液态Ni－Fe合金的超过冷与热力学性质

采用熔融玻璃净化法使液态Ｎｉ－１０％Ｆｅ和Ｎｉ－３５％Ｆｅ合金过冷度分别达到３７１（０．９０△Ｔ＿ｈ）和３４３Ｋ（０．９１△Ｔ＿ｈ）．实验测得其超过冷临界过冷度△Ｔｈ分别为４１３和３７６Ｋ．根据超过冷的定义导出一种测定深过冷熔体平均比热容的方法，从而得到两种深过冷合金的比热容为４１．０和４０．７Ｊ／（ｍｏｌ·Ｋ）．据此对快速凝固过程中的焓变△Ｈ＿（ＬＳ），熵变△Ｓ＿（ＬＳ），相变驱动力△Ｇ＿（ＬＳ）以及晶体形核率Ⅰ进行了理论计算．发现尽管过冷度超过了０．２Ｔ＿Ｌ，液态合金仍然发生异质形核．     

液态金属快速结晶的热力学驱动力

采用超高真空无容器悬浮熔炼技术使液态Ｆｅ和Ｎｉ的过冷度分别达２００和２３５Ｋ，借助量热法测定出其比热各为４８．６和４０．５Ｊ．ｍｏｌ＾－＾１．Ｋ＾－＾１。据此精确计算出深过冷Ｆｅ和Ｎｉ快速结晶的热力学驱动力△ＧＬＳ，并与Ｔｕｒｎｂｕｌｌ模型和Ｄｕｂｅｙ－Ｒａｍａｃｈａｎｄｒａｒａｏ模型的近似计算结果相比较，发现这两种近似模型在过冷度超过１００Ｋ时均产生大于１％的偏差。进一步分析发现，△ＧＬＳ的计算     

液态金属快速结晶的热力学驱动力

采用超高真空无容器悬浮熔炼技术使液态Ｆｅ和Ｎｉ的过冷度分别达２００和２３５Ｋ，借助量热法测定出其比热各为４８．６和４０．５Ｊ·ｍｏｌ~（－１）·Ｋ~（－１）．据此精确计算出深过冷Ｆｅ和Ｎｉ快速结晶的热力学驱动力△Ｇ_（ＬＳ），并与Ｔｕｒｎｂｕｌｌ模型和Ｄｕｂｅｙ－Ｒａｍａｃｈａｎｄｒａｒａｏ模型的近似计算结果相比较，发现这两种近似模型在过冷度超过１００Ｋ时均产生大于１％的偏差．进一步分析发现，△Ｇ_（ＬＳ）的计算偏差对深过冷液态金属中晶体形核率的影响极大，因此快速凝固研究中应尽可能精确计算△Ｇ_（ＬＳ）．     

Ni—Ni3Si系近共晶合金深过冷形核规律

采用大体积液态金属的微观净化技术,在Ｎｉ－Ｎｉ３Ｓｉ合金中使Ｎｉ－（６．０７－１９．７）％Ｓｉ和Ｎｉ－（２０．５－２２）％Ｓｉ两组合金分别获得了最大达３４４和２６５Ｋ的极限形核过冷度,并使其极限过冷度保持２０个循环过热周期不衰减。实验发现,Ｎｉ－Ｎｉ３Ｓｉ系近共晶合金深过冷凝固时,Ｎｉ３Ｓｉ总是领先于α相形核。     

过冷Cu70Ni30熔体在石英玻璃涂层壳型中过冷遗传性

在熔模铸造壳型内表面基体玻璃涂层（Ｂ）上，用溶胶－凝胶原理制备了非晶薄膜涂层（Ｆ），ＦＴＩＲ和ＴＧＡ－ＤＴＡ 分析结果表明，裂纹发生在室温～４００℃加热区间，产生的主要原因，是热处理过程中涂层吸附水、醇快速解附引起薄膜膨胀所致，这一过程中涂层的热失重占总失重量的８９．５％ 。为此，用分级热处理工艺制备了无裂纹Ｂ－Ｆ复合涂层，ＸＲＤ分析结果表明，该涂层为ＳｉＯ２ 玻璃态。将净化后获得深过冷的Ｃｕ７０Ｎｉ３０合金熔体浇入Ｂ－Ｆ涂层中，获得了１９８Ｋ深过冷，其过冷度遗传率达到了０．７６。     

新型Fe-Co-Ni-Zr-B非晶合金

新型Ｆｅ－Ｃｏ－Ｎｉ－Ｚｒ－Ｂ非晶合金日本东北大学材料研究所研究了新型铁基Ｆｅ－Ｃｏ－Ｎｉ－Ｚｒ－Ｂ系非晶合金的过冷液相区和软磁性能。实验的合金为五元的（Ｆｅ，Ｃｏ，Ｎｉ）７０Ｚｒ１０Ｂ２０。用电弧炉熔炼母合金，用熔体快淬法在氩气下制备了厚２０μｍ、...     

六方材料织构的近真ODF分析系统

采用熔融玻璃自分离净化工艺，可使液态（Ｎｉ０．５３Ｆｅ０．３３Ｃｏ０．１４）７３Ｂ１７Ｓｉ８Ｎｂ２合金稳定地获得０．３Ｔ１以上的过冷度。研究了电磁场在深过冷液态合金凝固过程中所起的作用。观察及分析结果表明，电磁场对于过冷度的影响甚微，但却对于形核及其生长产生明确的影响，使形核及生长表现出与自由凝固下完全不同的规律。电磁场对于进一步提高深过冷合金的热力学过冷度具有促进作用。     

深过冷净化的影响因素及工艺优化

系统地研究了熔融玻璃和循环过热相结合方法对净化效果的影响;提出了大体积液态金属获得深过冷的优化工艺;采用该工艺可快速、稳定地使６～２０ｇＮｉ８１．１５Ｓｉ１８．８５、Ｎｉ２８．６４Ｓｉ２１．３６、Ｎｉ７４．１７Ｓｉ２５．８３、Ｎｉ５０Ｃｕ５０、Ｆｅ７６Ｂ１２Ｓｉ１２合金分别获得２９９Ｋ（０２０２Ｔｍ）、２６９Ｋ（ｏ．１９Ｔｍ）、２６３Ｋ（０．１７２Ｔｍ）、３２０Ｋ（０．２０２Ｔｍ）、３６７Ｋ（０．２５７Ｔｍ）大过冷,并使其保持４～６个循环周期不衰减,同时采用该工艺还首次成功地制备Ｆｅ７６Ｂ１２Ｓｉ１２及Ｆｅ７６Ｂ１２Ｓｉ１０Ｃ２合金的块状纳米软磁材料。研究结果表明,净化玻璃的化学成分、循环过热温度及净化过程中熔融玻璃和合金液的良好排气条件是影响净化效果的主要因素。     

深过冷Fe—B—Si共晶块体纳米材料的凝固组织特征

在大气中利用循环过热与熔融玻璃净化相结合的方法,使６－２０ｇＦｅ７６Ｂ１２Ｓｉ１２合金液获得了３６７Ｋ的大过冷度,采用深过冷及深过冷加水淬的方法,成功地制备了样品直径为１１ｍｍ,高为１０ｍｍ,组织中颗粒平均尺寸约为２００ｎｍ的Ｆｅ７６Ｂ１２Ｓｉ１２合金块体给米材料,研究结果表明,在△Ｔ＝３６７Ｋ再辉后自然冷却室浊及△Ｔ＝３２９Ｋ再辉后水淬条件下,凝固组织为在细化的Ｆｅ２Ｂ（Ｓｉ）基体中分布的３０－     

深过冷Fe—30Co合金中亚稳相形成与组织演化

采用熔融玻璃净化法,在Ｆｅ－３０Ｃｏ（原子分数,％,下同）合金中获得了３０８Ｋ的过冷度,借助光学显微镜和透射电子显微镜观察了过冷度与组织演化的关系以及ｂｃｃ亚稳相的微观结构。     

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.     

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.     

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.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

A STUDY OF TEMPERATURE-DEPENDENT VALENCE BOND STRUCTURE OF TITANIUM

On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.     

Structural Optimization of Electromagnetic Swirling Flow in Nozzle of Slab Continuous Casting

During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality of the slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to control the flow field in mold.This technology can drive molten steel to rotate inside the submerged entry nozzle by electromagnetic force, thereby controlling the flow field. This research shows that it can reduce the impact of molten steel on the bottom of nozzle and partly reduce the negative pressure at the upper part of nozzle outlet which is even eliminated by optimizing the structure and angle of nozzle. The area of heat flux of the mold wall becomes larger, and the crest value of heat flux gets lower than that without swirling in nozzle and any nozzle optimization. The meniscus fluctuates smoothly, and the flow velocity at the top surface is within a reasonable range. The temperature field distribution in the mold is uniform which was beneficial to the growth of equiaxed crystal and decreased element segregation.     

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).