一种新型过共晶Al—Si合金变质剂

利用熔铸法（Ｉ／Ｍ）生产出一种过共晶Ａｌ－Ｓｉ合金变质剂，并对其进行了金相显微镜观察和ＳＥＭ观察，试验结果表明，该变质剂在制备过程中直接生成了大量ＡｌＰ化合物，在熔融铝中熔化速度很快，对过共晶Ａｌ－Ｓｉ合金初晶Ｓｉ有良好的变质效果，对Ａｌ－１８％Ｓｉ二元合金而言，Ｐ添加量控制在２０ｐｐｍ～８０ｐｐｍ，初晶硅平均尺寸可减小到２５μｍ～４０μｍ。     

用磷和硫细化变质Al—26%Si合金

用Ｐ和Ｓ对Ａｌ－２６％Ｓｉ合金进行了细化变质处理。经过细化变质处理后的Ａｌ－２６％Ｓｉ合金，初晶硅粒度达到２０μｍ以下，机械强度达到１６０～１７０ＭＰａ。研究表明，含Ｐ和Ｓ复合细化变质剂是细化变质过共晶铝硅合金的有效细化变质剂之一。     

锶在Al-Si合金LM6中的变质作用

用Ｓｒ对Ａｌ－Ｓｉ合金ＬＭ６（英国牌号,我国相近牌号为ＺＬ１０２）进行变质处理,当ＬＭ６合金处于过共晶成分范围时,获得细小弥散分布的共晶Ｓｉ组织,但初晶Ｓｉ尺寸较大,呈多角形块状。将ＬＭ６合金调整为亚共晶成分后,几乎没有初晶Ｓｉ析出,从而得到变质效果良好的细小,弥散共晶Ｓｉ组织。     

Sr对ZL104合金的变质作用

研究了ＡｌＳｒ中间合金对ＺＬ１０４合金中共晶Ｓｉ相的变质规律。结果表明,Ｓｒ对共晶Ｓｉ有很好的变质效果,Ｓｉ相由长针状变成尺寸为１～２μｍ的圆点状颗粒,变质效果长达４ｈ不衰退。变质后力学性能有较大提高     

Sr对ZL104合金的变质人艇

研究了Ａｌ－Ｓｒ中间合金对ＺＬ１０４合金中共晶Ｓｉ相的变质规律。结果表明，Ｓｒ对共晶Ｓｉ有很好的变质效果，Ｓｉ相由长针状变成尺寸为１－２μｍ的圆点状颗粒，变质效果长达４ｈ不衰退。变质后力学性能有较大提高。     

过共晶Al－Si合金用磷复合变质剂的研制

介绍了以磷及其化合物为主要原料，采用机械混合、压制成型的方法制备一种新型的过共晶ＡｌＳｉ合金用磷复合变质剂的制备过程，特点和使用方法。研究了该复合变质剂的变质效果并且确定了适宜的变质处理工艺。结果表明：自行研制的磷复合变质剂的制备工艺简单，技术可行，使用方便。Ａｌ２０％Ｓｉ合金经该变质剂变质处理后，初晶硅由板块状变成了均匀分布的团块状，平均尺寸为２０μｍ，共晶硅由粗大的长针状变成了短纤维状或细小颗粒状。变质后的合金力学性能显著提高，线膨胀系数降低。     

Al-Si合金宏观晶粒的尺寸突变与结构演化

本文研究了Ａｌ－Ｓｉ合金宏观晶粒尺寸与含Ｓｉ量的关系及结构演化规律。结果表明：宏观晶粒尺寸随含Ｓｉ量增加呈峰谷变化。即在３％Ｓｉ（质量分数，下同）左右达到谷底，在共晶点（１２％Ｓｉ）附近达到峰值；未变质共晶Ａｌ－Ｓｉ合金的宏观晶粒尺寸与纯Ａｌ相近。Ａｌ－Ｓｉ合金宏观晶粒的结构随含Ｓｉ量增加发生演化。其演化过程为：单一αａｌ→以α－Ａｌ为中心外围被共晶团环绕→单一共晶团组织→初生Ｓｉ为核心、周围环α     

Al—Si—Cu合金加入Sr复合变质剂的变质效果

用Ｓｒ，Ｎａ，Ｔｉ，Ｂ复合变质剂对Ａｌ－Ｓｉ－Ｃｕ亚共晶铸造合金进行变质处理，其作用与单独加Ｓｒ变质相比，能更好地细化共晶和晶粒，并具有良好的长效性。     

Al－Si－Cu合金加入Sr复合变质剂的变质效果

用Ｓｒ、Ｎａ、Ｔｉ、Ｂ复合变质剂对Ａｌ－Ｓｉ－Ｃｕ亚共晶铸造合金进行变质处理，其作用与单独加Ｓｒ变质相比，能更好地细化共晶和晶粒，并具有良好的长效性。     

新型细化剂对Al—Si—Cu合金组织和性能的影响

研究表明，ＡｌＴｉＣ系新型细化剂可使ＡｌＳｉＣｕ合金的铸态晶粒尺寸由４０００～５０００μｍ细化到２００～３００μｍ，共晶硅相的形状和尺寸由５０μｍ×２μｍ的长条细化到１μｍ左右的圆点，合金力学性能明显提高     

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.