Nd-Fe-B系磁体性能的提高

Nd-Fe－B磁体根据Nd2Fe14B单晶饱和磁化强度的理论值具有（BH）max为512kJ／m3（64MGOe）的磁特性，但目前能够大量稳定生产的Nd－Fe－B磁体之（BH）max仅为318kJ／m3。为了提高其磁性能，研究了Nd－Fe－B烧结磁体的各种构成相，即T1相（Nd2Fe14B相）、T2相（Nd11Fe4B4相）和富Nd相的相比率，对其烧结行为的影响，以及这些相的存在比率与其磁特性的关系。采用纯度为99．5％的钱、纯度为99．9％的电解铁和硼铁（B20．2％，余为Fe）为原料，在高频电炉中熔炼成Nd15Fe77B8成分的熔体，在铁模中铸锭，制备成粉末和一定规格的试样…     

稀土NdOOH纳米棒的制备及热稳定性研究

采用二（2-乙基己基）磺化琥珀酸钠（AOT）作为表面活性剂，用Nd（NO3）3·nH2O与双氧水（H2O2）作为反应物，在水／AOT／甲苯的体系中，加热回流5～10h，然后将所得到的产物自然冷却至室温，过滤、洗涤、干燥，制备出棒状NdOOH纳米粉。利用多种手段X-射线衍射（XRD）、透射电子显微镜（TEM）、热重TG及示差扫描（DSC）等手段对产物的物相、形貌、热学性能进行了表征和研究。结果表明：制备出的NdOOH纳米棒直径为100nm、长度0．5μm；产物在加热情况下脱水生成Nd2O3。     

Cf／SiC陶瓷基复合材料的制备工艺研究

以先驱体浸渍裂解（PIP）工艺制备了2DC／SiC复合材料，研究了低温裂解工艺（裂解温度低于1000℃）对2D Cf/SiC复合材料结构和性能的影响，为Cf／SiC复合材料的低温制备探索可行之路。研究表明，采用900℃裂解工艺制备的复合材料其力学性能达到或高于目前同类工艺制备的2D Cf／SiC复合材料力学性能，其弯曲强度达到329．6MPa，剪切强度32．1MPa，断裂韧性14．7MPa·m^1/2。并采用差热（TG-DTA）、红外光谱（IR）、X射线衍射（XRD）等对先驱体聚碳硅烷（PCS）及其低温裂解产物的结构和性能进行了研究。     

在高频下软磁性优良的非晶合金

日本电气公司新近开发了一种新型非晶软磁合金，其主要成分含铁（＞50at％）、铝（12at％）和氧（约35at％）。该合金在频率高于IOOMHz的高频领域中具有很好的软磁特性，在100MHz下的磁导率＞1000，饱和磁通密度为1．2T并且矫顽力很小（64A／m）。传统软磁材料因为电阻寸，在高频领域的磁导率降低，并且在100MHz下的磁导率达不到1000。本发明的新型非品软磁合金，适合于制作使用高频信号的移动式通讯机器用变压念。该合金是在氧气氛中将同一成分的铁一粘合金靶材进行溅射制得的薄膜（厚度为2um），经过热处理后，具有铁微晶（平均粒径…     

TC4／Ag-Cu—Ti／1Cr18Ni9Ti钎焊接头界面组织与结构

以Ag—Cu—Ti箔状钎料对钛合金TCA和不锈钢1Cr18Ni9Ti进行了真空钎焊。采用扫描电镜、能谱分析、金相显微镜和x一射线衍射等分析测试手段对钎焊过程中所形成的反应产物和接头界面结构进行了分析。结果表明：接头界面形成了Ti（s．s）、AS（s．s）、Ti—Cu金属问化合物等反应产物。连接温度较低（920℃）时,界面结构依次为1Cr18Ni9Ti／TiCu／Ag（s．s）＋少量Ti2cu／％2cu／Ti2cu＋Ti（s．s）／TC4;连接温度升高（960oC）时,界面结构为1Crl8Ni9Ti／Ti：Cu／Ti：Cu＋矩（s．s）／Ti2Cu／Ti2Cu＋Ti（s．s）／TCA;连接温度较高（1000oC）时,界面结构为1Crl8Ni9Ti／TiCu2／TiCu／Ti2Cu／Ti：Cu＋Ti（s．s）／TC4。提高钎焊温度与延长保温时间对钎焊接头界面组织结构有相似的影响,各反应相、反应层逐渐长大,金属问化合物反应相所占比例增大,而Ag（s．s）组织所占的比例变得更小,这种趋势随着焊接工艺参数的提高更加明显。     

27CrMo27S钢奥氏体连续冷却转变曲线

利用膨胀法结合金相-硬度法，在Gleeble-3800热模拟机上测定了27CrMo27S钢的临界点Ac1、Ac3以及Ms；测定了该钢在不同冷却速度下连续冷却时的膨胀曲线，获得了连续冷却转变曲线（CCT曲线）；研究了冷却速度对该钢组织及硬度的影响。结果表明在相当低的冷却速度范围内可获得贝氏体组织。当冷却速度小于1℃／s，转变产物为铁素体、珠光体和贝氏体（F＋P＋B），当冷却速度为1～6℃／s时转变产物是铁索体和贝氏体（F＋B），当冷却速度为8-24℃／s时转变产物是贝氏体和马氏体（B＋M），当冷却速度大于24℃／s时，转变产物为完全马氏体（M）。该钢种动态CCT曲线的测定可为生产实践和新工艺的制定提供一定的参考依据。     

电热水器用牺牲阳极研究

研制了一种高活化铝锌合金牺牲阳极，对合金的活化行为作了分析讨论，该阳极在城市自来水中开路电位达到-1000mV～1200mV（相对饱和甘汞电极，以下同），工作电位-950mV～-1100mV左右，电流效率52％-54％，实际电容量1300—1500A·h／kg。作为相同重量的热水器阳极，铝阳极的使用寿命约为镁阳极的2，3倍左右，该阳极是热水器中镁阳极理想的替代品。     

Sn作为添加剂的低温瞬时液相烧结Terfenol-D工艺的研究

采用一种以Sn作为添加剂的低温瞬时液相烧结方法来制备Terfenol-D。分别研究了粉末粒度、Sn含量、成型压力、烧结工艺对样品磁性能（包括磁致伸缩性能）和力学性能的影响。获得了在12×79．6kA／m磁场下，与磁场平行方向磁致伸缩值为5．46×10^-4。的烧结样品，其制备条件为：粉末粒度〈75μm，Sn含量为8％（质量分数，下同），成型压力为1．0GPa，在250℃持续烧结150s。     

六方BN陶瓷的高压气—固自蔓延高温国合成

采用高压气－固自蔓延高温合砀备了产物密度为１．７０ｇ／ｃｍ＾３的六方ＢＮ（ｎ－ＢＮ）陶瓷的高压气其最高抗中度和硬度分别为４２．８ＭＰａ和１０８（ＨＶ）；报氮气压力和怒吼忆隙率对反应物点燃和产物的影响，发现在适当的初孔隙率和氨气压力条件下，可以民没有纹的ｈ－ＢＮ陶瓷产物，其范围为：４８％≤５２％，，９５ＭＰａ≤ｐ≤１１０ＭＰａ。同时发现产物中的片状ｈ－ＢＮ颗粒内部出现分裂和弯折等现象。     

Fe—Ni—Cr合金在H2S／H2／CO2混合气氛中的高温腐蚀

研究了铬含量相当，镍含量分别为１８ｗｔ％和３９ｗｔ％的两种Ｆｅ－Ｎｉ－Ｃｒ合金在Ｈ２Ｓ／Ｈ２／ＣＯ２混合气氛中于６００℃的腐蚀动力学产物层结构。镍含量不同使腐蚀产物结构上有差异；１８ｗｔ％Ｎｉ合金的外腐蚀层为ＦｅＳ，其下是ＦｅＣｒ２Ｓ４和Ｃｒ３Ｓ４；而３９ｗｔ％Ｎｉ合金的腐蚀产物外层是疏松多孔，呈黑色粉状的（Ｎｉ，Ｆｅ）Ｓ，其下也是ＦｅＣｒ２Ｓ４与Ｃｒ３Ｓ４；而３９ｗｔ％Ｎｉ合金的腐蚀产物外层是疏     

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.     

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。     

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.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

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.