苯并三氮唑及其甲基衍生物在去离子水中对铜的缓蚀作用

采用电化学和分光光度法研究了苯并三氮唑和甲基苯并三氮唑在去离子水中对紫铜的腐蚀电化学行为的影响和吸附规律。结果表明，当浓度大于5mg/L时，苯并三氮唑和甲基苯并三氮唑均具有较好缓蚀性能，且甲基苯并三氮唑的缓蚀性能优于苯并三氮唑。这两种缓蚀剂属于阳极型缓蚀剂，吸附过程为放热反应，属化学吸附，服从Langmuir吸附等温式。     

两种曼尼希碱缓蚀剂的缓蚀性能

采用甲醛/苯甲醛、苯乙酮和水合肼为原料分别合成了AJ和BJ两种曼尼希碱缓蚀剂。通过静态挂片失重法、电化学测试法等方法研究了在15%HCl(质量分数)溶液中,这两种缓蚀剂对N80钢的缓蚀性能。结果表明:在15%的HCl溶液中,AJ和BJ缓蚀剂对N80钢具有良好的缓蚀作用,且BJ缓蚀剂的缓蚀效果要优于AJ缓蚀剂的;两种缓蚀剂均为阳极型缓蚀剂,都能自发吸附在N80钢表面,其行为均符合Langmuir吸附等温式。     

一种苯胺类席夫碱对N80钢在盐酸介质中的缓蚀性能

合成了一种席夫碱:4-氯-N-[(吡啶-4基)-亚甲基]苯胺(CNP),并采用失重法、电化学阻抗谱和动电位极化曲线等,研究了CNP对N80钢在1mol/L HCl溶液中的缓蚀性能。结果表明,在1mol/L HCl溶液中,当缓蚀剂摩尔浓度为1.0mmol/L时,缓蚀率达到86.17%。其在N80钢表面吸附满足Langmuir吸附等温式,是一种混合型缓蚀剂。     

一种新型的咪唑啉类缓蚀剂CPA-1对N80钢在CO2环境下的缓蚀性能评价

目的考察一种新型的咪唑啉类缓蚀剂CPA-1对N80钢在CO_2环境下的缓蚀性能。方法通过失重法、电化学阻抗谱和极化曲线,研究了在不同温度下缓蚀率和缓蚀剂浓度之间的关系,利用扫描电子显微镜和扫描电化学显微镜对表面形貌进行了观察分析,根据等温吸附模型研究了咪唑啉缓蚀剂在N80钢表面的吸附类型。结果失重结果表明,缓蚀剂的缓蚀效率随浓度的增大而升高,当温度为40℃、缓蚀剂质量浓度为250 mg/L时,缓蚀率达到95%;温度升高至80℃时,缓蚀率下降至87%。电化学试验表明,咪唑啉类缓蚀剂对阴极和阳极反应均有抑制作用。表面形貌分析表明,缓蚀剂能有效改善金属表面的腐蚀程度。结论咪唑啉类缓蚀剂CPA-1属于混合型缓蚀剂,对N80钢具有较好的缓蚀性能。缓蚀机理为通过吸附方式在金属表面形成一层吸附膜抑制金属腐蚀,吸附方式遵循Langmuir吸附等温模型,物理吸附和化学吸附均会在金属表面发生。     

酸化缓蚀剂含羟基双季铵盐的合成及性能评价

根据季铵化反应原理,以喹啉和1,3-二氯-2-丙醇合成了一种含羟基双季铵盐酸化缓蚀剂(BQ-1)。用红外光谱对其结构进行了表征,采用静态失重法和电化学测试研究了该缓蚀剂在15%HCl溶液中对N80钢的缓蚀性能。结果表明,该缓蚀剂具有明显的腐蚀抑制能力,在15%HCl、90℃下,5mmol/L该缓蚀剂对N80钢片的缓蚀率达96%以上,缓蚀性能优良;此外,该缓蚀剂是一种混合型缓蚀剂,在N80钢片表面的吸附作用符合Langmuir等温吸附规律。表面分析试验(SEM和EDS)验证了缓蚀剂分子在N80钢片表面确实形成了一层保护膜。     

1-十四烷基-4-羟甲基-1,2,3-三唑盐酸缓蚀剂的性能及机理研究

采用失重法、电化学测试法研究了1-十四烷基-4-羟甲基-1,2,3-三唑作为一种盐酸缓蚀剂的缓蚀性能及作用机理,并通过扫描电镜对加入不同浓度缓蚀剂的盐酸溶液中的钢片在腐蚀实验前后的表面状态进行了分析。同时研究了缓蚀剂分子在钢片表面的吸附规律并对相关的拟合参数进行了计算。结果表明,该三唑缓蚀剂是一种阴极抑制的缓蚀剂,其钢片表面的吸附行为符合Langmuir等温吸附模型,是一种典型的单分子层吸附。所合成的烷基三唑缓蚀剂具有优秀的缓蚀性能及较好的抗温性能。     

新型希夫碱酸化缓蚀剂的合成及性能评价

以苯胺和芳香醛为原料,通过Schiff反应合成了一种新型希夫碱酸化缓蚀剂ACR-1。采用静态失重法研究了盐酸浓度、腐蚀温度和缓蚀剂浓度对该缓蚀剂缓蚀效果的影响,并对该缓蚀剂在钢片表面的吸附模型进行了探讨;通过电化学法研究了该缓蚀剂的电化学机理。静态挂片失重法表明,腐蚀温度为90℃,腐蚀时间为4h,在ACR-1浓度为1.0%的15%盐酸溶液中,N80钢片的腐蚀速率为1.6733g.m-2.h-1,完全可以满足石油行业标准SY/T 5405-1996一级缓蚀剂产品的指标(3～4g.m-2.h-1);等温吸附行为研究结果表明,该缓蚀剂分子能自发的吸附在N80钢表面上,其在N80钢表面的吸附符合Langmuir单分子吸附模型;电化学法研究表明,ACR-1是一种以抑制阳极反应过程为主的混合型缓蚀剂,属于"几何覆盖效应"模型,并且可以在N80试片表面形成明显的保护性膜层,有效地抑制了试片在酸液中的腐蚀。     

盐酸介质中双子表面活性剂对N80钢的吸附缓蚀性能

采用静态失重法、电化学方法和扫描电镜等方法,研究了一种双子表面活性剂(DBA2-12)对N80钢在盐酸介质中的吸附缓蚀性能。结果表明,DBA2-12对N80钢在1 mol/L的盐酸溶液中具有较好的缓蚀性能。随着缓蚀剂浓度的增加,缓蚀率增大;随着实验温度升高,缓蚀率减小。该缓蚀剂在N80钢表面的吸附遵循Langmuir吸附等温式,是一种混合抑制型缓蚀剂。     

双缩乙二胺Schiff碱的合成及其酸化缓蚀性能

以乙二胺和芳香醛为原料合成了乙二胺双缩肉桂醛(NDCE)、乙二胺双缩苯甲醛(NDBE)、乙二胺双缩水杨醛(NDSE)和乙二胺双缩对二甲胺基苯甲醛(NDDE)四种双缩Schiff碱缓蚀剂,用元素分析和红外分析对其结构进行了表征,并采用静态失重法和电化学法研究了90℃时它们在15%(质量分数,下同)HCl中对N80钢的缓蚀性能。结果表明:NDCE的缓蚀效果最好,当NDCE的加量为0.75%时,缓蚀率达到99.17%,且NDCE在N80钢片表面的吸附行为符合Langmuir吸附等温模型;NDCE是一种混合型酸化缓蚀剂,在N80钢表面形成了一层保护膜,有效抑制了酸液对N80钢的腐蚀。     

曼尼希碱缓蚀剂的合成及其缓蚀效果

以甲醛、苄叉丙酮、对甲基苯胺为原料,通过曼尼希反应,制备了一种新型的曼尼希碱缓蚀剂(MHX),并采用正交试验优化了制备条件。采用静态失重法、电化学测试及分子动力学模拟的方法,研究了MHX添加量对N80钢片在HCl溶液中缓蚀效果的影响。结果表明：在90℃、添加1%MHX的20%HCl溶液中,N80钢片的腐蚀速率为2.6 g·m^-2·h^-1,缓蚀率为99.63%;该缓蚀剂是一种以抑制阳极为主的混合型缓蚀剂,可以大幅降低腐蚀电流密度,提高电极阻抗;MHX能够在N80钢表面吸附成膜,降低钢表面Fe的损耗,使其表面粗糙度降至93.81 nm; MHX分子在N80钢表面的吸附能为-7.59 eV,能有效取代H₂O分子吸附在金属表面,从而起到缓蚀作用。     

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.     

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。     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

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.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.