TiAl基合金的辉光离子碳氮共渗研究

对TiAl基合金辉光离子碳氮共渗层组织与硬度进行了分析，结果表明，TiAl基合金经过碳氟共渗后可在表面形成碳、氮化合物的复合相结构，在金相显微镜下观察为灰暗色。随着共渗温度的升高和时间的延长，表层硬度逐渐提高。因此，TiAl基合金经过辉光离子碳氮共渗可达到既提高抗高温氧化性．又提高耐磨性的双重效果。     

Plasma Alloying of TiAl with Niobium and Its Wear Resistance

将双层辉光离子渗铌技术应用于TiAl合金从而改善其耐磨性能。对TiAl渗铌合金层组织,室温和600℃高温摩擦学性能进行了研究。结果表明,TiAl经离子渗铌后表面形成厚度约12μm的铌合金层,渗层组织致密均匀,其组成物主要包括AlNb2、AlNb3、Ti2AlNb和Nb。铌合金层在600℃的耐磨性明显提高,并且室温耐磨和减摩性能均优于TiAl基材。     

温度对AISI304奥氏体不锈钢离子渗氮的影响

对AISI304奥氏体不锈钢进行脉冲电流辉光离子渗氮处理,在不同处理温度(480 ℃、520 ℃、580 ℃)下渗氮8 h后,获得了一定厚度的渗氮层.通过对渗层进行金相分析和硬度测试表明,随着渗氮温度升高,渗层厚度增大,显微硬度先增大后减小.综合温度对渗层厚度与显微硬度的影响,AISI304奥氏体不锈钢卡套辉光离子渗氮温度可采用520 ℃,渗氮后渗层厚度为90 μm,显微硬度为1317 HV0.1.     

TiAl基合金离子渗氮与耐磨性研究

对TiAl基合金高温离子渗氮后的显微组织、硬度、耐磨性进行了研究。结果表明:经高温离子渗氮处理后,TiAl基合金的渗层组织是由Ti2AlN、TiN和AlTi3化合物层与过渡层组成;对处理前后试样的表面硬度与耐磨性的研究显示,经不同工艺处理的试样其表面硬度和耐磨性显著提高。     

TiAl基合金离子渗氮与耐磨性研究

对TiAl基合金高温离子渗氮后的显微组织、硬度、耐磨性进行了研究.结果表明：经高温离子渗氮处理后,TiAl基合金的渗层组织是由Ti2AlN、TiN和AlTi3化合物层与过渡层组成;对处理前后试样的表面硬度与耐磨性的研究显示,经不同工艺处理的试样其表面硬度和耐磨性显著提高.     

钛合金离子渗氮后的组织及耐磨性能

对TC4及TA7钛合金分别在900℃进行离子渗氮工艺试验,借助于SEM、XRD等分析了渗层组织,测量了渗氮层显微硬度及渗氮深度,测试了渗氮层的耐磨性能。结果表明,钛合金离子渗氮可形成化合物层+扩散层的典型渗氮层,总渗氮深度可达100μm以上,渗氮层表面硬度达1200 HV0.1以上。TC4钛合金850℃渗氮16 h后,耐磨性能与基体相比显著提高。     

TiAl基合金高温气体渗氮

研究了TiAl基合金在氨气中进行的高温渗氮行为,采用XRD和EPMA对渗氮层进行的测试分析显示,渗层由TiN和Ti2AlN组成。其中TiN分布于外层而TiAlN分布于内层。通过对渗氮前后的合金表面硬度和耐磨性的对比结果表明：经过不同工艺渗氮的试样其表面硬度及其耐磨性都有不同程度的提高,当渗氮温度提高到940℃,渗氮时间延长到50h,试样的表面努氏硬度可达1286kg/mm^2。     

TiAl基合金离子渗碳与高温抗氧化性研究

研究了辉光离子渗碳处理对TiAl基合金的渗层组织、表面硬度和抗高温氧化性的影响。实验显示,渗碳处理可在TiAl基合金的表面形成由碳化物和过渡层组成的复合相结构,经不同渗碳处理的试样,其表面硬度和抗高温氧化性均得到明显提高。     

高温与强气流条件下渗硅TiAl基合金表面抗氧化性能分析

采用固体粉末包埋法在TiAl基合金表面渗硅，着重研究了渗硅层在高温强气流冲击条件下的抗循环氧化性能，用XRD及SEM／EDS分析了渗硅层氧化后的成分结构和形貌。结果表明，渗硅后形成以Tissi3、Al2O3和TiSi2、Si为主的复合渗层，在高温强气流冲击条件下，表面生成以SiO2为主的氧化层并与Al2O3层紧密结合。900℃循环氧化时间小于160h时，渗硅层在强气流冲击下的抗氧化性与静态空气中基本相同；氧化时间超过160h后增重略高于静态空气氧化。TiAl基合金渗硅后表现出良好的抗高温强气流循环氧化性能。     

不同气氛固溶氮化处理对不锈钢组织性能的影响

研究了3Cr13不锈钢在不同气氛下的固溶氮化.结果表明:1100℃、0.15MPa的N2、NH3气氛下,均可实现固溶氮化,并获得厚氮铁素体层.以NH3为渗剂固溶渗氮,得到的扩散层的晶粒比N2为渗剂的更加细小,试样表面硬度高达45HRC;高硬度的获得主要是靠渗氮层中形成与母相共格的合金元素氮化物的沉淀硬化.     

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.