Al熔体粘度的突变点及与熔体微观结构的关系

通过测量Ａｌ熔体的粘度，研究了Ａｌ熔体粘度随温度的变化规律，发现在升温过程中熔体粘度值在７８０和９５０℃左右发生突变。在降温过程中，粘度的突变发生在９３０和７５０℃。Ａｌ熔体氢含量的测定表明，氢含量随温度变化曲线也在７８０℃发生突变。通过对液态Ａｌ的分子动力学模拟，发现Ａｌ的第一近邻配位原子的排布方式随温度的变化在７８０℃左右与９５０℃左右也存在突变。探索了Ａｌ熔体液态微观结构与熔体粘度的内在联系     

合金元素Cu对过热铝熔体中氢含量的影响

Ａｌ－Ｃｕ合金熔体中的氢含量在７８０℃以下保持恒定，此后氢含量随温度升高急剧增加，分析表明合金元素Ｃｕ在７８０℃以下对过热名熔体中的氢含量起主导作用，即在此温度以下铝液吸氢程度取决于铝液表面氧化膜的性质。试验研究表明在同一热度下，铝熔体中氢含量随合金元素Ｃｕ加入量的增多而下降。     

过热铝熔体中氢含量的控制

通过用ＨＹＳＣＡＮⅡ测量不同过热度的铝熔体中的氢含量,研究了铝熔体过热温度和氢含量的关系,发现通过热速处理可控制过热铝熔体中的氢含量。试验结果表明：铝熔体中的氢含量在一定的过热度范围内,随温度升高而增加;氢在过热铝熔体中的存在形态不同,其可逆性也不同,通过热速处理可大大减少过热铝熔体中的氢含量。     

In-5％Cu合金的液态结构与粘滞性研究

利用高温液态金属X射线衍射仪研究了In-5％Cu合金熔体的结构。结果表明：随温度由400℃升高到900℃，In-5％Cu合金熔体的平均最近邻原子间距ri总体上呈现出减小的趋势，原子配位数Ns的变化比较复杂，R1和Ns都在600℃左右出现转折，原子团簇出现热收缩现象，其结构在600℃附近出现异常变化。利用回转振动粘度仪对In-5％Cu合金在液相线以上不同温度进行粘度测量的结果表明：随温度升高，In-5％Cu合金熔体的粘度值减小，总体上呈现指数变化规律，在600℃左右发生突变.粘度突变温度与结构突变温度一致。     

Al—Cu共晶合金熔体中稀土Ce与氢的相互作用

研究了不同稀土Ce含量对共晶成分Al-33.2Cu (质量分数,％,下同）熔体氢含量的影响。结果表明：在相同的保温时间和保温温度条件下,稀土的加入增加了合金熔体的氢含量。750℃,保温20min,加入0．6的Ce,Al-Cu共晶合金熔体的氢含量由0．06mL/100g增至0．16mL/100g。研究了不同Ce含量Al-Cu共晶合金熔体氢含量随温度变化的规律。实验 温度分别为720℃,750℃,800℃和850℃,含0．6Ce的Al-Cu共晶合金熔体氢含量的值分别为0．14、0．16、0．23和0．29mL/100g。     

Al－l8％Si过共晶合金熔体结构特征及磷的影响

用ＤＳＣ热分析和快速凝固方法对过共晶Ａｌ－１８％Ｓｉ合金熔体结构特征进行了分析研究，着重考察了液态过热温度和元素Ｐ对熔体结构特征的影响．结果表明，在液态区域其结构特征存在三个区域：低温微观不均匀区域、中温微观不均匀向微观均匀过渡区域和高温微观均匀区域．Ｐ增加低过热过共晶Ａｌ－ｌ８％Ｓｉ熔体的微观不均匀性．     

液态Ga的密度和黏度及其微观结构

通过测量Ga熔体的密度和黏度,研究了液态Ga密度和黏度随温度的变化规律及其熔体微观结构的变化。Ga熔体的密度-温度关系曲变化表明,密度随着温度的升高而降低,但宏观体积增大;Ga熔体的黏度随着温度的降低而增加,总体上呈现指数规律,在180~210℃之间存在突变点。     

Al—18%Si过共晶合金熔体结构特征及磷的影响

用ＤＳＣ热分析和快速凝固方法对过共晶Ａｌ－１８％Ｓｉ合金熔体结构特征进行了分析研究，着重考察了液态过热温度和元素Ｐ对熔体结构特征的影响，结果表明，在液态区域其结构特征存在三个区域，低温微观不均匀域，中温微观不均匀向微观均匀过渡区域和高温微观均匀区域，Ｐ增加低过热过共晶Ａｌ－１８％Ｓｉ熔体的微观不均匀性。     

Zn—Al合金的熔体结构特征及Cu和Fe的影响

采用熔体离心试验、ＤＴＡ热分析和快速凝固方法对ＺｎＡｌ合金熔体结构特征进行了试验研究，考察了Ｃｕ和Ｆｅ元素及温度对熔体结构特征的影响。结果表明，ＺＡ２７和ＺＡ４２合金液在８１０～８８５℃区域产生热效应变化，低温时呈现较明显的微观不均匀性，高温过热使熔体结构趋向均匀。熔体高温过热及快速凝固冷却使ＺＡ４２合金中αＡｌ固溶体的晶体常数值增加。     

氢对锻态Ti—25Al—10Nb—3V—1Mo合金热压缩行为的影响

利用等温压缩方法研究了氢对Ｔｉ３Ａｌ基的Ｔｉ－２５Ａｌ－１０Ｎｂ－３Ｖ－１Ｍｏ锻态合金热变形行为的影响。在９００－１０００℃范围内，氢含量为０．２％的试样可使峰值流变应力比未氢化试样降低２５％－３１％，即相当于降低热压缩温度将近５０℃。相匠试样中氢含量增加所产生的组织变化与在更高温度压缩后所产生的组织变化相当 。     

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.