离子束辅助沉积TiN薄膜在模拟口腔溶液中的耐蚀性

应用离子束辅助沉积技术(IBAD)在Fe-Cr-Mo合金基体上制备了TiN薄膜,在模拟口腔环境溶液中测定了其自腐蚀电位、腐蚀电流密度、极化电阻、极化曲线,并用未经表面镀膜的铁铬钼合金进行了对比。结果表明:经TiN薄膜处理的Fe-Cr-Mo软磁合金在口腔环境中的耐腐蚀性较未经表面镀膜处理的有明显提高;当氮气流量为1.5cm3/min,溅射时间为4 h,得到的膜厚为2μm,此时TiN膜在口腔溶液中的耐腐蚀性能最好。     

磁控溅射Ti膜对AZ91镁合金耐磨耐蚀性能的影响

目的通过表面镀Ti膜提高AZ91镁合金的耐磨性能。方法通过直流磁控溅射方法在AZ91镁合金表面镀Ti膜,用拉伸实验法在电子万能实验机上测定薄膜的附着强度,用原子力显微镜观察薄膜与基体的界面形貌,并分析不同溅射参数时膜基的结合能力。通过湿摩擦实验分析两种试样的耐磨性能,采用Js M-670l F冷场发射型扫描电子显微镜观测两种试样磨损后的表面形貌。采用动电位极化曲线测试装置测得两试样的极化曲线,从而判定其耐腐蚀能力。结果通过直流磁控溅射方法制备的Ti膜和AZ91镁合金基体的结合能力与溅射时间有关,当溅射时间为6 min时,膜基结合能力最佳,但结合其他两项参数,所制备试样采用的时间应为4 min。AZ91镁合金镀Ti膜后磨损率降低,腐蚀电流降低,腐蚀电位升高。结论直流磁控溅射方法镀Ti膜提高了AZ91镁合金的耐磨耐蚀性能。     

疏水性三嗪硫醇类分子膜的制备与表征

采用有机镀膜方法在低碳钢表面成功制备了疏水性三嗪硫醇类分子膜。通过循环伏安曲线分析了低碳钢表面有机镀膜的成膜过程,利用蒸馏水接触角和动电位极化曲线对所镀膜层的润湿性和耐腐蚀性能进行了表征。结果表明:低碳钢表面有机镀膜成膜过程同时存在3个反应,即基体与有机单体之间的电化学反应、金属有机化合物和有机单体之间的聚合反应及有机单体之间的聚合反应;有机镀膜后低碳钢表面蒸馏水静态接触角由基体的65.5°增大到96.3°,实现了由亲水到疏水特性转变;腐蚀电流从14.80μA/cm2降低到0.53μA/cm2,耐腐蚀性能得到显著提高。     

电弧离子镀方法制备的Ti/TiN多层膜的结构与耐腐蚀性能

采用电弧离子镀技术,通过周期性变换环境气氛,在7075Al合金上制备了Ti/TiN多层膜,并研究调制周期对多层膜的结构组成和腐蚀性能的影响。结果表明:多层膜与铝合金衬底界面结合较好,基本没有孔洞等缺陷。多层膜具有明显的层状特征,层间界面清晰。多层膜中TiN与单层中TiN薄膜有着相同的晶体结构,并存在(111)择优取向,每个调制周期内的TiN层都呈柱状生长。随着调制周期变小,多层膜阳极极化曲线的腐蚀电位增加,交流阻抗谱的阻抗值增大,容抗弧的半径也增大,即膜层的耐腐蚀性增加。多层膜调制周期的减小使得薄膜中含有的层界面增多,而贯穿至衬底表面的针孔等缺陷的数量将减少,这样,腐蚀性介质经过针孔等缺陷与衬底接触的机会变少,这将使薄膜的抗腐蚀能力得到改善。     

阴极弧径向不同位置膜层性能分布规律

利用阴极弧沉积的方法在201不锈钢基体上制备了TiN薄膜,研究了阴极弧径向不同位置大颗粒、膜厚以及膜层性能的分布规律.分别采用X射线衍射(XRD)和扫描电子显微镜(SEM)分析了膜层的相结构、膜层的表面形貌和截面形貌.研究了镀膜试样和基体在3.5%(质量分数)NaCl溶液中的腐蚀行为,并利用电化学方法分析其抗腐蚀性能,并采用球-盘式摩擦磨损、划痕测试以及微小压痕等方法测试了径向不同位置沉积的TiN薄膜摩擦磨损性能、膜基结合力以及硬度.结果表明,靠近靶材中心的位置,膜层的硬度、厚度最大,电化学腐蚀电位最高,在径向夹角20°处的膜层厚度、硬度最小.在靠近出气位置侧沉积的TiN薄膜大颗粒数目较多,造成表面缺陷增加,TiN薄膜的抗腐蚀性能下降.靠近弧源中心位置沉积的膜层摩擦磨损系数较大,两侧处的膜层摩擦系数较小,膜基结合力与表面形貌和膜层厚度有很大关系.     

多弧离子镀Ti/TiN膜的耐磨耐蚀性研究

本文介绍了AZ31镁合金镀Ti/TiN双层膜工艺,分析了膜层形貌,并对AZ31与镀膜样品进行了摩擦磨损和腐蚀试验。结果表明:在摩擦磨损试验中,AZ31的平均摩擦系数是0.3066,磨损失重率为0.25‰;而镀Ti/TiN膜的AZ31的平均摩擦系数仅为0.1849,磨损失重率仅为0.08‰,说明镀Ti/TiN膜的AZ31获得优良的耐磨性能。在动力学扫描极化试验中,镀Ti/TiN膜的AZ31的腐蚀电位是-20 mV,腐蚀电流是4.26×10-6mA/cm2,腐蚀速率是1.97×10-2mm/a;而AZ31的腐蚀电位是-250 mV,腐蚀电流是10.8257 mA/cm2,腐蚀速率是499.4435 mm/a,腐蚀电位向正方向转移230 mV,腐蚀电流、腐蚀速率极大减少。AZ31镁合金镀Ti/TiN膜极大地提高了镁合金的耐腐蚀性能。     

AZ31镁合金表面亲水薄膜的制备与腐蚀性能研究

在AZ31镁合金表面制备了具有亲水性功能的薄膜.室温下以不同外加电位、时间为条件对镁合金表面进行恒电位法有机镀膜,采用循环伏安法研究了镁合金表面有机膜的生长机理,并结合电化学特性曲线和盐雾腐蚀试验,通过分析镀膜时间和镀膜电位对有机薄膜耐腐蚀性能的影响,确定最佳有机镀膜时间为10min,镀膜电位为1.0 V.     

AZ31镁合金表面有机膜的耐腐蚀性能

采用有机镀膜的方法在AZ31镁合金表面制备了具有功能特性的有机薄膜.通过对循环伏安特性曲线的分析,研究了镁合金表面有机膜的生长机理.结果表明,有机膜的形成过程要经历形核、稳定生长和薄膜增厚3个阶段;结合盐雾腐蚀试验,分析了镁合金表面的耐腐蚀性能,探讨了有机镀膜的最佳工艺条件.     

含HF~-离子稀土转化膜耐蚀性能及表面特征研究

采用w(NaCl)=5%溶液浸泡和动电位极化曲线方法评估了转化膜的耐腐蚀性能,结合EDX和SEM等表面分析技术,研究了转化膜表面元素分布及表面形貌特征。结果表明:促进剂A的加入提高了膜层耐腐蚀性能。大量膜层表面不规则颗粒起源于碱腐蚀阶段,是由金属间化合物和异相粒子组成,如AlFeSiMn、β-AlFeSi等。该类颗粒的存在提高了异相界面阴极特性,为Ce沉积提供衬底,同时形成Cu/Al电偶极和尖端应力降低转化膜性能。     

预渗氮对H13钢表面电弧离子镀TiN薄膜性能的影响

采用MIP-800C多功能离子渗镀设备,分别在H13钢表面及经表面渗氮后的H13钢表面渗镀TiN薄膜.对两种状态下渗镀的TiN薄膜层的形貌与相组成进行观察分析,并检测了其显微硬度及膜基结合力.结果表明, 经表面渗氮后的H13钢表面渗镀的TiN薄膜较光滑致密,少有大颗粒出现;其显微硬度比未经表面渗氮渗镀的略高(由1831 HV0.025提高到2107HV0.025), 而膜基结合力(78 N)约为后者(44 N)的两倍.预先对H13钢进行表面渗氮能显著提高渗镀的TiN薄膜与基体的结合力及其力学性能.     

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.