Fe－Dy非晶膜晶化过程中结构及磁性变化SCIEI

用真空双源蒸镀法在ＮａＣｌ和Ｓｉ单晶衬底上制备Ｆｅ，Ｄｙ成分调制多层膜．研究了非晶膜晶化过程，等温退火后多层膜结构及磁性变化。结果表明，在２００℃以下退火，其沉积态非晶和成分调制结构几乎不变；３００℃开始晶化，首先出现Ｆｅ晶核，随温度升高，Ｆｅ，Ｄｙ逐步晶化，６００℃全部形成晶态ｂｃｃ－Ｆｅ和ｈｃｐ－Ｄｙ．饱和磁化强度Ｍｓ对非晶Ｆｅ，Ｄｙ膜晶化时Ｆｅ晶核的形成十分散感，而只有Ｆｅ晶粒的长大才导致矫顽力Ｈｃ增加．     

电子束加热时Fe—Dy多层膜的稳定性

用真空双源蒸镀法在ＮａＣｌ单晶衬底上制备了金属Ｆｅ－Ｄｙ（镝）多层膜，用透射电镜（ＴＥＭ）分析结构。结果表明，当Ｆｅ单层厚度≥２．４ｎｍ时，Ｆｅ为ｂｃｃ结构，无明显择尤取向特征；Ｄｙ单层厚度＜２．４ｎｍ时，Ｄｙ为非晶态，在透射电镜样品台上经１００ＫＶ加速的高强度电子束流加热多层膜，非晶Ｄｙ首先晶化变为ｈｃｐ结构，随加热时间的延长，晶粒长大。１５０Ｓ时Ｆｅ晶粒尺寸约３００ｎｍ，此时出现了铁镝氧化物。     

电子束加热时Fe－Dy多层膜的稳定性

用真空双源蒸镀法在ＮａＣ１单晶衬底上制备了金属Ｆｅ－Ｄｙ（镝）多层膜，用透射电镜（ＴＥＭ）分析结构。结果表明，当Ｆｅ单层厚度≥２．４ｎｍ时，Ｆｅ为ｂｃｃ结构，无明显择尤取向特征；Ｄｙ单层厚度＜２．４ｎｍ时，Ｄｙ为非晶态。在透射电镜样品台上经１００ｋｖ加速的高强度电子束流加热多层膜，非晶Ｄｙ首先晶化变为ｈｃｐ结构，随加热时间的延长，晶粒长大。１５０ｓ时Ｆｅ晶粒尺寸约３００ｎｒｎ，此时出现了铁镝氧化物。     

Fe／Y非晶多层膜的晶化反应及相演化研究

由Ｍｉｅｄｅｍａ半经验公式计算的Ｆｅ／Ｙ二元系自由能图，及退火时Ｆｅ／Ｙ非晶多层膜晶化过程的ＸＲＤ分析结果得出：Ｆｅ、Ｙ晶态自由能低于初始非晶态为晶化提供驱动力，形核势垒及临界晶核尺寸控制晶化反应的相选择。     

Ar~（＋）混合Fe－Dy多层膜的结构及性能

用真空双源蒸镀法在Ｓｉ单晶衬底上制备了Ｆｅ，Ｄｙ原子数比为３：２的Ｆｅ─Ｄｙ成分调制多层膜．用ＡＥＳ、ＲＢＳ、Ｘ射线衍射（ＸＲＤ）以及磁性测量分析了Ａｒ~（＋）混合前后Ｆｅ─Ｄｙ多层膜的相交．Ａｒ~（＋）离子注入能量１１０ｋｅＶ，剂量５×１０~（１５）─１×１０~（１７）／ｃｍ~２．结果表明，注入剂量为１×１０~（１７）／ｃｍ~２时，Ｆｅ，Ｄｙ完全混合，并且由晶态的Ｆｅ，Ｄｙ完全转变为Ｆｅ_（６０）Ｄｙ_（４０）（近似于该化学配比）的非晶态合金，随Ａｒ~（＋）注入量的增加，Ｆｅ一Ｄｙ多层膜的Ｍ_ｓ下降，在剂量５０×１０~（１５）／ｃｍ~２时下降幅度最大。     

STRUCTURE AND PROPERTIES OF Fe-Dy MULTILAYER IMPLANTED WITH Ar~(+)

用真空双源蒸镀法在Ｓｉ单晶衬底上制备了Ｆｅ，Ｄｙ原子数比为３：２的Ｆｅ─Ｄｙ成分调制多层膜．用ＡＥＳ、ＲＢＳ、Ｘ射线衍射（ＸＲＤ）以及磁性测量分析了Ａｒ~（＋）混合前后Ｆｅ─Ｄｙ多层膜的相交．Ａｒ~（＋）离子注入能量１１０ｋｅＶ，剂量５×１０~（１５）─１×１０~（１７）／ｃｍ~２．结果表明，注入剂量为１×１０~（１７）／ｃｍ~２时，Ｆｅ，Ｄｙ完全混合，并且由晶态的Ｆｅ，Ｄｙ完全转变为Ｆｅ_（６０）Ｄｙ_（４０）（近似于该化学配比）的非晶态合金，随Ａｒ~（＋）注入量的增加，Ｆｅ一Ｄｙ多层膜的Ｍ_ｓ下降，在剂量５０×１０~（１５）／ｃｍ~２时下降幅度最大。     

Ar^（＋）混合Fe－Dy多层膜的结构及性能SCIEI

用真空双源蒸镀法在Ｓｉ单晶衬底上制备了Ｆｅ，Ｄｙ原子数比为３：２的Ｆｅ─Ｄｙ成分调制多层膜．用ＡＥＳ、ＲＢＳ、Ｘ射线衍射（ＸＲＤ）以及磁性测量分析了Ａｒ^（＋）混合前后Ｆｅ─Ｄｙ多层膜的相交．Ａｒ^（＋）离子注入能量１１０ｋｅＶ，剂量５×１０^（１５）─１×１０^（１７）／ｃｍ~２．结果表明，注入剂量为１×１０^（１７）／ｃｍ~２时，Ｆｅ，Ｄｙ完全混合，并且由晶态的Ｆｅ，Ｄｙ完全转变为Ｆｅ_（６０）Ｄｙ_（４０）（近似于该化学配比）的非晶态合金，随Ａｒ^（＋）注入量的增加，Ｆｅ一Ｄｙ多层膜的Ｍ_ｓ下降，在剂量５０×１０^（１５）／ｃｍ~２时下降幅度最大。     

添加Dy和Nb对纳米复合Pr2Fe14B／α—Fe永磁合金结构和磁性的影响

研究了添加Ｄｙ和Ｎｂ对纳米复合Ｐｒ２Ｆｅ１４Ｂ／α－Ｆｅ永磁合金形成、组织结构及磁性能的影响。研究表明,对于三元的Ｐｒ９Ｆｅ８５Ｂ６非晶带的晶化过程,在α－Ｆｅ相初始晶化之后,晶化最终产物Ｐｒ２Ｆｅ１４Ｂ＋α－Ｆｅ形成之前出现Ｐｒ２Ｆｅ２３Ｂ３亚稳相。而添加Ｄｙ或同时添加Ｄｙ和Ｎｂ后晶化过程不出现亚稳相。添加Ｄｙ和Ｎｂ元素显著地提高了纳米复合永磁合金的磁性能。     

Fe/RE(Dy,Y)非晶多层膜的晶化方式及晶化温度

通过比较Ｆｅ／ＲＥ非晶多层膜中所有成分范围内非晶合金形成焓△Ｈ＾ａｍ与固溶体形成焓△Ｈ＾ＳＳ得出,在△Ｈ＾ａｍ〈△Ｈ＾ＳＳ成分范围内的非晶与在△Ｈ＾ａｍ〉△Ｈ＾ＳＳ成分范围内非晶的晶化方式及晶化温度不同。这从理论上系统地解释了多层膜晶化为一个缓慢过程,没有确定的晶化温度。     

FeCuNbSiB系纳米微晶的形成及磁性──Ⅰ．纳米微晶的高密度形核

对Ｆｅ７８Ｓｉ１３Ｂ９、Ｆｅ７７Ｃｕ１Ｓｉ１３Ｂ９和Ｆｅ７４Ｃｕ１Ｎｂ３Ｓｕ１３Ｂ９三种非晶合金的晶化过程进行了ＤＴＡ热分析和在位动态电镜观察．在Ｆｅ７７Ｃｕ１３Ｂ９非晶的晶化前期阶段，发现了条状调幅结构，这被认为是Ｃｕ元素Ｆｅ基非晶基体中的Ｓｐｉｎｏｄａｌ分解的产物，富Ｃｕ区还可以作为α－Ｆｅ晶核的产床，导致了高密度形核．     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.