硬段含量对TDI-BDO-PPG水性聚氨酯涂层穴蚀性能的影响

目的研究硬段含量对TDI-BDO-PPG水性聚氨酯(主要以TDI作硬段、BDO作扩链剂,PPG作软段的水性聚氨酯系列)在海水中穴蚀性能的影响。方法制备不同硬段含量的TDI-BDO-PPG水性聚氨酯,用超声波气蚀试验机对其进行穴蚀模拟试验。利用傅里叶红外光谱仪、拉伸试验机、激光共聚焦显微镜等设备,研究聚氨酯的结构特征峰、试样的拉伸性能及100%定伸永久变形率和试样穴蚀前后的表面形貌。结果涂有TDI-BDO-PPG水性聚氨酯的普通碳钢较其本身有更好的耐穴蚀性能。随着硬段含量从27%到50%逐渐增加,与氢键相关的振动峰明显增强,试样的伸长率降低,拉伸强度增加,100%定伸永久变形率增加,耐穴蚀时间逐渐缩短。试样耐穴蚀时间与硬段含量之间并非呈线性关系,而是当硬段含量在30%左右时才会表现出更好的耐穴蚀性能。穴蚀后,硬段含量为50%的涂层表面出现大范围细小均匀裂纹,硬段含量为35%的涂层表面局部出现少量大裂纹。结论硬段含量对TDI-BDO-PPG水性聚氨酯在海水中的穴蚀性能有显著影响。当硬段含量在较低范围内时,TDI-BDO-PPG水性聚氨酯表现出优异的拉伸性能、弹性性能及耐穴蚀性能。其中,硬段含量为30%的水性聚氨酯涂层的耐穴蚀性能最佳。     

两种Ni基喷涂层微观组织及性能的研究

利用AC-HAVF喷涂技术在水轮机叶片材料0Cr13Ni5Mo不锈钢上制备Ni67、Ni60/WC涂层,对两种涂层的微观组织及冲蚀磨损、空蚀性能进行研究.结果表明:涂层主要由Ni-Fe固溶体以及Cr0.19Fe0.7,Ni0.11,Cr26C3,CrB2等相组成,Ni60/WC涂层中还含有WC、M6C(Ni2 W4C或Fe3W3C)等硬质相;涂层与基体结合很好,两种涂层的孔隙率都很低,具有很高的结合强度和硬度;两种涂层的冲蚀磨损性能优异,磨损失重约为0Cr13Ni5Mo基体的20%,较基体有很大程度的提高,但耐空蚀性能较差,低于基体,耐空蚀性能有待提高.     

镍稀土对FeCrMoCBSi系非晶合金涂层性能的影响

设计了制备FeCrMoCBSi系非晶合金涂层用的粉芯线材L1和添加镍稀土的对比配方L2,用电弧喷涂技术制备了两种非晶合金涂层.采用X射线衍射仪(XRD)、扫描电镜(SEM)、差示扫描量热仪(DSC)、显微硬度仪测试了涂层的组织结构与性能,采用冲蚀磨损测试设备测试了两种涂层在30 °和90 °冲蚀角下的耐冲蚀磨损性能,并用SEM观察了涂层冲蚀后的表面形貌.结果表明,添加镍稀土的L2涂层与L1相比,非晶相含量升高了5.7 %,组织结构更加致密,截面平均显微硬度提高了149.6 HV0.1,晶化转变温度Tx增加了7 K,涂层在相同测试条件下的耐冲蚀性能也有所提高.     

水轮机叶片表面聚氨酯弹性涂层的抗磨蚀性分析

目的分析聚氨酯弹性涂层的抗磨蚀性机理,并研究其在水利工程表面防护中的应用。方法对水轮机叶片的气蚀磨损机理进行分析,采用PU喷涂技术在水轮机叶片钢材(0Cr13Ni5Mo)上做一层聚氨酯弹性耐磨涂层,并对涂层的性能进行检测与分析。结果当聚氨酯组分的官能度为2.4时,聚氨酯弹性涂层表现出优异的综合力学性能,涂层与水轮机叶片间的物理结合力达到12.6 MPa,涂层磨耗值保持在较低范围内(2~3 mg/1000 r)。结论聚氨酯弹性涂层能减缓含沙水流对水利工程中高速运转机械设备的冲刷磨损、空蚀破坏,延长水轮机叶片、水泵叶轮的使用寿命。     

水轮机的磨损及其焊接修复

本文介绍水轮机的主要磨损形式,其中气蚀磨损（也称作空蚀）、冲蚀磨损和气蚀与冲蚀复合磨损为目前水轮机的主要磨损方式。并介绍水轮机磨损焊接修复方法,推荐使用与母材相同类型的药芯焊丝对水轮机的磨损进行焊接修复。     

等离子喷涂WC/Co疏水涂层

超疏水涂层的耐磨性是限制其应用的重要因素。利用等离子喷涂结合十七氟癸基三甲氧基硅烷(FAS-17)的表面化学修饰制备出接近超疏水的WC/Co硬质合金涂层。结果表明:涂层的静态接触角最高达到147°;随着喷涂功率的增加,涂层接触角略微有所增加;拉曼光谱和XPS分析表明,FAS-17链通过水解及缩合反应成功枝接到涂层的表面;激光共聚焦显微镜(LSCM)观察发现,涂层表面粗糙度Ra为7.9μm;通过等离子火焰氧化处理后,涂层表面新生成的氧化物为WO_3,它能够提高涂层的疏水性能。最后,通过砂纸摩擦试验发现,其疏水性涂层表现出良好的耐磨性;水滴冲蚀测试发现,涂层有一定的耐雨淋性能。     

抗气蚀聚氨酯涂层的研究进展

随着水轮机和螺旋桨等过流件的尺寸和转速不断提高,气蚀损坏问题更加突出,因此易施工涂覆且便于设计调控的聚氨酯涂层始终是耐气蚀领域的研究热点。系统回顾了聚氨酯材料在气蚀防护领域的研究发展历程,深刻指出了这类材料作为耐气蚀涂层使用时存在的突出问题,例如耐水性、附着力、机械性能、耐磨性能和防污能力等较差,系统分析了这些因素导致涂层损坏失效的机理。针对上述问题,重点根据聚氨酯独特的分子结构,分别从表面能、电负性、化学键合、接枝改性、添加功能填料等方面,提出了改善聚氨酯涂层在复杂工况下应用性的解决办法。最后,鉴于我国对能够在海洋等苛刻环境中长期稳定服役的高性能气蚀防护涂层的急迫需求,对发展以自愈合聚氨酯为代表的集防污抗气蚀耐磨损自修复等功能于一体的新型聚氨酯材料进行了展望。     

压裂球座结构优化分析及耐冲蚀研究

目的 提升水平井分段压裂中投球滑套球座的抗冲蚀磨损性能.方法 基于流体力学、冲蚀理论,采用Fluent软件建立压裂球座固-液两相流冲蚀模型,对球座冲蚀磨损进行研究,分析不同角度下双锥面结构对球座冲蚀磨损的影响.在此基础上,开展球座冲蚀试验,研究3种不同表面材料对球座冲蚀的影响.结果 数值模拟显示,球座的冲蚀磨损主要发生在前端锥面上,最大冲蚀速率发生在锥面与密封面交接处.其原因是,锥段直径逐渐减小,导致固相颗粒在过流断面上的速度和浓度增加,动能增大,使得在斜面导流作用下对锥面的撞击与切削次数增多,冲击力增强,造成壁面材料损失.冲蚀试验结果显示,在3种不同表面材料球座的冲蚀中,双涂层(有机涂层+碳化钨涂层)球座的耐冲蚀能力优于碳化钨涂层和硬质合金球座.结论 设计双锥面结构球座时,合理地选择锥面角度能够有效提升球座的耐冲蚀性能,否则会导致球座的抗冲蚀性能下降.对球座进行表面喷涂强化处理时,较单一涂层而言,选择双涂层的抗冲蚀能力更好.     

热处理对电弧喷涂Ni-Ti涂层冲蚀磨损性能的影响

在2Cr13马氏体不锈钢基体上,采用氩气保护电弧喷涂技术制备了Ni-Ti涂层,在不同温度下对涂层进行了热处理,用冲蚀磨损试验机对涂层的冲蚀磨损性能进行了测试,用扫描电镜对涂层的显微组织和冲蚀磨损后的形貌进行了观察,用X射线衍射仪表征了涂层的相组成,测定了涂层的显微硬度.结果表明:涂层的冲蚀磨损性能与显微硬度无明显的联系;涂层的相结构、显微组织、层间结合力以及NiTi(B2)相具有的超弹性在涂层耐冲蚀磨损能中起着重要的作用;高温热处理(1050℃)后涂层中出现了较多的孔隙和裂纹,降低了涂层的耐冲蚀磨损性能.     

扫描速度对半导体激光熔覆钴基合金涂层组织与性能的影响

采用2 kW半导体激光器在304不锈钢表面进行同轴送粉的激光熔覆Co基合金试验。通过扫描电镜（SEM）、X射线衍射仪（XRD）研究了不同扫描速度下熔覆层的显微组织和相结构;采用显微硬度计、摩擦磨损试验机和气蚀装置分别测试了不同扫描速度下熔覆层的显微硬度、耐磨性与抗气蚀性能。结果表明,不同激光扫描速度下合金涂层皆无裂纹与气孔,随着扫描速度增加,合金涂层的硬度、耐磨性能与抗气蚀性能则先增强后降低,在激光扫描速度为900 mm/min时,合金涂层具有较好的硬度、耐磨性和抗气蚀性能。     

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.