从含铱树脂废料中选择性溶解铱的工艺研究

用王水对含铱树脂中的铱进行造液处理。实验表明,金属铱的溶解率可达90%,且金属基本不会损失。考察了王水浓度、加热温度、保温时间、料液比对于铱溶出率的影响;在王水浓度为80%,加热温度在85℃,保温时间为1.5 h,料液比为1:3的最佳条件下,金属铱的溶出率可达90%。     

含铱废料回收技术研究进展

铱由于其物理、化学性质稳定,被广泛应用于航空、电子、催化等高新技术行业,铱二次资源回收意义重大。基于对40多篇文献的分析,介绍了含铱废料的来源,综述了从不同废料中回收提纯铱的工艺,从铱金属和合金废料中回收铱包括溶解和精炼等工序,溶解的方法主要有碎化活化溶解,碱熔融预处理等;精炼的工艺主要有沉淀法、离子交换法、萃取法、氢还原法、高温氧化挥发法等。根据原料成分以及对铱纯度的要求,各种除杂的方法可以联合使用。     

Synthesis and characterization of red phosphorescent-conjugated polymers containing charged iridium complexes and carbazole unit

A series of homogeneous red-light phosphorescent polymers with charged iridium (Ir) complex in the backbones and carbazole unit on the side were synthesized by Suzuki polycondensation. These polymers are made up of three repeat units: (i) charged iridium (Ir) complex; (ii) 9,9-dihexylfluorene; (iii) 9,9-bis(N-carbazolyl-hexanyl)-fluorene. Their structures have been identified by nuclear magnetic resonance (NMR) and elemental analysis. All chelating polymers displayed good thermal stability, redox reversibility and film formation. Compared with our former study on these charged Ir complex containing polymers, the addition of carbazole unit has a strong influence on their hole injection and charge attraction ability as well as the host–guest energy transfer efficiency.     

Synthesis, characterization, and electroluminescent properties of iridium complex containing 4-phenybenzoquinoline ligand

A phosphorescent iridium(III) complex Ir(PBQ)₂(acac) (PBQ: 4-phenylbenzoquinoline, acac: acetylacetone) was designed and synthesized, and the single crystal of this complex was obtained. This complex shows well optoelectronic properties. The organic light emitting devices (OLEDs) based on this complex were successfully fabricated with the device configuration of ITO/NPB or TCTA (40 nm)/Ir-complex: CBP (7%, 30 nm)/BCP (15 nm)/Alq (30 nm)/LiF (1 nm)/Al (100 nm). Using TCTA as the hole-transporting material, the device gives an extremely high external quantum efficiency of 14.6% at 5.0 V, a brightness of 61,693 cd/m² at 16.0 V, and a power efficiency of 37.0 lm/W at 3.5 V.     

Synthesis and luminescence of red,fluorinated iridium (III) complexes containing alkenyl benzothiazole ligand

Two novel iridium(III) complexes (2-FSBT)₂Ir(acac) and (4-FSBT)₂Ir(acac) (2-FSBT, (E)-2-(2-fluorostyryl)benzo[d]thiazole; 4-FSBT, (E)-2-(4-fluorostyryl)benzo[d]thiazole; acac, acetylacetone) were synthesized and characterized by ¹H NMR and mass spectrometry. The organic light emitting diodes based on these complexes with the structure of ITO/m-MTDATA(10 nm)/NPB(20 nm)/CBP:Ir-complex(X %, 30 nm)/BCP(10 nm)/Alq₃(30 nm)/LiF(1 nm)/Al(100 nm) were fabricated. The device based on (2-FSBT)₂Ir(acac) exhibited a maximum efficiency of 9.32 cd/A, a luminance of 8800 cd/cm²; and the device based on (4-FSBT)₂Ir(acac) showed a maximum efficiency of 8.5 cd/A, a luminance of 6986 cd/cm². The Commission International de L’Eclairage (CIE) coordinates (1931) of these complexes were (0.619, 0.381) and (0.621, 0.378), respectively.     

Structure and phases in nickel-base self-fluxing alloy coating containing high chromium and boron

The structure of a nickel-base, self-fluxing alloy coating, containing chromium and boron thermal sprayed and fused, was investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and transmission electron microscopy (TEM). A lumpy M₆C carbide, a rodlike M₃B₂ boride of tetragonal structure, a rodlike M₇C₃ carbide of hexagonal structure, and a Ni-Ni₃B eutectic phase formed in the coating after fusing. Metals of M₆C, M₃B₂, and M₇C₃ phases are composed of chromium, molybdenum, and nickel; chromium and molybdenum; and mainly chromium, respectively. The nickel phase in the coating has the L1₂ type superlattice structure.     

Self-Diagnosis of GFRP composites containing carbon powder and fiber as electrically conductive phases

The electrical characteristics of glass fiber reinforced plastic (GFRP) composites have been investigated in order to incorporate a self-diagnosis function suitable for monitoring the health of structural materials. The electrical conductivity was introduced by adding carbon powder (CP) or carbon fibers (CF) into GFRP rods and sheets. The self-diagnosis ability of the composites was evaluated by measuring the change in electrical resistance as a function of stress (or strain) in tensile tests. The resistance of CFGFRP changed only slightly at small strain levels and increased nonlinearly with the applied stress due to cutting of the fibers at higher levels. CPGFRP showed high sensitivity to stress and the resistance changed linearly over a wide strain range. During cyclic loading tests, a residual resistance was also observed in CPGFRP composites after unloading. The residual resistance increased with maximum applied strain, showing that it can be used as an indicator of previously applied strain or stress. It is concluded that the CPGFRP composite is a promising material for simple diagnosis of dynamic damage and cumulative strain.     

铱及铱基合金多元化研究进展

概括论述了铱的特点和纯铱在室温条件下脆性断裂的几种可能机制,说明了纯铱在超高温应用领域存在的问题;系统地综述了世界各国在铱合金多元化方面的研究思路和取得的研究成果,展望了铱基合金在高温结构材料领域的发展前景,最后特别指出了铱合金未来的研究方向。     

Synthesis of bicyclometalated iridium complex containing 1,3,4-oxadiazole-based picolinic acid derivative and its optoelectronic properties in polymer light-emitting devices

A picolinic acid derivative bearing an 1,3,4-oxadiazole unit and its bicyclometalated iridium complex (PhOXD)₂Ir(BuPhOXD-Pic) were synthesized and characterized, in which BuPhOXD-Pic is 5-(4′-(5″-(4-tert-butylphenyl)-1″,3″,4″-oxadiazol-2″-yl) phenyl) picolinic acid and PhOXD is 2,5-diphenyl-1,3,4-oxadiazole. The optoelectronic properties of this iridium complex were studied in the double-layer polymer light-emitting devices using a blend of poly (9,9-dioctylfluorene) and 5-biphenyl-2-(4-tert-butyl) phenyl-1,3,4-oxadiazole as a host matrix. This complex exhibited a maximum luminance efficiency of 7.7 cd/A at 5.6 mA/cm² and a peak brightness of 5288 cd/m² at 153.7 mA/cm² in the devices. Compared to the (PhOXD)₂Ir(Pic) complex, the (PhOXD)₂Ir(BuPhOXD-Pic) complex displays better optoelectronic properties in the devices. This study provides a convenient way to improve the optoelectronic properties of iridium complexes by modifying an ancillary ligand of picolinic acid (Pic) with an 1,3,4-oxadiazole unit.     

Transformation and dissolution of second phases during solution treatment of an Al-Zn-Mg-Cu alloy containing high zinc

The transformation and dissolution of Mg(Zn,Cu, Al)_2 phase during solution treatment of an Al-Zn-MgCu alloy containing high zinc were investigated by means of optical microscopy(OM), scanning electron microscopy(SEM), energy-dispersive X-ray spectrometry(EDX) and X-ray diffraction(XRD). The results show that solution temperature is the main factor influencing phase dissolution. With solution temperature increasing, the content of residual phases decreases. Phase transformation from Mg(Zn, Cu, Al)2 to S(Al_2 CuMg) occurs under solution temperature of 450,460 and 465 ℃. Mg(Zn,Cu,Al)_2 phase is directly dissolved into the matrix under solution temperature of 470 and 475 ℃,and no S(Al_2 CuMg) phase transformed from Mg(Zn, Cu, Al)_2 phase is observed. The formation of S(Al_2 CuMg) phase is mainly controlled by Zn elemental diffusion. The mechanism of transformation and dissolution of second phases was investigated. At low temperature, the dissolution of Zn is faster than that of Mg and Cu, resulting in an appropriate condition to form S(Al_2 CuMg) phase. At high temperature, the dissolution of main alloying elements has no significant barrier among them to form S(Al_2 CuMg) phase.     

含LPSO相和W相Mg−Zn−Y−Zr合金铸造、力学和腐蚀性能的比较

为了开发新型铸造镁合金,研究含长周期堆垛相(LPSO)和W共晶相的Mg?Zn?Y?Zr合金.硬度和电导率测试结果表明,T6热处理的温度是合适的.与含W相的合金相比,含LPSO相合金的热裂敏感性更低,这与合金的凝固区间有关.然而,两者具有相同的流动性.在T6条件下,增加Y含量可以提高合金的屈服强度,但合金的其他拉伸性能基...     

Reactive plasma spraying of coatings containing in situ synthesized titanium hard phases

In this investigation, coatings of titanium composites containing in situ synthesized carbides or nitrides were deposited by reactive plasma spraying. Titanium powders were used as starting powder materials. Methane and nitrogen were used as reactive gases. Microstructural analyses revealed that titanium carbides and nitrides were synthesized during spraying. The coatings show high sliding wear resistance and good corrosion performance.     

硫酸亚铁电流滴定法测定铱化合物中铱量

采用硫酸亚铁电流滴定法测定铱化合物中铱元素含量,对化合物的溶解方法、试剂用量、吹气条件、共存元素干扰及测定过程影响因素等进行了研究并获得了最佳实验条件。结果表明,样品经过盐酸-过氧化氢高温高压处理转化后,可使铱价态统一为Ir(Ⅳ),再用硫酸亚铁电流滴定法测定。该方法可以避免某些铱化合物在常规溶解过程中由于铱价态不一致而导致的检测结果失真。方法的测定范围10%～60%,加标回收率99.75%～100.13%;四氯化铱、三氯化铱、氯铱酸、氯铱酸铵、醋酸铱、乙酰丙酮铱6种铱化合物的测定精密度均在0.10%～0.25%之间,均能很好满足铱化合物中高量铱测定的精密度和准确度要求。     

The high-temperature oxidation of nickel-20 wt. % chromium alloys containing dispersed oxide phases

Alloys of Ni-20 wt. % Cr containing 3 vol. % of a dispersed oxide phase have been prepared by a mechanical alloying method and oxidized in oxygen at 100 Torr in the temperature range of 900 to 1200°C. It appears that the dispersed oxide has four distinct effects on the oxidation: (1) the selective oxidation of chromium to form a continuous protective Cr ₂ O ₃ scale is promoted; (2) the rate of growth of Cr ₂ O ₃ is reduced compared with particle-free alloys; (3) the adhesion of the Cr ₂ O ₃ is greatly improved; and (4)the scale-forming reaction appears to be at the scale-metal interface in alloys containing a dispersion, but at the scale-oxygen interface in alloys without a dispersion. It appears that the nature of the dispersed oxide is not important, since very similar effects can be obtained with ThO ₂,Y ₂ O ₃,and CeO ₂ dispersions. It is demonstrated that a logical deduction from this evidence is that the growth of Cr ₂ O ₃ scales on dispersion-free systems must involve short-circuit diffusion of chromium through the scale, and that it seems probable that an effect of the dispersion must be to retard or eliminate this short-circuit process. It is suggested that the oxide particles act as nucleation centers for the oxide, thus reducing the oxide grain size; and it is shown that this simple hypothesis is sufficient to explain a number of the experimental observations.This work has been supported by the Naval Air Systems Command under Contract No. N00019-71-C-0079.     

Micro and sub-micro morphology of Mg65Cu25Y10 bulk amorphous alloy containing primary crystalline phases

Acoustic-frequency induction melting together with rapid quenching was used to prepare Mg65Cu25Y10 bulk amorphous alloy containing primary crystalline phases. Transmission electron microscopy （TEM）, X-ray diffractometry （XRD）, environmental scanning electron microscopy （ESEM） and atomic force microscopy （AFM） were used to study the amorphization and morphology of the prepared alloy. Under micro condition, the sample alloy is composed of amorphous structure with cauliflorate shape, primary CuMg2 dendrite phase, mixed primary CuMg2 and Cu2Y crystalline phases, as well as Mg phase with small size. Further study under sub-micro condition shows that, the planar amorphous structure of cauliflorate shape is composed of the three-dimensional sub-micro morphology of ＂bulge-concavity＂ pattern, which extends into the space in terms of certain period. It is estimated that the major factors influencing the micro and sub-micro morphologies of amorphous alloy are its super-cooling liquid structure, rapid quenching transformation, as well as the melting conditions.     

Adsorption and desorption of samarium atoms on the surface of pure iridium and iridium covered with a graphite monolayer

Methods of thermionic emission and thermodesorption spectroscopy (TDS) have been used to study the adsorption and condensation of samarium on the surface of pure iridium and iridium covered with a graphite monolayer (valence-saturated neutral substrate) Ir(111)-C. It is shown that at temperatures of 700 < T _a < 1200 K the work function φ decreases monotonically from 5.8 to 2.7 eV and during the subsequent deposition of samarium grows slowly to 2.9 eV. It has been found that in all TDS peaks there were observed several phases of samarium. The deposition of samarium onto an Ir-C surface at 700 < T < 1700 K led to a very weak change in the thermionic current in comparison with pure iridium. At temperatures above ～700 K, samarium is not condensed on the surface of Ir-C, but it is condensed at lower temperatures. By the method of temperature modulation, the heat of samarium desorption was determined to be E ～ 1.9 eV upon the desorption from an Ir-C surface (at a small coverage) and ～6 eV upon the desorption from pure Ir.     

原位合成含钛陶瓷相增强Fe基合金熔覆层研究

以Fe901、Ti、B_4C和h-BN粉为原料,采用反应等离子熔覆方法在Q235钢基本上原位合成了含钛陶瓷相增强Fe基合金熔覆层。研究表明:相比B_4C,Fe更易与h-BN反应形成铁硼化物,当同时添加B_4C和h-BN时,B_4C/h-BN比减小至一定值后将导致熔覆层中Fe B含量升高和Ti_2N、Ti B等中间产物形成,但却可抑制陶瓷相长大。熔覆层显微组织均具有梯度分布特征,Ti B_2大小和形态受熔池温度和成分影响。熔覆层显微硬度随h-BN添加量增加而降低,Ti:B_4C:BN摩尔比为3:1:0时熔覆层近表面层HV_(0.2)显微硬度可高达11.26 GPa。