Be/CuCrZr热等静压扩散连接界面特性

采用热等静压（HIP）技术对Be与CuCrZr合金进行扩散连接,比较了不同HIP工艺下制备的Be／CuCrZr接头性能,观察了接头区域的微观组织。结果表明：在580℃,140MPa下Be与CuCrZr直接扩散连接以及采用Ti（Be上PVD镀层）／Cu（CuCrZr上PVD镀层）作过渡层的间接扩散连接均达到了较好的连接效果。材料组合及连接工艺参数等对Be与CuCrZr合金的扩散连接存在着明显的影响。表面采用Ti镀层的间接扩散连接在580℃时可有效阻止Be与Cu形成脆性相。经过580℃,2hHIP处理后,CuCrZr硬度可恢复至初始状态的77％。     

铍／HR—1不锈钢热等静压扩散连接界面特性研究

采用热等静压（HIP）方法，对铍与HR－1不锈钢（SS）在加Cu单层或Cu/Ni双层过渡材料的条件下进行扩散连接。利用金相显微镜，扫描电镜（SEM）、俄歇电子能谱（AES）、显微力学探针（MPM）及拉伸试验分析了接头扩散区的显微组织，微区成分和力学性能。探讨了扩散区成分，组织，硬度及弹性模量分布的关系。研究表明，加Cu单层过渡材料能有效阻挡Fe向铍端的扩散，但不能阻挡铍向不锈钢端的扩散和消除合金元素Ni向Be/Fe及Be/Cu的偏聚，存在幅度较大的弹性模量跃变，造成应力集中和开裂。加Cu/Ni双层过渡材料能实现Be,Cu,Ni与不锈钢间的互扩散，其结合强度为50MPa，是实现铍与不锈钢扩散连接和提高接头质量的可选方法。     

Ti-Cu复合中间层在钨/CLAM钢扩散连接中的性能

采用Ti-Cu复合中间层扩散连接钨与CLAM钢,在30 MPa、1h和800~950℃的条件下,成功获得了W/Ti-Cu/CLAM钢接头。接头界面连接良好,中间层区域发现有Ti₂Cu或TiCu₄等金属间化合物产生。TiC脆硬层使得中间层/钢界面处的硬度远高于钢母材,同时造成了接头处钢母材的失C并软化现象。随焊接温度的升高,接头的剪切强度先升高后降低,在850℃时达到了274 MPa的最大值,剪切试样均断裂在W/中间层界面靠近钨侧处。     

TiNi形状记忆合金与不锈钢的瞬时液相扩散焊

采用AgCu金属箔作中间过渡层,对TiNi形状记忆合金与不锈钢进行了瞬时液相扩散焊,分析了接头的显微组织、元素分布和物相组成等,研究了接头的抗剪强度和断裂方式。结果表明:接头界面区由TiNi侧过渡区,中间区,不锈钢侧过渡区组成,主要相分别为Ti(Cu,Ni,Fe),AgCu,TiFe等。连接温度为860℃,保温时间为60min,连接压力为0.05MPa时,接头最大抗剪强度为239MPa。断裂发生在TiNi母材和AgCu中间层扩散界面上,断口为混合断裂形貌。通过中间层等温凝固过程动力学模型,结合界面形貌和元素扩散分析,认为TiNiSMA与不锈钢异种材料瞬时液相扩散焊过程存在明显的非对称性。     

TC4与93W合金热等静压扩散连接技术研究

以KOVAR合金作为中间过渡层材料,应用扩散连接技术,在热等静压机内对W-Fe-Ni合金与Ti-6Al-4V合金进行扩散连接。采用SEM对连接界面的元素分布进行了分析,并测试了连接件的抗拉强度。结果表明,采用140 MPa,980℃,30 min热等静压工艺、KOVAR合金为过渡层材料,可实现W-Fe-Ni合金与Ti-6Al-4V合金冶金结合,抗拉强度为190 MPa。     

钛合金与不锈钢的超塑性扩散连接研究

采用镍箔作为中间过渡层,在真空下对TC4钛合金与1Cr18Ni9Ti不锈钢进行了微细晶超塑性扩散连接。通过扫描电镜、X射线衍射及剪切强度试验等方法,对连接接头进行了微观分析和剪切强度测试。结果表明:采用镍箔作中间过渡层,能有效地防止铁与钛、碳间的相互扩散和迁移,避免界面上更多的金属间化合物产生,从而提高了接头性能。在连接温度为790℃、连接压力为3MPa,连接时间为30min的条件下,可获得钛合金与不锈钢的牢固连接,接头剪切强度可达131.1MPa,且试样无明显变形。     

钨合金-HR2钢连接界面特性

采用镍作为中间过渡层,通过热等静压(HIP)方法实现了W-Fe-Ni合金与HR2钢的扩散连接.采用拉伸试验测试了连接件的力学性能,采用金相显微镜(OM)、扫描电镜(SEM)、能谱(EDS)分析了连接试样界面的显微形貌及元素扩散行为.结果表明,在1200~1300℃,130 MPa,保温保压1 h的条件下,可以实现W-Fe-Ni合金与HR2钢的有效连接.拉伸试验中,当载荷达到650 MPa时,基体材料发生断裂,连接界面仍保持完好.结果表明,W-Fe-Ni合金与HR2钢结合紧密,连接界面无裂纹存在.母材与过渡层之间发生了充分的互扩散,W,Co,Cr,Mn等元素都扩散到对方母材基体中,镍表现出更易于向W-Fe-Ni合金一侧扩散的特性.连接界面实现了良好的冶金结合.     

Ti-6Al-4V/Cu/ZQSn10-10扩散连接

采用纯铜（cu）箔作中间过渡层在真空下对钛合金Ti-6Al-4V与锡青铜ZQSn10-10异种材料进行扩散连接。用冷场发射扫描电镜对连接接头进行微观分析,用拉伸试验获得接头强度。结果表明,采用铜箔作中间过渡层,可以防止一些低熔点组元的挥发,并且可以阻止某些元素（Sn、Pb等）向钛合金基体扩散,避免更多金属问化合物的产生,从而提高了接头性能。中间过渡层铜与锡青铜ZQSn10-10之间实现了良好的连接,未形成明显的过渡区;在中间过渡层铜与钛合金Ti-6Al-4V之间形成了较宽的过渡区,并有金属间化合物Cu3Ti2产生,对接头性能影响较大。最佳工艺参数是：连接温度为850℃、连接压力为10～15MPa、连接时间为30min,可获得钛合金与锡青铜的牢固连接,接头强度可达192MPa（达到锡青铜母材基体强度的80％）,且连接试样无明显变形。     

Si3N4陶瓷/Inconel 600合金液相诱导扩散连接接头的强度与断裂行为

利用Nb／Cu／Ni复合层作中间层，采用液相诱导扩散连接方法连接了Si3N4陶瓷／Inconel 600合金，用剪切试验评价接头强度，采用扫描电镜(SEM)观察接头的断口形貌，系统地分析了连接压力、连接时间，连接温度对Si3N4陶瓷／Inconel 600合金液相诱导扩散连接接头的强度和断裂行为的影响。结果表明，连接温度(在连接时间为3000s以及连接压力为5MPa条件下)、连接压力(在连接温度为1130℃以及连接时间为3000s条件下)和连接时间(在连接温度为1130℃以及连接压力为10MPa条件下)都与接头的剪切强度呈抛物线关系。     

以铝硅合金为过渡材料的Be激光焊接接头显微结构及剪切断口分析

以AlSi合金为过渡材料,运用激光焊接技术实现Be与Be的连接.采用扫描电镜(SEM)、微控电子万能试验机和纳米压痕仪对焊接接头的显微组织及性能进行研究.结果表明:熔合区和焊缝区组织由Be与AlSi合金形成的复合相构成,熔合区宽度约10 μm左右.焊接接头剪切强度～283 MPa,剪切断裂形式属于准解理断裂,断裂部位多在焊缝区,具有以准解理为主并伴有塑性的混合型断口特征,分析认为熔合区附近热应力诱发的微裂纹、焊缝中形成的金属间化合物以及气孔是导致焊接接头失效的裂纹源.     

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.     

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.