MIVM)中的分子对位能参数B(ij),B(ji)时,为避免出现计算超量问题,基于遗传算法,提出了一种新算法--多个体参与交叉遗传算法,并给出了新算法的实现方案.在新算法中,采用了轮盘选种法与优秀个体保存、多个体参与交叉和多点变异等策略;选择B(ij),B(ji)个体时,按照适应度函数值愈大,个体被选中的概率愈大的原则,选择二元合金溶液中一组元活度的计算值与实验测定值之间偏差(σ)建立的适应度函数f(x)最大为优化目标.采用Matlab软件编制新算法下的B(ij),B(ji)计算程序,并分别求算了Cd-Bi,Cd-Pb,Cd-Sn,Bi-Pb,Bi-Sn,Pb-Sn等6组二元合金溶液在773 K下合金溶液的参数B(ij),B(ji)优化值.由B(ij),B(ji)计算优化值和其他一些资料数据,使用MIVM进一步预测773 K下Cd-Bi-Pb,Cd-Bi-Sn,Cd-Pb-Sn,Cd-Bi-Pb-Sn多元合金溶液中组元Cd的活度,模型预测值与实验测定值之间的相对误差低于4.6%,偏差低于0.022,两者吻合很好.结果表明,所提出的多个体参与交叉遗传算法为求解MIVM中的参数B(ij),B(ji)提供了一种有力工具,从而也能提高MIVM对多元合金溶液中组元活度的预测效果.     

铁基非晶态合金的退火脆性

本文研究Fe₈₀B_20-xSi_x(x=6,8,10,12)非晶态合金的退火脆性规律,给出了合金成分原料纯度,薄带厚度以及薄带表面状态对非晶态合金退火脆性的影响。铁基非晶态合金在低温退火过程中已明显变脆。这种退火脆性是由非晶态合金亚稳特性决定的结构弛豫所致。     

脉冲电流对铁基合金凝固组织的影响

利用自行设计的脉冲电流发生装置和高温坩埚炉研究了脉冲电流对Fe70Cr18Ni12合金凝固组织的影响.结果表明,脉冲电流可明显细化Fe70Cr18Ni12合金的凝固组织,使该合金的晶粒尺寸由240 μm细化到1.8 μm;同时脉冲电流处理可改变合金凝固组织中奥氏体相和铁素体相的相对含量.     

镍含量对铁基激光熔覆层组织与性能的影响

通过对激光熔覆铁基合金进行成分设计和试验,获得了无裂纹熔覆层,探讨Ni元素含量变化对熔覆层物相组成、显微组织及其性能的影响。试验结果表明,三种熔覆层组织均匀,均为细密枝晶组织;不同Ni含量熔覆层的物相主要由γ-Fe相和α-Fe相组成,随着Ni含量的增加,熔覆层中γ-Fe相增加,而α-Fe相减少,熔覆层晶粒尺寸增大,表面里氏硬度降低,但抗腐蚀性能随着Ni增加而增强,熔覆层具有优良耐蚀性能的本质原因是复合氧化膜的钝化作用对腐蚀介质产生机械阻隔作用。     

合金流动性数学模型

针对自由晶粒阻塞流头的流头阻塞机制,推导出晶粒大小与合金流动性关系的数学模型。将适用于匀晶系及共晶系成份位于相图C₀ ≤ k₀C_E-角的合金成份与晶粒大小的关系式H代入此模型,得到了合金成份、结晶间隔与流动性的定性关系式。利用前人对共晶系合金所做的实验数据验证表明,这些模型适用于共晶系合金。     

Corrosion Behavior of Oxide Dispersion Strengthened Ferritic Alloys in Liquid Sodium

ＣｏｒｒｏｓｉｏｎＢｅｈａｖｉｏｒｏｆＯｘｉｄｅＤｉｓｐｅｒｓｉｏｎＳｔｒｅｎｇｔｈｅｎｅｄＦｅｒｉｔｉｃＡｌｏｙｓｉｎＬｉｑｕｉｄＳｏｄｉｕｍＰａｎＱｉｎｇｃｈｕｎ，ＳｈａｎＢｉｎｇｑｕａｎ，ＴｉａｎＹｕｎ，ＬｉｕＧｕａｎｇｚｕ①ＡＢＳＴＲＡＣＴＣ...     

半固态合金浆料挤压变形的液相偏析模型

描述了一种轴向挤压的半固态合金浆料的数学模型.半固态合金浆料的固相和液相可以相互邻接,它们的变形行为可以藕合.固相的增稠控制着流体流动行为,由此得到在液相中分布的压力可能会影响固相的增稠和液相的偏析.模型可以用来预测半固态合金试样径向上的液相体积分数的分布情况.     

真空液相烧结法制备三元硼化物硬质合金覆层材料

采用液相烧结法在钢基体表面制备三元硼化物硬质合金覆层,将三元硼化物硬质合金的优异性能赋予钢基体表面,获得了耐磨抗蚀、界面结合强度高的新型硬质覆层材料。同时确定了硬质合金覆层的化学配比(B、Fe、Mo元素成分的配比)和C、Cr、Ni合金元素的添加量。对硬质合金覆层的洛氏硬度的测量结果表明,覆层的硬度明显高于钢基体的硬度,其中5Cr2Ni0.8C材料试样的硬度最大;对硬质合金覆层以及覆层与钢基体的界面结合处的扫描电镜观察和能谱分析表明,铬加入后部分进入陶瓷硬质相,加强了其硬度,而镍元素只在铁基粘结相中存在,并且覆层与钢基体之间形成了致密的冶金结合。     

Activity Model of Fe-Si-B Ternary Metallic Melts

 According to the ion and molecule coexistence theory, the activity model of Fe Si B ternary system was established, and the influence of ratio xSi/xFe, boron content and temperature, etc on the activity of the melt compound was investigated. The results show that the FeB activity is high in the liquid iron, when xSi/xFe is 05; the activity of boron increases with increasing the boron content for different contents of xFe and xSi, and the activity of boron at the ratio xFe=04 is about one order of magnitude higher than that for the xFe=08; The activities of the melt compound were also affected by temperature, but the influencing extent was little. The equal activity diagrams of silicon and boron were drawn for the first time according to the model results.     

Microstructure of Fe-Based Alloy Hardfacing Coating Reinforced by TiC-VC Particles

Mierostrueture of the Fe-based alloy hardfaeing coating reinforced by TiC-VC particles was investigated by means of SEM, TEM, XRD and EPMA. The thermodynamics and effect of elements on the carbides were discussed. The result shows that TiC-VC carbides can be formed during arc welding. Carbides with particle size of 2 ～4μm are uniformly dispersed in the matrix. Evidently the covering components and their amount affect the microstrueture and hardness of the coatings. An excellent microstructure and hardness of hardfacing coating were obtained, while the amount of graphite, FeTi and FeV was controlled within the range of 8%- 10%, 15%- 18% and 8%- 12%, respectively.     

Fe－Bi－j三元溶液体系热力学参数的测定与模型计算

利用气液平衡实验方法和三元系液态合金组元间相互作用系数的计算模型，测定和计算了Ｆｅ－Ｂｉ－ｊ三元溶液体系在１８７３Ｋ时第三组元Ｃｒ，Ｃｕ，Ｃ，Ａｌ和Ｓｉ对Ｂｉ的活度相互作用系数以及ｌｎγ~０值。实验值与模型计算值符合良好。     

Ladle Furnace Liquid Steel Temperature Prediction Model Based on Optimally Pruned Bagging

 For accurately forecasting the liquid steel temperature in ladle furnace (LF), a novel temperature prediction model based on optimally pruned Bagging combined with modified extreme learning machine (ELM) is proposed. By analyzing the mechanism of LF thermal system, a thermal model with partial linear structure is obtained. Subsequently, modified ELM, named as partial linear extreme learning machine (PLELM), is developed to estimate the unknown coefficients and undefined function of the thermal model. Finally, a pruning Bagging method is proposed to establish the aggregated prediction model for the sake of overcoming the limitation of individual predictor and further improving the prediction performance. In the pruning procedure, AdaBoost is adopted to modify the aggregation order of the original Bagging ensembles, and a novel early stopping rule is designed to terminate the aggregation earlier. As a result, an optimal pruned Bagging ensemble is achieved, which is able to retain Bagging′s robustness against highly influential points, reduce the storage needs as well as speed up the computing time. The proposed prediction model is examined by practical data, and comparisons with other methods demonstrate that the new ensemble predictor can improve prediction accuracy, and is usually consisted compactly.     

含钡合金在钢液中的脱氧行为研究

在MoSi2炉上采用MgO质坩蜗对钢管进行了含钡合金脱氧行为的研究。实验中钡系合金主要选取SiAUBa、SiCaBa、SiAlBaCa、SiAlBeCaSr及用于钙处理的SiCa包芯线，选用Al作为对比脱氧剂，考察了钡系合金脱氧的全氧含量，脱氧产物的分布、尺寸和形貌，探讨了钡系合金脱氧和对夹杂物变性作用的机理。     

CaO-SiO2-V2O3三元系活度模型及其应用

 根据熔渣结构的分子离子共存理论建立了CaO SiO2 V2O3三元系活度模型,应用该模型对用钒氧化物矿代替钒铁直接合金化冶炼高速钢的工艺过程进行了热力学计算和分析。 结果表明：在高温下,SiC比Si、C的还原性能强。SiC和Si与V2O3反应时渣钢间V的分配比随碱度的提高而下降,而C与V2O3反应时渣钢间V的分配比随碱度变化不大。Si和C与V2O3反应时渣钢间V的分配比随Si、C含量的提高而下降。     

Si Al、Si Ba和Al Ba二元合金熔体组元活度的计算

 根据Miedema二元合金生成热模型，结合相关热力学数据，对硅钙钡系中的各二元合金在1 873 K下的活度进行计算。结果表明，采用该模型对Si Al合金活度的计算结果与实测结果吻合较好；并对Si Ba和Al Ba合金熔体1 873 K下各组元的活度进行了计算，为含钡合金的成分设计和生产提供理论依据。     

Model Experiments on Melting of Alloys with Low Melting Temperature in a Medium with High Melting Temperature

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Evolution and Removal of Inclusions in Fe-Based Amorphous Alloys

Metallurgical and Materials Transactions A - Fe-based amorphous alloys generally suffer from deteriorated glass forming ability and soft magnetic properties due to the impurities in industrial raw...