E.C.Bain在X射线金相学方面的重要贡献

Ｅ．Ｃ．Ｂａｉｒ在１９２１－１９２７年间将Ｘ射线粉晶法引入金相学研究，首先发现ＡｕＣｕ３及Ａｕ３Ｃｕ超点阵结构、Ｆｅ－Ｍｎ的奥氏体面心立方结构、高速钢中的Ｆｅ３Ｗ３Ｃ（Ｍ６Ｃ）碳化物以及铬镍不锈钢中的Ｓｉｇｍａ相。他还对奥氏体的转变进行了深入的研究，提出奥氏体／马氏体相变的晶体学关系（Ｂａｉｎ关系），发展出用Ｘ射线测定残留奥氏体的方法，终于在１９３０年开创奥氏体恒温转变的研究，在中温转变得出的以他     

超低碳奥氏体不锈钢带极电渣堆焊接头的熔合区特征

超低碳奥氏体不锈钢带极电渣堆焊接头的熔合区特征主要表现为碳扩散层和马弑全带的形成,碳扩散层的形成受合金元素与碳的浓度梯度,原子扩散,热处理工艺和堆焊工艺等因素的影响;增碳层中的碳化物主要为Ｍ２３Ｃ６,马氏体带由位错马氏体,孪晶体马氏体,残余奥氏体和少量碳化物组成;熔合区化学成分的变化是马氏体带形成的主要原因。     

铝基复合材料－不锈钢摩擦焊接过渡区的显微结构特征

研究了铝基复合材料与奥氏体不锈钢间异种金属摩擦焊焊接过渡区在不同焊接条件下的显微组织变化规律．扫描电镜（ＳＥＭ）观察到强度较高的奥氏体不锈钢在焊接过程中发生明显的塑性变形，焊接界面附近不同部位变形机制和特征不同，变形方式主要是形成形变孪晶、滑移带和位错亚结构；透射电镜（ＴＥＭ）观察到过渡区是由微晶氧化物Ｆｅ（Ａｌ，Ｃｒ）_２Ｏ_４或ＦｅＯ·（Ａｌ，Ｃｒ）_２Ｏ_３氧化物层和ＦｅＡｌ_３金属间化合物层组成     

高强钢焊接接头组织遗传问题的研究

用奥氏体不锈钢焊条Ａ４０２焊接调质状态下的４０ＣｒＮｉ２Ｍｏ钢和１５ＭｎＭｏＶ钢,焊后发现在焊缝４０ＣｒＮｉ２Ｍｏ钢一侧的熔合区有仅股有细化反而出现了组织更为粗大的高碳马氏体,并且在高碳马氏体的晶界有细小的呈网状分布的碳化物颗粒析出。这一现象是焊接过程中组织遗传的典型特征,为此给出了组织遗传的定义,分析了接头产生组织脆化的原因。     

铁基合金激光熔覆组织及高温时效转变的TEM研究

利用ＡＴＥＭ研究了铁基多元合金ＦｅＣｒＷＮｉＣ激光熔覆层的微观组织、亚稳相结构特征以及高温时效时的亚稳相转变机制。结果表明组织为亚共晶组织,即γ＋（γ＋Ｍ７Ｃ３）,γ奥氏体为具有较高合金度的过饱和亚稳相,Ｍ７Ｃ３（Ｍ为Ｃｒ,Ｆｅ,Ｗ）为六方结构的Ｃｒ基亚稳合金碳化物。熔覆组织在高温时效时存在两类碳化物形成机制,即亚稳γ中析出Ｍ２３Ｃ６、Ｍ２Ｃ与ＭＣ碳化物以及Ｍ７Ｃ３→Ｍ２３Ｃ６与Ｍ７Ｃ３→Ｍ６Ｃ的碳化物原位转变机制。熔覆组织具有较高的显微硬度并存在显著的二次硬化特征     

铁基合金激光熔覆组织及高温时效转变的TEM研究

利用ＡＴＥＭ研究了铁基金元合金Ｆｅ－Ｃｒ－Ｗ－Ｎｉ－Ｃ激光熔覆层的微观组织,亚稳相结构特征以及高温时效时的亚相变转机制。结果表明组织为亚共晶组织,即γ＋（γ＋ＭＣ）,γ－奥氏体为具有较高合金度的过饱和亚稳相,Ｍ７Ｃ３（Ｍ为Ｃｒ,Ｆｅ,Ｗ）为六方结构的Ｃｒ基亚稳合金碳化物。     

高碳钢中马氏体形貌及其结构

研究了含C量1.6%超高碳钢不同淬火条件下马氏体的形貌及其亚结构.结果表明,超高碳钢淬火组织随奥氏体化温度变化而发生显著变化.奥氏体化温度较高时形成粗大孪晶马氏体;奥氏体化温度较低时淬火组织为位错亚结构的板条马氏体、枣核状马氏体和少量孪晶马氏体,以及未溶碳化物.高分辨电镜观察表明,三维形态像枣核状的马氏体的亚结构为高密度位错.这是由于奥氏体化时碳化物分解比铁索体向奥氏体转变慢;碳化物分解过程中在碳化物原位形成位错堆积;淬火时马氏体优先在位错堆积处形核,并以位错滑移机制长大、增厚,最终形成板条马氏体或枣核状马氏体.     

ZG0Cr13Mn8N钢奥氏体中碳化物连续冷却析出动力学的研究

在用马氏体点变化法测得ＺＧ０Ｃｒ１３Ｍｎ８Ｎ钢奥氏体中碳化物等温析出动力学曲线（ＰＴＴ图）的基础上,研究了冷却速度对ＺＧ０Ｃｒ１３Ｍｎ８Ｎ钢中碳化物连续冷却析出动力学的影响,并获得了该钢奥氏体中碳化物连续冷却析出动力学曲线（ＰＣＴ图）。     

马氏体钢双相区奥氏体组织特征及形成机理

采用双相区再加热-淬火（IQ）工艺,研究了马氏体钢在双相区再加热过程中奥氏体的组织特征及形成机理。结果表明,经890 ℃奥氏体化900 s后淬火处理获得板条马氏体组织的试验钢,经随后的双相区750 ℃再加热-淬火处理,在马氏体组织的基础上获得了由亚温铁素体和块状或针状马氏体组成的双相组织。马氏体钢在双相区再加热过程中,针状奥氏体的形成过程可以分为3个阶段：以板条马氏体间碳化物（Fe₃C）为奥氏体形核点及C元素在奥氏体内的扩散控制奥氏体在板条界间生长;板条马氏体内C向奥氏体内扩散控制其沿板条方向长大;Mn向奥氏体扩散并控制铁素体-奥氏体两相达到最终的平衡状态。钢在750 ℃再加热过程中,C、Mn元素由铁素体向奥氏体相中扩散,其扩散过程控制着奥氏体的形核与长大,扩散的结果是C、Mn元素在奥氏体内富集,实现C、Mn元素在两相之间的配分。     

团球状共晶体奥氏体-贝氏体钢抗冲击磨料磨损行为

采用ＴＥＭ，ＳＥＭ；电子探针和 ＭＤＬ－１０型动载磨料磨损实验机研究 Ｍｇ－Ｃｅ－ＡＩ复合变质团球状共晶体奥－贝钢（简称ＡＢＮＥ钢）复相组织的形成及抗冲击磨料磨损行为结果表明，钢中贝氏体组织由板条铁素体与残余奥氏体组成，团球状共晶体是（Ｆｅ， Ｍｎ）３Ｃ和奥氏体两相伪共晶组织 ＡＢＮＥ钢在中、低冲击工况下耐磨性优于奥－贝钢、奥－贝球铁、团球状碳化物中锰钢，其原因与国球状共晶体可有效地减轻磨料的侵入深度和阻碍微切削作用，以及磨损表面形成大量纳米晶粒和非晶态组织。在亚表层存在形变马氏体与形变贝氏体组织有关     

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.